8 - VU-DARE Home

8
dƌŝĂůͲďĂƐĞĚĞĐŽŶŽŵŝĐĞǀĂůƵĂƟŽŶƐŝŶŽĐĐƵƉĂƟŽŶĂů
ŚĞĂůƚŚ͗ƉƌŝŶĐŝƉůĞƐ͕ŵĞƚŚŽĚƐ͕ĂŶĚƌĞĐŽŵŵĞŶĚĂƟŽŶƐ
:ŽŚĂŶŶĂ D ǀĂŶ ŽŶŐĞŶ
DĂƌŝĞŬĞ & ǀĂŶ tŝĞƌ
Emile Tompa
WaƵlieŶ D oŶŐeƌƐ
llaƌĚ : ǀaŶ Ěeƌ eeŬ
DaƵƌiƚƐ t ǀaŶ TƵlĚeƌ
:ƵĚiƚŚ E oƐmaŶƐ
:KĐĐƵƉŶǀŝƌŽŶDĞĚ͕ĂĐĐĞƉƚĞĚĨŽƌƉƵďůŝĐĂƟŽŶ
Chapter 8
ABSTRACT
ZeƐoƵƌĐeƐ Ĩoƌ oĐĐƵpaƟoŶal ŚealƚŚ aƌe ƐĐaƌĐe͘ To alloĐaƚe aǀailaďle ƌeƐoƵƌĐeƐ aƐ
eĸĐieŶƚlǇ aƐ poƐƐiďle͕ ĚeĐiƐioŶͲmaŬeƌƐ ŶeeĚ iŶĨoƌmaƟoŶ oŶ ƚŚe ƌelaƟǀe eĐoŶomiĐ
meƌiƚƐ oĨ oĐĐƵpaƟoŶal ŚealƚŚ aŶĚ ƐaĨeƚǇ ;K,^Ϳ iŶƚeƌǀeŶƟoŶƐ͘ EĐoŶomiĐ eǀalƵaƟoŶƐ
ĐaŶ pƌoǀiĚe ƚŚiƐ iŶĨoƌmaƟoŶ ďǇ ĐompaƌiŶŐ ƚŚe ĐoƐƚƐ aŶĚ ĐoŶƐeƋƵeŶĐeƐ oĨ ƚǁo oƌ
moƌe alƚeƌŶaƟǀe iŶƚeƌǀeŶƟoŶƐ͘ ,oǁeǀeƌ͕ oŶlǇ a Ĩeǁ oĨ ƚŚe ƐƚƵĚieƐ ƚŚaƚ ĐoŶƐiĚeƌ ƚŚe
eīeĐƟǀeŶeƐƐ oĨ K,^ iŶƚeƌǀeŶƟoŶƐ ƚaŬe ƚŚe eǆƚƌa Ɛƚep oĨ ĐoŶƐiĚeƌiŶŐ ǁŚeƚŚeƌ ƚŚeǇ
aƌe eĸĐieŶƚ iŶ ƚeƌmƐ oĨ ƚŚeiƌ ƌeƐoƵƌĐe impliĐaƟoŶƐ͘ Doƌeoǀeƌ͕ ƚŚe meƚŚoĚoloŐiĐal
ƋƵaliƚǇ oĨ eĐoŶomiĐ eǀalƵaƟoŶƐ iŶ ƚŚe oĐĐƵpaƟoŶal ŚealƚŚ liƚeƌaƚƵƌe iƐ ŐeŶeƌallǇ
poor.
EīeĐƟǀeŶeƐƐ ƚrialƐ are ĐommoŶlǇ ƵƐeĚ aƐ a ǀeŚiĐle Ĩor eĐoŶomiĐ eǀalƵaƟoŶƐ͕ ƐiŶĐe
ƚŚeǇ proǀiĚe a ƵŶiƋƵe opporƚƵŶiƚǇ ƚo reliaďlǇ eƐƟmaƚe ƚŚe reƐoƵrĐe impliĐaƟoŶƐ
oĨ a Ŷeǁ iŶƚerǀeŶƟoŶ ǁiƚŚoƵƚ ƐƵďƐƚaŶƟallǇ ŚiŐŚer reƐearĐŚ eǆpeŶƐeƐ. TŚe preƐeŶƚ
paper aimƐ ƚo Śelp oĐĐƵpaƟoŶal ŚealƚŚ reƐearĐŚerƐ ĐoŶĚƵĐƚ ŚiŐŚ ƋƵaliƚǇ ƚrialͲďaƐeĚ
eĐoŶomiĐ eǀalƵaƟoŶƐ ďǇ ĚiƐĐƵƐƐiŶŐ ƚŚe ƚŚeorǇ aŶĚ meƚŚoĚoloŐǇ ƚŚaƚ ƵŶĚerlie
ƚŚem͕ aŶĚ ďǇ proǀiĚiŶŐ reĐommeŶĚaƟoŶƐ Ĩor ŐooĚ praĐƟĐe reŐarĚiŶŐ ƚŚeir ĚeƐiŐŶ͕
aŶalǇƐiƐ͕ aŶĚ reporƟŶŐ. TŚe preƐeŶƚ paper ǁill alƐo Śelp ĐoŶƐƵmerƐ oĨ ƚŚiƐ liƚeraƚƵre
ǁiƚŚ ƵŶĚerƐƚaŶĚiŶŐ aŶĚ ĐriƟĐallǇ appraiƐiŶŐ ƚrialͲďaƐeĚ eĐoŶomiĐ eǀalƵaƟoŶƐ oĨ K,^
iŶƚerǀeŶƟoŶƐ.
ϮϰϬ
WrŝŶĐŝpůeƐ͕ ŵethŽĚƐ͕ aŶĚ reĐŽŵŵeŶĚaƟŽŶƐ
INTRODUCTION
ZeƐoƵrĐeƐ Ĩor oĐĐƵpaƟoŶal ŚealƚŚ are ƐĐarĐe ;ϭ͖ϮͿ. TŚereĨore͕ ĚeĐiƐioŶͲmaŬerƐ iŶ ƚŚiƐ
ĮelĚ iŶĐreaƐiŶŐlǇ Đall ƵpoŶ aĚǀiƐorƐ aŶĚ reƐearĐŚerƐ ƚo Ŷoƚ oŶlǇ ĚemoŶƐƚraƚe ƚŚaƚ
oĐĐƵpaƟoŶal ŚealƚŚ aŶĚ ƐaĨeƚǇ ;K,^Ϳ iŶƚerǀeŶƟoŶƐ are eīeĐƟǀe͕ ďƵƚ alƐo eĸĐieŶƚ iŶ
ƚermƐ oĨ ƚŚeir reƐoƵrĐe impliĐaƟoŶƐ. EĐoŶomiĐ eǀalƵaƟoŶƐ proǀiĚe iŶĨormaƟoŶ oŶ
ƚŚe relaƟǀe eĸĐieŶĐǇ oĨ ƚǁo or more alƚerŶaƟǀe iŶƚerǀeŶƟoŶƐ aŶĚ are ĚeĮŶeĚ aƐ
͞the ĐŽŵparaƟǀe aŶaůǇƐŝƐ ŽĨ aůterŶaƟǀe ĐŽƵrƐeƐ ŽĨ aĐƟŽŶ ŝŶ terŵƐ ŽĨ ďŽth theŝr ĐŽƐtƐ
aŶĚ ĐŽŶƐeƋƵeŶĐeƐ͟ ;ϭͿ. TŚe maiŶ aƐpeĐƚƐ oĨ aŶǇ eĐoŶomiĐ eǀalƵaƟoŶ are ƚo iĚeŶƟĨǇ͕
meaƐƵre͕ ǀalƵe͕ aŶĚ Đompare ƚŚe ĐoƐƚƐ aŶĚ ĐoŶƐeƋƵeŶĐeƐ oĨ alƚerŶaƟǀeƐ ;ϭͿ.
/Ŷ ƚŚe ŚealƚŚĐare ƐeĐƚor͕ eĐoŶomiĐ eǀalƵaƟoŶƐ are iŶĐreaƐiŶŐlǇ ďeiŶŐ ĐoŶĚƵĐƚeĚ aŶĚ
plaǇ aŶ imporƚaŶƚ role iŶ maŶǇ ĐoƵŶƚrieƐ ǁŚeŶ ĚeĐiĚiŶŐ ǁŚeƚŚer ;ŶeǁͿ ƚreaƚmeŶƚƐ
ƐŚoƵlĚ ďe ĐoǀereĚ ďǇ pƵďliĐ ĨƵŶĚiŶŐ ;ϭͿ. ,oǁeǀer͕ oŶlǇ a Ĩeǁ oĨ ƚŚe ƐƚƵĚieƐ ƚŚaƚ
ĐoŶƐiĚer ƚŚe eīeĐƟǀeŶeƐƐ oĨ K,^ iŶƚerǀeŶƟoŶƐ ƚaŬe ƚŚe eǆƚra Ɛƚep oĨ ĐoŶƐiĚeriŶŐ
ǁŚeƚŚer ƚŚeǇ are eĸĐieŶƚ iŶ ƚermƐ oĨ ƚŚeir reƐoƵrĐe impliĐaƟoŶƐ ;ϯͿ. Doreoǀer͕
ƚŚe meƚŚoĚoloŐiĐal ƋƵaliƚǇ oĨ ƚŚoƐe ƚŚaƚ Ěo iƐ ŐeŶerallǇ poor ;ϰͲϳͿ. ZeaƐoŶƐ Ĩor ƚŚiƐ
maǇ ďe ƚŚe ĚiƐƟŶĐƚ ĐŚalleŶŐeƐ ƚŚaƚ ĐoŶĨroŶƚ reƐearĐŚerƐ ǁŚeŶ ƚrǇiŶŐ ƚo iĚeŶƟĨǇ ƚŚe
reƐoƵrĐe impliĐaƟoŶƐ oĨ K,^ iŶƚerǀeŶƟoŶƐ aƐ ǁell aƐ a laĐŬ oĨ reĐommeŶĚaƟoŶƐ oŶ
Śoǁ ƚo Ěeal ǁiƚŚ ƚŚeƐe iƐƐƵeƐ ;ϯͿ. DaŶǇ eĐoŶomiĐ eǀalƵaƟoŶ ƚeǆƚ ďooŬƐ aŶĚ arƟĐleƐ
are ĚeƐiŐŶeĚ Ĩor ƵƐe iŶ ŚealƚŚĐare ƐeƫŶŐƐ aŶĚ maǇ ƚŚereĨore ďe ĚiĸĐƵlƚ ƚo aĚapƚ ƚo
ƚŚe oĐĐƵpaƟoŶal ŚealƚŚ ĐoŶƚeǆƚ ;ϰͿ.
EīeĐƟǀeŶeƐƐ ƚrialƐ are a ĐommoŶlǇ ƵƐeĚ ǀeŚiĐle Ĩor eĐoŶomiĐ eǀalƵaƟoŶƐ͕ aƐ ƚŚeǇ
proǀiĚe a ƵŶiƋƵe opporƚƵŶiƚǇ ƚo reliaďlǇ eƐƟmaƚe ƚŚe reƐoƵrĐe impliĐaƟoŶƐ oĨ a Ŷeǁ
iŶƚerǀeŶƟoŶ ǁiƚŚoƵƚ ƐƵďƐƚaŶƟallǇ ŚiŐŚer reƐearĐŚ eǆpeŶƐeƐ. lƚŚoƵŐŚ Ɛome eīorƚƐ
Śaǀe ďeeŶ ƵŶĚerƚaŬeŶ ƚo improǀe ƚŚe ƋƵaliƚǇ oĨ ;ƚrialͲďaƐeĚͿ eĐoŶomiĐ eǀalƵaƟoŶƐ
iŶ oĐĐƵpaƟoŶal ŚealƚŚ ;ϯ͖ϴ͖ϵͿ͕ more ŶeeĚƐ ƚo ďe ĚoŶe ƚo aĐĐompliƐŚ ƚŚiƐ. TŚereĨore͕
ƚŚe preƐeŶƚ paper aimƐ ƚo Śelp oĐĐƵpaƟoŶal ŚealƚŚ reƐearĐŚerƐ ĐoŶĚƵĐƚ ŚiŐŚ ƋƵaliƚǇ
ƚrialͲďaƐeĚ eĐoŶomiĐ eǀalƵaƟoŶƐ ďǇ ĚiƐĐƵƐƐiŶŐ ƚŚe ƚŚeorǇ aŶĚ meƚŚoĚoloŐǇ ƚŚaƚ
ƵŶĚerlie ƚŚem͕ aŶĚ ďǇ proǀiĚiŶŐ reĐommeŶĚaƟoŶƐ Ĩor ŐooĚ praĐƟĐe reŐarĚiŶŐ ƚŚeir
ĚeƐiŐŶ͕ aŶalǇƐiƐ͕ aŶĚ reporƟŶŐ.
Ϯϰϭ
8
Chapter 8
DESIGN OF AN ECONOMIC EVALUATION
<ŝŶĚŽĨĞĐŽŶŽŵŝĐĞǀĂůƵĂƟŽŶƐ
ŚooƐiŶŐ ƚŚe appropriaƚe ŬiŶĚ oĨ eĐoŶomiĐ eǀalƵaƟoŶ Ĩor a parƟĐƵlar oĐĐƵpaƟoŶal
ŚealƚŚ ĚeĐiƐioŶ ĐoŶƚeǆƚ ĐaŶ ďe a ĐŚalleŶŐe aƐ a reƐƵlƚ oĨ ƚŚe relaƟǀe ĐompleǆiƚǇ oĨ ƚŚe
ĚeĐiƐioŶͲmaŬiŶŐ ĐoŶƚeǆƚ ƚŚaƚ ŐeŶerallǇ iŶĐlƵĚeƐ mƵlƟple ƐƚaŬeŚolĚerƐ ;e.Ő. ǁorŬerƐ͕
emploǇerƐ͕ iŶƐƵraŶĐe ĐompaŶieƐ͕ pƵďliĐ poliĐǇ maŬerƐͿ. &oƵr ŬiŶĚƐ oĨ eĐoŶomiĐ
eǀalƵaƟoŶƐ are ĚiƐƟŶŐƵiƐŚeĚ. TŚere are ƐimilariƟeƐ aĐroƐƐ ƚŚe ĨoƵr ŬiŶĚƐ. TŚe maiŶ
ĚiīereŶĐe iƐ ƚŚe meƚriĐ ƵƐeĚ ƚo meaƐƵre ƚŚe ŬeǇ oƵƚĐome ;ŚealƚŚ aŶĚͬor ƐaĨeƚǇ͕ iŶ
ƚŚe ĐaƐe oĨ K,^ iŶƚerǀeŶƟoŶƐͿ ;ϭϬͿ.
