A critique of recent economic evaluations of community water fluoridation

Background:

Although community water fluoridation (CWF) results in a range of potential contaminant exposures, little attention has been given to many of the possible impacts. A central argument for CWF is its cost-effectiveness. The U.S. Government states that $1 spent on CWF saves $38 in dental treatment costs.

Objective:

To examine the reported cost-effectiveness of CWF.

Methods:

Methods and underlying data from the primary U.S. economic evaluation of CWF are analyzed and corrected calculations are described. Other recent economic evaluations are also examined.

Results:

Recent economic evaluations of CWF contain defective estimations of both costs and benefits. Incorrect handling of dental treatment costs and flawed estimates of effectiveness lead to overestimated benefits. The real-world costs to water treatment plants and communities are not reflected.Conclusions: Minimal correction reduced the savings to $3 per person per year (PPPY) for a best-case scenario, but this savings is eliminated by the estimated cost of treating dental fluorosis.     

The application of multilevel modelling to dental caries data

Clinical studies of dental caries experience generate multiple outcome data for each participant, with information collected for each individual tooth surface. This paper investigates multilevel modelling as a method of analysis for dental caries data, allowing for full use of the data collected at surface level. Data from a clinical trial of a caries preventive agent in adolescents are modelled. The effect of tooth position within the mouth on the development of dental caries is investigated, with the results showing the importance of differentiating between the upper and lower arches, when modelling the probabilities of caries developing on teeth. Calculation of the intracluster correlation using the threshold model is suggested for use in multilevel logistic regression modelling of caries data. This model, which assumes that a dichotomous outcome is based on an underlying continuous variable with a threshold point where the outcome changes from zero to one, is identified to be appropriate for the analysis of caries which is a continuous process, but is only identified as present in a clinical trial when it has reached a certain level of severity.     

饮水氟对儿童龋齿的影响

目的探讨饮水氟含量与儿童龋齿患病率之间的相关关系和预防龋齿的适宜饮水氟浓度.方法采用流行病学方法调查江苏省某县新淮村[饮水氟含量范围和均值分别为0.18～0.76和(0.36±0.11)mg/L,8～13岁小学生290名]和瓦庙村[饮水氟含量范围和均值分别为0.57～4.50和(2.46±0.80)mg/L,8～13岁小学生222名]儿童龋齿患病率,并按照饮水氟含量不同将儿童分为不同接触组,即＜0.5,0.5,1.0,1.5,2.0,2.5,3.0,3.5和≥4.0mg/L等9个组,探讨饮水氟含量与儿童龋齿患病率之间的剂量-效应关系,并计算饮水氟含量的基准剂量95%可信限下限(BMDL).结果低浓度时(饮水氟含量＜2.72 mg/L)随着饮水氟含量的增加,儿童龋齿患病率逐渐降低;当饮水氟含量＞2.72mg/L时,随着饮水氟含量的增加,儿童龋齿患病率逐渐升高.饮水氟含量和儿童龋齿患病率之间的剂量-效应关系为U型曲线.根据这一剂量-效应关系,分别计算低浓度和高浓度时饮水氟含量的BMDL为3.09和2.59 mg/L.考虑到龋齿致病原因和摄氟途径的复杂性,计算所得的参考剂量(RfD)值为1.55和1.29 mg/L.结论根据WHO的推荐值及国内外的研究结论,结合本次调查结果,可以认为在研究地区预防龋齿最佳的饮水氟浓度为1.0～1.5 mg/L.     

Community water fluoridation: attitudes and opinions from the New Zealand Oral Health Survey

Objective: To report the responses of adult participants in the 2009 New Zealand Oral Health Survey (NZOHS) to questions about community water fluoridation (CWF). Methods: The study used quantitative data from the NZOHS. All adult participants aged 18 years and over in the nationally representative NZOHS sample were included in the study (n=3475). Univariate analysis and multinominal logistic regression models were used to examine the associations between variables. Results: Overall, 57.7% of respondents thought that there were dental benefits to adding fluoride to drinking water and 31.7% responded that they did not know. More than 45% of respondents did not know whether there were health risks from adding fluoride to drinking water. Overall, 42.0% of respondents were strongly or somewhat in favour of CWF. Conclusion and implications: People in the Māori, Pacific and Asian ethnic groups, from the two most deprived quintiles, with no education after high school and who brushed their teeth less than twice a day expressed significantly greater uncertainty about CWF than other population groups. This study suggests further research is required to gain a greater understanding of health literacy about CWF and the cultural appropriateness of CWF in NZ.     

