Predicting poverty. Data mining approaches to the health and demographic surveillance system in Cuatro Santos, Nicaragua.

BACKGROUND: In order to further identify the needed interventions for continued poverty reduction in our study area Cuatro Santos, northern Nicaragua, we aimed to elucidate what predicts poverty, measured by the Unsatisfied Basic Need index. This analysis was done by using decision tree methodology applied to the Cuatro Santos health and demographic surveillance databases. METHODS: Using variables derived from the health and demographic surveillance update 2014, transferring individual data to the household level we used the decision tree framework Conditional Inference trees to predict the outcome "poverty" defined as two to four unsatisfied basic needs using the Unsatisfied Basic Need Index. We further validated the trees by applying Conditional random forest analyses in order to assess and rank the importance of predictors about their ability to explain the variation of the outcome "poverty." The majority of the Cuatro Santos households provided information and the included variables measured housing conditions, assets, and demographic experiences since the last update (5 yrs), earlier participation in interventions and food security during the last 4 weeks. RESULTS: Poverty was rare in households that have some assets and someone in the household that has a higher education than primary school. For these households participating in the intervention that installed piped water with water meter was most important, but also when excluding this variable, the resulting tree showed the same results. When assets were not taken into consideration, the importance of education was pronounced as a predictor for welfare. The results were further strengthened by the validation using Conditional random forest modeling showing the same variables being important as predicting the outcome in the CI tree analysis. As assets can be a result, rather than a predictor of more affluence our results in summary point specifically to the importance of education and participation in the water installation intervention as predictors for more affluence. CONCLUSION: Predictors of poverty are useful for directing interventions and in the Cuatro Santos area education seems most important to prioritize. Hopefully, the lessons learned can continue to develop the Cuatro Santos communities as well as development in similar poor rural settings around the world.

Recall intervals and time used for examination and prevention by dentists in child dental care in Denmark, Iceland, Norway and Sweden in 1996 and 2014.

OBJECTIVE: The purpose of the present study was to explore intervals between regular dental examination and the time dentists spent for examination and preventive dental care of children in 1996 and 2014. PARTICIPANTS AND METHODS: In Denmark, Norway and Sweden, random samples of dentists working with children were included, while in Iceland all dentists were mailed questionnaires. Complete information was provided by 1082 of 1834 dentists (64%) in 1996 and 1366 of 2334 dentists (59%) in 2014. Results were assessed using chi-square and analysis of variance with post-hoc tests. RESULTS: Some trends were consistent in all countries, but considerable differences in routines between the countries persisted during the period. The most used and maximum planned recall intervals were on average 14.8 (sd 4.8) and 18.5 (sd 4.6) months in 2014, respectively 3.1 and 3.5 months longer than in 1996 (p⟨0.05). In 2014 dentists used ample time delivering preventive care to children. Dentists reported spending significantly more time providing preventive care for caries risk children than for other children both in 1996 and 2014. Concurrent with extended intervals, dentists reported spending longer performing routine examinations in three of the four countries in 2014 than in 1996. CONCLUSIONS: This study of trends in dental care delivered by dentists during recent decades showed moves towards extended recall intervals and preventive care individualized according to caries risk. In addition, extending intervals could necessitate more time for a routine dental examination.

Evaluating a peer intervention strategy for the promotion of sexual health-related knowledge and skills in 10- to 14-year-old girls. Findings from the "Entre amigas" project in Nicaragua.

