Journal of epidemiology and biostatistics最新文献

Background: The prevalence of HIV in prisons is often higher than in the surrounding community, because prisons contain a high proportion of injecting drug users (IDUs). Reliable estimation of HIV prevalence in UK prisons only began in the 1990s. Edinburgh, Scotland, experienced a major IDU-related HIV epidemic which began in 1983. We sought retrospectively to estimate HIV prevalence in Edinburgh Prison over the period 1983-94.

Methods: Prison records of all 477 male HIV-positive patients (332 IDUs) in the Edinburgh City Hospital Cohort (believed to include three-quarters of HIV-positive Edinburgh IDUs) were abstracted from Edinburgh Prison. Using this information and the seroconversion intervals of the patients, the number of person-years spent inside the prison by these individuals while HIV-positive was estimated for each calendar month. From this, HIV prevalence was inferred.

Results: HIV prevalence in the prison rose from January 1983, as prevalence among Edinburgh IDUs increased, reaching a peak of 8% in December 1984. Prevalence during 1985-86 was 5-6% and then gradually declined, as the surviving HIV-infected IDUs spent less time in the prison.

Discussion: These figures are probably underestimates, as some HIV-positive prisoners are not in the cohort. However, the degree of underestimation should not be great and trends over time are reliable. Our estimate for August 1991, 4.1%, compares favourably with the estimate 4.5%, from an anonymous unlinked survey conducted in the prison that month. Prevalence estimates from other UK prisons are reviewed and suggestions made for other uses of database linkage in HIV and IDU epidemiology.

Background: Estimates of maternal age-specific prevalence of Down's syndrome are needed for the assessment of environmental factors, for counselling and monitoring screening programmes. The estimates should relate to populations of women who have not received prenatal screening. This is normally achieved by using data collected before the widespread use of screening. The problem of under-ascertainment in some data-sets has been recognised in the literature, but has not been dealt with satisfactorily in the statistical models used to estimate live-birth prevalence.

Methods: In this paper we develop a model that takes explicit account of under-ascertainment and apply this model to data from nine published studies. The primary aim of our analysis is to provide an improved model for live-birth prevalence. A secondary aim is to examine the ascertainment rates in the nine studies.

Results: The proposed model provides a good fit to all but one of the nine studies, although exclusion of this study does not affect the estimated risks. The estimate of risk weighted across the maternal age distribution is 1.41 in 1000 live-births [90% confidence interval (CI) 1.37-1.49].

Discussion: Comparing this figure with those obtained from published rate schedules suggests that the proposed model predicts rates that are some 10% higher than those obtained when ascertainment is assumed to be complete in all studies. The predicted rates are similar to those calculated when only those studies known to have high levels of acertainment are included.

Background: A federal law effective in 1995 makes it mandatory for all German States to build up population-based cancer registries. Although the law provides a model of cancer registration, each State may modify this by State-specific regulations, as long as they ensure data exchange between the registries and between registries and scientific institutions. The 'Network of German Population-Based Cancer Registries' constitutes the basis for cooperation among the German cancer registries. In order to improve the cooperation between physicians and epidemiologists, and to demonstrate the benefits of cancer registration, the network published a booklet containing facts on time-trends in cancer incidence during the last two decades.

Methods: Information on cancer incidence and mortality was derived from the population-based cancer registries of Saarland, the former German Democratic Republic (until 1989), the City of Hamburg and the region of Münster. Altogether these registries cover a population of about 23 million. Sixteen types of cancer were selected for the analyses.

Results: Major increases in cancer incidence were observed for female lung cancer, testicular cancer, cancer of the oral cavity, malignant melanoma of the skin and non-Hodgkin's lymphoma. Incidence rates also increased for cancer of the female breast, prostate cancer and colorectal cancer. A decrease was observed for stomach and cervical cancer.

Discussion: In 1998, only a small fraction of all German adults were monitored by a population-based cancer registry, making it impossible to work out accurate incidence rates for the whole of Germany. Several new cancer registries have been built up recently. Data summaries of existing German population-based cancer registries assist in enhancing the completeness of new cancer registries.

Background: Independent analyses of data from a case-control study conducted by the American College of Gastroenterology (ACG) were performed to evaluate and quantify potential risks of gastrointestinal (GI) bleeding associated with use of analgesics at over the counter (OTC) doses.

Methods: Information on recent (within the past week) use of multiple analgesics, plus data on tobacco, alcohol and other factors, were obtained from 627 patients enrolled in the ACG GI bleeding registry and from 590 procedure-matched controls. Odds ratios (OR) were calculated as the measure of association between GI bleeding and the exposures of interest.

Results: Risk of GI bleeding was increased 2-3 fold among recent users of aspirin, ibuprofen and other nonsteroidal anti-inflammatory drugs (NSAIDs) at OTC doses, with risk increasing in a dose-related manner. In contrast, no excess was found among acetaminophen (paracetamol) users. Alcohol consumption was also a risk factor, with doubled risks of GI bleeding among drinkers.

Discussion: While these study results are not definitive, the findings are consistent with limited other data also reviewed, and suggest the need for further epidemiologic research to clarify the association between use of NSAIDs at OTC levels and risk of GI bleeding, and to determine whether NSAIDs and alcohol may interactively combine to enhance risk.