Universal and targeted policy to achieve health equity: a critical analysis of the example of community water fluoridation cessation in Calgary,Canada in 2011

In May of 2011, a decision was made by city council in Calgary, Canada, to cease community water fluoridation and to re-allocate the annual operating costs to targeted dental programming. The purpose of this study was to critically analyze this decision as an example of a shift from a universal approach (fluoridation) to a targeted approach (dental programming delivered to children in low-income communities). We were especially interested in how the concept of equity played out in the deliberations, and we used Hilary Graham’s three conceptualizations of equity as a framework. We examined publicly available municipal council documents pertaining to this policy decision, with a prominent focus on the 26 January 2011 meeting of the Standing Policy Committee on Utilities and Environment at which Calgarians (citizens and professionals) were invited to speak. We extracted and critiqued statements or exchanges pertaining to equity or related concepts (e.g. poverty). We observed different perspectives on the concept of equity, and the notion of community water fluoridation as equitable. In particular, there was a tendency, expressed strongly by some participants in the debate, to conflate equity and poverty (Graham’s ‘disadvantages’ conceptualization of equity), such that a targeted approach was seen as the only viable way of addressing the dental health needs of children living in poverty. This research is timely considering the apparently increasing frequency of cessation of fluoridation in Canada, the consequent search for alternative approaches to preventive dental health, and the apparently strong appeal of a targeted approach.     

Assessing generalisability by location in trial-based cost-effectiveness analysis: the use of multilevel models

Cost-effectiveness analysis (CEA) in health care is increasingly conducted alongside multicentre and multinational randomised controlled clinical trials (RCTs). The increased use of stochastic CEA is designed to account for between-patient sampling variability in cost-effectiveness data assuming that observations are independently distributed. However, between-location variability in cost-effectiveness may result if there is a hierarchical structure in the data; that is, if there is correlation in costs and outcomes between patients recruited in particular locations. This may be expected in multi-location trials given that centres and countries often differ in factors such as clinical practice, patient case-mix and the unit costs of delivering health care. A failure to acknowledge this feature may lead to misleading conclusions in a trial-based economic study. Multilevel modelling (MLM) is an analytical framework that can be used to handle hierarchical cost-effectiveness data. Using data from a recently conducted economic analysis, this paper shows how multilevel modelling can be used to obtain (a) more appropriate estimates of the population average incremental cost-effectiveness and associated standard errors compared to standard stochastic CEA; and (b) location-specific estimates of incremental cost-effectiveness which can be used to explore appropriately the variability between centres/countries of the cost-effectiveness results.     

马鞍山市学龄前儿童龋病发病相关因素logistic分析

目的　探讨学龄前儿童引发龋病的相关因素。方法　采用分层随机抽样方法对本市 3840名 7岁以下儿童进行口腔检查并对其父母问卷调查 ,用SPSS软件进行非条件logistic回归分析。 结果　年龄、饮食习惯、日刷牙次数、家族史、口腔清洁度的OR值分别为 1.6 34 8、1.35 17、1.30 44、0 .6 734和 8.4878,(P <0 .0 5 ) ,差异有显著性。结论　学龄前儿童的饮食习惯、卫生、习惯与龋病的发病有关。     

Intermediate and advanced topics in multilevel logistic regression analysis

Multilevel data occur frequently in health services, population and public health, and epidemiologic research. In such research, binary outcomes are common. Multilevel logistic regression models allow one to account for the clustering of subjects within clusters of higher‐level units when estimating the effect of subject and cluster characteristics on subject outcomes. A search of the PubMed database demonstrated that the use of multilevel or hierarchical regression models is increasing rapidly. However, our impression is that many analysts simply use multilevel regression models to account for the nuisance of within‐cluster homogeneity that is induced by clustering. In this article, we describe a suite of analyses that can complement the fitting of multilevel logistic regression models. These ancillary analyses permit analysts to estimate the marginal or population‐average effect of covariates measured at the subject and cluster level, in contrast to the within‐cluster or cluster‐specific effects arising from the original multilevel logistic regression model. We describe the interval odds ratio and the proportion of opposed odds ratios, which are summary measures of effect for cluster‐level covariates. We describe the variance partition coefficient and the median odds ratio which are measures of components of variance and heterogeneity in outcomes. These measures allow one to quantify the magnitude of the general contextual effect. We describe an R² measure that allows analysts to quantify the proportion of variation explained by different multilevel logistic regression models. We illustrate the application and interpretation of these measures by analyzing mortality in patients hospitalized with a diagnosis of acute myocardial infarction. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.     

