Referendum opposition to fluoridation and health literacy: a cross-sectional analysis conducted in three large US cities

OBJECTIVE

To explore health literacy as a marker of voter confusion in order to understand the basis for public opposition to community water fluoridation.

DESIGN

A cross-sectional study.

SETTING

Conducted in three large US cities of San Antonio, Texas (602 voting precincts); Wichita, Kansas (171 voting precincts); and Portland, Oregon (132 voting precincts). Precinct-level voting data were compiled from community water fluoridation referendums conducted in San Antonio in 2002, Wichita in 2012 and Portland in 2013.

PARTICIPANTS

Voter turnout expressed as a percentage of registered voters was 38% in San Antonio (n=2 92 811), 47% in Wichita (n=129 199) and 38% in Portland (n=164 301).

MAIN OUTCOME MEASURES

The dependent variable was the percentage of votes in favour of fluoridating drinking water. Precinct-level voting data were mapped to precinct scores of health literacy, and to US Census and American Community Survey characteristics of race/ethnicity, age, income and educational attainment. Multilevel regression with post-stratification predicted the precinct mean health literacy scores, with weights generated from the National Association of Adult Literacy health literacy survey, with item response theory computed scoring for health literacy. Predictive models on voter support of community water fluoridation were compared using robust linear regression to determine how precinct-level characteristics influenced voter support in order to determine whether health literacy explained more variance in voting preference than sociodemographic characteristics.

RESULTS

Precinct-level health literacy was positively associated with voter turnout, although sociodemographic characteristics were better predictors of turnout. Approximately 60% of voters opposed community water fluoridation in Wichita and Portland, whereas in San Antonio, a small majority (53%) voted in favour of it. Models suggest that a one SD increase in health literacy scores predicted a 12 percentage point increase support for community water fluoridation.

CONCLUSION

Educational attainment and health literacy are modifiable characteristics associated with voting precincts' support for community water fluoridation.

Knowledge and Attitudes Towards Fluoride Supplementation: A Survey of Pediatric Medical and Dental Providers in the State of Hawai'i

Hawai'i has the lowest rate of community water fluoridation in the nation, which has contributed to poor oral health for children statewide. When properly prescribed, the benefits of fluoride supplementation for oral health outweigh any potential side effects to the body. Official recommendations give pediatric healthcare providers the authority to prescribe fluoride supplements and guide parents in daily usage. However, knowledge of actual practice and adherence for both providers and patients have never been examined in Hawai'i. This study aims to evaluate pediatric healthcare providers' attitudes, knowledge, and practices, regarding fluoride supplementation. A 37-item survey was developed investigating these domains, and was distributed to pediatric dentists, family practitioners, and pediatricians in the state. One hundred and three responses were collected during the time period of May 2014 through May 2015. Descriptive and bivariate associations with several outcomes were assessed. The majority (87%) reported at least some knowledge of the official guidelines. There was uncertainty in knowledge of fluorosis and the seriousness of the health risk. A recent educational session on fluoride was associated with more knowledge of the guidelines and the signs and symptoms of fluorosis. The majority of providers started fluoride at the recommended age whereas there was more variablility on stopping fluoride. On the patient side, providers reported that 67% of the parents forget to administer and 53% reported that their child does not like the taste. This study provides some information regarding the clinical use of fluoride supplementation in children. More efforts are needed to raise awareness in a consistent manner by both the dental and medical communities on the importance of fluoride supplementation to promote oral health in children while addressing concerns of professionals and the community.

Knowledge of primary care professionals about fluoride topics

BACKGROUND

Scientific evidence on the benefits of fluoride was responsible for an important change in dental practice. Individual and collective actions have been planned to impact the epidemiology of oral health. However, questions around this topic persist, making discussions and researches still necessary. In this regard, the aim of this study was to verify the fluoride-related knowledge of pediatricians (PP) and dentists (DS) working in primary care, comparing related aspects such as its multiple sources of intake and dental fluorosis.

