No abstract

OBJECTIVES. Individual epidemiological investigations into the association between chlorination by-products in drinking water and cancer have been suggestive but inconclusive. Enough studies exist to provide the basis for a meaningful meta-analysis. METHODS. An extensive literature search was performed to identify pertinent case-control studies and cohort studies. Consumption of chlorinated water, surface water, or water with high levels of chloroform was used as a surrogate for exposure to chlorination by-products. Relative risk estimates were abstracted from the individual studies and pooled. RESULTS. A simple meta-analysis of all cancer sites yielded a relative risk estimate for exposure to chlorination by-products of 1.15 (95% CI: 1.09, 1.20). Pooled relative risk estimates for organ-specific neoplasms were 1.21 (95% CI: 1.09, 1.34) for bladder cancer and 1.38 (95% CI: 1.01, 1.87) for rectal cancer. When studies that adjusted for potential confounders were pooled separately, estimates of relative risks did not change substantially. CONCLUSIONS. The results of this meta-analysis suggest a positive association between consumption of chlorination by-products in drinking water and bladder and rectal cancer in humans.

Community factors, as measured by county characteristics, explain a substantial amount of variation in hospital readmission rates.

Payers, accreditors, and consumers are using quality improvement (QI) methods, but little is known about whether physicians do so. The results from this 2003 national physician survey indicate that most do not. Physicians do not routinely use data for assessing their performance and are reluctant to share those data. They infrequently participate in redesign activities. Physicians in larger and salaried groups are more likely to be engaged in QI. The science of QI has been "institutionalized" but not yet "professionalized."Accelerating physicians' adoption of and participation in QI requires building the infrastructure to support quality and paying attention to professionalism, knowledge, and skills.