ϭͿ oƐƚͲeīeĐƟǀeŶeƐƐ aŶalǇƐiƐ ;EͿ͗ oƐƚƐ aŶĚ Ɛome ĐoŶƐeƋƵeŶĐeƐ ;e.Ő.
proĚƵĐƟǀiƚǇ͕ ŚealƚŚĐare ƵƟliǌaƟoŶ impliĐaƟoŶƐͿ are meaƐƵreĚ iŶ moŶeƚarǇ
ƵŶiƚƐ͕ ǁŚereaƐ ƚŚe ŬeǇ oƵƚĐome iƐ meaƐƵreĚ iŶ ŶaƚƵral ƵŶiƚƐ ;ϭͿ.
ϮͿ oƐƚͲďeŶeĮƚ aŶalǇƐiƐ ;Ϳ͗ oƚŚ ĐoƐƚƐ aŶĚ ĐoŶƐeƋƵeŶĐeƐ are meaƐƵreĚ iŶ
moŶeƚarǇ ƵŶiƚƐ. /Ŷ ďƵƐiŶeƐƐ aĚmiŶiƐƚraƟoŶ͕ Ɛ are ƐomeƟmeƐ ĚeƐĐriďeƐ
aƐ reƚƵrŶͲoŶͲiŶǀeƐƚmeŶƚ aŶalǇƐeƐ.
ϯͿ oƐƚͲƵƟliƚǇ aŶalǇƐiƐ ;hͿ͗ oƐƚƐ aŶĚ Ɛome ĐoŶƐeƋƵeŶĐeƐ are meaƐƵreĚ
iŶ moŶeƚarǇ ƚermƐ͕ ǁŚereaƐ ƚŚe ŬeǇ oƵƚĐome iƐ meaƐƵreĚ iŶ ƵƟliƚǇ ƵŶiƚƐ.
hƟliƟeƐ are oŌeŶ eǆpreƐƐeĚ iŶ ƚermƐ oĨ YƵaliƚǇ ĚũƵƐƚeĚ >iĨe zearƐ ;Y>zƐͿ
;ϭͿ.
ϰͿ oƐƚͲmiŶimiƐaƟoŶ aŶalǇƐiƐ ;DͿ͗ KŶlǇ ĐoƐƚƐ are ĐoŶƐiĚereĚ aĐroƐƐ
alƚerŶaƟǀeƐ͕ aƐ iƚ iƐ aƐƐƵmeĚ ƚŚaƚ ƚŚe ĐoŶƐeƋƵeŶĐeƐ are Ɛimilar. DƐ
are ĐoŶƐiĚereĚ iŶappropriaƚe iĨ ƚŚere iƐ ƵŶĐerƚaiŶƚǇ reŐarĚiŶŐ a poƐƐiďle
ĚiīereŶĐe iŶ ƚŚe maŐŶiƚƵĚe oĨ ĐoŶƐeƋƵeŶĐeƐ ;ϭͿ.
tŚiĐŚ ŬiŶĚ oĨ eĐoŶomiĐ eǀalƵaƟoŶ iƐ moƐƚ appropriaƚe ĚepeŶĚƐ oŶ ƚŚe ƐƚaŬeŚolĚerƐ
iŶǀolǀeĚ aŶĚ ƚŚe ƋƵeƐƟoŶ ďeiŶŐ aƐŬeĚ. 'eŶerallǇ͕ emploǇerƐ are moƐƚ iŶƚereƐƚeĚ
iŶ Ɛ ƚŚaƚ ĐaŶ proǀiĚe iŶƐiŐŚƚ iŶƚo ƚŚe impaĐƚ oĨ aŶ iŶƚerǀeŶƟoŶ oŶ a ĐompaŶǇ͛Ɛ
ďoƩomͲliŶe͕ ǁŚereaƐ pƵďliĐ poliĐǇ maŬerƐ maǇ ďe more iŶƚereƐƚeĚ iŶ EƐ aŶĚ
hƐ͕ parƟĐƵlarlǇ iĨ moŶeƚarǇ meaƐƵreƐ Ěo Ŷoƚ aĚeƋƵaƚelǇ ĐapƚƵre imporƚaŶƚ ŚealƚŚ
oƵƚĐomeƐ ;ϭ͖ϴ͖ϭϭͿ. TŚereĨore͕ iƚ iƐ reĐommeŶĚeĚ ƚŚaƚ reƐearĐŚerƐ ĐoŶĚƵĐƚ ǀarioƵƐ
ŬiŶĚƐ oĨ eĐoŶomiĐ eǀalƵaƟoŶƐ ǁiƚŚiŶ ƚŚe Ɛame ƐƚƵĚǇ iŶ orĚer ƚo iŶĨorm all releǀaŶƚ
ƐƚaŬeŚolĚerƐ ;ϯͿ.
ϮϰϮ
WrŝŶĐŝpůeƐ͕ ŵethŽĚƐ͕ aŶĚ reĐŽŵŵeŶĚaƟŽŶƐ
tŚĞŶƚŽƵŶĚĞƌƚĂŬĞĂŶĞĐŽŶŽŵŝĐĞǀĂůƵĂƟŽŶ
EĐoŶomiĐ eǀalƵaƟoŶƐ are oŌeŶ ĐoŶĚƵĐƚeĚ aloŶŐƐiĚe ;͞piŐŐǇďaĐŬeĚ͟ oŶƚoͿ ƚrialƐ
eǀalƵaƟŶŐ ƚŚe eīeĐƟǀeŶeƐƐ oĨ K,^ iŶƚerǀeŶƟoŶƐ. sarioƵƐ ĚeƐiŐŶ aƐpeĐƚƐ are
ƚŚereĨore ƚǇpiĐallǇ ĚeƚermiŶeĚ ďǇ ƚŚe reƋƵiremeŶƚƐ oĨ ƚŚe eīeĐƟǀeŶeƐƐ ƚrial ;e.Ő.
alƚerŶaƟǀeƐ͕ oƵƚĐome meaƐƵreƐͿ. ,oǁeǀer͕ ƚo eŶƐƵre ƚŚaƚ all releǀaŶƚ eĐoŶomiĐ
Ěaƚa iƐ ĐolleĐƚeĚ iŶ a ǀaliĚ͕ reliaďle͕ aŶĚ eĸĐieŶƚ ǁaǇ͕ iƚ iƐ imporƚaŶƚ ƚo ĐoŶƐiĚer ƚŚe
reƋƵiremeŶƚƐ Ĩor ƚŚe eĐoŶomiĐ eǀalƵaƟoŶ aƚ ƚŚe earlieƐƚ poƐƐiďle ƐƚaŐe ;ϭϮͲϭϰͿ.
eďaƚe eǆiƐƚƐ aƐ ƚo ǁŚeƚŚer aŶ eĐoŶomiĐ eǀalƵaƟoŶ ƐŚoƵlĚ ďe iŶĐlƵĚeĚ iŶ a ƚrial
ďeĨore ƚŚe eīeĐƟǀeŶeƐƐ oĨ a Ŷeǁ iŶƚerǀeŶƟoŶ iƐ eƐƚaďliƐŚeĚ. ,oǁeǀer͕ Ŷoƚ iŶĐlƵĚiŶŐ
aŶ eĐoŶomiĐ eǀalƵaƟoŶ ǁoƵlĚ riƐŬ loƐiŶŐ ƚŚe opporƚƵŶiƚǇ ƚo ƐimƵlƚaŶeoƵƐlǇ ĐolleĐƚ
ĐoƐƚ aŶĚ eīeĐƚ Ěaƚa ;ϭϰͿ. lƐo͕ ƚŚe aďƐeŶĐe oĨ ƐƚaƟƐƟĐallǇ ƐiŐŶiĮĐaŶƚ ĐoŶƐeƋƵeŶĐeͬ
eīeĐƚ ĚiīereŶĐeƐ ďeƚǁeeŶ ƚŚe alƚerŶaƟǀeƐ ďeiŶŐ ĐompareĚ ĚoeƐ Ŷoƚ ŶeĐeƐƐarilǇ
implǇ ƚŚaƚ ƚŚe Ŷeǁ alƚerŶaƟǀe iƐ Ŷoƚ ĐoƐƚͲeīeĐƟǀe aŶĚͬor ĐoƐƚͲďeŶeĮĐial. EĐoŶomiĐ
eǀalƵaƟoŶƐ are aďoƵƚ ƚŚe ũoiŶƚ ĚiƐƚriďƵƟoŶ oĨ ĐoƐƚƐ aŶĚ ĐoŶƐeƋƵeŶĐeƐ͕ aŶĚ ĐoƵlĚ
ĚemoŶƐƚraƚe Đlear ĐoƐƚͲeīeĐƟǀeŶeƐƐͬĐoƐƚͲďeŶeĮƚ ǁŚeŶ ŶeiƚŚer ĐoƐƚ Ŷor ĐoŶƐeƋƵeŶĐe
ĚiīereŶĐeƐ are iŶĚiǀiĚƵallǇ ƐiŐŶiĮĐaŶƚ ;ϭϰͿ. lƐo͕ ĐoƐƚ ƐaǀiŶŐƐ miŐŚƚ oĐĐƵr iŶ ƚŚe
aďƐeŶĐe oĨ ŚealƚŚ improǀemeŶƚƐ aŶĚ ĐoƵlĚ ƚŚƵƐ ďe miƐƐeĚ iĨ aŶ eĐoŶomiĐ eǀalƵaƟoŶ
is not performed.
dƌŝĂůĚĞƐŝŐŶ
WraŐmaƟĐ randomiǌed Đontrolled trials ;ZTsͿ are ŐenerallǇ aĐŬnoǁledŐed as tŚe
ďest ǀeŚiĐle for eĐonomiĐ eǀalƵaƟons͕ ďeĐaƵse tŚeǇ enaďle tŚe eǀalƵaƟon of tŚe
resoƵrĐe impliĐaƟons of K,^ interǀenƟons Ƶnder ͞real life͟ ĐondiƟons. TŚis setƵp
inĐreases tŚe eǆternal ǀaliditǇ of resƵlts͕ ǁŚile tŚe internal ǀaliditǇ is ŐƵaranteed
ďǇ tŚe randomiǌaƟon of parƟĐipants ;ϰ͖ϭϰͿ. titŚin tŚe oĐĐƵpaƟonal ŚealtŚ seƫnŐ͕
Śoǁeǀer͕ parƟĐipantͲleǀel randomiǌaƟon maǇ not alǁaǇs ďe feasiďle ;e.Ő. ǁŚen
interǀenƟons inĐlƵde orŐaniǌaƟonal ĐomponentsͿ. /n sƵĐŚ Đases͕ randomiǌaƟon at
tŚe leǀel of departments or loĐaƟons miŐŚt proǀide a more feasiďle approaĐŚ ;i.e.
ĐlƵsterͲZTsͿ ;ϯͿ.
To ensƵre tŚat tŚe resƵlts of an eĐonomiĐ eǀalƵaƟon are Őeneraliǌaďle to oĐĐƵpaƟonal
ŚealtŚ praĐƟĐe͕ trial ĐondiƟons sŚoƵld resemďle dailǇ praĐƟĐe as mƵĐŚ as possiďle.
&or eǆample͕ parƟĐipants sŚoƵld ďe similar to tŚose ǁŚo ǁill eǆperienĐe tŚe
Ϯϰϯ
8
Chapter 8
interǀenƟon if it is implemented ďroadlǇ͕ monitorinŐ sŚoƵld ďe done Ƶnder roƵƟne
ĐirĐƵmstanĐes͕ and interǀenƟons sŚoƵld ďe Đompared to ƵsƵal praĐƟĐe.
WĞƌƐƉĞĐƟǀĞ
n essenƟal aspeĐt of an eĐonomiĐ eǀalƵaƟon is its perspeĐƟǀe. WerspeĐƟǀe refers to
tŚe ͞point of ǀieǁ͟ taŬen to idenƟfǇ releǀant Đosts and ĐonseƋƵenĐes for inĐlƵsion
in tŚe eǀalƵaƟon. TŚe ĐŚosen perspeĐƟǀe maǇ ďe tŚat of anǇ releǀant staŬeŚolder
or an aŐŐreŐate of staŬeŚolders sƵĐŚ as a soĐietal perspeĐƟǀe. TŚe perspeĐƟǀe
determines ǁŚiĐŚ Đosts and ĐonseƋƵenĐes are inĐlƵded. /n tŚe soĐietal perspeĐƟǀe͕
for eǆample͕ all Đosts and ĐonseƋƵenĐes are Đonsidered irrespeĐƟǀe of ǁŚo paǇs or
ďeneĮts͕ ǁŚereas onlǇ tŚose ďorne ďǇ emploǇers are inĐlƵded ǁŚen tŚe emploǇer͛s
perspeĐƟǀe is applied. 'iǀen tŚis faĐt͕ tŚe perspeĐƟǀe is a ĐriƟĐal element in an
analǇsis and sŚoƵld tŚerefore ďe stated eǆpliĐitlǇ ;ϭͿ.