METHODS

A group of PP and DS answered as self-administered questionnaire related to fluoride knowledge. PP group presented a lower level of adherence (34%) in comparison to the DS group (70%).

RESULTS

Fluoride-related topics were learnt at undergraduate courses by 95,95% of dentists and 38.46% of pediatricians. Ninety-two per cent of DS and 78.57% of PP claimed to know the clinical aspects of dental fluorosis. Pediatricians tend to indicate the use of fluoridated dentifrices at any age but advise less about the right amount to be placed on the toothbrush in comparison to DS.

CONCLUSIONS

Dentists and pediatricians presented limited fluoride-related knowledge. Continued education/training is encouraged and necessary at this level in order to deliver the benefits of fluoride use to populations.

Acceptability of Salt Fluoridation in a Rural Latino Community in the United States: An Ethnographic Study

Compared to other population groups in the United States, caries (tooth decay) is a disproportionately prevalent disease among Latino populations, especially among low-income and rural sub-groups and children under five years of age. Fluoride is a primary preventive for caries. While water fluoridation is a major and effective public health means for delivering fluoride on a mass scale, it does not reach many rural areas or population groups such as Latinos who eschew drinking water from municipal sources. This study examines the acceptability to such groups of salt fluoridation, an alternate means of delivering fluoride long used on a global scale. An ethnographic study in California's rural Central Valley was performed. Thirty individual interviews and 5 focus groups (N = 61) were conducted in Spanish to investigate low-income Latino migrant caregivers' experiences, views and understandings of domestic salt, oral health, caries prevention and fluoride. Audio data were transcribed, translated, coded and thematically analyzed. Table salt was readily available and frequently consumed. Both adult and child daily sodium consumption was high. Despite a general feeling that it was good, and present in dentifrices or dietary supplements, most participants had little knowledge about fluoride. Concerns were raised about cardio-vascular and other possibly deleterious effects if an increase in salt consumption occurred because fluoridated salt was viewed as having 'extra' benefits. Once informed about fluoride's safety and role in caries prevention, most participants expressed willingness to use fluoridated salt, especially if it benefitted children. Reassurance about its safety and benefits, and demonstration of its taste, were important aspects of acceptance. Taste was paramount. Participants would not consume more fluoridated salt than their current salt as that would result in unpleasant changes in food flavor and taste. While salt fluoridation is acceptable, the feasibility of producing and distributing fluoridated salt in the United States is, however, complex and challenging.

Survey of Oral Health Awareness in Neuchâtel 9th Graders

The oral health habits of pupils had not yet been analyzed for the canton of Neuchâtel. A questionnaire was provided to 9th grade high school pupils (final year) of the three schools located in the Neuchâtel area to asses both oral health knowledge and habits in this connection. The average age was 15.5±0.8 years, and 78.1% of the questionnaires were returned. The prophylaxis program was conducted for a total of 4.5 h during pupils’ entire time at school. The results showed that both knowledge and oral health habits could be improved. As a positive outcome, 99% of the pupils brush their teeth before going to bed. Comparisons with similar 10-year-old studies from other cantons (Bern, Vaud) showed major differences in knowledge, for example on the importance of fluoridation. Only 54% of the pupils in Neuchâtel knew that fluoride offers some protection against caries, in spite of the fact that 89% thought that brushing with fluoridated toothpaste protects against caries. Most of the pupils used a fluoridated toothpaste. Furthermore, we found that self-reported sugar consumption was correlated with caries experience, but brushing frequency was not. We recommend introducing a review course for pupils in their last school year, in order to practice interdental cleaning, redefine appropriate, tooth-friendly snacks, and emphasize the importance of regular dental check-ups.

Dental attendance, perceptions of cost and self-care of school year 12 and 13 students: A focus on Southland, New Zealand

BACKGROUND AND OBJECTIVES

Adolescents and emerging adults can provide dentists with many challenges. Little information is available on their perceptions of dental costs once they turn 18 and dentistry is no longer State-funded. The aim of this study was to explore the use of dental care by Southland students in years 12 and 13, their perceptions of the cost of four common dental procedures, self-related oral health and dental self-care habits, time off school related to dental problems, and knowledge and views regarding fluoride.

