The summary standardized incidence ratio (SIR), standardized mortality ratio (SMR), and 95% confidence intervals (CIs) were calculated using a random-effect model of meta-analysis.
The subgroup analyses were conducted using the so-called mixed-effects model of meta-analysis [ 57].
Influence analysis was also carried to assess whether summary OR was driven by any one study in the recessive model of meta-analysis (Sterne et al, 2002).
Hereby, D2 expresses the relative variance reduction when the model of meta-analysis is changed from a random-effects model into a fixed-effect model.
Based on the random effects model of meta-analysis, we found an overall incidence rate of 262 per 100,000 per year.
Alternative methods that rely on bagging or boosting generate aggregate models that must be statistically parsed to obtain final models, while the trees built here provide a straightforward model of meta-gene interactions.
If a study reported the effect estimates for two or more domains of physical activity separately, then we pooled the results into a single measure using fixed effects model of meta-analysis.
Although we used the random effects model of meta-analysis to derive an overall incidence rate, the large degree of heterogeneity identified implies that interpretation should be with caution.
Unlike Tagliaferri et al. [ 38], who reported an average incidence and mortality rate in their review, we used the random effects model of meta-analysis to calculate an overall incidence rate.
For each combination of N, K, p C, θ, according to the random effects model of meta-analysis, we simulated K within-studies log odds ratios θ i from the N distribution for the values of the heterogeneity parameter τ from 0 to 0.9 in the increments of 0.1.
The statistic is calculated as the weighted sum of the squared differences between individual study effects and the pooled effect across the included studies, with the weights defined by the model of meta-analysis used i.e. fixed effect or random-effects.
