Multilevel Poisson Regression Models Research Articles

Risk of Hemorrhage Attributed to Underlying Chronic Diseases and Uninterrupted Aspirin Therapy of Patients Undergoing Minor Oral Surgical Procedures: A Retrospective Cohort Study.

ObjectivesThis study aimed to estimate the risk of bleeding following minor oral surgical procedures and uninterrupted aspirin therapy in high-risk patients or patients with existing chronic diseases compared to patients who did not use aspirin during minor oral surgery at a public hospital.MethodsThis retrospective cohort study analyzed the data of 2912 patients, aged 20 years or older, who underwent 5251 minor oral surgical procedures at a district hospital in Thailand. The aspirin group was comprised of patients continuing aspirin therapy during oral surgery. The non-aspirin group (reference) included all those who did not use aspirin during surgery. Immediate and late-onset bleeding was evaluated in each procedure. The risk ratio of bleeding was estimated using a multilevel Poisson regression.ResultsThe overall cumulative incidence of immediate bleeding was 1.3% of total procedures. No late-onset bleeding was found. A significantly greater incidence of bleeding was found in the aspirin group (5.8% of procedures, p<0.001). After adjusting for covariates, a multilevel Poisson regression model estimated that the bleeding risk in the aspirin group was 4.5 times higher than that of the non-aspirin group (95% confidence interval, 2.0 to 10.0; p<0.001). However, all bleeding events were controlled by simple hemostatic measures.ConclusionsHigh-risk patients or patients with existing chronic diseases who continued aspirin therapy following minor oral surgery were at a higher risk of hemorrhage than general patients who had not used aspirin. Nonetheless, bleeding complications were not life-threatening and could be promptly managed by simple hemostatic measures. The procedures could therefore be provided with an awareness of increased bleeding risk, prepared hemostatic measures, and postoperative monitoring, without the need for discontinuing aspirin, which could lead to more serious complications.

Are school and home environmental characteristics associated with oral health-related quality of life in Brazilian adolescents and young adults?

The aim of this study was to test the association of contextual school and home environmental characteristics and individual factors with oral health-related quality of life (OHRQoL) in a representative sample of Brazilian adolescents and young adults. Individual-level data from 3854 fifteen- to nineteen-year-olds who participated in the Brazilian Oral Health Survey were pooled with contextual city-level data. The dependent variable was the frequency of impacts of oral disorders on daily performances (OIDP extent), as a measure of OHRQoL. Contextual school and home environmental characteristics were categorized into three equal groups according to tertiles of the contextual variable's scores (low, moderate and high). Individual demographic, socioeconomic and oral clinical measures were the covariates. The association between contextual and individual characteristics and OIDP extent was estimated using multilevel Poisson regression models. The mean of OIDP extent was 0.9 (standard error 0.1). Adolescents and young adults living in the cities with high levels of lack of security at school (RR 1.33; 95% CI=1.02-1.74), moderate levels of bullying at school (RR 1.56; 95% CI=1.20-2.03) and moderate levels of low maternal schooling (RR 1.43; 95% CI=1.06-1.92) had a higher mean OIDP extent. Male sex, higher age, skin colour, poor individual socioeconomic status and worse oral clinical measures were also associated with higher mean of OIDP extent. Poor school and home environmental characteristics were independently associated with poor OHRQoL in individuals aged between 15 and 19years. Our findings suggest the place where they study and the maternal level of education are meaningful aspects for their oral health.

Factors associated with the number of calves born to Norwegian beef suckler cows

A retrospective cohort study was performed to evaluate factors associated with the number of calves born to Norwegian beef suckler cows. Production data from 20,541 cows in 2210 herds slaughtered over a three-year period (1st of January 2010 to 23rd of January 2013) were extracted from the national beef cattle registry. This study’s inclusion criteria were met for 16,917 cows (from 1858 herds) which gave birth to 50,578 calves. The median number of calves born per cow was 2 (min 1, max 18). Two multilevel Poisson regression models with herd random effects showed that early maturing breeds (Hereford and Aberdeen Angus) gave birth to more calves than late maturing breeds (Charolais and Limousin) in four out of five areas of Norway. The significant breed-region interaction indicated that the coastal South East region of Norway, which has a relatively long growing season and gentle topography, yielded the highest number of calves born for all but one breed (Simmental). Cows that needed assistance or experienced dystocia at their first calving produced fewer calves than those that did not: incidence rate ratio 0.87 (95% confidence interval (CI) 0.84–0.91) for assistance and 0.70 (95% CI: 0.66–0.75) for dystocia, respectively. Cows in larger herds (>30 cows) produced 11% more calves in their lifetime compared to cows in smaller herds (≤30 cows) (P<0.001). The herd random effects were highly significant, suggesting that unmeasured factors at the herd level were responsible for a large amount of the unexplained variation in the number of calves born. The large inter-herd variation indicate systematic differences in herd level factors influencing the number of calves born to each cow.

