Fluoridation discontinuation in Calgary

1
A study of the dental health impact of
fluoridation cessation in Calgary:
study overview
Lindsay McLaren PhD
Associate Professor and Applied Public Health Chair
Department of Community Health Sciences and O’Brien Institute for Public Health
University of Calgary
PHO Rounds – Thurs Nov 13 2014
2
Outline
• Situate fluoridation within program of research in population/public
health
• Focus on fluoridation cessation
• Overview of study of fluoridation cessation in Calgary, AB
3
• Fluoridation is a quintessential example of Geoffrey Rose’s
population-level approach to prevention
Rose G. (1985) Sick
individuals
and sick populations.
Int J Epidemiol
1985;14:32-28.
Rose G. (1992) The
Strategy of
Preventive Medicine,
Oxford:
Oxford University
Press.
4
• Ongoing debate: whether / extent to which Rose’s population-level
approach is equitable in its impact
• McLaren et al. Rose’s population strategy of prevention need not increase social
inequalities in health. Int J Epidemiol 2010;39:372-377.
• McLaren L, Emery JCH. Drinking water fluoridation and oral health inequalities in
Canadian children. Can J Public Health 2012; 103(suppl.1):S49-s56.
• Fluoridation as window into population/public health more generally
5
Fluoridation & dental health
• Evidence base: overall supportive of benefit of fluoridation for population
dental health; however methodological quality is “low to moderate”
• McDonagh et al. 2000 “the York review”
• Note upcoming: Iheozor-Ejiofor et al. Water fluoridation for the prevention of dental
caries: Cochrane review (protocol)
• McLaren L, McIntyre L. Drinking water fluoridation in Canada: review and
synthesis of published literature. Report prepared for the Public Health
Agency of Canada. April 2011.
• Key finding: of the large number of instances of change in fluoridation status in
Canadian communities, very few have been exploited as a research opportunity
6
Fluoridation cessation
• Important to keep evidence base up to date
• Changing exposure to fluoride
• Changing oral health epidemiology
• “Since 2005 more than 30 communities have voted to discontinue
fluoridation of their municipal water supplies …”
• J Can Dent Assoc 2013;79:d77
7
Fluoridation cessation in Calgary
• Council vote in February 2011, stopped adding fluoride in May 2011
• Provincial context
• 2008/09: transition to province-wide health system structure (Alberta Health
Services)
• Opportunity and impetus for province-wide oral health surveillance (AHS Oral
Health Action Plan 2010)
• McLaren L, Shwart L, Potestio M, McNeil D, Faris P, Lorenzetti D, McIntyre L,
Patterson S. Alberta Oral Health Surveillance Project. Grant from Alberta
Health & Wellness [now called Alberta Health]; 2012-2014.
8
Study objectives
• Primary objective: To examine the short-term impact of fluoridation
cessation on child oral health and oral health equity, via a comparison
of Calgary and Edmonton.
• Secondary objective: pilot some active surveillance methods for
consideration within a provincial oral health surveillance system
• Secured addition funding
• McLaren L, Shwart L, Faris P, McNeil D, McIntyre L, Patterson S, Potestio M.
Fluoridation discontinuation in Calgary: a natural experiment to identify
implications for child oral health and oral health equity. CIHR, 2013-15.
9
Background literature
• Reviewed published research on dental health impact of fluoridation
cessation*
1. Focus on deliberate discontinuation of fluoridation, as opposed to
unintended interruption;
