Table. 3.

Proportion of 30 subgroup analyses claiming a subgroup effect which met each criterion

Criteria No (criterion not met) Yes (criterion met)
1. Is the subgroup variable a characteristic measured at baseline? 3 (10.0) 27 (90.0)
2. Was the subgroup variable a stratification factor at randomisation? 29 (96.7) 1 (3.3)
3. Was the hypothesis specified a priori? 19 (63.3) 11 (36.7)
4. Was the subgroup analysis one of small number of subgroup hypotheses tested (≤ 5)? 10 (33.3) 20 (66.7)
5. Was the test of interaction significant (interaction P < 0.05)? 0 30 (100)
6. Was the significant interaction effect independent, if there were multiple significant interactions? 16 (53.3) 14 (46.7)
7. Was the direction of subgroup effect correctly pre-specified? 25 (83.3) 5 (16.7)
8. Was the subgroup effect consistent with evidence from previous studies? 20 (66.7) 10 (33.3)
9. Was the subgroup effect consistent across related outcomes? 20 (66.7) 10 (33.3)
10. Was there indirect evidence to support the apparent subgroup effect (biological rationale, laboratory tests, animal studies)? 28 (93.3) 2 (6.7)
Korean J Pain 2021;34:139~155 https://doi.org/10.3344/kjp.2021.34.2.139
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