The Social Implications of Technology Diffusion: Uncovering the Unintended Consequences of People’s Health-Related Mobile Phone Use in Rural India and China

After three decades of mobile phone diffusion, thousands of mobile-phone-based health projects worldwide (“mHealth”), and hundreds of thousands of smartphone health applications, fundamental questions about the effect of phone diffusion on people’s healthcare behavior continue to remain unanswered. This study investigated whether, in the absence of specific mHealth interventions, people make different healthcare decisions if they use mobile phones during an illness. Following mainstream narratives, we hypothesized that phone use during an illness (a) increases and (b) accelerates healthcare access. Our study was based on original survey data from 800 respondents in rural Rajasthan (India) and Gansu (China), sampled from the general adult population in 2014 in a three-stage stratified cluster random sampling design. We analyzed single- and multi-level logistic, Poisson, and negative binomial regression models with cluster-robust standard errors. Contrary to other research at the intersection of mobile phones and healthcare, we captured actual health-related mobile phone use during people’s illnesses irrespective of whether they own a phone. Our analysis produced the first quantitative micro-evidence that patients’ personal mobile phone use is correlated with their healthcare decisions. Despite a positive association between phone use and healthcare access, health-related phone use was also linked to delayed access to public doctors and nurses. We considered theoretical explanations for the observed patterns by augmenting transaction cost and information deficit arguments with the prevailing health system configuration and with notions of heuristic decision-making during the healthcare-seeking process. Our study was a first step toward understanding the implications of mobile technology diffusion on health behavior in low- and middle-income countries in the absence of specific mHealth interventions. Future research will have to explore the causal relationships underlying these statistical associations. Such a link could potentially mean that development interventions aimed at improving access to healthcare continue to require conventional solutions to sustain healthcare equity.

Brief Report: Decentralizing ART Supply for Stable HIV Patients to Community-Based Distribution Centers: Program Outcomes From an Urban Context in Kinshasa, DRC.

Facility-based antiretroviral therapy (ART) provision for stable patients with HIV congests health services in resource-limited countries. We assessed outcomes and risk factors for attrition after decentralization to community-based ART refill centers among 2603 patients with HIV in Kinshasa, Democratic Republic of Congo, using a multilevel Poisson regression model. Death, loss to follow-up, and transfer out were 0.3%, 9.0%, and 0.7%, respectively, at 24 months. Overall attrition was 5.66/100 person-years. Patients with >3 years on ART, >500 cluster of differentiation type-4 count, body mass index >18.5, and receiving nevirapine but not stavudine showed reduced attrition. ART refill centers are a promising task-shifting model in low-prevalence urban settings with high levels of stigma and poor ART coverage.

Free and total p-cresol sulfate levels and infectious hospitalizations in hemodialysis patients in CHOICE and HEMO.