2. Repeated cross-sectional design, and
3. Focus on children (of any age).
• One Canadian study (British Columbia)  results are complex
• Maupomé et al. Community Dent Oral Epidemiol 2001
• Maupomé et al. Caries Res 2001
* Systematic review currently underway
10
Background literature (cont’d)
• Internationally: 8 studies in 7 countries
Studies that observed an adverse oral health effect of Studies that did not observe an adverse oral health
fluoridation discontinuation
effect of fluoridation discontinuation
• USA (Lemke J Am Dent Assoc 1970)
• Scotland (Stephen Br Dent J 1987)
• Scotland*^ (Attwood Lancet 1988; Attwood Int Dent J
1991)
• The Netherlands (Kalsbeek Caries Res 1993)
• Wales*^ (Thomas Br Dent J 1995)
• Finland* (Seppa Community Dent Oral Epidemiol 1998;
•
•
Seppa L; Caries Res 2000)
Germany (Kunzel Community Dent Oral Epidemiol 2000)
Cuba (Kunzel Caries Res 2000)
Availability of other widespread forms of fluorides and
dental caries prevention was highlighted
* cessation occurred in 1980 or later + included comparison community
^ trend of adverse oral health effect (not statistically significant) apparent within 2-3 years
11
Study design
• Repeated cross-sectional design with comparison group
• Edmonton is suitable comparison community:
• Similar size and demographic composition to Calgary
• No indication that Edmonton was revisiting fluoridation
• Stakeholders in Edmonton and Calgary expressed that a comparison of the two cities would
be useful (Potestio et al. 2013)
• High quality pre-cessation population-based oral health data available
2003/04
2004/05
2005/06
2006/07
2007/08
2008/09
2009/10
2010/11
2011/12
2012/13
2013/14
Calgary
--
O
--
--
--
--
O
X
--
--
O
Edmonton
--
O
--
--
--
--
--
--
--
--
O
where O = observation (data collection); X = intervention (fluoridation cessation)
12
Pre-cessation data
• High-quality population-based oral health surveys conducted by
former health regions in Alberta
• Patterson S. Oral Health Status of Albertan Schoolchildren: A compilation of
regional surveys [presentation]. 2009.
• Similarities across pre-cessation surveys, in terms of sampling, data
collection, and procedures
13
Pre-cessation data (cont’d)
• Data gathered via open mouth exam conducted in schools
Indicator
Notes
DMFT/deft*
• Based on detailed criteria for decay, missing/extracted, filled; similar across surveys
Treatment levels*
• No decay experience; complete caries care; partial caries care; no caries care
Sealants
• Presence* and need
Referrals
• Immediate/urgent, and oral hygiene
Fluorosis
• Tooth Surface Index of Fluorosis*
Trauma
• Edmonton 2004/05 and Calgary 2009/10 only
* Also available post-cessation
14
Post-cessation data (2013/14): sampling
• Sampling: stratified random sample
• Strata = median neighbourhood income quartile where school was located
• Same as pre-cessation Calgary surveys
• Developed sampling weights for all four surveys
• To account for complex sampling and imbalance in SES (differential response)
• To permit better representation of underlying target population at the time
15
Post-cessation data: data collection
• (1) Open mouth exam
• Iowa protocol: d1d2-3 index
• Fluorosis (TSIF)
• Calibration
• Theory and hands-on component
• 2 sessions in each city, + spot checks of incoming data
• Examiners
• 5 assessment teams (1 RDH + 1 clerk)
• Note to parents
• Confirm that assessment took place
• One of four outcomes checked
• Resource list “how can I get dental treatment for my child”
16
Post-cessation data: data collection (cont’d)
• (2) Questionnaire
• Items drawn from high-quality oral health surveys
• Statistics Canada (CHMS), CDC Division of Oral Health
• Pilot-tested with convenience sample of parents of 6-7 year old children
• Translated versions available
• French, Punjabi, Tagalog, and Chinese. Later added Spanish.
• Same for all study materials
Thematic areas included in questionnaire
Child’s dental
health incl.
behaviors
Use of dental
professionals,
incl. insurance
Child’s food &
beverage
consumption
Child’s use of
fluoride
supplements
Residential
history
Sociodemographic
information
17
Post-cessation data: data collection (cont’d)
• (3) Fingernail clippings
• Small random sample (n=30) in each city
• Valid and reasonably non-intrusive biomarker of total fluoride intake over a
long period of time (e.g., 1 year)
• E.g., Marthaler 2005
18
Anticipated contributions and next steps
1. Comparison of summary oral health metrics in Calgary and
Edmonton pre- and post-cessation
2. Nuanced profile of oral health status amongst Calgary and
Edmonton schoolchildren in 2013/14
3. Baseline and methodological platform for future surveys
19
Research team
• Luke Shwart DMD, MBA
• Steve Patterson BSc, DDS, MPH
• Deborah McNeil RN, PhD
• Melissa Potestio PhD
• Peter Faris PhD
• Lynn McIntyre MD, MHSc, FRCPC
• Salima Thawer RDH MPH
• Barry Maze DMD
• Jodi Siever MSc
20
Thank you
[email protected]
21

Download Report