METHODS

After ethical approval, a 26-question survey was conducted of all Southland students in years 12 and 13. Data were statistically analysed in SPSS version 20 with the alpha value set at 0.05.

RESULTS

The participation rate was 49.6%. Regular attendance for examinations was reported by 77.5% with non-attendance mainly related to attitudes around lack of importance or necessity. Reported dental attendance varied according to gender, ethnicity and decile rating of school attended. Although some were accurate in their estimations of dental costs, the standard deviation for all procedures was large. The majority thought that costs put people off going to the dentist. While 74.8% brushed their teeth at least twice daily, only 26.6% flossed regularly. Knowledge regarding fluoride was lacking.

CONCLUSIONS

It may be advantageous to include education regarding costs of dental care with patients of this age. This may motivate them to improve their self-care and ensure that their oral health is of a high standard before their dental needs are no longer State-funded.

New Zealand dentists' views on community water fluoridation

OBJECTIVE

To determine whether New Zealand general dental practitioners support community water fluoridation (CWF), and to gauge their opinions on its possible systemic side-effects.

METHODS

An online survey was conducted in 2010, involving the 1174 general dental practitioners who had email addresses on the Dental Register and were contactable in New Zealand. A total of 465 dentists (39.6%) participated.

RESULTS

Most practitioners (93.5%) reported supporting community water fluoridation; the other 6.5% either were unsure or did not support it. Higher proportions of more recent graduates supported CWF. Some 85.6% of practitioners thought that drinking fluoridated water was a harmless way to prevent dental caries, but 6.2% felt that fluoridated water may cause other health problems. There were no systematic differences by sociodemographic and practice characteristics, except that a higher proportion of males and more experienced practitioners reported being confident in discussing CWF-related issues.

CONCLUSIONS

Most New Zealand dental practitioners support community water fluoridation, although a very small proportion believe that it is harmful and/or does not prevent caries.

Cities without cavities: democracy, risk, and public health

This essay examines the history of fluoride debates in four Canadian cities. It argues that fluoride's opponents were primarily motivated by what they saw as the health and environmental risks of adding fluoride to the water supply. They also believed that fluoridating the public water supply was a fundamental violation of civil liberties. The fluoride debates have much to teach us about how people evaluate potential health risks and how they respond to state interventions in the field of public health.

'Into every home, into every body': organicism and anti-statism in the British anti-fluoridation movement, 1952-1960

This article argues that the anti-fluoridation campaigns in the 1950s stemmed from concerns about both the increasing 'chemicalization' of food and the growing authority of the state over the private home and individual body. The British Housewives League (BHL), an organization typically thought insignificant after the late 1940s, was in fact at the centre of these campaigns. Steeped in the beliefs of inter-war and wartime organicism, the housewives believed that government intervention in food production and distribution was producing a post-war diet laden with harmful chemicals. The Ministry of Health's proposals to test water fluoridation in select communities in the early 1950s only further convinced the housewives that the state was harming the nation both physically and politically. More and more citizens would have no choice but to drink impure, potentially harmful water, they argued, and the burgeoning state would continue encroaching on private homes and bodies. While scholars have already demonstrated that what we now think of as 'leftist' environmental ideas were popular among 'rightist' movements of the 1930s and 1940s, the anti-fluoridation campaigns show that the BHL continued in the post-war years to intertwine our present-day notions of 'left' and 'right' ideologies.

Public opinions on community water fluoridation

BACKGROUND

Community water fluoridation (CWF) is currently experiencing social resistance in Canada. Petitions have been publicly registered, municipal plebiscites have occurred, and media attention is growing. There is now concern among policy leaders whether the practice is acceptable to Canadians. As a result, this study asks: What are public opinions on CWF?

METHODS

Data were collected in April 2008 from 1,005 Canadian adults by means of a national telephone interview survey using random digit dialling and computer-assisted telephone interview technology. Descriptive and bivariate and multivariate logistic regression analyses were undertaken.