The uremic syndrome is attributed to progressive retention of compounds that, under normal conditions, are excreted by the healthy kidneys. p-cresol sulfate (PCS), a prototype protein-bound uremic retention solute, has been shown to exert toxic effects in vitro. Recent studies have identified relations between increased levels of PCS and indoxyl sulfate (IS) and adverse clinical outcomes in hemodialysis patients. We explored the relationship between free and total PCS and IS with infection-related hospitalizations (IH) and septicemia in 2 cohorts, Choices for Healthy Outcomes in Caring for end-stage renal disease (ESRD) Study (CHOICE) and Hemodialysis Study (HEMO).We measured free and total levels of PCS and IS in stored specimens in CHOICE, a cohort of 464 incident hemodialysis patients enrolled in 1995 to 1998 and followed for an average of 3.4 years and in a prevalent dialysis cohort of 495 patients enrolled in HEMO from 1995 to 2000 and followed for an average of 4.4 years. We measured free PCS and IS using mass spectroscopy. The 2 cohorts were linked to United States Renal Data System (USRDS) Medicare billing records to ascertain IH over follow-up. We examined the association of free and total levels of PCS and IS with IH and septicemia using multilevel Poisson regression models adjusted for demographics, comorbidities, clinical factors, and laboratory tests including residual kidney function. We stratified patients a priori based on gastrointestinal (GI) disease as PCS and IS are produced in colon.In CHOICE, highest tertile of free PCS in multivariable model was associated with 50% higher risk of IH [95% CI = 1.01-2.23] compared with lowest tertile in patients with no-GI disease. A significant trend was noted between greater levels of free PCS and septicemia in no-GI disease group in both cohorts, while no association was noted in GI disease group. Total PCS concentrations were not associated with either IH or septicemia in either cohort. No significant risk of IH or septicemia was noted with higher levels of free or total IS in either GI or no-GI disease group.These results suggest an association between higher concentrations of free PCS and infection-related and sepsis-related hospitalizations in hemodialysis patients. Better methods of dialysis should be developed to evaluate the utility of removing PCS and its effect on the outcome and also therapies to decrease gastrointestinal tract production of uremic solutes.

The influence of social deprivation on dental caries in Swedish children and adolescents, as measured by an index for primary health care: The Care Need Index

The objective was to examine associations between a primary Care Need Index (CNI) and dental caries experience. Dental journal records for 300 988 individuals in western Sweden, aged 3-19 years in 2007-09, were completed with official socioeconomic information. The CNI (independent variable), originally developed for assessing primary care need, was calculated for residential areas (small areas, parishes, dental clinics) based on markers of material deprivation, sociodemographic characteristics, social instability and cultural needs. Dental caries (dependent variable) was registered using the decayed, missing, filled teeth (DMFT) system. Multilevel Poisson regression and logistic regression models were used. All analyses were adjusted for age and gender. In the most deprived areas, the incidence rate ratio (IRR) for dental caries was up to five times higher than in the most affluent areas (reference); in small areas, the IRR for decayed teeth (DT) was 3.74 (95% CI: 3.39-4.12) and 5.11 (CI: 4.45-5.87) for decayed surfaces approximally (DSa). Caries indices including fillings (decayed filled teeth [DFT], decayed filled surfaces approximally [DFSa]) produced lower IRRs, with similar pictures at the parish and dental clinic level. The intracluster correlation was low overall, but stronger at lower geographical levels. The odds ratios for ≥3 caries lesions in the two most deprived areas of the CNI deciles were high, with a DT OR of 3.55 in small areas (95% CI: 3.39-3.73), compared with the eight more affluent deciles. There were strong associations between an index for assessing need in primary care, the CNI and dental caries in Swedish children and adolescents.

A population-based study on the impact of orofacial dysfunction on oral health-related quality of life among Brazilian schoolchildren

Objective: The aim of the present study was to assess the impact of orofacial dysfunction on oral health-related quality of life (OHRQoL) among Brazilian schoolchildren.Material and methods: A population-based study was conducted with 531 children aged eight to 10 years at schools in the city of Campo Magro, Brazil. The Brazilian version of the Child Perceptions Questionnaire (CPQ8–10) was the outcome variable used to measure the impact on OHRQoL. The main independent variable was orofacial function, which was diagnosed using the Nordic Orofacial Test-Screening (NOT-S). Descriptive, bivariate and multiple Poisson regression analyses were performed using a multilevel approach, with the significance level set to 5%.Results: The mean (±SD) total CPQ8–10 score was 13.95 ± 0.5. The multilevel Poisson regression model revealed that the mean CPQ8-10 score was higher among girls (RR: 1.38, 95% CI: 1.17–1.63; p < 0.001) than boys and that children from families with a higher income had lower CPQ8–10 scores (RR: 0.67, 95% CI: 0.51–0.88; p = 0.004) than those from families with a lower income. Children who sought dental care due to pain or factors other than prevention (RR: 1.41; 95% CI: 1.18–1.68), those with orofacial dysfunction (RR: 1.62; 95% CI: 1.30–2.02) and those with a history of traumatic dental injury (RR: 1.39; 95% CI: 1.15–1.69) also experienced a greater impact on OHRQoL.Conclusions: Schoolchildren with orofacial dysfunction experience a greater negative impact on OHRQoL.

