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Important Confounding Variables (important + confounding_variable)
Selected AbstractsAgreement between GPRD smoking data: a survey of general practitioners and a population-based survey,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 7 2004James D. Lewis MD, MSCE Abstract Background Cigarette smoking is a common habit that is associated with many diseases. Smoking is often an important confounding variable in pharmacoepidemiological studies. The General Practice Research Database (GPRD) is widely used in pharmacoepidemiological research. In this study, we compare data recorded in the GPRD with the smoking history obtained from direct query of general practitioners (GPs) and from a population-based survey. Methods We completed a mailed survey of GPs caring for a random sample of 150 patients with inflammatory bowel disease. The survey asked the GP to categorize the patients smoking status on a specified date. These results were then compared to the data recorded in the GPRD. Smoking status of 225,308 randomly selected GPRD patients without inflammatory bowel disease was compared to the results of a population-based household survey. Results Completed surveys with usable data were received from GPs on 136 of the 150 patients (91%). The sensitivity and positive predictive value of the database for current smoking were 78% (95%,CI: 52,94) and 70% (95%,CI: 46,88) respectively. The sensitivity and positive predictive value of former smoking were 53% (95%,CI: 28,77) and 60% (95%,CI: 32,84) respectively. Current and former smoking rates in the GPRD were 79% and 29% respectively of expected rates according to the population-based survey . Conclusions Current smoking is more completely recorded in the GPRD than former smoking. These data need to be considered when planning GPRD studies where smoking is an important exposure variable. Copyright © 2003 John Wiley & Sons, Ltd. [source] A systematic review of nursing contributions to mobility rehabilitation: examining the quality and content of the evidenceJOURNAL OF CLINICAL NURSING, Issue 11c 2007Rosie Kneafsey BSc Aims., This paper summarizes the results of a systematic literature review to examine the quality and content of the evidence relating to nursing approaches to improving the mobility and movement of older people. Background., Older people experiencing health breakdown often develop problems with movement and mobility and nurses play a role in helping patients to either adapt to or overcome these difficulties. Methods., Electronic searches were undertaken of Medline, CINAHL, Amed and Cochrane Database of systematic reviews. Papers about nursing approaches to promoting mobility and movement were critically appraised using quality assessment checklists. Papers addressing safe moving and handling, falls prevention, health promotion, rehabilitation or teamworking in general were excluded. Results., Sixteen research and 33 informational papers were included and comprise the review. Many research papers used weak designs and small sample sizes, limiting their ability to control for important confounding variables. Although numerous studies examined effectiveness, only one used a randomised controlled trial design. Papers were grouped into four interlinked sets. These were promoting mobility and preventing immobility; walking and exercise; neuro-developmental principles; and rehabilitation patient handling. Conclusions., Specific foci for nursing assessment and interventions to promote patients' mobility have been identified. However, the fragmented nature of the evidence makes it difficult to make recommendations for nursing practice. Future research should be conducted by multi-professional research teams to identify the most effective approaches to promoting patients' mobility and to explore overlaps between different members of the rehabilitation team. Relevance to clinical practice., Regaining the ability to move and walk is often a key concern for patients who have suffered health breakdown. Although nurses provide patients with assistance the evidence available does little to direct nurses as to the best approach towards mobility rehabilitation. It is important that nurses play a role in measuring the efficacy of different interventions to promote rehabilitation. [source] The efficacy of the non-stress test in preventing fetal death in post-term pregnancyPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2001Tong Li Summary We conducted a case,control study to examine the efficacy of non-stress testing in preventing fetal death in post-term pregnancy. The analysis was based on data from the 1988 National Maternal and Infant Health Survey, which was a nationally representative sample of live births, fetal deaths and infant deaths that occurred in 1988. Information on whether a woman had non-stress testing was obtained from a questionnaire sent to prenatal care providers and hospitals. Cases were post-term women (with 42 weeks or more gestation) who had fetal deaths. Three post-term controls, who had live births and who delivered at the same time or later than the cases, were randomly chosen and individually matched to each case by maternal race. The proportion of women who had one or more non-stress tests during pregnancy was compared between cases and controls. Non-stress testing was used in 30.9% of the 126 cases and in 28.5% of the 375 controls. The race-adjusted odds ratio for exposure to non-stress test was 1.12 [95% CI 0.72, 1.75]. After controlling for other important confounding variables the odds ratio was 1.05 [95% CI 0.57, 1.91]. These results do not support the efficacy of non-stress testing in post-term pregnancies. A more detailed evaluation of this widely used screening procedure is needed. [source] Identification of occupational cancer risk in British Columbia: A population-based case,control study of 2,998 lung cancers by histopathological subtypeAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2009Amy C. MacArthur MHSc Abstract Background Few studies have investigated occupational lung cancer risk in relation to specific histopathological subtypes. Methods A case,control study was conducted to evaluate the relationship between lung cancer and occupation/industry of employment by histopathological subtype. A total of 2,998 male cases and 10,223 cancer controls, diagnosed between 1983 and 1990, were identified through the British Columbia Cancer Registry. Matched on age and year of diagnosis, conditional logistic regression analyses were performed for two different estimates of exposure with adjustment for potentially important confounding variables, including tobacco smoking, alcohol consumption, marital status, educational attainment, and questionnaire respondent. Results For all lung cancers, an excess risk was observed for workers in the primary metal (OR,=,1.31, 95% CI, 1.01,1.71), mining (OR,=,1.53, 95% CI, 1.20,1.96), machining (OR,=,1.33, 95% CI, 1.09,1.63), transport (OR,=,1.50, 95% CI, 1.08,2.07), utility (OR,=,1.60, 95% CI, 1.22,2.09), and protective services (OR,=,1.27, 95% CI, 1.05,1.55) industries. Associations with histopathological subtypes included an increased risk of squamous cell carcinoma in construction trades (OR,=,1.25, 95% CI, 1.06,1.48), adenocarcinoma for professional workers in medicine and health (OR,=,1.73, 95% CI, 1.18,2.53), small cell carcinoma in railway (OR,=,1.62, 95% CI, 1.06,2.49), and truck transport industries (OR,=,1.51, 95% CI, 1.00,2.28), and large cell carcinoma for employment in the primary metal industry (OR,=,2.35, 95% CI, 1.11,4.96). Conclusions Our results point to excess lung cancer risk for occupations involving exposure to metals, polyaromatic hydrocarbons and asbestos, as well as several new histopathologic-specific associations that merit further investigation. Am. J. Ind. Med. 52:221,232, 2009. © 2008 Wiley-Liss, Inc. [source] | ||||||||||