K,^ interǀenƟons are tǇpiĐallǇ iniƟated ďǇ ĐompanǇ manaŐement͖ eitŚer to ĐomplǇ
ǁitŚ tŚe laǁ͕ in an eīort to saǀe moneǇ ;i.e. redƵĐed siĐŬness aďsenĐe ĐostsͿ͕ or for
moral reasons ;ϭϭͿ. onseƋƵentlǇ͕ most eĐonomiĐ eǀalƵaƟons of sƵĐŚ interǀenƟons
are performed from tŚe emploǇer͛s perspeĐƟǀe ;ϰͲϳ͖ϭϱͿ͕ ďƵt otŚer perspeĐƟǀes
maǇ also ďe releǀant͖ e.Ő. ǁorŬer͛s͕ insƵrer͛s͕ and soĐietal perspeĐƟǀe. tŚen tŚe
emploǇer͛s perspeĐƟǀe is applied͕ ŬeǇ ǁorŬer oƵtĐomes͕ sƵĐŚ as tŚe ǀalƵe of ǁorŬer
ŚealtŚ͕ are oŌen not inĐlƵded in tŚe analǇsis͕ ďƵt simplǇ tŚe ŚealtŚͲrelated eǆpenses
inĐƵrred ďǇ an emploǇer ;e.Ő. prodƵĐƟǀitǇ impliĐaƟonsͿ. TŚis is a ĐriƟĐal oǀersiŐŚt͕
as oĐĐƵpaƟonal ŚealtŚ is essenƟallǇ aďoƵt ǁorŬer ŚealtŚ. soĐietal perspeĐƟǀe is
parƟĐƵlarlǇ ƵsefƵl to Đonsider as tŚe perspeĐƟǀe in a stƵdǇ͕ as it proǀides insiŐŚt into
tŚe net eīeĐt aĐross all staŬeŚolders. ,ereďǇ͕ it ďeƩer ensƵres tŚat tŚe soĐietal Đosts
of an interǀenƟon are less tŚan tŚe ďeneĮts eǆperienĐed ďǇ all staŬeŚolders͕ ratŚer
tŚan simplǇ tŚe ĐompanǇ͛s Đosts ďeinŐ less tŚan its ďeneĮts ;ϯͿ. TŚis informaƟon
ǁill ensƵre tŚat tŚere is a net soĐietal ďeneĮt͕ ratŚer tŚan simplǇ Đost sŚiŌinŐ from
one staŬeŚolder to anotŚer. /n addiƟon͕ tŚe disaŐŐreŐated informaƟon on Đosts and
ĐonseƋƵenĐes from a soĐietal perspeĐƟǀe proǀides a Őood sense of tŚeir distriďƵƟon
aĐross staŬeŚolders. ^ƵĐŚ informaƟon Đan ďe tŚe laƵnĐŚ pad for ďarŐaininŐ ďetǁeen
tŚem ;ϭͿ. TŚis maǇ ďe of parƟĐƵlar importanĐe in ĐoƵntries ǁitŚ dƵalͲpaǇer ;e.Ő.
TŚe EetŚerlandsͿ and Ƶniǀersal ŚealtŚĐare sǇstems ;e.Ő. TŚe hnited <inŐdomͿ͕ sinĐe
Ϯϰϰ
WrŝŶĐŝpůeƐ͕ ŵethŽĚƐ͕ aŶĚ reĐŽŵŵeŶĚaƟŽŶƐ
emploǇers ŐenerallǇ ďear most of tŚe Đosts of K,^ interǀenƟons͕ ǁŚereas in sƵĐŚ
ũƵrisdiĐƟons tŚe ŚealtŚĐare sǇstem andͬor Őoǀernment reaps a larŐe part of tŚeir
ďeneĮts ;i.e. redƵĐed mediĐal spendinŐͿ ;ϭϲͿ. TŚerefore͕ it is reĐommendaďle to
sƵpplement ĮndinŐs from tŚe emploǇer͛s perspeĐƟǀe ǁitŚ tŚose from otŚer releǀant
perspeĐƟǀes͕ parƟĐƵlarlǇ tŚe soĐietal one.
ŶĂůǇƟĐƟŵĞĨƌĂŵĞ
ZesearĐŚers also need to deĐide aďoƵt tŚe Ɵme frame oǀer ǁŚiĐŚ Đosts and
ĐonseƋƵenĐes are analǇsed. TŚe analǇƟĐ Ɵme frame oƵŐŚt to Đoǀer tŚe enƟre period
oǀer ǁŚiĐŚ Đosts and ĐonseƋƵenĐes Ňoǁ from tŚe alternaƟǀes Ƶnder ĐonsideraƟon
;ϭϮͿ. TŚis Ɵme frame ŐenerallǇ eǆtends ďeǇond tŚe folloǁͲƵp needed to estaďlisŚ tŚe
eīeĐƟǀeness of a neǁ interǀenƟon. To illƵstrate͕ tŚe folloǁͲƵp of an eīeĐƟǀeness
trial maǇ ďe terminated aŌer tŚe oĐĐƵrrenĐe of tŚe ĐliniĐal eǀent of interest ;e.Ő.
inĐidenĐe of ZepeƟƟǀe ^train /nũƵrǇ ;Z^/ͿͿ. /f tŚis folloǁͲƵp ǁoƵld ďe Ƶsed for tŚe
eĐonomiĐ eǀalƵaƟon͕ all Đosts and ĐonseƋƵenĐes inĐƵrred dƵrinŐ tŚe ĐoƵrse of
tŚe disorder or its reĐƵrrenĐes ǁoƵld not ďe taŬen into aĐĐoƵnt ;e.Ő. Z^/Ͳrelated
mediĐaƟon andͬor operaƟon ĐostsͿ͕ leadinŐ to an ƵnderesƟmaƟon of tŚe total Đosts
and ĐonseƋƵenĐes. ltŚoƵŐŚ tŚe opƟmal folloǁͲƵp period is ŐenerallǇ ƵnŬnoǁn͕
researĐŚers and readers sŚoƵld at least feel ĐonĮdent tŚat tŚe most important Đosts
and ĐonseƋƵenĐes are Đoǀered ďǇ tŚe ĐŚosen analǇƟĐ Ɵme frame. ddiƟonallǇ͕ fƵtƵre
Đosts and ĐonseƋƵenĐes tŚat oĐĐƵr aŌer tŚe measƵrement period Đan ďe esƟmated
ƵsinŐ informaƟon and data from ǀarioƵs soƵrĐes. TŚis is parƟĐƵlarlǇ important to do
if fƵtƵre Đosts and ĐonseƋƵenĐes are eǆpeĐted to ďe sƵďstanƟal ;e.Ő. manǇ of tŚe
;ŚealtŚͿ ďeneĮts of preǀenƟǀe interǀenƟons are tŚoƵŐŚt to oĐĐƵr in tŚe fƵtƵreͿ.
/ĚĞŶƟĮĐĂƟŽŶ͕ŵĞĂƐƵƌĞŵĞŶƚ͕ĂŶĚǀĂůƵĂƟŽŶŽĨƌĞƐŽƵƌĐĞƵƐĞ
/n eĐonomiĐ eǀalƵaƟons͕ Đosts and some ĐonseƋƵenĐes are eǆpressed in monetarǇ
Ƶnits. &or tŚis pƵrpose͕ releǀant resoƵrĐe Ƶse ĐateŐories sŚoƵld ďe idenƟĮed͕
measƵred͕ and ǀalƵed. s disĐƵssed earlier͕ releǀant resoƵrĐe Ƶse ĐateŐories for
inĐlƵsion in an eĐonomiĐ eǀalƵaƟon depend on its perspeĐƟǀe. KtŚer faĐtors tŚat
miŐŚt determine tŚe releǀanĐe of a resoƵrĐe Ƶse ĐateŐorǇ are͕ amonŐst otŚers͕
tŚe ĐoƵntrǇ or ũƵrisdiĐƟon in ǁŚiĐŚ tŚe stƵdǇ is ƵndertaŬen and tŚe natƵre of tŚe
Ϯϰϱ
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Chapter 8
alternaƟǀes ďeinŐ Đompared.
Ōer releǀant resoƵrĐe Ƶse ĐateŐories are idenƟĮed͕ researĐŚers sŚoƵld determine
Śoǁ to Đost tŚem. osƟnŐ ŐenerallǇ inǀolǀes tŚree steps͖ ϭͿ tŚe measƵrement of
ƋƵanƟƟes of resoƵrĐes ĐonsƵmed ;YͿ͕ ϮͿ tŚe assiŐnment of Ƶnit priĐes ;WͿ͕ and ϯͿ tŚe
ǀalƵaƟon of resoƵrĐes ĐonsƵmed ďǇ mƵlƟplǇinŐ tŚeir ƋƵanƟƟes ďǇ tŚeir respeĐƟǀe
unit prices ;YΎWͿ ;ϭͿ. TŚese esƟmates sŚould ďe reported separatelǇ so tŚat readers
can ũudŐe tŚe releǀance of tŚese measures to Śis or Śer seƫnŐ ;ϭϳͿ.
DeaƐƵreŵeŶt ŽĨ ƋƵaŶƟƟeƐ ŽĨ reƐŽƵrĐeƐ ĐŽŶƐƵŵeĚ
Zesource use data are ideallǇ collected prospecƟǀelǇ tŚrouŐŚ a data collecƟon
process tŚat is fullǇ inteŐrated into tŚe eīecƟǀeness trial ;ϭ͖ϭϯͿ. lso͕ ǁŚen collecƟnŐ
selfͲreported resource use data͕ researcŚers Śaǀe to ďalance recall ďias aŐainst
completeness of informaƟon. ^Śorter recall periods reduce tŚe risŬ of parƟcipants
forŐeƫnŐ important informaƟon. ,oǁeǀer͕ collecƟnŐ data ǁitŚ relaƟǀelǇ sŚort
recall periods ;e.Ő. a couple of ǁeeŬsͿ oǀer a lonŐer period of Ɵme maǇ ďe oǀerlǇ
ďurdensome to parƟcipants and maǇ tŚus increase tŚe risŬ of missinŐ data and dropͲ
outs. TŚerefore͕ it maǇ ďe ďeƩer to maǆimiǌe completeness at tŚe cost of some
recall ďias ;ϭϰͿ͖ e.Ő. ďǇ usinŐ ϮͲ to ϯͲmontŚ recall periods in a trial ǁitŚ a lonŐͲterm
folloǁͲup ;шϭϮ montŚsͿ ;ϭϴͿ. lso͕ care sŚould ďe taŬen to collect resource use data
conƟnuouslǇ durinŐ folloǁͲup and to aǀoid tŚe need for eǆtrapolaƟon of resource
use esƟmates ďetǁeen measurement periods.
ƐƐŝŐŶŵeŶt ŽĨ ƵŶŝt prŝĐeƐ
hnit prices used for ǀaluinŐ resource use ouŐŚt to reŇect opportunitǇ costs͖ i.e.
͞the ǀaůƵe ŽĨ a reƐŽƵrĐe ŝŶ ŝtƐ ŵŽƐt hŝŐhůǇ ǀaůƵeĚ aůterŶaƟǀe ƵƐe͟ ;ϴͿ. In a world of
perfect marŬets͕ sucŚ costs are reǀealed ďǇ tŚe marŬet price of a Őood or serǀice.
,oweǀer͕ if a compeƟƟǀe marŬet does not eǆist for a Őood or serǀice͕ marŬet prices
oŌen are an inaccurate measure of its ǀalue. &or eǆample͕ if a premium is paid for a
Őood or serǀice due to restricted marŬet entrǇ͕ marŬet prices maǇ oǀeresƟmate tŚe
opportunitǇ costs at tŚe societal leǀel. tŚen tŚe societal perspecƟǀe is applied͕ an
adũustment sŚould tŚerefore ďe made to tŚe marŬet price͖ e.Ő. ďǇ usinŐ tŚe price of a
comparaďle Őood or serǀice ;ϴͿ. &or tŚe emploǇer͛s perspecƟǀe͕ tŚe actual purcŚase
Ϯϰϲ
WrŝŶĐŝpůeƐ͕ ŵethŽĚƐ͕ aŶĚ reĐŽŵŵeŶĚaƟŽŶƐ
costs incurred ďǇ tŚe emploǇer maǇ ďe more appropriate͕ as tŚeǇ ďeƩer represent
tŚe sum of moneǇ tŚat is not aǀailaďle to tŚe emploǇer for its ďest alternaƟǀe
use ;ϭϮ͖ϭϵͿ. TŚus͕ appropriate unit prices maǇ ǀarǇ ďetween perspecƟǀes͕ and
researcŚers sŚould ensure tŚat tŚeǇ reŇect tŚe true resource implicaƟons to tŚe
decisionͲmaŬer at Śand ;ϴͿ.
ďrief descripƟon of tŚe metŚods used for measurinŐ and ǀaluinŐ tŚe most freƋuentlǇ
used resource use cateŐories in economic eǀaluaƟons of K,^ interǀenƟons is
proǀided ďelow. TŚe most freƋuentlǇ used resource use cateŐories are͖ interǀenƟon͕
ŚealtŚcare͕ producƟǀitǇ͕ and worŬer͛s compensaƟon costs ;ϰͲϳ͖ϭϱͿ.
/ŶterǀeŶƟŽŶ ĐŽƐtƐ
InformaƟon on tŚe marŬet price of an interǀenƟon maǇ ďe deriǀed from ǀendors
or companǇ andͬor researcŚ proũect records. DanǇ trials͕ Śoweǀer͕ assess noǀel
interǀenƟons tŚat eitŚer Śaǀe no predeĮned price weiŐŚts associated witŚ tŚem or
for wŚicŚ tŚe use of marŬet prices is inappropriate ;e.Ő. wŚen tŚe societal perspecƟǀe
is appliedͿ ;ϭϮͿ. In sucŚ cases͕ tŚe actual interǀenƟon costs can ďe assessed usinŐ a
ďoƩomͲup microͲcosƟnŐ approacŚ͕ in wŚicŚ detailed data reŐardinŐ tŚe ƋuanƟƟes
of resources consumed as well as tŚeir unit prices are collected per interǀenƟon
component separatelǇ. ^ucŚ resources maǇ include interǀenƟon staī Śours͕
materials used͕ depreciaƟon͕ oǀerŚead acƟǀiƟes͕ sƋuare feet of oĸce space͕ and
traǀelinŐ ;ϭ͖ϯ͖ϭϮͿ. lso͕ worŬers maǇ ďe taŬen awaǇ from tŚeir reŐular producƟon
acƟǀiƟes to parƟcipate in tŚe interǀenƟon and tŚis sŚould ďe accounted for as well.
osts associated witŚ tŚe interǀenƟon͛s eǀaluaƟon sŚould not ďe included unless it
is a condiƟon of implementaƟon ;ϴͿ.
YuanƟƟes of resources consumed can ďe measured usinŐ administraƟǀe dataďases͕
eǆpert panels͕ surǀeǇs or interǀiews witŚ interǀenƟon parƟcipants andͬor proǀiders͕
interǀenƟon operaƟon loŐs͕ or oďserǀaƟons ;ϮϬͿ. hnit prices maǇ ďe collected from
administraƟǀe dataďases͕ scienƟĮc literature͕ ǀendors͕ andͬor cosƟnŐ manuals ;e.Ő.