Association Between Alcohol Outlets and HIV Prevalence in U.S. Counties.

The current study examines associations between on- and off-premise alcohol retail outlets and HIV prevalence in counties across the United States during a 3-year period. Health department and U.S. Census Bureau surveillance data were analyzed from 1,523 counties in 47 states, representing more than 86% of the U.S. population. Multilevel Poisson regression models were used to examine the association between the number of on- and off-premise alcohol outlets in a county and HIV prevalence in the same county, adjusting for the between-year correlation of HIV prevalence within each county. When we adjusted for potential confounders, number of on-premise alcohol outlets within a county was positively associated with HIV prevalence, whereas off-premise alcohol outlets were negatively associated with HIV prevalence. The relations observed in this study are consistent with the niche theory of assortative drinking, which maintains that drinkers who are prone to risk taking may be attracted to alcohol outlets where they can expand their social networks to include similarly high-risk individuals who engage in both heavy drinking and sexual risk taking. This is the largest study conducted to date to examine the association between alcohol retail outlet types and HIV prevalence. Natural experiments are needed to examine specific policy changes that reduce outlet density and its association with HIV incidence.

Identifying Strategies to Limit Youth Drinking in the Home.

The present study aims to better understand the situational, contextual, and social event-level characteristics that contribute to youth drinking behavior in the home. We used survey data from 1,217 adolescents (15-18 years, 47.7% female) living in 24 midsized, noncontiguous California cities. The study focused on those who reported at least one drink during their last drinking occasion at home or a friend's home (n = 336). We obtained data about total drinks at last event as well as contextual and situational characteristics at last event, including adult presence, number of people present, participant's home or friend's home, ease of alcohol access, and gender ratio. We also gathered information on individual-level characteristics such as past-year drinking behavior, perceived drinking norms, age, ethnicity, and gender. Multilevel Poisson regression models were used to analyze the data. Among the full sample, the number of people at the event and the perceived ease of access were positively associated with an increase in number of drinks consumed. Among females, having a responsible adult present was associated with consuming fewer drinks. Among males, having more boys at the event was related to consuming fewer drinks, whereas increased perceived access to alcohol was positively associated with consuming more drinks. Parents may be able to manage or manipulate the home drinking environment to reduce heavy drinking and alcohol-related problems. Future research is needed to explore additional contextual factors that may enable or inhibit heavy drinking.

Some further aspects of sampling: Comment on Williams and Bornmann

The numerical-algorithmic procedures of fractional counting and field normalization are often mentioned as indispensable requirements for bibliometric analyses. Against the background of the increasing importance of statistics in bibliometrics, a multilevel Poisson regression model (level 1: publication, level 2: author) shows possible ways to consider fractional counting and field normalization in a statistical model (fractional counting I). However, due to the assumption of duplicate publications in the data set, the approach is not quite optimal. Therefore, a more advanced approach, a multilevel multiple membership model, is proposed that no longer provides for duplicates (fractional counting II). It is assumed that the citation impact can essentially be attributed to time-stable dispositions of researchers as authors who contribute with different fractions to the success of a publication’s citation. The two approaches are applied to bibliometric data for 254 scientists working in social science methodology. A major advantage of fractional counting II is that the results no longer depend on the type of fractional counting (e.g., equal weighting). Differences between authors in rankings are reproduced more clearly than on the basis of percentiles. In addition, the strong importance of field normalization is demonstrated; 60% of the citation variance is explained by field normalization.

Do flexicurity policies protect workers from the adverse health consequences of temporary employment? A cross-national comparative analysis

Flexicurity policies comprise a relatively novel approach to the regulation of work and welfare that aims to combine labour market flexibility with social security. Advocates of this approach argue that, by striking the right balance between flexibility and security, flexicurity policies allow firms to take advantage of loose contractual arrangements in an increasingly competitive economic environment while simultaneously protecting workers from the adverse health and social consequences of flexible forms of employment. In this study, we use multilevel Poisson regression models to test the theoretical claim of the flexicurity approach using data for 23 countries across three waves of the European Social Survey. We construct an institutional typology of labour market regulation and social security to evaluate whether inequalities in self-reported health and limiting longstanding illness between temporary workers and their permanent counterparts are smaller in countries that most closely approximate the ideal type described by advocates of the flexicurity approach. Our results indicate that, while the association between temporary employment and health varies across countries, institutional configurations of labour market regulation and social security do not provide a meaningful explanation for this cross-national variation. Contrary to the expectations of the flexicurity hypothesis, our data do not indicate that employment-related inequalities are smaller in countries that approximate the flexicurity approach. We discuss potential explanations for these findings and conclude that there remains a relative lack of evidence in support of the theoretical claims of the flexicurity approach.