PURPOSE: Report effects on knowledge of sexual health and gender from an intervention using peer methodology in Nicaragua. DESIGN: A prepost nonequivalent control group design. SETTING: Ciudad Sandino, Managua, Nicaragua. SUBJECTS: A total of 599 girls were surveyed, 60% nonintervened and 40% intervened. INTERVENTION: Peer methodology consisted of (1) meetings in which girls talked and worked with other girls, (2) mothers taking an active role in the peer groups, and/or (3) girls watching the soap opera "Sexto Sentido." MEASURES: Indices measuring changes in sexual knowledge and gender vision. RESULTS: Girls participating in the peer groups were twice as likely to have satisfactory sexual health-related self-esteem as those who did not participate. Eleven percent of the girls achieved satisfactory self-esteem as a result of the (peer groups x mothers) interaction and 15% due to the (peer groups x mothers x "Sexto Sentido") interaction. Girls participating in the peer groups were three times as likely to have satisfactory gender visions; if exposed to all three components, they were almost four times as likely to develop satisfactory gender visions. CONCLUSIONS: Peer methodology, participation of a female family member, and an educational soap opera seem beneficial in promoting sexual health-related knowledge and gender vision in young girls.

The value of caries preventive care among 19-year olds using the contingent valuation method within a cost-benefit approach.

OBJECTIVES: The aim of this study was to explore adolescents with high and no caries experience and their preferences for caries preventive dental care. Their willingness-to-pay (WTP) for preventive dental care was elicited using the contingent valuation method (CVM) within a cost-benefit approach. METHODS: Eighty-two individuals (19-year olds) agreed to participate in an exploratory case-control study. Thirty individuals with high caries experience formed the test group. The control group consisted of 52 individuals with no caries experience, selected randomly from a caries-free population. Using personal questionnaires in combination with the CVM, we elicited respondents' WTP for preventive dental care. The data were used to: (a) compare WTP between study groups, and (b) calculate net social benefit (NSB) in cost-benefit analysis (CBA). RESULTS: The result shows a mean yearly WTP for the high- and low-risk group of 1405 SEK and 1087 SEK (7.70 SEK = US$1; July 2005), respectively. Two variables were associated with the differences between the groups: caries risk (i.e. group designation) and housing. Using these WTP values, the CBA showed positive NSB values for both study groups. CONCLUSIONS: Through use of the CVM, 19-year olds' WTP for caries preventive measures was elicited. An NSB >0 was found, which means that benefits exceeded the costs for prevention. Despite the small sample size and restriction to one Swedish county, the results indicate that the methods used in this study are suitable for further testing and analyses.

A pilot study of the use of oral health-related quality of life measures as an outcome for analysing the impact of caries disease among Swedish 19-year-olds.

OBJECTIVES: To be useful as a supplement for health economic evaluations in caries preventive care, the oral health-related quality of life (OHRQOL) measures must be able to discriminate for caries disease. The aim of this study was therefore to explore whether any differences existed in perceived OHRQOL among adolescents with either high or no caries experience. METHODS: Eighty-two individuals (all 19-year-olds) agreed to participate in a pilot exploratory case-control study. Thirty individuals with high caries experience formed the test group. The control group consisted of 52 individuals with no caries experience, selected randomly from a caries-free population. OHRQOL scores were collected for analysis through personal interviews using two OHRQOL measures, the Child Perceptions Questionnaire (CPQ(11-14)) and Oral Health Impact Profile-14 (OHIP-14). RESULTS: The OHRQOL measures used were not able to discriminate between young adults with high and no caries risk experience with respect to perceived OHRQOL. Despite a consistently higher impact score for the test group throughout the overall and subscale scores, the differences were not statistically significant except for one of the subscale scores, oral symptoms. CONCLUSIONS: This study indicates that the prevalence and incidence of caries must be seen as too low in Sweden to have major influence on young adults' perceived OHRQOL and well-being. Therefore, the usefulness of OHRQOL measures in supplementing outcome measurement in health economic evaluations, particularly those that focus on caries preventive strategies, must be questioned.

The effect of five years' implementation of caries-preventive methods in Swedish high-risk adolescents.