RESULTS

Approximately 1 in 2 Canadian adults surveyed knew about CWF. Of these, 80% understood its intended use, approximately 60% believed that it was both safe and effective, and 62% supported the idea of having fluoride added to their local drinking water. Those with greater incomes [OR=1.4; p<0.001] and education [OR=1.6; p<0.001] were more likely to know about CWF. Those with greater incomes [OR=1.3; p<0.03] and those who visited the dentist more frequently [OR=1.8; p<0.002] were more likely to support CWF, and those with children [OR=0.5; p<0.02], those who accessed dental care using public insurance [OR=0.2; p<0.03], and those who avoided fluoride [OR=0.04; p<0.001] were less likely to support CWF.

CONCLUSION

It appears that Canadians still support CWF. In moving forward, policy leaders will need to attend to two distinct challenges: the influence of anti-fluoride sentiment, and the potential risks created by avoiding fluoride.

Increasing the public health effectiveness of fluoridated salt

This paper aims at assessing the public health potential of salt fluoridation schemes. There is now solid evidence which shows that the cariostatic effectiveness of universal salt fluoridation is equivalent to that of water fluoridation in both the permanent and primary dentition. In countries of continental Europe, only domestic salt is fluoridated, and its consistent use may be expected to warrant a 30% reduction of caries prevalence. However, the effectiveness in the population at large is lower because only part of the population uses the fluoridated domestic salt. Under these conditions, it must be assumed that the effectiveness is further reduced because families in low S-E strata use fluoridated salt (FS) less frequently than those in the higher S-E strata who are known to use preventive methods like toothbrushing twice a day with a fluoride dentifrice more regularly. Model calculations tend to show that in Germany, where FS has reached a market share of 60%, the overall effectiveness is 14% instead of 30%. For France with a market share of 30% of the fluoridated domestic salt, model calculations lead to an overall effectiveness of 8%. In order to obtain a substantial decline of caries in the entire population, it is important to aim for a high market share of the FS of 80%, or preferably 90%. This goal can be reached with a relatively small budget. The task of health ministries would be to promote the switch from unfluoridated salt to FS; however, such promotion is often withheld by health ministries. It is possible, through modest price increases of salt, to finance effective campaigns inducing the majority of the population to use the fluoridated variety. On a world wide scale, fluoridation of salt has established itself as an efficient public health measure. It may be particularly beneficial for developing countries because it is by far the cheapest method and it is compatible with the use of fluoridated toothpastes.

Aesthetically objectionable fluorosis in the United Kingdom

OBJECTIVES

A cross-sectional national survey to explore perceptions of dental fluorosis and to determine the proportion of people regarding fluorosis as aesthetically objectionable at differing levels of defect.

METHODS

A survey using a multistage stratified random probability sample of 6,000 UK adult households. Face-to-face interviews were carried out using a structured questionnaire and photographs of different levels of dental fluorosis. Respondents were interviewed about the parameters of satisfaction, attractiveness and need for treatment for dental fluorosis.

RESULTS

The proportion of respondents perceiving teeth as unattractive, unsatisfactory and requiring treatment increased with increasing severity of dental fluorosis. Using agreement between the three negative perceptions as a measure, 14% of the sample perceived mild dental fluorosis as aesthetically objectionable, 45% at moderate level and 91% at severe levels.

CONCLUSION

Negative perceptions of dental fluorosis were lower than reported previously. Three parameters were included in the approach to estimate aesthetically objectionable fluorosis which may provide a more realistic measure than those used previously. The nature of the index and the sample included suggest that findings of this survey provide a reasonable indicator of the likely impact of water fluoridation. Findings may have important implications for fluoridation policies in the United Kingdom and elsewhere.

What the papers say: how does the United Kingdom press treat water fluoridation and does it matter?

This is a case study to investigate in an objective way how fluoridation is reported in the press. All press cuttings collected by a reputable national agency covering a 9-month period were studied; were rated as being profluoridation, antifluoridation or neutral. The rating system was calibrated before the study by comparing the scores given by the author and a selected group of experts. Overall, press article coverage was antifluoridation, though it is not clear how intentional this is.