;ϮϭͿͿ.
Ϯϰϳ
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Chapter 8
,eaůthĐare ĐŽƐtƐ
IdeallǇ͕ all ŚealtŚcare serǀice use is measured to reduce tŚe liŬeliŚood tŚat
;uneǆpectedͿ sŚiŌs in ŚealtŚcare uƟliǌaƟon rates are missed. ltŚouŐŚ tŚis approacŚ
will increase tŚe ǀaliditǇ of tŚe results͕ it maǇ not alwaǇs ďe feasiďle. n alternaƟǀe
strateŐǇ is to limit data collecƟon to tŚose ŚealtŚcare serǀices tŚat are related to
tŚe alternaƟǀes andͬor condiƟon under studǇ ;ϭϮͿ. descripƟon of tŚe care patŚ
for tŚe condiƟon under studǇ miŐŚt proǀide researcŚers witŚ a clear picture of wŚat
tŚose ŚealtŚcare serǀices are. In all cases͕ care sŚould ďe taŬen to include tŚe most
important cost driǀers.
,ealtŚcare uƟliǌaƟon can ďe measured tŚrouŐŚ a ǀarietǇ of means͕ includinŐ
retrospecƟǀe ƋuesƟonnaires͕ prospecƟǀe resource use diaries ;i.e. cost diariesͿ͕ and
insurance or Śospital dataďases. ataďases͕ Śoweǀer͕ maǇ not alwaǇs contain all
reƋuired data͕ and tŚeir ǀaliditǇ and reliaďilitǇ maǇ not ďe ǀerǇ ŚiŐŚ ;ϭϬͿ. Doreoǀer͕
ŚealtŚcare costs ďorne ďǇ parƟcipants ;e.Ő. coͲpaǇments͕ oǀerͲtŚeͲcounter
medicaƟonͿ are tǇpicallǇ not included in tŚese dataďases. TŚerefore͕ researcŚers are
oŌen dependent on selfͲreport data to measure tŚese ŚealtŚcare uƟliǌaƟon items. To
ǀalue ŚealtŚcare uƟliǌaƟon͕ unit prices maǇ eitŚer ďe esƟmated usinŐ a microͲcosƟnŐ
approacŚ͕ or ďased on predeĮned price weiŐŚts͕ prices accordinŐ to professional
orŐaniǌaƟons͕ or tariīs. TǇpicallǇ͕ seǀeral metŚods are used simultaneouslǇ ;ϭϬ͖ϭϵͿ.
WrŽĚƵĐƟǀŝtǇ ĐŽƐtƐ
&or emploǇers͕ an important ďeneĮt of K,^ interǀenƟons are tŚe resulƟnŐ cŚanŐes
in producƟǀitǇ loss. WroducƟǀitǇ loss can ďe deĮned as tŚe companǇ͛s output loss
correspondinŐ to reduced laďour input ;i.e. Ɵme and eīortsͬsŬills of tŚe worŬforceͿ.
ccordinŐ to tŚis deĮniƟon͕ to ǀalue producƟǀitǇ loss is to ǀalue tŚe output loss
;ϮϮͿ. hnfortunatelǇ͕ Śoweǀer͕ oďũecƟǀe measurement of tŚe true impact of reduced
laďour input on a companǇ͛s output is oŌen impossiďle to esƟmate. TŚerefore͕
researcŚers tǇpicallǇ use proǆies of producƟǀitǇ loss͕ wŚicŚ are oŌen esƟmated usinŐ
;selfͲreportedͿ data on tŚe parƟcipants͛ leǀel of aďsenteeism ;i.e. sicŬness aďsenceͿ
andͬor presenteeism ;i.e. reduced performance wŚile at worŬͿ. TŚe metŚodoloŐies
used for measurinŐ and ǀaluinŐ aďsenteeism and presenteeism are a ĮercelǇ
deďated topic in tŚe Įeld of economic eǀaluaƟons. elow͕ a ďrief descripƟon of tŚe
Ϯϰϴ
WrŝŶĐŝpůeƐ͕ ŵethŽĚƐ͕ aŶĚ reĐŽŵŵeŶĚaƟŽŶƐ
most freƋuentlǇ used metŚods is proǀided. &or more informaƟon aďout tŚe main
deďates and deǀelopments reŐardinŐ tŚe idenƟĮcaƟon͕ measurement͕ and ǀaluaƟon
of producƟǀitǇ we refer to otŚer puďlicaƟons͖ ;ϮϮ͖ϮϯͿ.
TŚe two main metŚods for esƟmaƟnŐ aďsenteeism costs are tŚe ,uman apital
pproacŚ ;,Ϳ and tŚe &ricƟon ost pproacŚ ;&Ϳ. &or ďotŚ metŚods͕ tŚe numďer
of sicŬness aďsence daǇs Śas to ďe collected͕ for wŚicŚ administraƟǀe dataďases͕ selfͲ
report ;ƋuesƟonnairesͿ͕ or reports ďǇ otŚers can ďe used ;ϵͿ. &or tŚe &͕ it is also
important to idenƟfǇ tŚe numďer and duraƟon of diīerent aďsence periods. ccordinŐ
to tŚe ,͕ aďsenteeism costs are eƋual to tŚe amount of moneǇ parƟcipants would
Śaǀe earned Śad tŚeǇ not ďeen inũured or ill ;ϰ͖ϮϭͿ. TŚerefore͕ in tŚe ,͕ sicŬness
aďsence daǇs are tǇpicallǇ ǀalued usinŐ actual waŐe rates of parƟcipants ;includinŐ
emploǇment oǀerŚeads and ďeneĮtsͿ and represent losses for tŚe enƟre duraƟon of
aďsence ;ϭ͖ϭϵ͖ϮϰͿ. It is arŐued tŚat tŚe , oǀeresƟmates tŚe true societal cost of
sicŬness aďsence͕ as tŚe possiďle replacement of worŬers witŚ lonŐͲterm sicŬness
aďsence is not taŬen into account ;ϭ͖ϰͿ. TŚerefore͕ tŚe & was deǀeloped͕ in wŚicŚ
producƟon losses are assumed to ďe conĮned to tŚe ƟmeͲspan companies need to
replace a sicŬ worŬer ďǇ a formerlǇ unemploǇed person to restore tŚe companǇ͛s
iniƟal producƟon leǀel ;i.e. fricƟon periodͿ ;ϮϯͿ. In tŚe &͕ aďsenteeism is tǇpicallǇ
ǀalued usinŐ aŐeͲ͕ ŐenderͲ andͬor educaƟonͲspeciĮc price weiŐŚts ;ϮϱͿ. TŚe lenŐtŚ of
tŚe fricƟon period depends on tŚe state ;i.e. tŚe unemploǇment rateͿ and eĸciencǇ
of tŚe laďour marŬet. s sucŚ͕ fricƟon periods tǇpicallǇ diīer ďetween countries and
sŚould ďe esƟmated per countrǇ separatelǇ ;ϭͿ. If tŚere are important cŚanŐes in
tŚe economic climate͕ it maǇ ďe necessarǇ to esƟmate tŚe fricƟon period anew. In
tŚe EetŚerlands͕ a fricƟon period of Ϯϯ weeŬs is currentlǇ assumed ;ϮϭͿ. TŚus͕ if a
sicŬness aďsence period eǆceeds Ϯϯ weeŬs͕ aďsenteeism costs are truncated at tŚe
costs of Ϯϯ weeŬs. &urtŚermore͕ as a reducƟon of laďour input is oŌen assumed to
cause a less tŚan proporƟonal reducƟon in producƟǀitǇ͕ <oopmanscŚap et al. ;ϭϵϵϱͿ
also proposed tŚe applicaƟon of an elasƟcitǇ factor of Ϭ.ϴ͕ wŚicŚ is oŌen used in
economic eǀaluaƟons tŚat applǇ tŚe &. TŚis elasƟcitǇ factor implies tŚat a ϭϬϬй
loss of laďor input corresponds witŚ an ϴϬй reducƟon in producƟǀitǇ ;ϮϱͿ.
In tŚe economic eǀaluaƟon literature͕ tŚe need to consider presenteeism as
a component of tŚe costs incurred from producƟǀitǇ loss is increasinŐlǇ ďeinŐ
Ϯϰϵ
8
Chapter 8
recoŐniǌed ;ϵͿ. Wresenteeism is tǇpicallǇ esƟmated usinŐ parƟcipant selfͲreport
or report ďǇ otŚers. &or tŚis purpose͕ ǀarious instruments Śaǀe ďeen deǀeloped͕
includinŐ ďotŚ Őeneric ;ϮϲͲϮϵͿ and diseaseͲspeciĮc ƋuesƟonnaires ;ϯϬ͖ϯϭͿ. Dost of
tŚese ƋuesƟonnaires measure worŬ performance in terms of points͕ percentaŐes͕ or
proporƟons ;ϯϮͿ. TŚese responses can tŚen ďe used to esƟmate tŚe total numďer of
worŬinŐ daǇs lost due to presenteeism ďǇ usinŐ tŚe eƋuaƟon͗
W с ; ʹ Ϳ Ύ p
where W is full worŬinŐ daǇs lost due to presenteeism͕ is total worŬinŐ daǇs͕ A is
sicŬness aďsence daǇs͕ and p is the proporƟon of lost worŬ performance esƟmated
ďǇ the instrument used in the studǇ ;ϮϮͿ. To ǀalue the numďer of lost worŬinŐ daǇs
due to presenteeism͕ actual waŐe rates of parƟcipants͕ or aŐeͲ͕ ŐenderͲ͕ andͬor ũoďͲ
speciĮc price weiŐhts can ďe used. Zesearchers should ďe aware͕ howeǀer͕ that the
esƟmated numďer of worŬ daǇs lost due to presenteeism maǇ ǀarǇ widelǇ ďetween
instruments. This suŐŐests a lacŬ of comparaďilitǇ amonŐ instruments͕ ďut it is sƟll
unclear which instrument proǀides the ďest presenteeism esƟmate ;ϮϮͿ. 'iǀen its
siŐniĮcance͕ howeǀer͕ iŐnorinŐ presenteeism maǇ lead to seǀere underesƟmaƟons
;ϮϮͿ. Therefore͕ researchers are recommended to include this resource use cateŐorǇ
wheneǀer possiďle. To assess the possiďle inŇuence of the choice of instrument͕
sensiƟǀitǇ analǇses can ďe performed ;^ee ďelowͿ.
tŽrŬerƐ͛ ĐŽŵpeŶƐaƟŽŶ ĐŽƐtƐ
torŬers͛ compensaƟon is an insurance proŐram͕ oīered in some countries ;e.Ő.
anada͕ hnited ^tatesͿ͕ throuŐh which worŬers maǇ receiǀe waŐe replacement andͬ
or medical ďeneĮts in the eǀent of an occupaƟonal inũurǇ or disease. &undinŐ usuallǇ
comes from premiums paid ďǇ emploǇers ;ϴͿ. To esƟmate worŬers͛ compensaƟon
costs͕ total claim costs per parƟcipant can ďe oďtained from companǇ andͬor
worŬplace insurance records. It is ŐenerallǇ inadeƋuate͕ howeǀer͕ to use worŬers͛
compensaƟon costs as the sole cost cateŐorǇ͕ as theǇ do not reŇect the full eǆtent of
worŬͲrelated inũuries and illnesses ;ϰͿ. DanǇ compensaďle inũuries and illnesses Őo
unreported and others are not compensaďle ;ϰͿ. then supplemenƟnŐ healthcare
ϮϱϬ
WrŝŶĐŝpůeƐ͕ ŵethŽĚƐ͕ aŶĚ reĐŽŵŵeŶĚaƟŽŶƐ
andͬor producƟǀitǇ costs with worŬers͛ compensaƟon costs͕ douďle counƟnŐ should
ďe aǀoided. lso͕ insurance premiumͲrelated waŐe replacement ďeneĮts should ďe
eǆcluded for the societal perspecƟǀe͕ as theǇ consƟtute ͞transfer paǇments͟ from
the emploǇer ǀia the insurer to the worŬer rather than depleted sources ;ϭ͖ϰͿ
/ĚĞŶƟĮĐĂƟŽŶ͕ŵĞĂƐƵƌĞŵĞŶƚ͕ĂŶĚǀĂůƵĂƟŽŶŽĨŽƵƚĐŽŵĞƐ
s noted ďefore͕ Es haǀe the ŬeǇ outcome measured in natural units. The most
appropriate outcome used for this purpose depends on the nature of the alternaƟǀes
ďeinŐ compared͕ the condiƟon under studǇ͕ andͬor the applied perspecƟǀe.
^omeƟmes͕ there maǇ ďe some concern aďout whether the chosen outcome
captures all releǀant conseƋuences. If this is a concern͕ it is adǀisaďle to conduct
mulƟple Es usinŐ diīerent outcomes ;ϴͿ. In hs͕ the ŬeǇ outcome is measured
in uƟlitǇ units͕ ŐenerallǇ Ŭnown as Y>zs. TheǇ capture ďoth the duraƟon of surǀiǀal
and healthͲrelated ƋualitǇ of life in a sinŐle measure ;ϭ͖ϭϮ͖ϭϰͿ. n adǀantaŐe of Y>zs
is that theǇ proǀide a Őeneral indeǆ score that allows decisionͲmaŬers to compare
the conseƋuences of a ranŐe of interǀenƟons for diīerent health issues ;ϭ͖ϭϬͿ.
,oweǀer͕ eǀen thouŐh Y>zs are the preferred outcome measure when healthcare
interǀenƟons for paƟents are eǀaluated from the societal perspecƟǀe ;ϭϯ͖Ϯϭ͖ϯϯͿ͕
theǇ haǀe not Ǉet ďeen freƋuentlǇ used in economic eǀaluaƟons of K,^ interǀenƟons
;ϰ͖ϲ͖ϳ͖ϯϰͿ. This maǇ ďe due to the fact that Y>zs maǇ not reŇect what occupaƟonal
health decisionͲmaŬers feel is most important in terms of outcomes. In the case of
a worŬplace safetǇ proŐrams͕ for eǆample͕ outcomes such as worŬer safetǇ maǇ ďe
more meaninŐful to decisionͲmaŬers than a uƟlitǇͲweiŐhted health measure ;ϭϭͿ.