AIM: To study the effectiveness of four different preventive programmes within a group of adolescents at high risk of caries. SUBJECTS AND METHODS: In 1995, a cohort of 12-year-olds was examined for caries and completed a questionnaire. Subjects identified as being at high risk were examined every year until 2000 when they were 17 years old. This high-risk group was subdivided into four groups, each individual randomly assigned to one of four preventive programmes: (A) information on tooth-brushing techniques; (B) prescription of fluoride lozenges; (C) semi-annual applications of fluoride varnish; (D) quarterly appointments where participants were given individualised information on oral hygiene and diet as well as an application of fluoride varnish. The outcomes examined were the caries increment in dentine, enamel and fillings. Poisson regression was used to assess the influence of background, preventive factors and habits. RESULTS: The number of 12-year-olds in the high-risk group was 1,134 in 1995, of which 925 were still participants in 2000. The differences between the programmes in mean 5-year increment were not significant. Less risk of caries increment was shown for those who had at least one sealant and for those who belonged to the fluoride varnish group (C). A higher risk was observed for adolescents from working-class homes, and for those who reported often eating sweets and not brushing their teeth twice a day at all examinations during the whole study period. CONCLUSIONS: The preventive programmes tested were equal in showing low efficiency in adolescents with high caries risk.

Cost-effectiveness of different caries preventive measures in a high-risk population of Swedish adolescents.

OBJECTIVES: A total of 3373 12-year-olds agreed to participate in an intervention study evaluating different caries preventive measures. The study, titled 'Evaluation of caries preventive measures', was performed between 1995 and 1999 at 26 dental health clinics throughout Sweden. At the start of the study, the subjects were classified as individuals at high or low risk of developing caries. The high-risk group consisted of 1165 subjects. The children in the high-risk group were randomly assigned to one of four preventive programs. The programs represent a step-wise increase in fluoride content, contact with dental personnel and cost. The aim of the present cost-effectiveness analysis (CEA) study performed from a societal perspective is to compare costs and consequences of caries preventive programs in a caries high-risk population. By 'costs' is meant both treatment costs and costs contributed by the patient and the patient's family. Costs contributed by patients and their families consist of out-of-pocket expenses, transportation costs, and time. Conclusions are that it is important to consider the perspective from which a study is carried out. Costs contributed by the patient and the patient's family have a high impact on total costs for children and younger adolescents but decrease with time as the adolescents get older. The present study shows an incremental cost-effectiveness of 2043 SEK (8.54 SEK = 1 US dollar, December 1999) per averted decayed enamel and dentine missing and filled surface (DeMFS), of which treatment costs represent 1337 SEK using the unit cost for a nurse. This means a yearly cost of approximately 334 SEK.

Different analytical approaches in an experimental cohort study on preventive measures for caries in adolescents. A comparison between incidence density and increment analysis.

AIM: To use different analytical approaches to data from a longitudinal, quasi-experimental study evaluating caries-preventive measures in order to estimate the differences in results due to the analytical tool used. METHODS: 1,165 patients at high risk for caries underwent yearly examinations in 1996, 1997 and 1998 and randomly received one out of four tested preventive measures. Two analytical methods were used: (1) increment was calculated using the indices DMFS(a) and D(e)MFS(a), (2) incidence density was calculated for each individual using new approximal dentin lesions or dentin and enamel lesions in the numerator and the risk time for the surfaces in the denumerator. The Poisson regression with overdispersion was used for multivariate modelling of the outcomes. RESULTS: In all analyses of approximal dentine as well as dentine and enamel caries bad oral health at baseline increased the risk of new approximal dentine caries. In the incidence analysis poor oral health behaviour also increased the risk. CONCLUSION: Since the difference between the two analytical methods are small for young individuals the method of preference would be increment analysis.

Caries rates related to approximal caries at ages 11-13: a 10-year follow-up study in Sweden.