Attitudes to water fluoridation in South Africa 1998. Part I. Analysis by age, sex, population and province

The successful implementation of water fluoridation (WF) depends upon support from the public. A survey was conducted in 1998 by the Human Sciences Research Council to assess attitudes of the South African population towards WF. A representative sample of 2,220 persons over the age of 18 years was interviewed. Questions relating to current knowledge, sources of information, the purpose of water fluoridation and its desirability as a public health measure were put to respondents. Only 25% of the population had heard or read of WF. The major sources of information were the electronic and printed media (40% and 27% respectively), while 2.5% heard about it from dentists. Just over a third of the sample (35.5%) identified the purpose of WF as protecting teeth from decay; 28% said it was to purify water and 28.5% were uncertain of, or did not know its purpose. Nearly two-thirds (61.9%) indicated that fluoride should be added to drinking water if it can reduce tooth decay, while 9% were not in favour and 29% were uncertain. The results suggest that most people do not know what WF is or does, though most were in agreement that it should be implemented to reduce tooth decay.

Estimating the benefits of community water fluoridation using the willingness-to-pay technique: results of a pilot study

OBJECTIVES

To estimate the health and non-health effects of fluoridation on well-being using the willingness-to-pay technique.

METHODS

A pilot study of 100 people was undertaken in which the willingness-to-pay technique was used to estimate the welfare effects of community water fluoridation in the city of Sheffield, in the United Kingdom. In view of the pilot nature of the study, it was decided to use quota sampling based on age and sex rather than random sampling. Reasons for respondents' answers and their previous knowledge of fluoridation were also noted.

RESULTS

Sixty-two percent of respondents were in favour of fluoridation, 31% were opposed, and 7% were unsure. Thirty-one respondents refused to answer the willingness-to-pay questions. The mean willingness to pay for those in favour of fluoridation was less than that for those opposed to fluoridation. The main reasons given for opposing fluoridation were its impact on freedom of choice and the desire for pure water. Nineteen percent of the sample held incorrect information on the effects of fluoridation.

CONCLUSIONS

The study illustrates how a simple referendum can miss important information regarding the intensity of individuals' preferences. An important aspect of the willingness-to-pay technique is its ability to identify 'losers' and quantify their welfare loss. This issue has been ignored by all previous economic evaluations of fluoridation. Further investigation is required to replicate this work on a larger sample of individuals, and to develop the willingness-to-pay technique.

Symptoms experienced during periods of actual and supposed water fluoridation

Fluoridation of water is a controversial measure because of the suspicion that it has harmful effects on health. Opinions differ as to the reality of these fears. In Kuopio, after distressing disputes over the fluoridation issue, the City Council decided to stop fluoridation at the end of 1992. In fact, however, it was discontinued at the end of November, one month early, without the public being told. The aim of this study was to find out whether the occurrence of 25 selected symptoms was connected with exposure to fluoridated water. In order to do this we compared the prevalence of symptoms during the months before and after the undisclosed cessation of fluoridation and after the cessation had been officially announced. Postal inquiries concerning symptoms were sent to 1000 randomly selected adults in November, to a further 1000 in December 1992 and again to the same 2000 people in March 1993. The response rates were 40-26%. The percentage of those with two or more symptoms was the same (45%) in November and in December but decreased to 32% in March. The mean number of symptoms per respondent decreased from 1.9 in November to 1.4 in March (P < 0.001) and in December-March from 1.8 to 1.2. The decrease was most significant for symptoms related to the skin. Since the occurrence and mean number of symptoms were fairly similar during actual and supposed fluoridation, the results do not support the theory that the symptoms considered in this study are caused by the physical effect of fluoridated water. On the other hand, the significant reduction in the number of symptoms only after the respondents had become aware of the discontinuation of fluoridation reveals that fluoridation may have psychological effects which present as perceived symptoms.

The fluoridation war: a scientific dispute or a religious argument?

