Effectiveness and reach of a directed-population approach to improving dental health and reducing inequalities: a cross sectional study

Abstract

BackgroundChildsmile School adopts a directed-population approach to target fluoride varnish applications to 20% of the primary one (P1) population in priority schools selected on the basis of the proportion of enrolled children considered to be at increased-risk of developing dental caries. The study sought to compare the effectiveness of four different methods for identifying individuals most in need when a directed-population approach is taken.MethodsThe 2008 Basic National Dental Inspection Programme (BNDIP) cross-sectional P1 Scottish epidemiological survey dataset was used to model four methods and test three definitions of increased-risk. Effectiveness was determined by the positive predictive value (PPV) and explored in relation to 1-sensitivity and 1-specificity.ResultsComplete data was available on 43470 children (87% of the survey). At the Scotland level, at least half (50%) of the children targeted were at increased-risk irrespective of the method used to target or the definition of increased-risk. There was no one method across all definitions of increased-risk that maximised PPV. Instead, PPV was highest when the targeting method complimented the definition of increased-risk. There was a higher percentage of children at increased-risk who were not targeted (1-sensitivity) when caries experience (rather than deprivation) was used to define increased-risk, irrespective of the method used for targeting. Over all three definitions of increased-risk, there was no one method that minimised (1-sensitivity) although this was lowest when the method and definition of increased-risk were complimentary. The false positive rate (1-specificity) for all methods and all definitions of increased-risk was consistently low (<20%), again being lowest when the method and definition of increased-risk were complimentary.ConclusionDeveloping a method to reach all (or even the vast majority) of individuals at increased-risk defined by either caries experience or deprivation is difficult using a directed-population approach at a group level. There is a need for a wider debate between politicians and public health experts to decide how best to reach those most at need of intervention to improve health and reduce inequalities.

Theoretical and practical challenges of proportionate universalism: a review

“…The objectives of actions following PU should be both to increase overall health population and to flatten the social gradient ( 46 ). In the majority of interventions included in the review, authors stated aiming at reducing health inequality, target access or geographical inequalities but not flattening directly the social gradient ( Table 2 ) ( 37 , 38 , 47 – 53 ). Reviews included also did not identify interventions following this objective ?…”

“…Once the need has been determined, the next step is to ensure that no misclassifications occurred. Brewster et al tested different techniques of health-risk measurements to determine if a targeted intervention reached its target ( 53 ). They found out that almost 50% of the children targeted with their postal code (selection of most deprived areas) were indeed not at-risk according to other measurements (clinical antecedents, other indexes of deprivation) ( 53 ).…”

“…Brewster et al tested different techniques of health-risk measurements to determine if a targeted intervention reached its target ( 53 ). They found out that almost 50% of the children targeted with their postal code (selection of most deprived areas) were indeed not at-risk according to other measurements (clinical antecedents, other indexes of deprivation) ( 53 ). According to Cornia and Stewart, two types of targeting errors could occur: exclusion, when an intervention fails to identify people in need, and inclusion, when the intervention identifies wrong people ( 63 , 66 ).…”

Caries Epidemiology and Community Dentistry: Chances for Future Improvements in Caries Risk Groups. Outcomes of the ORCA Saturday Afternoon Symposium, Greifswald, 2014. Part 1

“…However, they found that identifying a maximum number of children at increased risk through a directed population approach was difficult, particularly when the intervention was clinically based, e.g. with increased fluoride applications, as it did not address the underlying determinants of inequality [Brewster et al, 2013]. At the Scottish level only 50% of those targeted were actually considered to be at increased risk.…”

How effective and cost-effective is water fluoridation for adults? Protocol for a 10-year retrospective cohort study

“…92 With sufficient time, caries remains almost universal and the difficulties of accurately predicting which individuals or communities are at highest risk are well recognised. 93,94 Undoubtedly, populationwide interventions to prevent caries remain essential if the greatest burden of disease is to be avoided.…”