Predicting future caries risk is a difficult but important clinical task. The aim of this study was to analyze radiographically the relationship between approximal caries (4d-7m) at ages 11-13 (baseline) and future approximal caries. We followed 534 individuals prospectively through annual bitewing radiographs from 11 to 22 years of age. Two measures were used: individual-based incidence of the first new approximal caries lesion and surface-based incidence of approximal lesions. In the group with no approximal caries lesions at baseline, the individual-based incidence was 19 first new approximal lesions/100 person-years; the corresponding value for those with 3 approximal lesions at baseline was 71. Individuals with no approximal lesions at baseline developed 3.1 new lesions/100 tooth surface-years; the corresponding value for those with 3 lesions at baseline was 7.7. The highest risk for developing new approximal lesions was within the first 2 years after baseline.

The association of bacterial adhesion with dental caries.

Saliva adhesion of bacteria is a key event in oral biofilm formation. Here, we used partial least-squares (PLS) analysis to correlate adhesion of cariogenic (Streptococcus mutans Ingbritt) and commensal (Actinomyces naeslundii LY7) model bacteria, and their agglutinin and acidic proline-rich protein ligands, respectively, with high and low caries experiences in 38 children reflecting today's skewed caries distribution. Adhesion of S. mutans was among the factors correlating strongest with high caries experience when PLS modeled together with traditional factors (e.g., sugar intake, lactobacilli counts). Saliva phenotypes with high agglutinin levels and Db-s (an acidic PRP variant) coincided with both high caries experience and S. mutans adhesion. A. naeslundii adhesion correlated with low caries experience. Non-Db phenotypes (i.e., acidic PRP-1 and PRP-2 variants) coincided with both low caries experience and S. mutans, but high A. naeslundii, adhesion. Thus, bacterial adhesion may modulate susceptibility and resistance to dental caries.

Oral health behaviour and self-esteem in Swedish children.

This study focus on the socio-psychological concept of self-esteem and examines its association with oral health behaviour and with some background variables that have been shown to be of importance in previous studies. In 1995, 3370 12-year-olds answered a questionnaire on social and demographic factors. Questions on attitudes and behaviour were also included. After reducing the number of variables and constructing new variables, multivariate analyses were performed. A polytomous regression on self-esteem showed that having very poor self-esteem as opposed to poor, good and very good self-esteem was associated with being a girl, not living with one's biological parents, poor social support, having less interest in politics, poor adaptation in school and poor oral health behaviour. The results also showed that being a boy, choosing statements reflecting less exemplary behaviour, and being less well adapted in school increased the risk of having poor oral health behaviour, as did ethnic group affiliation and having poor self-esteem. Our results showed that self-esteem is a crucial intervening variable between variables measuring social background and outcome variables, especially oral health behaviour.

Evaluation of caries preventive measures.

This article describes the aims, methods and baseline results of a project evaluating preventive measures within a selected high-risk group. In 1995 a cohort of 3373 12-year-olds was examined with regard to caries. A high-risk group was identified and randomly divided in four different groups, receiving different preventive programs. The whole study group will be examined every other year until the adolescents are 18 years old. The high-risk group will be examined every year and given the four different preventive measures until the adolescents are 18 years of age. A questionnaire will be answered by the adolescents every other year, in order to learn more about the links between demographic data, social background, lifestyle and health behaviour. Analysis of baseline results showed that the social distribution of the study group is comparable to that of the background population as well as to the distribution in rural and urban areas. The mean DMFT was 1.5, which is in accordance with the national figure. The 28 dentists who collect the data and perform the caries diagnostics were calibrated and the mean inter- and intra-reproducibility was 0.78 and 0.82, respectively. In conclusion, it seems that the study group is representative of 12-year-olds in Sweden; thus, inferences drawn from the results of the project may be valid for adolescents in Sweden as a whole.

Caries-preventive methods used for children and adolescents in Denmark, Iceland, Norway and Sweden.