北京市海淀区儿童龋齿情况调查及预防保健措施分析

目的：了解海淀区幼儿园儿童口腔保健状况,为制定相应干预措施提供依据。方法对北京市海淀区幼儿园2012年1月至12月开展儿童口腔保健情况进行调查,对2012年海淀区幼儿园口腔检查年报资料进行分析。结果海淀区幼儿园100％开展了口腔龋齿防治工作;海淀区在园儿童龋齿患病率为53．19％,龋齿治疗率为61．37％,龋齿充填率49．32％,各年龄组儿童的患龋率、龋齿治疗率、龋齿充填率随年龄组增长而呈上升趋势（χ2值分别为1211．28、1933．92、5649．82,均P＜0．05）,4～5岁组是新生龋齿高发人群。结论海淀区幼儿园儿童龋齿防治工作良好,应加强3～4岁儿童口腔龋齿的预防工作,龋齿的预防应提前到社区小年龄组儿童,保健医师应提高健康教育知识技能,做好儿童家长的口腔保健知识宣传。     

北京市2001～2005年托幼园所儿童健康状况分析

【目的】探讨北京市2001~2005年托幼园所儿童健康状况的动态变化。【方法】采用时间序列比较法对北京市托幼园所2001~2005年集体儿童保健年报资料进行分析。【结果】5年间儿童营养不良逐年下降,低体重、发育迟缓、消瘦患病率分别为0.28%、0.33%、0.24%,儿童体格趋于肥胖逐年增高,达5.73%,贫血患病率为0.75%,患龋率及龋均较高,分别为38.83%和1.49,各类健康指标城区好于郊区。【结论】北京市托幼园所儿童健康状况良好,儿童肥胖的干预是工作重点,五官保健不容忽视,郊区园所儿童保健需进一步加强。     

2018年石渠县学龄前儿童患龋率及其防治状况

目的调查甘孜州石渠县学龄前儿童患龋发生情况,为调整和制定当地口腔防治工作规划提供参考依据。方法2018-07,采用分层随机整群抽样方法,从石渠县农村和城市分别随机抽取1所城市幼儿园和2所农村幼儿园,由经过培训的执业医生和护士进行患龋及口腔填充情况进行全面检查,采用卡方检验、趋势卡方检验对数据进行统计分析。结果本次研究共调查460名学龄前儿童,患龋人数为297人,患龋率为64.57%。卡方趋势检验显示,6岁组及大班儿童患龋率最高(χ^2年龄=19.856,P<0.01;χ^2年级=19.628,P<0.01)。患龋牙齿数共1096颗,其中1度、2度、3度、4度和5度分别占34.03%、33.49%、13.87%、5.38%及13.23%,趋势卡方检验显示患龋严重程度随着年龄和年级的增加而升高(χ^2年龄=24.822,P<0.01;χ^2年级=14.527,P<0.01)。学龄前儿童口腔防治填充率为6.74%,其中接受窝沟封闭术4.57%,进行预防性树脂填充者2.17%。结论甘孜州石渠县学龄前儿童患龋水平高,口腔防治填充率低,需不断加强对该年龄儿童龋齿的三级预防,突出重点,以改善当地的高患龋情况。     

无为县生活饮用水氟含量调查

目的：全面掌握无为县饮水氟含量,为改水工程及地方病防治提供依据。方法：对无为县23个乡镇按东西南北中方位抽取5个行政村,对每个行政村按5个方位抽取1份饮用水水样,检测饮用水水样含氟量。结果：通过对全县23个乡镇,115个行政村抽取575份水样检测,氟化物含量范围为0．05～0．81mg／L,饮水氟含量平均为0．3mg／L,低于0．5mmg／L的地区占95．3％;低于0．4mmg／L的地区占87．1％。结论：无为县属低水氟含量地区,应当采取措施补充氟化物,防止儿童龋齿发生。     

