Abstract: Despite the theoretical success of obviating the need for hypothesis-generating studies, they live on in epidemiological practice. Adopting a Bayesian approach, we put this elegant logic into quantitative terms at the study planning stage for studies where the prior belief in the null hypothesis is high i. We consider not only type I and II errors as is customary but also the probabilities of false positive and negative results, taking into account typical imperfections in the data. We concentrate on a common source of imperfection in the data: non-differential misclassification of binary exposure classifier. In context of an unmatched case-control study, we demonstrate—both theoretically and via simulations—that although non-differential exposure misclassification is expected to attenuate real effect estimates, leading to the loss of ability to detect true effects, there is also a concurrent increase in false positives.
Examples of Hypothesis
Hypothesis Generation | Optimizely Blog
The etiology of brain cancer is poorly understood. The only confirmed environmental risk factor is exposure to ionizing radiation. Because nuclear reactors emit ionizing radiation, we examined brain cancer incidence rates in the USA in relation to the presence of nuclear reactors per state. Data on brain cancer incidence rates per state for Whites by sex for three age groups all ages, 50 and older, and under 50 were obtained from cancer registries.
Seminar 7: Using Case Studies for Hypothesis Testing
Niebuhr and Amy M. Background: Herpes family viruses can cause central ner-vous system inflammatory changes that can present with symptoms indistinguishable from schizophrenia and there-fore are of interest in schizophrenia research. Most existing studies of herpes viruses have used small populations and postdiagnosis specimens.
Jump to navigation. Background: More than 5 years ago, publications of two randomized placebo-controlled trials respectively assessing lovastatin a statin and gemfibrozil a fibrate for cardiovascular disease prevention, reported significantly lower incidence of melanoma, the deadliest form of skin cancer, in participants receiving these lipid-lowering drugs. Due to increased liver cancer in rodents fed statins and fibrates, trials in humans have commonly monitored cancer incidence. A systematic review of all similar trials prior to showed no association of statin or fibrate exposure with lower melanoma incidence Cochrane Database Syst Rev.