Table 3.
Meta-analysis and univariate metaregression results for identifying covariates to explain heterogeneity in the estimated pooled RRs: Kaplan-Meier versus competing-risks method*
| Strata | Largest number of EI | Highest ratio of CR to EI | ||||
|---|---|---|---|---|---|---|
| Number of strata | Meta-analysis RR (95% CI) | Metaregression p value | Number of strata | Meta-analysis RR (95% CI) | Metaregression p value | |
| Followup | ||||||
| < 10 years | 3 | 1.05 (0.99–1.12) | 3 | 1.59 (1.45–1.73) | ||
| ≥ 10 years | 4 | 1.31 (1.03–1.66) | 0.125 | 4 | 1.31 (1.03–1.66) | 0.203 |
| Ratio of CR to EI† | ||||||
| < 1 | 1 | 1.02 (0.96–1.08) | 0 | |||
| 1–10 | 5 | 1.18 (1.01–1.38) | 0.342 | 4 | 1.33 (1.09–1.62) | |
| > 10 | 1 | 1.30 (0.63–2.72) | 0.581 | 3 | 1.60 (1.46–1.75) | 0.161 |
RR = risk ratio; EI = event of interest; CR = competing risks; CI = confidence interval.
* n = 6 studies, 7 strata; Gillam et al. [17] estimated the cumulative incidence of revision after THA for three nonmutually exclusive subsets of data; the subset with the largest number of EI included two mutually exclusive strata (patients with osteoarthritis aged < 70 years, and those aged ≥ 70 years); the subset with the highest rate of CRs included two mutually exclusive strata (cementless Austin Moore prostheses, cemented Thompson prostheses).
†