Study name (quality rating) | Subgroup analysis credibility rating (from phase II) | (A) What is the definition of the subgroup in this study? | (B) What are the results of the subgroup-specific interaction test? | (C) What are the results of subgroup-specific analyses for this subpopulation in this study? | (D) What are the results of other subgroup-relevant analyses for this subpopulation in this study? |
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Study A (enter quality rating) | Enter subgroup analysis credibility rating from phase II | Clearly define the subgroup (or subpopulation) as described in the study (e.g., ages 65 years and older). |
Abstract results of formal tests for interaction, and indicate the presence or absence of statistical significance (i.e., not significant (NS), significant (S), or not reported (NR)) and all available p values. Note: The correct analysis is not to test the significance of the intervention effect in one subgroup or another, but whether the effect differs significantly between subgroups [54, 59]. |
Abstract results of subgroup-specific stratified analyses conducted in the study (e.g., p values and intervention-effect measures of association [odds ratios, relative risks, mean changes] reported by subgroup) [53]. Enter the intervention effect with 95% confidence intervals for the main average and subgroup-specific analyses. Report results of subgroup analyses as absolute and relative risk reductions. Absolute risk reduction estimates give the probability an individual will benefit from an intervention [60]. Note: Estimates can be generated for patients with differing baseline risks that represent types of patients seen in clinical practice by multiplying baseline risk by a pooled homogeneous relative risk estimate [61, 62]. | Abstract numerical results and statistical tests of other types of relevant subgroup analyses (e.g., findings with and without subgroup-adjustment in a logistic regression model, multivariable analyses predicting outcomes including subgroup variables). |
Women’s Health Study Ridker, 2005 [63] (Good) | Moderate |
Age groups: 45–55 years 55–64 years ≥65 years | Interaction test for outcome of total myocardial infarction (MI): p = 0.03 (S) |
Relative risk reduction (95% CI) for total MI: Main average effect: 1.02 (0.84 to 1.25), p = 0.83 45–55 years: 1.23 (0.87 to 1.75), p = 0.25 55–64 years: 1.17 (0.86 to 1.59), p = 0.32 ≥65 years: 0.66 (0.44 to 0.97), p = 0.04 Absolute risk reduction (95% CI) for total MI (calculated): Main average effect: 0.000 (−0.002 to 0.002) 45–55 years: −0.001 (−0.003 to 0.001) 55–64 years: −0.002 (−0.006 to 0.002) ≥65 years: 0.010 (0.001 to 0.020) p = 0.04 | NA |