Denmark, Iceland, Norway, and Sweden have all had a similar decline in dental caries during the last 20 years, although the decline has come later in Iceland. The purpose of this study was to compare the caries-preventive methods used for children and adolescents in these four countries. Questionnaires were sent to random samples of dentists, dental hygienists, and dental nurses working with children during 1995 and 1996. The results showed that the use of preventive methods was generally consistent between the countries. Nevertheless there were differences between the countries concerning the choice of preventive strategy for risk patients and also in how prevention was implemented. Danish dental care providers chose oral hygiene education as the priority, which they put into practice. Apart from fluoride varnish for some patients, most of them did not use or recommend fluoride except fluoride toothpaste. The Norwegian and Icelandic dental care providers chose both oral hygiene education and the use of fluoride as priorities, while most Swedish dental care providers preferred to provide dietary advice and oral hygiene education, and additional fluoride for risk patients. The differences could not be explained by other variables than nationality, implying that there are differences between the dental cultures in the four countries. The informational basis of decisions on preventive strategies varied between the different dental professionals in each country as well as between the countries, indicating that national professional cultures are being shaped differently. Despite the differences in choice of preventive methods, the dental health of children varies little across the frontiers. This raises the question of the significance of the choice of preventive methods to the decline of dental caries and points towards an urgent need to develop evidence-based preventive strategies.

Distribution of caries in 12-year-old children in Sweden. Social and oral health-related behavioural patterns.

OBJECTIVE: To describe the distribution of caries in 12-year-old children in Sweden according to socio-demographic and oral health related behaviour. PARTICIPANTS: The study group consisted of 3,373 12-year-old children residing in catchments of 26 different public dental health clinics in Sweden, geographically well represented. METHOD: The clinical examination for dental caries was performed by 28 calibrated dentists. A questionnaire on lifestyle was distributed to the children with questions on ethnicity, socio-economic level and oral health as well as overall health attitudes. RESULTS: The proportion of 12-year-old children with no experience of dentine caries was 47% and 35% were completely free from all caries. Intraoral distribution of caries showed most lesions on the first molar mesial surface, with 80% enamel and 20% dentine caries. Almost all children brushed their teeth twice a day and a third of the children had an extra intake of fluoride. Decayed surfaces including enamel caries (DeS) was chosen as a measure of ongoing caries and used when dividing children into three caries groups; caries free (50%), 1-3 lesions (40%) and the high caries group (10%) with more than 3 lesions. These groups showed distribution differences. More non-Swedish children, children from workers' homes, and children who brushed their teeth less than twice a day were found in the high caries group. More children from workers' homes living in big cities and snacking more than once a week were also found in the high caries group. This could not be shown for other social groups. Also children who had an extra intake of fluoride were classified in the high caries group.

Methods of evaluating dental care costs in the Swedish public dental health care sector.

Twenty-six Swedish dental health care clinics participating in the intervention study "Evaluation of caries preventive measures" have been analysed with focus on costs, with the aim of demonstrating techniques suitable for evaluating direct dental care costs and also finding out whether charges are acceptable as a proxy for real costs. Three different approaches to calculating unit costs are discussed: average treatment time cost and two methods of different allocation of overhead cost. Average treatment time cost shows treatment time cost regardless of who (dentist, dental hygienist or nurse) provides the dental care. The other two methods reflect both the differences of treatment costs depending on practitioners' skill level and competence (salary) and the methods of handling overhead cost allocation. Our conclusions are that the proposed methods seem useful for evaluating costs in cost-effectiveness and cost-benefit analysis. The alternative to average treatment time cost or unit time cost depends on what data is available and the perspective of the analysis. This study also concludes that charges are not sufficient as an alternative to a more detailed cost evaluation, at least not in Swedish public dental health care, since charges do not cover costs.

Caries development from 11 to 22 years of age: a prospective radiographic study. Prevalence and distribution.

