A case-control design involving only cases may be used when brief exposure causes a
transient change in risk of a rare acute-onset disease. The design resembles a retrospective …

As more studies of the reproducibility and validity of epidemiologic tools are reported in the
American Journal of Epidemiology, the Kappa statistic (*) conceived by Cohen (1) is …

Background Many anecdotes and several uncontrolled case series have suggested that
emotionally stressful events, and more specifically, anger, immediately precede and appear to …

▪ Abstract The first decade of experience with case-crossover studies has shown that the
design applies best if the exposure is intermittent, the effect on risk is immediate and transient, …

Objective. —To determine the relative risks of nonfatal myocardial infarction (MI) triggered
by sexual activity among the general population and in patients with prior coronary heart …

Background: The annual cut-off date of birth for entry to school in British Columbia, Canada,
is Dec. 31. Thus, children born in December are typically the youngest in their grade. We …

Objective To compare the results of a randomised and an observational evaluation of the
same policy that restricted reimbursement for nebulised respiratory medications in adult …

Purpose To assess case‐only designs for surveillance with administrative databases.
Methods We reviewed literature on two designs that are observational analogs to crossover …

Background Despite anecdotal evidence suggesting that heavy physical exertion can trigger
the onset of acute myocardial infarction, there have been no controlled studies of the risk of …

Background—Marijuana use in the age group prone to coronary artery disease is higher
than it was in the past. Smoking marijuana is known to have hemodynamic consequences, …