K J Rothman

..To describe a bias that can occur in the analysis of data from certain randomized trials...

..A depressed Apgar score at 5 minutes is a marker for perinatal insults, including neurologic damage. We examined the association between 5-minute Apgar score and the risk of epilepsy hospitalization in childhood...

..We aimed to examine the association of five-minute Apgar score with prevalence of neurologic disability and with cognitive function in early adulthood...

..Case descriptions suggest IBS patients are more likely to have other disorders, including migraine, fibromyalgia, and depression. We sought to examine the prevalence of these conditions in cohorts of people with and without IBS...

..Causal inference in epidemiology is better viewed as an exercise in measurement of an effect rather than as a criterion-guided process for deciding whether an effect is present or not...

..In this paper, we review the problem with the PRR and show how the corresponding odds ratio represents an improvement over the PRR...

..If the exclusions from the denominator would be negligibly small or the relative number of excluded cases with 'known' causes is small, then the exclusion of just the cases with 'known' causes will introduce little bias...

..The goal of restricting study populations is to make patients more homogeneous regarding potential confounding factors and treatment effects and thereby achieve less biased effect estimates...

..Recent studies have shown that both female and male obesity may delay time-to-pregnancy (TTP). Little is known about central adiposity or weight gain and fecundability in women...

..The successful conduct of this pilot study suggests that the internet may be a useful tool to recruit and follow subjects in prospective cohort studies...

..These results support the theory that some women who develop gestational diabetes may have underlying biochemical changes that induce nondisjunction and the development of chromosomal defects...

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..The objective of this study was to examine the relation of factors that are present at birth to subsequent hospitalization for childhood pneumococcal disease...

..Lower concentrations of albumin have been positively related to coronary disease. The aim of this project was to assess the association between serum albumin and carotid atherosclerosis...

..Investigation of the relation between relative dose of supplemental folic acid or total folate intake and NTD risk is limited...

..Postterm delivery is a risk factor for perinatal complications, some of which increase risk for neurologic morbidity. We aimed to examine the association between postterm delivery and risk for epilepsy in childhood...

..In the presence of effect-measure modification, different analytic approaches produce different summary estimates...

..26, 1.68). In this setting, analytic strategies using EPS or disease risk scores were not generally superior to "conventional" models. Various ways to use EPS and disease risk scores behaved differently with smaller study size...

..6, 5.3) in multiparous women. Epidural anesthesia increases the risk for operative vaginal deliveries in both nulliparous and multiparous women, and increases risk for cesarean deliveries in nulliparous more so than in multiparous women...

..The overall 30-day case fatality rate was 38% and showed less seasonal variation. We found evidence of weak seasonal variation in hospitalization for SAH and almost no seasonal variation in a 30-day case fatality rate after SAH...

..In 2003, the National Kidney Foundation introduced guidelines for the control of parathyroid hormone, calcium, and phosphorus in hemodialysis patients...

..Nonexperimental studies of drug effects in large automated databases can provide timely assessment of real-life drug use, but are prone to confounding by variables that are not contained in these databases and thus cannot be controlled...

..Increasing validity based on PS trimming may be a unique advantage of PS's over conventional outcome models...

..0; 95% CI, 0.9-1.1.) Misclassification of IBS would have biased the rate ratio toward the null. We observed a small increase in IBS among people with asthma, and no association between oral steroids and IBS onset among asthma patients...

..Understanding predictors of transfer may assist practitioners, patients, and policy makers in considering the appropriateness of individuals for birth center delivery or to target further education to reduce nonmedical transfers...

..These results also call for population studies that can more directly measure individual fumonisin intakes and assess effects on the developing embryo...

..We believe that the prevalence and incidence information that we report is a useful description of population rates in the United States for these conditions...

..Cohort studies with less than 10 years of follow-up gave estimates 11% higher than cohort studies with longer follow-up periods. No meaningful difference was seen by menopausal status or type of beverage consumed...

..We suggest that the FDA's arguments defending their practice are insufficient to justify medical research that violates the Declaration of Helsinki...

..There is substantial concern regarding the potential cardiovascular adverse effects of selective coxibs and nonselective NSAIDs, but many patients with arthritis experience important clinical benefits from these agents...

..Such analyses have been proposed to address confounding by indication, but there is little empirical evidence that they achieve better control than conventional multivariate outcome modeling...

..When surrogacy holds, PSC is a useful approach to adjust for unmeasured confounding using validation data...

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..Observational studies cannot replace trials, nor do trials make observational studies unnecessary. Both designs are susceptible to particular bias, so neither provides perfect information...

..Cardiovascular events such as acute myocardial infarction and stroke vary seasonally, with a peak incidence during the winter and a trough during the summer. Few data exist on the seasonal variation of atrial fibrillation...

..Preliminary findings from a randomized trial indicate that patients who received TSI had about half the mortality rate of those assigned to placebo...

..3), respectively. We found that increasing age was associated with increased mortality from bacteraemia in patients with haematological malignancies. An increased burden of comorbidity among the elderly did not explain this association...

..These simulation studies and other analytical results suggest that standard model-building tools designed to create good predictive models of the exposure will not always lead to optimal PS models, particularly in small studies...

..We investigated whether the risk difference for invasive breast cancer attributable to estrogen plus progesterone replacement therapy is greater among women with a first-degree family history of the disease...

..From this fitted curve, estimates of the seasonal intensity of occurrence (i.e., peak-to-low ratio of the fitted curve) can be generated...

..The purpose of this study is to quantify the effect of misclassification of OTC use in research that uses prescription claims data as the sole source of exposure information...

..Two recent publications reported that greater epoetin alfa (EPO) doses were associated with increased mortality rates. We assessed whether confounding-by-indication might account for these results...