Hazardous drinking in people aged 50 years or older: a cross-sectional picture of Europe, 2011-2013.

To assess gender and age differences in hazardous drinking and to analyse and compare the factors associated with it in men versus women, and in 50 to 64-year-old versus ≥65-year-old people in Europe. Cross-sectional study with data from 65,955 people aged ≥50 years from 18 countries (SHARE project, 2011-2013). The outcome variable, hazardous drinking, was calculated using an adaptation of the AUDIT-C test. Several individual (sociodemographic, life-style and health factors) and contextual variables (country socioeconomic indicators and alcohol policies) were analysed. The prevalence of hazardous drinking was estimated by each exposure variable. To estimate associations, multilevel Poisson regression models with robust variance were fit, yielding prevalence ratios and their 95% confidence intervals (95%CI). Overall, the prevalence of hazardous drinking was 21.5% (95%CI = 21.1-22.0), with substantial differences between countries. The proportion of hazardous drinking was higher in men than in women [26.3%(95%CI = 25.6-27.1); 17.5%(95%CI = 17.0-18.0), respectively], as well as in middle-aged people than in older people [23.6%(95%CI = 23.0-24.3); 19.2%(95%CI = 18.6-19.8), respectively]. At the individual level, associations were found for migrant background, marital status, educational level, tobacco smoking, depression and self-perceived health. At the contextual level, hazardous drinking was associated with gender inequalities in society (only in women) and alcohol advertising regulations (both genders). One in five people aged ≥50 years in the countries studied is a hazardous drinker, with large differences by countries, gender and age group. Interventions and policies aimed at preventing or reducing alcohol use in this population should account for country, gender and age differences, as well as individual characteristics. Copyright © 2016 John Wiley & Sons, Ltd.

Socioeconomic Gradient in Childhood Obesity and Hypertension: A Multilevel Population-Based Study in a Chinese Community.

BackgroundThis study aims to assess evidence for any socioeconomic gradients in childhood obesity and hypertension in a population-representative sample in Hong Kong, China.MethodsThe data of a stratified random sampled growth survey collected in 2005–2006 was matched with a population by-census. Obesity was defined using the International Obesity Task Force standard and hypertension was defined using the Hong Kong norm table. Family socioeconomic status (SES) was measured by maternal education level. Neighbourhood SES was measured by median household income of the neighbourhood. Multilevel Poisson regression models with robust standard error were used to test the association. Body mass indices of children’s parents were included as potential confounders. Intra-school/neighbourhood correlations were adjusted using random factors.ResultsTotally 14842 children (age 6–19 years) included in the analysis, in which 16.6% of them were overweight or obese. Children whose mother only completed secondary school or below had higher risk of childhood obesity (RR 1.41, 95% CI 1.13–1.76, p = 0.003) and hypertension (RR 1.18, 95% CI 1.01–1.36, p = 0.03). Meanwhile, children in the lowest neighbourhood SES group had higher risk of childhood underweight (RR 1.61, 95% CI 1.04–2.49, p = 0.03), overweight (RR 1.35, 95% CI 1.05–1.72, p = 0.02), and obesity (RR 2.07, 95% CI 1.11–3.88, p = 0.02).ConclusionsSocioeconomic gradient in childhood obesity and hypertension existed in Hong Kong, one of the most developed cities in China. These results have implications for policymakers and public health experts and highlight the need to monitor trends in other parts of China.