Doreoǀer͕ occupaƟonal health decisionͲmaŬers are ŐenerallǇ unfamiliar with Y>zs͕
and Y>zs seem to lacŬ sensiƟǀitǇ to mild condiƟons that are oŌen the focus of
K,^ interǀenƟons ;e.Ő. of worŬsite health promoƟon proŐramsͿ ;ϯϱͿ. Therefore͕
more sensiƟǀe uƟlitǇ measures are warranted for economic eǀaluaƟons of K,^
interǀenƟons andͬor uƟlitǇ measures that are more applicaďle to the occupaƟonal
health seƫnŐ͖ e.Ő. the recentlǇ conceptualiǌed ͞iseaseͲdũusted torŬinŐ zears͕͟
which aims to eǆpress the amount of worŬinŐ Ǉears lost due to poor worŬinŐ
condiƟons and associated illness ;ϯϲ͖ϯϳͿ.
Ϯϱϭ
8
Chapter 8
ANALYSIS OF AN ECONOMIC EVALUATION
elow͕ we discuss some important issues in the analǇsis of trialͲďased economic
eǀaluaƟons. To illustrate some of them͕ data is used from an economic eǀaluaƟon
that was preǀiouslǇ performed alonŐside a ϭϮͲmonth praŐmaƟc ZT͕ in which
construcƟon worŬers at risŬ for cardioǀascular disease either receiǀed a lifestǇle
interǀenƟon or usual pracƟce. E in terms of ŬiloŐram ďodǇ weiŐht loss was
performed from the societal perspecƟǀe and a from that of the emploǇer.
Zesource use cateŐories included interǀenƟon͕ healthcare͕ aďsenteeism͕ and sports
costs and were eǆpressed in ϮϬϬϴ Euros. Dore detailed informaƟon aďout this trialͲ
ďased economic eǀaluaƟon can ďe found elsewhere͖ ;ϯϴͿ.
^ĂŵƉůĞƐŝǌĞ
IdeallǇ͕ economic outcomes are used in the sample siǌe calculaƟon of a trial ;ϭϯͿ.
,oweǀer͕ althouŐh ǀarious techniƋues haǀe ďeen proposed to esƟmate the
appropriate sample siǌe for economic endpoints ;ϯϵͲϰϮͿ͕ sample siǌe calculaƟons are
tǇpicallǇ performed ďased on primarǇ outcomes ;ϭϬ͖ϭϯ͖ϭϰͿ. This is due to the fact that
cost data are riŐht sŬewed and therefore reƋuire larŐer sample siǌes to detect releǀant
diīerences than ;healthͿ outcome data. ,oweǀer͕ a larŐe sample siǌe maǇ neither ďe
feasiďle nor ethicallǇ acceptaďle ;ϭϰ͖ϰϯͿ. lso͕ a larŐe numďer of parameters has to ďe
speciĮed to perform sample siǌe calculaƟons for economic endpoints ;e.Ő. ǀariance
parameters of eīecƟǀeness measures͕ cost measures͕ incremental costͲeīecƟǀeness
raƟosͿ͕ manǇ of which are hard to predict a priori ;ϯϵ͖ϰϭ͖ϰϮͿ. onseƋuentlǇ͕ trialͲ
ďased economic eǀaluaƟons are tǇpicallǇ underpowered for economic outcomes
;ϭϬͿ. >ow powered studies haǀe imprecise and uncertain cost esƟmates and should
ďe interpreted with cauƟon ;ϰϯͿ. Doreoǀer͕ if studies are liŬelǇ to ďe underpowered͕
researchers are recommended to use esƟmaƟon rather than hǇpothesis tesƟnŐ ;i.e.
ďǇ usinŐ conĮdence interǀals rather than pͲǀaluesͿ ;ϰϳͿ.
ĚũƵƐƟŶŐĨŽƌĚŝīĞƌĞŶƟĂůƟŵŝŶŐ
InterǀenƟons maǇ haǀe diīerent Ɵme proĮles of costs and conseƋuences. tithin
occupaƟonal health͕ interǀenƟon costs are ŐenerallǇ incurred immediatelǇ͕ while
ϮϱϮ
WrŝŶĐŝpůeƐ͕ ŵethŽĚƐ͕ aŶĚ reĐŽŵŵeŶĚaƟŽŶƐ
conseƋuences such as producƟǀitǇ costs miŐht eǆtend into the future ;ϰϰͿ. Two
tǇpes of adũustments should ďe made to account for these diīerences in ƟminŐ.
The Įrst concerns the adũustment of cost data for inŇaƟon͖ i.e. “the general upward
prŝĐe ŵŽǀeŵent ŽĨ gŽŽdƐ and ƐerǀŝĐeƐ͟ ;ϭϮͿ. ue to inŇaƟon͕ prices drawn from
diīerent Ǉears are ŐenerallǇ not comparaďle ;ϴͿ. ll prices should therefore ďe
adũusted to the same reference Ǉear usinŐ consumer price indices and the applied
reference Ǉear should ďe stated eǆplicitlǇ ;ϭϳͿ. The second adũustment concerns the
adũustment of cost and outcome data for Ɵme preferences of indiǀiduals when theǇ
are collected oǀer a period of more than one Ǉear ;ϭϮͿ. Eǀen within a world with
ǌero inŇaƟon͕ indiǀiduals haǀe a preference for receiǀinŐ ďeneĮts todaǇ rather than
in the future ;ϭͿ. Therefore͕ costs and conseƋuences incurred in diīerent Ǉears haǀe
to ďe discounted at some rate to esƟmate their present ǀalue ;ϰϰͿ. The appropriate
discount rate depends on the ďorrowinŐ cost of moneǇ and other conteǆtual factors.
'uidelines for discount rates used in puďlic sector proũects are proǀided ďǇ some
ũurisdicƟons. &or eǆample͕ in the Eetherlands͕ cost data should ďe discounted at ϰй
and health outcomes at ϭ.ϱй͕ while ďoth should ďe discounted at ϯ.ϱй in the hnited
<inŐdom ;Ϯϭ͖ϯϯͿ.
/ŶƚĞŶƟŽŶͲƚŽͲƚƌĞĂƚĂŶĚŵŝƐƐŝŶŐĚĂƚĂ
'uidelines for conducƟnŐ trials prescriďe that all parƟcipants should ďe included in
the analǇses͕ all retained in the Őroup to which theǇ were allocated ;i.e. intenƟonͲ
toͲtreat analǇsisͿ ;ϰϱͿ. ,oweǀer͕ true intenƟonͲtoͲtreat analǇses are oŌen hampered
ďǇ missinŐ data͕ which are ŐenerallǇ ineǀitaďle in trials. &or economic eǀaluaƟons͕
this proďlem is eǀen more pronounced͕ ďecause total costs are tǇpicallǇ the sum
of numerous cost components. s such͕ cost data will alreadǇ ďe incomplete if one
component is missinŐ ;ϭϯͿ. DissinŐ data itself maǇ haǀe no relaƟon to oďserǀed and
unoďserǀed factors amonŐ parƟcipants ;DZ͗ DissinŐ ompletelǇ t ZandomͿ͕
maǇ onlǇ haǀe a relaƟonship to oďserǀed factors ;DZ͗ DissinŐ t ZandomͿ͕ or maǇ
also haǀe a relaƟonship to unoďserǀed factors ;DEZ͗ DissinŐ Eot t ZandomͿ ;^ee
oǆ ϭ for a more detailed descripƟonͿ ;ϰϲͿ. ,istoricallǇ͕ completeͲcase analǇses ;i.e.
eliminaƟnŐ cases with missinŐ dataͿ were used to deal with missinŐ data and this
is sƟll an oŌen used approach in trialͲďased economic eǀaluaƟons ;ϰϳͿ. ,oweǀer͕
Ϯϱϯ
8
Chapter 8
completeͲcase analǇses reduce the power of a studǇ and lead to ďiased esƟmates
if missinŐ data are not DZ ;ϭϮ͖ϭϯͿ. If the rate of missinŐ data is smaller than ϱй͕
completeͲcase analǇses maǇ ďe considered. If more than ϱй of data are missinŐ͕
researchers should use imputaƟon techniƋues to Įll in missinŐ ǀalues. EowadaǇs͕
mulƟple imputaƟon is ŐenerallǇ recommended to impute missinŐ data ;ϭϯ͖ϭϰͿ.
then usinŐ mulƟple imputaƟon͕ mulƟǀariate reŐression techniƋues are used to
predict missinŐ ǀalues on the ďasis of oďserǀed factors ;ϭϮ͖ϭϰͿ. To account for the
uncertaintǇ aďout the missinŐ data͕ seǀeral diīerent imputed datasets are created
;ϰϲͿ. s a rule of thumď͕ thite et al. ;ϮϬϭϭͿ suŐŐested that the numďer of datasets
should at least ďe eƋual to the percentaŐe of incomplete cases ;ϰϴͿ. The imputed
datasets are suďseƋuentlǇ analǇsed separatelǇ to oďtain a set of parameter esƟmates͕
which can then ďe pooled usinŐ Zuďin͛s rules to oďtain oǀerall esƟmates͕ ǀariances͕
and ϵϱй conĮdence interǀals ;ϵϱйIsͿ ;ϰϲ͖ϰϴ͖ϰϵͿ. DulƟple imputaƟon leads to
unďiased esƟmates if missinŐ data are DZ ;ϭϮͿ. Zesearchers should ďear in mind͕
howeǀer͕ that cost and conseƋuence esƟmates deriǀed usinŐ mulƟple imputaƟon are
less reliaďle and precise than those ďased on a ϭϬϬй complete dataset ;ϭϰͿ. EǀerǇ
endeaǀor should therefore ďe made to minimiǌe the amount of missinŐ data.
Žǆϭ͗dǇƉĞƐŽĨŵŝƐƐŝŶŐĚĂƚĂ;ϰϲͿ
ϭͿ DissinŐ ompletelǇ t Zandom ;DZͿ͗ The ͞missinŐness͟ of data has no
relaƟonship to oďserǀed and unoďserǀed factors amonŐ parƟcipants. &or eǆample͕
sicŬness aďsence data maǇ ďe missinŐ ďecause of proďlems with the reŐistraƟon of
this data due to a temporarǇ computer proďlem.
ϮͿ DissinŐ t Zandom ;DZͿ͗ The ͞missinŐness͟ of data has a relaƟonship to
oďserǀed factors amonŐ parƟcipants͕ ďut not to unoďserǀed factors. &or eǆample͕
missinŐ sicŬness aďsence duraƟons maǇ ďe lonŐer than aǀailaďle sicŬness aďsence
duraƟons ďut onlǇ ďecause older emploǇees maǇ ďe more liŬelǇ to haǀe missinŐ
sicŬness aďsence data.
ϯͿ DissinŐ Eot t Zandom ;DEZͿ͗ Eǀen aŌer the oďserǀed data are taŬen into
account͕ sǇstemaƟc diīerences remain ďetween the missinŐ ǀalues and the
oďserǀed ǀalues. This means that the ͞missinŐness͟ of data also has a relaƟonship
to unoďserǀed factors. &or eǆample͕ in trials relǇinŐ on selfͲreported sicŬness
aďsence͕ parƟcipants with lonŐer sicŬness aďsence duraƟons maǇ ďe more liŬelǇ to
forŐet to return their cost diaries ďecause theǇ are not feelinŐ well.
Ϯϱϰ
WrŝnĐŝpleƐ͕ ŵethŽdƐ͕ and reĐŽŵŵendaƟŽnƐ
/ŶĐƌĞŵĞŶƚĂůĂŶĂůǇƐŝƐŽĨĐŽƐƚƐĂŶĚĐŽŶƐĞƋƵĞŶĐĞƐ
Ōer costs and conseƋuences haǀe ďeen ƋuanƟĮed͕ their mean diīerences ďetween
the interǀenƟon and control Őroup;sͿ as well as the staƟsƟcal siŐniĮcance of these
diīerences need to ďe assessed ;ϭϮͿ.
s menƟoned aďoǀe͕ cost data are tǇpicallǇ riŐht sŬewed. This is caused ďǇ the fact
that onlǇ a small proporƟon of parƟcipants incur hiŐh costs and costs are naturallǇ
ďound ďǇ ǌero ;^ee &iŐure ϭͿ ;ϭͿ.
8
&ŝŐƵƌĞ ϭ͗ ŝƐƚƌŝďƵƟŽŶ ŽĨ ƚŚĞ ƐŽĐŝĞƚĂů ĐŽƐƚƐ ƉĞƌ ƉĂƌƟĐŝƉĂŶƚ ŝŶ Ă ƚƌĂŝůͲďĂƐĞĚ ĞĐŽŶŽŵŝĐ
ĞǀĂůƵĂƟŽŶ ŽĨ Ă ůŝĨĞƐƚǇůĞ ŝŶƚĞƌǀĞŶƟŽŶ ĨŽƌ ĐŽŶƐƚƌƵĐƟŽŶ ǁŽƌŬĞƌƐ Ăƚ ƌŝƐŬ ĨŽƌ ĐĂƌĚŝŽǀĂƐĐƵůĂƌ
ĚŝƐĞĂƐĞĐŽŵƉĂƌĞĚƚŽƵƐƵĂůƉƌĂĐƟĐĞ;ϯϴͿ
The sŬewed cost distriďuƟon complicates the analǇsis of cost data͕ as it ǀiolates
the assumpƟons of standard staƟsƟcal tests͕ such as independent tͲtests and linear
reŐression analǇses. standard approach to descriďe sŬewed data is to proǀide
a summarǇ measure of the distriďuƟon in the form of a median. ,oweǀer͕ this is
inappropriate for cost data as decisionͲmaŬers need to ďe aďle to esƟmate the total
Ϯϱϱ
Chapter 8
cost of implemenƟnŐ a new interǀenƟon ;total implementaƟon costs с mean costs
per parƟcipant Ύ numďer of parƟcipantsͿ. s such͕ the arithmeƟc mean is ŐenerallǇ
ǀiewed as the most informaƟǀe measure to descriďe cost data ;ϭ͖ϭϰ͖ϱϬͿ. sarious
methods are currentlǇ used to compare cost data ďetween studǇ arms͕ includinŐ
standard nonͲparametric tests ;e.Ő. DannͲthitneǇ hͿ͕ tͲtests on loŐͲtransformed
data͕ and nonͲparametric ďootstrappinŐ. ^tandard nonͲparametric tests compare
the distriďuƟon of the data instead of means and are therefore inappropriate.
