Table 2.

Adjustments in the analyses.

Time ElementControl GroupsPower CalculationsNegative Results
Article types included
Clinical descriptiveClinical hypothesis-testingClinical hypothesis-testingClinical hypothesis-testing
Clinical hypothesis-testingMainly laboratory studiesControlled drug trialControlled drug trial
Mainly laboratory studiesGenetic associationDrug use, otherDrug use, other
Animal studiesOtherMainly laboratory studiesMainly laboratory studies
OtherGenetic associationGenetic association
Animal studiesAnimal studies
OtherOther
Article types excluded
Pure epidemiologyClinical descriptiveClinical descriptiveClinical descriptive
Epidemiology, otherPure epidemiologyPure epidemiologyPure epidemiology
Controlled drug trialEpidemiology, otherEpidemiology, otherEpidemiology, other
Drug use, otherControlled drug trial
Genetic associationDrug use, other
Animal studies