The aim was to assess the distribution and pattern of caries development longitudinally in teenagers and adolescents whose treatment had been based on remineralizing rather than restorative strategies. A baseline cohort of 536 children was studied, using bite-wing radiographs, from 11 to 22 years of age. The results showed a slow but continuous increase in both enamel and dentin caries of approximal surfaces. At 21, 29% of all posterior approximal surfaces had enamel caries according to the radiographic diagnoses, 14% had dentin caries and another 5% were restored. At the age of 20 21, the skewed distribution of DMFS(appr) apparent at 12 and 15 had given way to a more uniform picture and the percentage of individuals with no decayed approximal surfaces (DMFS(appr) = 0) decreased from 71 at 12-13 to 28 at 20-21 years of age. The proportion of DFS(occl) in relation to all DFS decreased from 83% at 12 to 52% at 21. The occlusal, mesial and distal surfaces of the first molar accounted for 60% of all restored surfaces at 21.

Costs for prevention of dental caries in a group of Swedish teenagers.

The aim of this study was to analyse the costs for 4 years of prevention of dental caries in 92 Swedish adolescents. Using records, the total time allocated to prevention between 1987 and 1991 was calculated. Costs for prevention was assessed from the total cost for dental service at the clinic. The cost for one hour of dental service was SEK 860, 80 pounds. The total cost for prevention in the study group during 4 years was SEK 40,162, 3,744 pounds. The amount spent on prevention in the low or average caries active group of adolescents during 4 years was less than half the sum spent in the high caries active group.

Allocation of dental caries prevention in Swedish teenagers.

In this study, the hypothesis that teenagers with high caries activity on proximal surfaces receive more preventive care in the Swedish Public Dental Health Service than those with lower caries activity on these surfaces, was tested in an audit study. Dental records and bitewing radiographs from 1987 and 1991 were used to assess caries progression in 406 teenagers from the age of 13 to the age of 17. The time allocated to prevention during the period was also registered. Caries progression as a measure of disease activity was tested. The results showed that the hypothesis could not be verified. The Odds ratio was 1.35, indicating that the chance to get more than 15 min preventive time during 4 yr was only 1.35 times higher if you were highly caries active than if you were less caries active. Although the reproducibility of the method to use caries progression as a measure of disease activity was not high, it was considered a better indicator of active disease than the number of DMF surfaces.

Buccal attachment loss in Swedish adolescents.

A case referent study was performed to identify factors connected with loss of buccal attachment in adolescents. The study group was identified among 18-year-olds who had participated 2 years earlier in a study of periodontal conditions in adolescents. The criterion for inclusion in the case group was buccal attachment loss (greater than or equal to 1 mm) in one or more sites. Information on 28 variables, identified earlier as being related to recessions, was collected in a clinical examination, interview and observation. The referent group consisted of 66 subjects and the case group of 71 subjects. The case group comprised 2 subgroups, one identified as having buccal attachment loss in 1987 and the other with attachment loss occurring in the years 1987-89. Statistical analyses, using the chi 2 test, logistic regression and a variance component model, were performed to detect factors related to buccal attachment loss. These factors were thin alveolar tissue, narrow width of the attached gingiva and presence of teeth with buccal displacement. The results indicate that the anatomy of the buccal alveolar process is related to the presence of buccal attachment loss in populations with a high level of oral hygiene. To evaluate the importance of possible risk factors or etiological factors for development of buccal loss of tooth support, prospective epidemiological or experimental studies are needed.

Marginal bone loss in 16-year-old Swedish adolescents in 1975 and 1988.

The study was designed to compare the prevalence of marginal bone loss in 2 cohorts of 16-year-old adolescents, born in 1959 and 1972, respectively. Bitewing radiographs from 400 adolescents in each group were evaluated and the presence of bone loss (distance between the cemento-enamel junction and the alveolar crest greater than 2 mm), calculus, restorations and proximal dental caries were recorded. The prevalence of bone loss was 3.5% in 1975 as well as in 1988. Bone loss was found most frequently at the mesial and distal surfaces of the first maxillary molar. The prevalence of calculus was 12% in 1975 and 7% in 1988. The mean DFS for proximal surfaces was 3.1 in 1975 and 0.8 in 1988. No statistically verified dependence was found between bone loss and calculus, or bone loss and proximal caries.