Frequency and Determinants of a Short-Interval Follow-up Recommendation After an Abnormal Screening Mammogram

PurposeAfter imaging assessment of an abnormal screening mammogram, a follow-up examination 6 months later is recommended to some women. Our aim was to identify which characteristics of lesions, women, and physicians are associated to such short-interval follow-up recommendation in the Quebec Breast Cancer Screening Program. MethodsBetween 1998 and 2008, 1,839,396 screening mammograms were performed and a total of 114,781 abnormal screens were assessed by imaging only. Multivariate analysis was done with multilevel Poisson regression models with robust variance and generalized linear mixed models. ResultsA short-interval follow-up was recommended in 26.7% of assessments with imaging only, representing 2.3% of all screens. Case-mix adjusted proportion of short-interval follow-up recommendations varied substantially across physicians (range: 4%-64%). Radiologists with high recall rates (≥15%) had a high proportion of short-interval follow-up recommendation (risk ratio: 1.82; 95% confidence interval: 1.35-2.45) compared to radiologists with low recall rates (<5%). The adjusted proportion of short-interval follow-up was high (22.8%) even when a previous mammogram was usually available. ConclusionsShort-interval follow-up recommendation at assessment is frequent in this Canadian screening program, even when a previous mammogram is available. Characteristics related to radiologists appear to be key determinants of short-interval follow-up recommendation, rather than characteristics of lesions or patient mix. Given that it can cause anxiety to women and adds pressure on the health system, it appears important to record and report short-interval follow-up and to identify ways to reduce its frequency. Short-interval follow-up recommendations should be considered when assessing the burden of mammography screening.

Do the ball-ended probe cause less damage than sharp explorers?-An ultrastructural analysis.

BackgroundNo evidence about damage caused by ball-ended probes on tooth is available. No study compared probing defects caused by ball-ended probes with sharp explorers during tactile examinations of primary teeth. This exploratory study aimed to compare ultrastructural defects caused by ball-ended probes with sharp explorers during tactile examinations of primary teeth.MethodsForty-nine primary extracted teeth were tactile examined as performed for caries activity assessment. Surfaces were randomly divided into groups based on probe type (ball-ended probe or sharp explorer). Two examiners probed different surfaces using the sharp explorer and the ball-ended probe. The order for examination was randomly determined. Images were captured using environmental scanning electron microscopy (ESEM) before and after probing. Two external examiners evaluated independently the ESEM images and scored them as: 0) no damage, 1) slight marks, 2) distinct marks, 3) marks with discontinuity, 4) enamel break-offs. Multilevel Poisson regression models were used to analyze associations between probing ultrastructural damage and surface type, baseline condition and probe type. Prevalence ratios (PR) were calculated with 95 % confidence interval (CI).ResultsThe most common defects observed on the dental surfaces were probing marks without discontinuity (scores 1 and 2). Ball-ended probes caused significantly less severe damage than sharp explorers (PR: 0.28; CI: 0.11–0.76, p = 0.01).ConclusionBall-ended probes cause less damage than sharp explorers when probing gently dental surfaces of primary teeth.

Adherence to diabetes care processes at general practices in the National Capital Region-Delhi, India.

Aim:To assess the level of adherence to diabetes care processes, and associated clinic and patient factors at general practices in Delhi, India.Methods:We interviewed physicians (n = 23) and patients with diabetes (n = 406), and reviewed patient charts at general practices (government = 5; private = 18). We examined diabetes care processes, specifically measurement of weight, blood pressure (BP), glycated hemoglobin (HbA1c), lipids, electrocardiogram, dilated eye, and a foot examination in the last one year. We analyzed clinic and patient factors associated with a number of care processes achieved using multilevel Poisson regression model.Results:The average number of clinic visits per patient was 8.8/year (standard deviation = 5.7), and physicians had access to patient's previous records in only 19.7% of patients. Dilated eye exam, foot exam, and electrocardiogram were completed in 7.4%, 15.1%, and 29.1% of patients, respectively. An estimated 51.7%, 88.4%, and 28.1% had ≥1 measurement of HbA1c, BP, and lipids, respectively. Private clinics, physician access to patient's previous records, use of nonphysicians, patient education, and the presence of diabetes complication were positively associated with a number of care processes in the multivariable model.Conclusion:Adherence to diabetes care processes was suboptimal. Encouraging implementation of quality improvement strategies like Chronic Care Model elements at general practices may improve diabetes care.

A novel method for identifying settings for well-motivated ecologic studies of cancer.