TransformaƟons to normaliǌe the distriďuƟon are not straiŐhƞorward and are
oŌen sensiƟǀe to departures from distriďuƟonal assumpƟons ;ϭϯͿ. Doreoǀer͕ ďacŬͲ
transformaƟons are oŌen complicated. Therefore͕ researchers increasinŐlǇ faǀour
the nonͲparametric ďootstrap ;ϭϯ͖ϱϬͿ͕ which can ďe used to esƟmate ϵϱйIs around
mean cost diīerences while aǀoidinŐ distriďuƟonal assumpƟons ;oǆ ϮͿ ;ϱϭͿ.
ŽǆϮ͗EŽŶͲƉĂƌĂŵĞƚƌŝĐďŽŽƚƐƚƌĂƉƉŝŶŐ
tith nonͲparametric ďootstrappinŐ͕ staƟsƟcal analǇses are ďased on repeatedlǇ samplinŐ
with replacement from the oďserǀed data. In short͕ a sample of N parƟcipants is repeatedlǇ
drawn with replacement from ďoth the interǀenƟon and control Őroup separatelǇ͕ where N
eƋuals the numďer of parƟcipants per studǇ arm. EǀerǇ resample ;i.e. ďootstrap sampleͿ is
the eƋuiǀalent of a repeƟƟon of the trial. ^ince resamples haǀe ďeen drawn with replacement
;i.e. per sample͕ parƟcipants can ďe drawn more than onceͿ͕ these ďootstrap samples diīer
from one another. Wer ďootstrap sample͕ the staƟsƟcs of interest is calculated ;e.Ő. the
diīerence in arithmeƟc mean costs and eīects͕ incrementalͲcost eīecƟǀeness raƟos͕ costͲ
ďeneĮt esƟmatesͿ. Ǉ doinŐ so mulƟple Ɵmes͕ a distriďuƟon for the staƟsƟcs of interest
is Őenerated that proǀides an approǆimaƟon of its populaƟon samplinŐ distriďuƟon͕ which
can then ďe used to esƟmate conĮdence interǀals ;ϭϮͿ. t least ϮϬϬϬ ďootstrap samples are
recommended͕ and preferaďlǇ more ;ϱϮͿ. sarious methods haǀe ďeen proposed to esƟmate
ďootstrapped ϵϱй conĮdence interǀals͕ of which the ďias corrected and accelerated method
is currentlǇ the preferred one ;ϱϭ͖ϱϯͿ. EonͲparametric ďootstrappinŐ is aǀailaďle in manǇ
soŌware pacŬaŐes͕ includinŐ ^W^^͕ ^^͕ ^TT͕ and Z.
ŽŵƉĂƌŝŶŐŝŶĐƌĞŵĞŶƚĂůĐŽƐƚƐĂŶĚĐŽŶƐĞƋƵĞŶĐĞƐ
The core of anǇ economic eǀaluaƟon is the analǇsis of the relaƟon ďetween the
costs and conseƋuences of alternaƟǀes. The preferred methods for conducƟnŐ such
analǇses diīer ďetween the tǇpes of economic eǀaluaƟons and are discussed ďelow.
Ϯϱϲ
WrŝnĐŝpleƐ͕ ŵethŽdƐ͕ and reĐŽŵŵendaƟŽnƐ
CŽƐtͲeīeĐƟǀeneƐƐ analǇƐŝƐ and ĐŽƐtͲuƟlŝtǇ analǇƐŝƐ
In Es and hs͕ an incremental costͲeīecƟǀeness raƟo ;IEZͿ is calculated ďǇ
diǀidinŐ the mean diīerence in cost ;ѐ ostͿ ďetween studǇ arms ďǇ that in eīect ;ѐ
EīectͿ. The IEZ indicates the addiƟonal costs of a new interǀenƟon in comparison
with a control condiƟon per unit of eīect Őained ;ϭ͖ϭϮͿ.
ostinterǀenƟon ʹ ostcontrol
ѐ ost
с
EīectinterǀenƟon ʹ Eīectcontrol
с
IEZ
ѐ Eīect
To illustrate͕ a descripƟon of the calculaƟon and interpretaƟon of the eǆample trial͛s
IEZ is proǀided in oǆ ϯ.
Žǆϯ͗ĂůĐƵůĂƟŽŶĂŶĚŝŶƚĞƌƉƌĞƚĂƟŽŶŽĨƚŚĞŝŶĐƌĞŵĞŶƚĂůĐŽƐƚͲĞīĞĐƟǀĞŶĞƐƐƌĂƟŽ;/ZͿŽĨĂ
ůŝĨĞƐƚǇůĞŝŶƚĞƌǀĞŶƟŽŶĨŽƌĐŽŶƐƚƌƵĐƟŽŶǁŽƌŬĞƌƐĂƚƌŝƐŬĨŽƌĐĂƌĚŝŽǀĂƐĐƵůĂƌĚŝƐĞĂƐĞĐŽŵƉĂƌĞĚ
ƚŽƵƐƵĂůƉƌĂĐƟĐĞ;ϯϴͿ
urinŐ followͲup͕ interǀenƟon Őroup parƟcipants siŐniĮcantlǇ decreased their ďodǇ weiŐht
ďǇ Ϯ.ϬϮ ŬiloŐram compared to the control Őroup ;ѐ EīectͿ. Dean societal costs per parƟcipant
were nonͲsiŐniĮcantlǇ hiŐher in the interǀenƟon Őroup compared to the control Őroup ďǇ
ΦϮϵϯ ;ѐ ostͿ. hsinŐ this informaƟon͕ the IEZ can ďe calculated͖
IEZ͗ ΦϮϵϯͬϮ.ϬϮ с Φϭϰϱ
This IEZ indicates that societǇ has to paǇ Φϭϰϱ per parƟcipant in the interǀenƟon Őroup for
each addiƟonal ŬiloŐram ďodǇ weiŐht loss compared to usual pracƟce.
8
IEZs are ŐenerallǇ hard to interpret. &or eǆample͕ neŐaƟǀe IEZs miŐht represent
reduced costs and posiƟǀe eīects indicaƟnŐ a winͲwin situaƟon or increased costs
and neŐaƟǀe eīects indicaƟnŐ a loseͲlose situaƟon ;ϭϰͿ. Therefore͕ IEZs are oŌen
ŐraphicallǇ illustrated on costͲeīecƟǀeness planes ;EͲplanesͿ͕ in which incremental
eīects are ploƩed on the yͲaǆis and incremental costs on the zͲaǆis ;&iŐure ϮͿ ;ϱϰ͖ϱϱͿ.
If an IEZ is located either in the ^outh East Yuadrant ;^EͲYͿ or the Eorth test
Yuadrant ;EtͲYͿ͕ the choice ďetween alternaƟǀes is clear ;assuminŐ there is no
uncertaintǇ surroundinŐ the IEZͿ. In the ^EͲY͕ the new interǀenƟon is more
eīecƟǀe and less costlǇ than the control condiƟon and is therefore said to dominate
Ϯϱϳ
Chapter 8
the control condiƟon. In the EtͲY͕ the opposite is true and the new interǀenƟon is
dominated ďǇ the control condiƟon. If a new interǀenƟon is more eīecƟǀe and more
costlǇ ;EEͲY͗ Eorth East YuadrantͿ or less eīecƟǀe and less costlǇ ;^tͲY͗ ^outh
test YuadrantͿ͕ the decision whether or not to adopt it depends on the soͲcalled
͞willinŐnessͲtoͲpaǇ͟ ;ʄͿ. That is͕ the maǆimum amount of moneǇ decisionͲmaŬers
are willinŐ to paǇ for an addiƟonal unit of eīect ;ϭͿ. To illustrate͕ a hǇpothesiǌed ʄ is
depicted as the diaŐonal line in &iŐure Ϯ and diǀides the EͲplane into a costͲeīecƟǀe
and a nonͲcostͲeīecƟǀe halǀe. IEZs located to the riŐht of this line are considered
acceptaďle͕ whereas IEZs located to the leŌ are considered inacceptaďle ;ϭϰ͖ϱϰ͖ϱϱͿ.
The more decisionͲmaŬers are willinŐ to paǇ for an addiƟonal unit of eīect͕ the
steeper the slope of this line ;ϭϰͿ.
EĞǁƚƌĞĂƚŵĞŶƚ
ŵŽƌĞĐŽƐƚůǇ
EŽƌƚŚ ǁĞƐƚ
ƋƵĂĚƌĂŶƚ
,ǇƉŽƚŚĞƐŝǌĞĚ
ǁŝůůŝŶŐŶĞƐƐͲƚŽͲƉĂǇ
;ȜͿ
EĞǁŝŶƚĞƌǀĞŶƚŝŽŶ
ŝƐŵŽƌĞĞĨĨĞĐƚŝǀĞ
ďƵƚ ŵŽƌĞĐŽƐƚůǇ
ŽŶƚƌŽů ĐŽŶĚŝƚŝŽŶ
ĚŽŵŝŶĂƚĞƐ
EĞǁƚƌĞĂƚŵĞŶƚ
ůĞƐƐ ĞĨĨĞĐƚŝǀĞ
EĞǁƚƌĞĂƚŵĞŶƚ
ŵŽƌĞĞĨĨĞĐƚŝǀĞ
EĞǁŝŶƚĞƌǀĞŶƚŝŽŶ
ŝƐůĞƐƐ ĐŽƐƚůǇ ďƵƚ
ůĞƐƐ ĞĨĨĞĐƚŝǀĞ
^ŽƵƚŚ ǁĞƐƚ
ƋƵĂĚƌĂŶƚ
&ŝŐƵƌĞϮ͗ŽƐƚͲĞīĞĐƟǀĞŶĞƐƐƉůĂŶĞ
Ϯϱϴ
EŽƌƚŚ ĞĂƐƚ
ƋƵĂĚƌĂŶƚ
EĞǁŝŶƚĞƌǀĞŶƚŝŽŶ
ĚŽŵŝŶĂƚĞƐ
^ŽƵƚŚ ĞĂƐƚ
ƋƵĂĚƌĂŶƚ
EĞǁƚƌĞĂƚŵĞŶƚ
ůĞƐƐ ĐŽƐƚůǇ
WrŝnĐŝpleƐ͕ ŵethŽdƐ͕ and reĐŽŵŵendaƟŽnƐ
tith parƟcipantͲleǀel data͕ it is natural to consider represenƟnŐ the uncertaintǇ
surroundinŐ IEZs usinŐ ϵϱйIs. ,oweǀer͕ as a raƟo measure͕ esƟmaƟnŐ ϵϱйIs
around IEZs is not straiŐhƞorward and͕ more importantlǇ͕ ϵϱйIs around IEZs
suīer from the same interpretaƟon proďlem as IEZs ;ϱϱͿ. Therefore͕ alternaƟǀe
methods haǀe ďeen proposed to esƟmate the uncertaintǇ surroundinŐ IEZs. urrent
Őuidelines recommend usinŐ the ďootstrap method descriďed in oǆ Ϯ. In this
case͕ ďoth incremental costs and eīects are calculated per ďootstrap sample. The
uncertaintǇ surroundinŐ an IEZ can then ďe ŐraphicallǇ illustrated ďǇ ploƫnŐ these
ďootstrapped incremental costͲeīect pairs ;EͲpairsͿ on a EͲplane. s indicated ďǇ
the eǆample trial͛s EͲplane proǀided in &iŐure ϯ͕ EͲpairs commonlǇ coǀer more
than one Ƌuadrant.
8
&ŝŐƵƌĞϯ͗ŽƐƚͲĞīĞĐƟǀĞŶĞƐƐƉůĂŶĞĨŽƌĂůŝĨĞƐƚǇůĞŝŶƚĞƌǀĞŶƟŽŶĨŽƌĐŽŶƐƚƌƵĐƟŽŶǁŽƌŬĞƌƐĂƚƌŝƐŬ
ĨŽƌĐĂƌĚŝŽǀĂƐĐƵůĂƌĚŝƐĞĂƐĞĐŽŵƉĂƌĞĚƚŽƵƐƵĂůƉƌĂĐƟĐĞ;ϯϴͿ
ďďreǀiaƟon͗ EtͲY͗ Eorth test Yuadrant͕ EEͲY͗ Eorth East Yuadrant͕ ^tͲY͗ ^outh test
Yuadrant͕ ^EͲY͗ ^outh East Yuadrant͕ IEZ͗ Incremental ostͲEīecƟǀeness ZaƟo
lthouŐh EͲplanes Őiǀe a Őood impression of the uncertaintǇ surroundinŐ the IEZ͕
theǇ do not proǀide a summarǇ measure of the ũoint uncertaintǇ of costs and eīects
;ϱϲͿ. Therefore͕ costͲeīecƟǀeness acceptaďilitǇ curǀes ;EsͿ were introduced
Ϯϱϵ
Chapter 8
that proǀide insiŐht into the proďaďilitǇ that a new interǀenƟon is costͲeīecƟǀe
compared to the control condiƟon. This proďaďilitǇ can ďe esƟmated ďǇ determininŐ
what proporƟon of EͲpairs is located in the costͲeīecƟǀe half of the EͲplane ;i.e. to
the riŐht of the preǀiouslǇ menƟoned line with the slope eƋual to ʄͿ;&iŐure ϮͿ. ^ince
it is ŐenerallǇ unŬnown what decisionͲmaŬers are willinŐ to paǇ for an addiƟonal unit
of eīect͕ ʄ is ǀaried ďetween its natural ďounds ;ranŐe͗ Ϭ to ьͿ and the proďaďilitǇ
that the new interǀenƟon is costͲeīecƟǀe compared to the control condiƟon is
esƟmated for a ranŐe of ʄs. These ǀalues can then ďe ploƩed on Es that show the
proďaďilitǇ of costͲeīecƟǀeness ;zͲaǆisͿ for ǀarious ʄs ;yͲaǆisͿ ;ϱϱͲϱϳͿ. To illustrate͕
the E of the eǆample trial is proǀided in &iŐure ϰ.