Communal water fluoridation is not considered controversial by the vast majority of the scientific community; however, politically it has persisted as an issue that many legislators and community leaders have avoided because of an aura of dispute, it has been a battleground for vigorous opposition by a very small but outspoken minority who have fought it with the dedication of religious zealots. This paper reviews the nature of the opposition, who they are, the broad thrust of their arguments, some of the specific issues they have raised, and their techniques.

The effectiveness of community water fluoridation in the United States

Grand Rapids, the first city in the world to implement controlled water fluoridation, has served as a model for thousands of other communities. Fluoridation is one of the greatest public health and disease-preventive measures of all time. Its advantages include effectiveness for all, ease of delivery, safety, equity, and low cost. Today, nearly 56 percent of the US population lives in fluoridated communities (62% of those on central water supplies). Previously observed caries reductions of one-half to two-thirds are no longer attainable in the United States because other fluoride methods and products have reduced the caries prevalence in all areas, thus diluting the measurement of effectiveness, and because benefits of fluoridation are dispersed in many ways to persons in nonfluoridated areas. Water fluoridation itself, however, remains as effective as it ever was among groups at high risk to dental caries. Contrary to early beliefs that stressed the importance of preeruptive fluoride exposure, fluoridation also provides an important source of topical fluoride and facilitates remineralization. Although data on effectiveness and safety are compelling, future progress of water fluoridation will be affected by economic, political, and public perception factors.

Factors associated with the use of fluoride supplements and fluoride dentifrice by infants and toddlers

Dental fluorosis may be associated with the inappropriate use of fluoride dentifrices and/or dietary fluoride supplements by young children, especially for those who consume optimally fluoridated water. Studies to date have used retrospective designs that rely on anamnestic responses of adults to determine fluoride exposures in their children. The 1986 National Health Interview Survey (NHIS) collected information on current use of fluoride-containing dental products (dentifrices, drops, tablets, and mouthrinses) by all household members during home interviews. This report contains information obtained from adults for 1,996 children younger than two years of age. Nearly half of the children used fluoride dentifrices or dietary fluoride supplements. Eleven percent of the children younger than one year of age and nearly 60 percent of children between one and two years of age reportedly used a fluoride toothpaste. Dietary fluoride supplements were used about equally in these age groups (about 16%). The use of a fluoride dentifrice was similar across racial-ethnic groups, but the use of dietary fluoride supplements was less among blacks and Hispanics. A significantly higher proportion of children whose respondent knew the purpose of water fluoridation used some type of fluoride product. Because young children tend to swallow dentifrices, the findings of this study suggest the need for educational programs targeted to parents and health care providers regarding the appropriate use of fluorides and the risk of fluorosis when they are used inappropriately.

Risks of the "big three": what dentists and patients believe about dental amalgam, fluoride and HIV

Dental professionals have seriously considered the risks to the public from dental amalgam, fluoridated water and HIV transmission in the dental office. These issues are important to the public, who typically rely on practicing dentists for information about just how serious the risks are.

A study of mothers' attitudes towards the prevention of caries with particular reference to fluoridation and vaccination

Three hundred and fifteen mothers of pre-school children from socially deprived areas in Scotland were interviewed to assess their knowledge of, and attitudes towards, caries prevention. Thirty-five per cent of them believed that the dental profession had the most important part to play in the prevention of dental disease, while thirty-five per cent were complacent about their children's teeth and did not feel that preventive measures were necessary. Sixty-seven per cent thought that a caries vaccine would be acceptable if it posed no health risks and reduced caries experience by 50 per cent. This proportion increased to 78 per cent if all caries could be avoided by being immunized. Significantly more mothers held positive attitudes towards a hypothetical vaccine than to the more realistic prospect of fluoridation of public water supplies. This study has shown that mothers in deprived areas have little understanding of how to control dental disease and see little point in taking a personal initiative to alter their children's behaviour to reduce the risk of caries. They prefer to leave the control of disease to the dental profession. The idea that dental disease might be reduced by a vaccine was more acceptable than fluoridation.