A low within-country variability and a large between-country variability in cancer incidence may indicate that ecologic factors are involved in the etiology of the disease. The aim of this study is to explore the within- and between-country variability of cancer incidence to motivate high-quality ecologic studies. We extracted age-standardized incidence rate estimates (world standard population) from 135 regions for the ten most frequent invasive cancers in Europe for non-Hispanic white populations from Cancer Incidence in Five Continents, Volume X. We fitted weighted multilevel Poisson regression models with random country effects for each cancer and sex. We estimated intraclass correlation coefficients (ICCs) and 95% confidence intervals (95% CIs). A high ICC indicates a low within- and a high between-country variability of rates. The two cancer sites with the highest ICC among men were prostate cancer (0.96, 95% CI: 0.92-0.99) and skin melanoma (0.78, 0.64-0.93). Among women, high ICCs were observed for lung cancer (0.84, 0.73-0.95) and breast cancer (0.80, 0.69-0.91). The two most prominent sex differences for ICC occurred for cancers of the head and neck (men: 0.70, 0.55-0.85, women: 0.19, 0.08-0.30) and breast cancer (men: 0.04, 0.01-0.07, women: 0.80, 0.69-0.91). ICCs were relatively low for pancreatic cancer (men: 0.23, 0.10-0.35; women: 0.13, 0.04-0.21) and leukemia (men: 0.12, 0.04-0.21; women: 0.08, 0.02-0.14). For cancers with high ICC for which systematic factors of the health care system, screening and diagnostic activities are not plausible explanations for between-country variations in incidence, cross-country sex-specific ecologic studies may be especially promising.

Racial Differences in Oral Health-Related Quality of Life: A Multilevel Analysis in Brazilian Children.

This cross-sectional study aimed to assess the influence of race/ethnicity on Brazilian children' oral health-related quality of life (OHRQoL). A multistage random sampling selected a representative sample of 1,134 twelve-years-old children from public schools of Santa Maria, a city in Southern Brazil. Participants were examined by 4 calibrated clinicians (minimum Kappa-value for inter-examiner agreement of 0.8) and the Brazilian short version of the Child Perceptions Questionnaire (CPQ11-14) was administered. The children's parents or guardians answered questions regarding their demographics and socioeconomic status. Associations were analyzed using multilevel Poisson regression models. Children from racial/ethnic minority groups had poorer OHRQoL. The mean CPQ11-14 score was 1.08 times higher for non-white children than their white counterparts' score. "Social" and "Emotional well-being" were the most affected domains for non-white children, with significantly higher mean scores as compared to white children (RR 1.19, 95% CI, 1.07-1.33; and RR 1.14; 95% CI 1.04-1.24). This association remained significant even after adjusting for individual and contextual covariates. OHRQoL disparities are prevalent among children from racial/ethnic minority groups. Non-white children have lower OHRQoL compared to white children.

Effect of a policy to reduce user fees on the rate of skilled birth attendance across socioeconomic strata in Burkina Faso.

Background. In Sub-Saharan Africa, maternal and neonatal morbidity and mortality rates are associated with underutilization of skilled birth attendance (SBA). In 2007, Burkina Faso introduced a subsidy scheme for SBA fees. The objective of this study was to evaluate the effect of Burkina Faso’s subsidy policy on SBA rate across socioeconomic status (SES) strata.Methods. We used a quasi-experimental design. The data sources were two representative surveys (n = 1408 and n = 1403) of women from Houndé and Ziniaré health districts of Burkina Faso, and a survey of health centres assessing structural quality of care. Multilevel Poisson regression models were used with robust variance estimators. We estimated adjusted rate ratios (RR) and rate differences (RD) as a function of time and SES.Results. For lowest-SES women, immediately upon the introduction of the subsidy policy, the rate of SBA was 45% higher (RR = 1.45, 95% confidence interval (CI): 1.19–1.77) than expected in the absence of subsidy introduction. The results indicated a sustained effect after introduction of the subsidy policy, based on RR estimate (95% CI) of 1.48 (1.21–1.81) at 2 years. For middle-SES women, the RR estimates were 1.28 (1.09–1.49) immediately after introduction of the subsidy policy and 1.30 (1.11–1.51) at 2 years, respectively. For highest-SES women, the RR estimates were 1.19 (1.02–1.38) immediately after subsidy introduction and 1.21 (1.06–1.38) at 2 years, respectively. The RD (95% CI) was 14% (3–24%) for lowest-SES women immediately after introduction of the policy, and the effect was sustained at 14% (4–25%) at 2 years.Conclusion. Our study suggests that the introduction of a user-fee subsidy in Burkina Faso resulted in increased rates of SBA across all SES strata. The increase was sustained over time and strongest among the poorest women. These findings have important implications for evidence-informed policymaking in Burkina Faso and other countries in Sub-Saharan Africa.