&ŝŐƵƌĞϰ͗ŽƐƚͲĞīĞĐƟǀĞŶĞƐƐĂĐĐĞƉƚĂďŝůŝƚǇĐƵƌǀĞĨŽƌĂůŝĨĞƐƚǇůĞŝŶƚĞƌǀĞŶƟŽŶĨŽƌĐŽŶƐƚƌƵĐƟŽŶ
ǁŽƌŬĞƌƐĂƚƌŝƐŬĨŽƌĐĂƌĚŝŽǀĂƐĐƵůĂƌĚŝƐĞĂƐĞĐŽŵƉĂƌĞĚƚŽƵƐƵĂůƉƌĂĐƟĐĞ;ϯϴͿ
Eote͗ This costͲeīecƟǀeness acceptaďilitǇ curǀe corresponds with the costͲeīecƟǀeness
plane in &iŐure ϯ and indicates the proďaďilitǇ of the interǀenƟon ďeinŐ costͲeīecƟǀeness for
diīerent ǀalues of willinŐnessͲtoͲpaǇ per ŬiloŐram ďodǇ weiŐht loss.
ϮϲϬ
WrŝnĐŝpleƐ͕ ŵethŽdƐ͕ and reĐŽŵŵendaƟŽnƐ
This E indicates that if decisionͲmaŬers are not willinŐ to paǇ anǇthinŐ to oďtain an
addiƟonal ŬiloŐram ďodǇ weiŐht loss ;i.e. ʄсϬͿ͕ there is a Ϭ.ϯϯ proďaďilitǇ that the new
interǀenƟon is costͲeīecƟǀe compared to the control condiƟon. If decisionͲmaŬers
are willinŐ to paǇ ΦϮϬϬϬ ;i.e. ʄсϮϬϬϬͿ͕ this proďaďilitǇ is Ϭ.ϵϱ. then interpreƟnŐ
Es͕ two approaches can ďe used ďǇ decisionͲmaŬers. If their willinŐness to
paǇ is Ŭnown͕ theǇ haǀe to ũudŐe whether the proďaďilitǇ of costͲeīecƟǀeness at
this ceilinŐ raƟo is acceptaďle. If their willinŐness to paǇ is unŬnown͕ theǇ should
consider whether the ceilinŐ raƟo at an acceptaďle proďaďilitǇ of costͲeīecƟǀeness
is acceptaďle to them. The laƩer miŐht depend on the scale of the outcome measure
and the preǀalence of the condiƟon under studǇ.
CŽƐtͲďeneĮt analǇƐŝƐ
In health economics and ďusiness administraƟon͕ ǀarious measures eǆist for
comparinŐ costs and ďeneĮts. Kf them͕ the Eet eneĮts ;EͿ͕ eneĮt ost ZaƟo
;ZͿ͕ and ZeturnͲKnͲInǀestment ;ZKIͿ are the most freƋuentlǇ used measures in
occupaƟonal health research and can ďe esƟmated usinŐ the followinŐ eƋuaƟons ;ϲͿ͗
N с eneĮtƐ ʹ CŽƐtƐ
CZ с eneĮtƐ ͬ CŽƐtƐ
ZK/ с ;eneĮtƐ ʹ CŽƐtƐͿ ͬ CŽƐtƐ ΀ΎϭϬϬ΁
where CŽƐtƐ are deĮned as interǀenƟon costs and eneĮtƐ as the diīerence in
moneƟǌed outcomes ďetween the interǀenƟon and control Őroup ;e.Ő. diīerence
in producƟǀitǇ costsͿ. eneĮts are esƟmated ďǇ suďtracƟnŐ the mean eǆpenses
incurred ďǇ the interǀenƟon Őroup parƟcipants from those of the control Őroup.
,ereďǇ͕ posiƟǀe ďeneĮts indicate reduced spendinŐ. The E indicates the amount of
moneǇ Őained aŌer costs are recoǀered ;i.e. net loss or net saǀinŐsͿ. The Z indicates
the amount of moneǇ returned per monetarǇ unit inǀested. The ZKI indicates
the percentaŐe of proĮt per monetarǇ unit inǀested ;ϱϴ͖ϱϵͿ. InterǀenƟons can ďe
reŐarded as cost saǀinŐ if the followinŐ criteria are met͗ EхϬ͕ Zхϭ͕ and ZKIхϬй.
To illustrate͕ a descripƟon of the calculaƟon and interpretaƟon of the eǆample trial͛s
costͲďeneĮt esƟmates is proǀided in oǆ ϰ.
Ϯϲϭ
8
Chapter 8
Žǆϰ͗ĂůĐƵůĂƟŽŶĂŶĚŝŶƚĞƌƉƌĞƚĂƟŽŶŽĨƚŚĞĐŽƐƚͲďĞŶĞĮƚĞƐƟŵĂƚĞƐŽĨĂůŝĨĞƐƚǇůĞŝŶƚĞƌǀĞŶƟŽŶ
ĨŽƌĐŽŶƐƚƌƵĐƟŽŶǁŽƌŬĞƌƐĂƚƌŝƐŬĨŽƌĐĂƌĚŝŽǀĂƐĐƵůĂƌĚŝƐĞĂƐĞŝŶĐŽŵƉĂƌŝƐŽŶƚŽƵƐƵĂůƉƌĂĐƟĐĞ
(38)
Dean interǀenƟon costs per parƟcipant were ΦϲϬϱ. urinŐ followͲup͕ aǀeraŐe aďsenteeism
costs per parƟcipant were ΦϯϯϬϮ in the interǀenƟon Őroup and ΦϯϲϬϰ in the control Őroup.
Thus͕ the aďsenteeism ďeneĮts per parƟcipant were ΦϯϬϮ ;ΦϯϲϬϰ Ͳ ΦϯϯϬϮͿ. hsinŐ this
informaƟon͕ costͲďeneĮt esƟmates can ďe calculated͖
E͗ ΦϯϬϮ Ͳ ΦϲϬϱ с ΦͲϯϬϯ
Z͗ ΦϯϬϮ ͬ ΦϲϬϱ с Ϭ.ϱϬ
ZKI͗ ;;ΦϯϬϮ ͬ ΦϲϬϱͿͬ ΦϯϬϮͿΎϭϬϬ с ͲϱϬй
These costͲďeneĮt esƟmates indicate that the interǀenƟon resulted in a net loss to the
emploǇer of ΦϯϬϯ. lso͕ per Euro inǀested͕ the emploǇer Őained ΦϬ.ϱϬ and suīered a loss of
ϱϬй. Thus͕ the interǀenƟon cannot ďe reŐarded as costͲďeneĮcial in terms of aďsenteeism
costs.
ostͲďeneĮt esƟmates͕ and Zs and ZKIs in parƟcular͕ are tǇpicallǇ presented
without an indicaƟon of their uncertaintǇ. If uncertaintǇ is suďstanƟal and this is not
taŬen into account͕ wronŐ conclusions could ďe drawn. Therefore͕ we recommend
the use of the preǀiouslǇ descriďed ďootstrap method ;oǆ ϮͿ to esƟmate the
uncertaintǇ surroundinŐ costͲďeneĮt esƟmates. In this case͕ the E͕ Z͕ andͬor
ZKI are calculated per ďootstrap sample ;i.e. ďootstrapped Es͕ Zs͕ and ZKIsͿ.
^uďseƋuentlǇ͕ ϵϱйIs can ďe esƟmated usinŐ the ďias corrected and accelerated
method ;ϱϭ͖ϱϯͿ. Eǀen thouŐh Zs and ZKIs are raƟo measures͕ esƟmaƟnŐ their
ϵϱйIs is straiŐhƞorward as the denominator ;i.e. interǀenƟon costsͿ is tǇpicallǇ
posiƟǀe. DanǇ occupaƟonal health decisionͲmaŬers͕ howeǀer͕ maǇ lacŬ the necessarǇ
staƟsƟcal ďacŬŐround to interpret ϵϱйIs ;ϭϭͿ. possiďle waǇ to deal with this issue
is to determine what proporƟon of ďootstrapped Es͕ Zs͕ andͬor ZKIs indicate
cost saǀinŐs ;i.e. ͞the proďaďilitǇ of Įnancial return͟Ϳ. KccupaƟonal health decisionͲ
maŬers can suďseƋuentlǇ use this informaƟon to consider whether the estaďlished
proďaďilitǇ of Įnancial return is acceptaďle to them.
then reporƟnŐ results͕ economists and policǇ maŬers prefer the E͕ whereas
the Z and ZKI are more familiar to ďusiness manaŐers. s such͕ it is recommendaďle
to report at least two of them ;i.e. E and ZͬZKIͿ͕ so that the results can ďe easilǇ
interpreted ďǇ all staŬeholders. nother adǀantaŐe of this approach is that it maŬes
the results easilǇ comparaďle with those of other studies͕ ďecause diīerent metrics
ϮϲϮ
WrŝnĐŝpleƐ͕ ŵethŽdƐ͕ and reĐŽŵŵendaƟŽnƐ
are used in the literature to esƟmate whether K,^ interǀenƟons Őenerate cost
saǀinŐs ;ϲͿ.
^ĞŶƐŝƟǀŝƚǇĂŶĂůǇƐŝƐ
Economic eǀaluaƟons are oŌen conducted in the conteǆt of incomplete informaƟon
and uncertaintǇ͕ which necessitates the use of proǆǇ measures͕ and inǀariaďlǇ͕ the
need to maŬe assumpƟon aďout the methods and unit prices used for ǀaluinŐ resource
use͕ the methods used for dealinŐ with incomplete data͕ and the waǇ in which
adũustments are made for diīerenƟal ƟminŐ ;ϰ͖ϴͿ. Therefore͕ sensiƟǀitǇ analǇses
should ďe undertaŬen to assess how studǇ results would chanŐe for diīerent ŬeǇ
assumpƟons and parameter ǀalues ;i.e. the roďustness of studǇ resultsͿ ;ϭϳ͖ϲϬͿ. The
ranŐes of ǀalues tested͕ and arŐuments for selecƟnŐ these ranŐes͕ must ďe clearlǇ
descriďed ;ϭϬ͖ϭϳͿ. sarious Ŭinds of sensiƟǀitǇ analǇses eǆist. KneͲwaǇ sensiƟǀitǇ
analǇses assess the impact of chanŐes to a sinŐle parameter at a Ɵme͕ while mulƟple
parameters are ǀaried simultaneouslǇ in mulƟͲwaǇ sensiƟǀitǇ analǇses ;ϲϭͿ.
DISCUSSION
Zesources for occupaƟonal health are scarce. This maŬes it necessarǇ for decisionͲ
maŬers to haǀe informaƟon on the relaƟǀe eĸciencǇ of K,^ interǀenƟons in order to
allocate aǀailaďle resources to their ďest use. s such͕ economic eǀaluaƟons of K,^
interǀenƟons are ďecominŐ increasinŐlǇ important͕ manǇ of which are conducted
alonŐside eīecƟǀeness trials. TrialͲďased economic eǀaluaƟons proǀide a uniƋue
opportunitǇ to reliaďlǇ esƟmate the resource implicaƟons of K,^ interǀenƟons
at low incremental cost ;ϭϬ͖ϭϰͿ. ,oweǀer͕ it is criƟcal that hiŐh ƋualitǇ trialͲďased
economic eǀaluaƟons are performed when this informaƟon is used to inform
allocaƟon decisions.
esiŐninŐ a hiŐh ƋualitǇ trialͲďased economic eǀaluaƟon reƋuires close collaďoraƟon
ďetween occupaƟonal health specialists͕ indiǀiduals eǆecuƟnŐ the trial͕ and health
economists ;ϭϰͿ. areful consideraƟons must ďe made reŐardinŐ the perspecƟǀe͕ the
analǇƟc Ɵme frame͕ the idenƟĮcaƟon͕ measurement͕ and ǀaluaƟon of resource use
and outcomes͕ as well as the methods used for calculaƟnŐ sample siǌes͕ comparinŐ
Ϯϲϯ
8
Chapter 8
costs and conseƋuences͕ and handlinŐ missinŐ data and uncertaintǇ. The laƩer is of
parƟcular importance͕ as few economic eǀaluaƟons in occupaƟonal health report on
the uncertaintǇ surroundinŐ their incremental costͲconseƋuence esƟmates ;ϰͲϳ͖ϭϱͿ.
&ailinŐ to esƟmate ǀalues under uncertaintǇ maŬes it impossiďle to determine the
certaintǇ of results and could thus lead to inappropriate decisionͲmaŬinŐ. To ƋuanƟfǇ
precision͕ nonͲparametric ďootstrappinŐ can ďe used as a staƟsƟcal techniƋue for
dealinŐ with the riŐht sŬewed nature of cost data ;ϭ͖ϳͿ. n oǀerǀiew of our core
recommendaƟons for trialͲďased economic eǀaluaƟons in occupaƟonal health can
ďe found in ppendiǆ ϭ.
TrialͲďased economic eǀaluaƟons maǇ also haǀe shortcominŐs͕ includinŐ limited
sample siǌes͕ limited comparators͕ and truncated Ɵme horiǌons ;ϭϰͿ. To deal with the
laƩer͕ researchers miŐht consider eǆtrapolaƟnŐ economic eǀaluaƟon results ďeǇond
the followͲup of a trial ďǇ usinŐ decision analǇƟc modelinŐ͕ in which eǆpected
costs and conseƋuences ďetween alternaƟǀes are compared ďǇ sǇnthesiǌinŐ
informaƟon from mulƟple sources ;e.Ő. scienƟĮc literature͕ studǇ resultsͿ ;ϭ͖ϭϯ͖ϭϰͿ.