乌鲁木齐市十一所幼儿园乳牙患龋病情况调查

【目的】 了解乌鲁木齐市11所幼儿园学龄前儿童乳牙患龋病情况,掌握儿童口腔保健中的薄弱环节,为进一步降低儿童乳牙龋齿发病率提供依据。 【方法】 对乌鲁木齐市11所幼儿园4 306名学龄儿童进行乳牙龋病检查,并进行数据资料的统计分析。 【结果】 乳牙患龋率平均为45.01%;龋均为1.61,乳磨牙龋均为0.84;乳切牙龋均为0.77,5~6岁为乳牙龋齿高发年龄,并随年龄的增长而逐渐上升。 【结论】 提高自我口腔保健意识,加强托儿所、幼儿园儿童口腔卫生保健健康教育,普及规范的口腔卫生保健知识,健全初级口腔卫生服务体系,提高儿童口腔健康水平,逐步降低儿童龋病的发生。     

福州市台江区学龄前儿童龋病现况调查及饮食影响因素分析

目的 了解福州市台江区学龄前儿童患龋情况,探讨影响龋病发病的相关饮食因素,为龋病防治措施的制定提供依据。方法 按照第三次全国口腔健康流行病学抽样调查的要求,采取分层整群抽样的方法,随机抽取福州市台江区4所幼儿园共536名儿童进行龋病的检查,对其家长进行问卷调查,对患龋率和龋均等指标做统计分析。结果 福州市台江区学龄前儿童患龋率为57.3%,龋均为2.38,其中男童患龋率为63.2%,龋均为2.79;女童患龋率为51%,龋均为1.94 ,不同性别之间患龋率和龋均差异有统计学意义(P<0.05);大班患龋率为65.1%,龋均为3.05;中班患龋率为63.1%,龋均为2.20;小班患龋率为36.8%,龋均为1.46,不同年级之间患龋率和龋均差异有统计学意义(P<0.05);城镇儿童患龋率为55.0%,龋均为2.29;女童患龋率为63.1%,龋均为2.62,城乡儿童之间患龋率和龋均差异有统计学意义(P<0.05);龋病的饮食因素中每日吃零食的次数、乳饮料、碳酸饮料差异有统计学意义(P<0.05)。 结论 年级、性别、零食、乳饮料、碳酸饮料是学龄前儿童龋病的饮食影响因素。     

西安市某高校幼儿园242名儿童口腔卫生状况及分析

目的 针对242名儿童口腔健康存在的问题,探讨口腔卫生习惯与儿童龋齿的关系。方法 通过对西安某高校幼儿园242名儿童做口腔健康全面检查,对4~6岁的儿童的换牙、龋齿、严重龋齿(>4颗)、缺牙、牙结石、延迟换牙和补牙情况进行检查分析。并对242名儿童及家长进行访谈,填写问卷,并将结果进行统计分析。结果 242人中龋齿71人,重度龋齿18人,补牙人数为28人,牙结石人数26人。儿童的口腔卫生习惯与龋齿的发病原因直接相关,导致龋齿发生的原因依次为:1)细菌因素:主要是菌斑,细菌的存在是龋病发生的必然条件;如无刷牙习惯;2)食物因素:过多食用零食,喜好甜食,而全身的营养支持不够;3)宿主因素:影响可能是牙齿排列或形态不整齐、不规则。 结论 242名儿童中龋齿严重,今后应提高儿童乳牙保护意识,养成良好的口腔卫生习惯,可有效防止龋齿的发生和发展。     

东海县改水降氟工作进展及效果分析

目的:总结东海县20余年地方性氟中毒病区改水降氟工作的进展,评价改水降氟控制地方性氟中毒的效果。方法:将2007年全县改水降氟工程进行监督、水氟动态监测、自来水普及率调查及国家地方性氟中毒监测点的结果录入Excel电子表格进行统计分析。结果:至2007年底,累计建改水降氟工程65处,受益村93个,改水村总人口数为21.35万人,各类氟中毒病区中,重病区村的改水率最高,达到100%,中病区村的改水率次之,为86.49%,轻病区村的改水率最低,为68.49%,总改水率为76.86%,自来水普及率为78.66%,实际受益人口16.79万人,改水工程水氟合格率为91.17%。国家地方性氟中毒监测点结果发现8~12岁学生氟斑牙的患病率为22.73%,氟骨症患病率为6.00%,达到非病区的标准。结论:东海县的改水降氟工作取得了显著成效。