Subgroup analysis involves assessing an association between an intervention (or other factor) and a subset of the patients that were exposed. Subgroup analysis can be decided upon a priori or performed post hoc
Non-experimental observational study design used to assess the effect of an intervention based on comparison of outcomes prior to its use and afterward
Scientific information is an economic commodity, and that scientific journals are a medium for its dissemination and exchange. As such it is subject to economic factors that affect the value of scientific information and how it is exchanged.
Retrospective studies are designed to analyse pre-existing data, and are subject to numerous biases as a result. Types of retrospective studies include: case series; retrospective cohort studies; case-control studies
Standardised Mortality Ratio SMR is the ratio of the observed or actual hospital mortality and the predicted hospital mortality for a specified time period.
Fisher's Exact Test is to compare categorical data; more complicated to perform than the Chi square test; only generally applicable in 2 x 2 contingency table