Clarifying the debate on population-based screening for breast cancer with mammography: A systematic review of randomized controlled trials on mammography with Bayesian meta-analysis and causal model.

BACKGROUND: The recent controversy about using mammography to screen for breast cancer based on randomized controlled trials over 3 decades in Western countries has not only eclipsed the paradigm of evidence-based medicine, but also puts health decision-makers in countries where breast cancer screening is still being considered in a dilemma to adopt or abandon such a well-established screening modality. METHODS: We reanalyzed the empirical data from the Health Insurance Plan trial in 1963 to the UK age trial in 1991 and their follow-up data published until 2015. We first performed Bayesian conjugated meta-analyses on the heterogeneity of attendance rate, sensitivity, and over-detection and their impacts on advanced stage breast cancer and death from breast cancer across trials using Bayesian Poisson fixed- and random-effect regression model. Bayesian meta-analysis of causal model was then developed to assess a cascade of causal relationships regarding the impact of both attendance and sensitivity on 2 main outcomes. RESULTS: The causes of heterogeneity responsible for the disparities across the trials were clearly manifested in 3 components. The attendance rate ranged from 61.3% to 90.4%. The sensitivity estimates show substantial variation from 57.26% to 87.97% but improved with time from 64% in 1963 to 82% in 1980 when Bayesian conjugated meta-analysis was conducted in chronological order. The percentage of over-detection shows a wide range from 0% to 28%, adjusting for long lead-time. The impacts of the attendance rate and sensitivity on the 2 main outcomes were statistically significant. Causal inference made by linking these causal relationships with emphasis on the heterogeneity of the attendance rate and sensitivity accounted for the variation in the reduction of advanced breast cancer (none-30%) and of mortality (none-31%). We estimated a 33% (95% CI: 24-42%) and 13% (95% CI: 6-20%) breast cancer mortality reduction for the best scenario (90% attendance rate and 95% sensitivity) and the poor scenario (30% attendance rate and 55% sensitivity), respectively. CONCLUSION: Elucidating the scenarios from high to low performance and learning from the experiences of these trials helps screening policy-makers contemplate on how to avoid errors made in ineffective studies and emulate the effective studies to save women lives.

Challenges in evaluating PM concentration levels, commuting exposure, and mask efficacy in reducing PM exposure in growing, urban communities in a developing country.

Particulate matter (PM) contributes to an increased risk of respiratory and cardiovascular illnesses, cancer, and preterm birth complications. This project assessed PM exposure in Eastern Indonesia's largest city, where air quality has not been comprehensively monitored. We examined the efficacy of wearing masks as an individual intervention effort to reduce in-transit PM exposures. Handheld particulate counters were used to investigate ambient air quality for spatial analysis, as well as the differences in exposure to PM2.5 and PM10 (µg/m(3)) by different transportation methods [e.g. motorcycle (n=97), pete-pete (n=53), and car (n=55); note: n=1 means 1m(3) of air sample]. Mask efficacy to reduce PM exposure was evaluated [e.g. surgical masks (n=39), bandanas (n=52), and motorcycle masks (n=39)]. A Monte Carlo simulation was used to provide a range of uncertainty in exposure assessment. Overall PM10 levels (91±124 µg/m(3)) were elevated compared to the World Health Organization (WHO)'s 24-hour air quality guideline (50 µg/m(3)). While average PM2.5 levels (9±14 µg/m(3)) were below the WHO's guideline (25 µg/m(3)), measurements up to 139 µg/m(3) were observed. Compared to cars, average motorcycle and pete-pete PM exposures were four and three times higher for PM2.5, and 13 and 10 times higher for PM10, respectively. Only surgical masks were consistent in lowering PM2.5 and PM10 (p<0.01). Young children (≤5) were the most vulnerable age group, and could not reach the safe dosage even when wearing surgical masks. Individual interventions can effectively reduce individual PM exposures; however, policy interventions will be needed to improve the overall air quality and create safer transportation.

Life in a landfill slum, children's health, and the Millennium Development Goals.

People living in slums can be considered left behind with regard to national successes in achieving Millennium Development Goals (MDGs). The objective of this study was to evaluate the living and working conditions of waste pickers and their children in a landfill slum located in the largest city in eastern Indonesia. A total of 113 people from the landfill slum and 1184 people from the general population participated in face-to-face interviews. Municipal solid waste (MSW) was analyzed for metals, metalloids and fecal indicator bacteria. Ambient air quality including particulate matter was measured in the landfill. Households in the landfill slum were 5.73 (p=0.04) times more likely to be below the international poverty line (MDG 1: Poverty) and 15.6 times (p<0.01) more likely to have no one in the household possessing a primary education (MDG 2: Universal Education), and 107 times (p<0.01) more likely not to have improved sanitation facilities (MDG 7: Environmental Sustainability) when compared to the general population. Diarrhea is one of the leading causes of death in children under five in Indonesia. Young children living in the landfill slum were 2.87 times (p=0.02) more likely to develop diarrhea than their general population counterparts. Other survey results and environmental measurements suggest that landfill slum children have additional adverse health effects (e.g. infections and poisoning). Poverty underlies several MDG issues that directly or indirectly affect child health. Therefore, eradicating extreme poverty will continue to be the most critical challenge for the MDGs beyond 2015.

Childhood acute respiratory infections and household environment in an Eastern Indonesian urban setting.

This pilot study evaluated the potential effect of household environmental factors such as income, maternal characteristics, and indoor air pollution on children's respiratory status in an Eastern Indonesian community. Household data were collected from cross-sectional (n = 461 participants) and preliminary childhood case-control surveys (pneumonia cases = 31 diagnosed within three months at a local health clinic; controls = 30). Particulate matter (PM2.5 and PM10) was measured in living rooms, kitchens, children's bedrooms, and outside areas in close proximity once during the case-control household interviews (55 homes) and once per hour from 6 a.m. to midnight in 11 homes. The household survey showed that children were 1.98 times (p = 0.02) more likely to have coughing symptoms indicating respiratory infection, if mothers were not the primary caregivers. More children exhibited coughing if they were not exclusively breastfed (OR = 2.18; p = 0.06) or there was a possibility that their mothers were exposed to environmental tobacco smoke during pregnancy (OR = 2.05; p = 0.08). This study suggests that household incomes and mother's education have an indirect effect on childhood pneumonia and respiratory illness. The concentrations of PM2.5 and PM10 ranged from 0.5 to 35.7 µg/m3 and 7.7 to 575.7 µg/m3, respectively, based on grab samples. PM was significantly different between the case and control groups (p < 0.01). The study also suggests that ambient air may dilute indoor pollution, but also introduces pollution into the home from the community environment. Effective intervention programs need to be developed that consider multiple direct and indirect risk factors to protect children.