&or more detailed informaƟon aďout decision analǇƟc modelinŐ we refer to other
puďlicaƟons͖ ;ϭϰ͖ϲϮͿ. lso͕ eǀen thouŐh we recommend a praŐmaƟc ;clusterͲͿZT
desiŐn for economic eǀaluaƟons͕ we are aware that randomiǌaƟon itself maǇ not
alwaǇs ďe feasiďle andͬor desired in the occupaƟonal health seƫnŐ. In those cases͕
well eǆecuted nonͲrandomiǌed studies maǇ proǀide ǀaluaďle informaƟon͕ ďut it is
criƟcal that eīorts ďe made to control for selecƟon ďias ;e.Ő. ďǇ usinŐ propensitǇ
score matchinŐͿ ;ϲϯ͖ϲϰͿ.
then interpreƟnŐ economic eǀaluaƟons of K,^ interǀenƟons͕ it is important to
ďear in mind that their results maǇ not ďe directlǇ applicaďle to other countries
and ũurisdicƟons due to diīerences in healthcare͕ social securitǇ sǇstems͕ and other
factors. serďeeŬ et al. ;ϮϬϭϬͿ demonstrated that economic eǀaluaƟon results can
ďe Őeneraliǌed from one countrǇ to another. ,oweǀer͕ to enaďle the necessarǇ
calculaƟons͕ researchers need to proǀide an eǆtensiǀe descripƟon of the interǀenƟon͕
a detailed list of resource use as well as informaƟon of the healthcare sǇstem in the
oriŐinal studǇ and the allocaƟon of costs to ǀarious staŬeholders ;ϲϱͿ.
Ϯϲϰ
WrŝnĐŝpleƐ͕ ŵethŽdƐ͕ and reĐŽŵŵendaƟŽnƐ
Ǉ simultaneouslǇ proǀidinŐ recommendaƟons for Őood pracƟce in the economic
eǀaluaƟon of K,^ interǀenƟons and discussinŐ the methods and principles that
underlie them͕ the present paper aimed to help researchers in conducƟnŐ and
reporƟnŐ hiŐh ƋualitǇ trialͲďased economic eǀaluaƟons. ^uch studies are eǆpected to
contriďute to the deǀelopment of a sound eǀidence ďase on the resource implicaƟons
of K,^ interǀenƟons ;ϯ͖ϰͿ͕ which is a necessarǇ prereƋuisite for eǀidenceͲďased
pracƟces occurrinŐ in occupaƟonal health ;ϭϭͿ. The present paper maǇ also ďe
helpful to consumers of this literature with understandinŐ and criƟcallǇ appraisinŐ
trialͲďased economic eǀaluaƟons of K,^ interǀenƟons͕ which miŐht help improǀe
the uptaŬe of their results.
ĐŬŶŽǁůĞĚŐĞŵĞŶƚƐ
te would liŬe to thanŬ all authors of the eǆample trial for the proǀision of their data.
8
Ϯϲϱ
Chapter 8
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cƟǀitǇ Impairment ƋuesƟonnaire for paƟents with sǇmptoms of 'astroͲEsophaŐeal
ZeŇuǆ isease ;tWIͲ'EZͿ ͲͲ Zesults from a crossͲsecƟonal studǇ. salue ,ealth
ϮϬϬϮ͖ϱ;ϮͿ͗ϭϬϲͲϭϭϯ.
ZeillǇ D͕ racco ͕ Zicci :&͕ ^antoro :͕ ^teǀens T. The ǀaliditǇ and accuracǇ of the torŬ
WroducƟǀitǇ and cƟǀitǇ Impairment ƋuesƟonnaire ͲͲ irritaďle ďowel sǇndrome ǀersion
;tWI͗I^Ϳ. Aliŵent Wharŵacol dher ϮϬϬ4͖ϮϬ;4Ϳ͗4ϱϵͲ4ϲϳ.
Wrasad D͕ tahlƋǀist W͕ ^hiŬiar Z͕ ^hih zT. reǀiew of selfͲreport instruments measurinŐ
healthͲrelated worŬ producƟǀitǇ. WharŵacoconoŵicƐ ϮϬϬ4͖ϮϮ;4Ϳ͗ϮϮϱͲϮ44.
EaƟonal InsƟtute for ,ealth and are Eǆcellence ;EIEͿ. 'uide to the methods of
technoloŐǇ appraisal ΀Internet΁. ΀ited ϮϬϭϯ uŐust Ϯϭ΁. ǀailaďle from͗ hƩp͗ͬͬwww.
nice.orŐ.uŬͬmediaͬ4ϱͬϭEͬ'uideToDethodsTechnoloŐǇppraisalϮϬϭϯ.pdf
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Chapter 8
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,amďerŐͲǀan Zeenen ,,͕ Wroper <I͕ ǀan den erŐ D. torŬsite mental health
interǀenƟons͗ a sǇstemaƟc reǀiew of economic eǀaluaƟons. Kccup nǀiron Med
ϮϬϭϮ͖ϲϵ;ϭϭͿ͗8ϯϳͲ84ϱ.
raǌier :͕ eǀerill D͕ 'reen ͕ ,arper Z͕ ooth . reǀiew of the use of health status
measures in economic eǀaluaƟon. ,ealth dechnol AƐƐeƐƐ ϮϬϬϵ͖ϯ;ϵͿ͗iͲiǀ͕ ϭͲϭϲ4.
heŐaŬi <. Economic eǀaluaƟon of interǀenƟons for occupaƟonal health. Thesis ;WhͿ͕
sriũe hniǀersiteit msterdam͕ ϮϬϭϬ.
EǇsinŬ WE͕ ,amďerŐͲǀan Zeenen ,,͕ ǀan 'ool ,͕ ,oeǇmans E͕ urdorf . Deten
ǀan ǀerloren arďeidsũaren door ǌieŬte͗ iseaseͲdũusted torŬinŐ zears ;tzsͿ͗
serŬenninŐ ǀan een nieuwe maat. ilthoǀen͗ ZIsD͖ ϮϬϭϬ. Zeport Eo.͗ ϮϳϬϮ44ϬϬϭ.
'roeneǀeld I&͕ ǀan tier D&͕ Wroper <I͕ osmans :E͕ san Dechelen t͕ ǀan der eeŬ
:. ostͲeīecƟǀeness and costͲďeneĮt of a lifestǇle interǀenƟon for worŬers in
the contrucƟon industrǇ at risŬ for cardioǀascular disease. J Kccup nǀiron Med
ϮϬϭϭ͖ϱϯ;ϲͿ͗ϲϭϬͲϲϭϳ.
riŐŐs ,͕ 'raǇ D. Wower and sample siǌe calculaƟons for stochasƟc costͲeīecƟǀeness
analǇsis. Med eciƐ MaŬing ϭϵϵ8͖ϭ8;ϮͿ͗^8ϭͲ^ϵϮ.
'afni ͕ talter ^͕ irch ^͕ ^endi W. n opportunitǇ cost approach to sample siǌe
calculaƟon in costͲeīecƟǀeness analǇsis. ,ealth con ϮϬϬ8͖ϭϳ;ϭͿ͗ϵϵͲϭϬϳ.
'ardiner :͕ ^irďu D͕ Zahďar D,. hpdate on staƟsƟcal power and sample siǌe
assessments for costͲeīecƟǀeness studies. ǆpert Zeǀ WharŵacoeconoŵicƐ KutcoŵeƐ
ZeƐ ϮϬϬ4͖4;ϭͿ͗8ϵͲϵ8.
l D:͕ san ,out ͕ Dichel ͕ ZuƩen &&,. ^ample siǌe calculaƟon in economic
eǀaluaƟons. ,ealth con ϭϵϵ8͖ϳ;4Ϳ͗ϯϮϳͲϯϯϱ.
riŐŐs . Economic eǀaluaƟon and clinical trials͗ siǌe maƩers. BMJ ϮϬϬϬ͖ϯϮϭ;ϳϮϳϯͿ͗ϭϯϲϮͲ
ϭϯϲϯ.
'oossens D͕ Eǀers ^͕ slaeǇen :͕ ZuƩenͲǀan DƂlŬen D͕ ǀan der >inden ^. Wrinciples
of economic eǀaluaƟon for interǀenƟons of chronic musculosŬeletal pain. uropean
Journal oĨ Wain ϭϵϵϵ͖ϯ;4Ϳ͗ϯ4ϯͲϯϱϯ.
Doher ͕ ,opewell ^͕ ^chultǌ <&͕ Dontori s͕ 'otǌsche W͕ eǀereauǆ W:͕ et al. KE^KZT
ϮϬϭϬ EǆplanaƟon and ElaďoraƟon͗ updated Őuidelines for reporƟnŐ parallel Őroup
randomised trials. BMJ ϮϬϭϬ͖ϯ4Ϭ͗c8ϲϵ.
^terne :͕ thite IZ͕ arlin :͕ ^praƩ D͕ ZoǇston W͕ <enward D'͕ et al. DulƟple
imputaƟon for missinŐ data in epidemioloŐical and clinical research͗ potenƟal and
piƞalls. BMJ ϮϬϬϵ͖ϯϯ8͗ďϮϯϵϯ.
Eoďle ^D͕ ,ollinŐworth t͕ TillinŐ <. DissinŐ data in trialͲďased costͲeīecƟǀeness
analǇsis͗ the current state of plaǇ. ,ealth con ϮϬϭϮ͖Ϯϭ;ϮͿ͗ϭ8ϳͲϮϬϬ.
thite IZ͕ ZoǇston W͕ tood D. DulƟple imputaƟon usinŐ chained eƋuaƟons͗ Issues
and Őuidance for pracƟce. StaƟƐt Med ϮϬϭϭ͖ϯϬ;4Ϳ͗ϯϳϳͲϯϵϵ.
Zuďin . DulƟple imputaƟon for nonresponse in surǀeǇs. Eew zorŬ͗ :ohn tileǇ Θ
^ons͖ ϭϵ8ϳ.
Thompson ^'͕ arďer :. ,ow should cost data in praŐmaƟc randomised trials ďe
analǇsed͍ BMJ ϮϬϬϬ͖ϯϮϬ;ϳϮ4ϯͿ͗ϭϭϵϳͲϭϮϬϬ.
arďer :͕ Thompson ^'. nalǇsis of cost data in randomiǌed trials͗ an applicaƟon of
the nonͲparametric ďootstrap. StaƟƐt Med ϮϬϬϬ͖ϭϵ;ϮϯͿ͗ϯϮϭϵͲϯϮϯϲ.
haudharǇ D͕ ^tearns ^. EsƟmaƟnŐ conĮdence interǀals for costͲeīecƟǀeness
raƟos͗ n eǆample from a randomiǌed trial. StaƟƐt Med ϭϵϵϲ͖ϭϱ;ϭϯͿ͗ϭ44ϳͲϭ4ϱ8.
WrincipleƐ͕ ŵethodƐ͕ and recoŵŵendaƟonƐ
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ϱ8.
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<elleǇ <. The eīects of nonͲnormal distriďuƟons on conĮdence interǀals around
the standardiǌed mean diīerence͗ ootstrap and parametric conĮdence interǀals.
ducaƟonal and WƐǇchological MeaƐureŵent ϮϬϬϱ͖ϲϱ;ϭͿ͗ϱϭͲϲϵ.
lacŬ t. The E plane͗ Őraphic representaƟon of costͲeīecƟǀeness. Med eciƐ
Making ϭϵϵϬ͖ϭϬ;ϯͿ͗ϮϭϮͲϮϭ4.
riŐŐs ,͕ K͛rien :͕ lacŬhouse '. ThinŬinŐ outside the ďoǆ͗ recent adǀances in the
analǇsis and presentaƟon of uncertaintǇ in costͲeīecƟǀeness studies. Ann Zeǀ Wuďlic
,ealth ϮϬϬϮ͖Ϯϯ͗ϯϳϳͲ4Ϭϭ.
&enwicŬ E͕ Darshall ͕ >eǀǇ ͕ Eichol '. hsinŐ and interpreƟnŐ costͲeīecƟǀeness
acceptaďilitǇ curǀes͗ an eǆample usinŐ data from a trial of manaŐement strateŐies for
atrial ĮďrillaƟon. BMC ,ealth Serǀ ZeƐ ϮϬϬϲ͖ϲ;ϭͿ͗ϱϮ.
&enwicŬ E͕ K͛rien :͕ riŐŐs . ostͲeīecƟǀeness acceptaďilitǇ curǀes Ͳ facts͕ fallacies
and freƋuentlǇ asŬed ƋuesƟons. ,ealth con ϮϬϬ4͖ϭϯ;ϱͿ͗4ϬϱͲϭϱ.
Whillips ::. Zeturn on inǀestment in traininŐ and performance improǀement proŐrams.
Ϯnd ed. urlinŐton͗ Elseǀier͖ ϮϬϬϯ.
^tone Wt. ZeturnͲonͲinǀestment models. Appl NurƐ ZeƐ ϮϬϬϱ uŐ͖ϭ8;ϯͿ͗ϭ8ϲͲϭ8ϵ.
'iĸn ^. ealinŐ with uncertaintǇ in the economic eǀaluaƟon of health care
technoloŐies. Thesis ;WhͿ͕ hniǀersitǇ of zorŬ͕ ϮϬϭϬ.
riŐŐs ͕ ^culpher D͕ uǆton D. hncertaintǇ in the economic eǀaluaƟon of healthcare
technoloŐies͗ the role of sensiƟǀitǇ analǇsis. ,ealth con ϭϵϵ4͖ϯ͗ϵϱͲϭϬ4.
riŐŐs ͕ laǆton <͕ ^culpher D. ecision modellinŐ for health economic eǀaluaƟon.
Eew zorŬ͗ Kǆford hniǀersitǇ Wress͖ ϮϬϬϲ.
eheũia Z,͕ tahďa ^. WropensitǇ scoreͲmatchinŐ methods for nonͲeǆperimental causal
studies. Zeǀiew oĨ conoŵicƐ and StaƟƐƟcƐ ϮϬϬϮ͖84;ϭͿ͗ϭϱϭͲϭϲϭ.
aliendo D͕ <opeiniŐ ^. ^ome pracƟcal Őuidance for the implementaƟon of propensitǇ
score matchinŐ. Journal oĨ conoŵic SurǀeǇƐ ϮϬϬ8 &eď ϭ͖ϮϮ;ϭͿ͗ϯϭͲϳϮ.
serďeeŬ :͕ Wulliainen D͕ <anŬaanpaa E͕ Taimela ^. TransferrinŐ results of occupaƟonal
safetǇ and health costͲeīecƟǀeness studies from one countrǇ to another Ͳ a case studǇ.
Scand J tork nǀiron ,ealth ϮϬϭϬ͖ϯϲ;4Ϳ͗ϯϬϱͲϯϭϮ.
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