Table III.
Between-trial heterogeneity τ2among different types of meta-analysis, according to intervention comparisons and outcomes, based on 14 886 binary outcome meta-analyses in the Cochrane Database of Systematic Reviews; the ratios correspond to exp(βl) and exp(γp) in model (2).*
| Between-meta-analysis | |||
|---|---|---|---|
| Outcome types | τ2(95% CI)† | Ratio of τ2(95% CI) | SD ψfor log(τ2) |
| Objective outcomes | 0.51 (0.20 to 0.92) | ||
| All-cause mortality | 0.02 (0.01 to 0.02) | 1 (reference) | |
| Semi-objective outcomes | 1.23 (1.08 to 1.38) | ||
| Obstetric outcomes | 0.03 (0.02 to 0.04) | 1.53 (1.09 to 2.17) | |
| Cause-specific mortality/major morbidity | 0.02 (0.02 to 0.03) | 1.26 (0.85 to 1.87) | |
| event/composite (mortality or morbidity) | |||
| Resource use/hospital stay/process | 0.10 (0.07 to 0.13) | 4.95 (3.57 to 7.24) | |
| Surgical/device-related success/failure | 0.12 (0.08 to 0.16) | 6.10 (4.02 to 9.03) | |
| Withdrawals/drop-outs | 0.05 (0.04 to 0.07) | 2.58 (1.75 to 3.97) | |
| Internal/external structure-related outcomes | 0.07 (0.06 to 0.10) | 3.46 (2.27 to 5.18) | |
| Subjective outcomes | 0.90 (0.82 to 0.98) | ||
| General physical health indicators | 0.10 (0.07 to 0.15) | 5.22 (3.28 to 8.57) | |
| Adverse events | 0.15 (0.13 to 0.18) | 7.89 (6.03 to 10.6) | |
| Infection/onset of new acute/chronic disease | 0.08 (0.07 to 0.10) | 4.24 (3.27 to 5.71) | |
| Signs/symptoms reflecting | 0.13 (0.11 to 0.15) | 6.57 (5.04 to 9.08) | |
| continuation/end of condition | |||
| Pain | 0.16 (0.12 to 0.21) | 8.24 (5.89 to 12.1) | |
| Quality of life/functioning (dichotomised) | 0.08 (0.05 to 0.13) | 4.08 (2.27 to 7.11) | |
| Mental health indicators | 0.12 (0.07 to 0.19) | 6.22 (3.53 to 10.7) | |
| Biological markers (dichotomised) | 0.17 (0.14 to 0.21) | 8.74 (6.51 to 12.2) | |
| Subjective outcomes (various)§ | 0.07 (0.05 to 0.09) | 3.48 (2.33 to 4.99) | |
| Between-comparison | |||
| Intervention comparison types | τ2(95% CI)‡ | Ratio of τ2(95% CI) | SD κfor log(τ2) |
| Pharmacological vs. Placebo/control | 0.08 (0.07 to 0.09) | 0.64 (0.50 to 0.81) | 1.21 (1.07 to 1.36) |
| Pharmacological vs. Pharmacological | 0.06 (0.05 to 0.07) | 0.51 (0.39 to 0.66) | 1.28 (1.10 to 1.46) |
| Non-pharmacological‡vs. Placebo/control | 0.06 (0.05 to 0.08) | 0.51 (0.38 to 0.70) | 1.43 (1.21 to 1.66) |
| Non-pharmacological‡vs. Pharmacological | 0.22 (0.13 to 0.34) | 1.81 (1.04 to 2.96) | 0.75 (0.07 to 1.40) |
| Non-pharmacological‡vs. Non-pharmacological‡ | 0.12 (0.10 to 0.15) | 1 (reference) | 1.11 (0.91 to 1.32) |