2.5. Data analyses
Dichotomous data were analyzed by using the pooled event rates and
OR computed using the Mantel Haenszel method (with 95% Confidence Interval(CI)). Continuous outcomes measured on the same scale were expressed as a mean value and standard deviation and were analyzed by using weighted mean. I-square (I2) test was performed to assess the impact of study heterogeneity on the results of the meta-analysis. According to the Cochrane review guidelines, if severe heterogeneity was present at I2>50%, the random effect models were chosen. Otherwise, the fixed effect models were used. Z value (Z) is the overall effect. Moreover, a sensitivity analysis was conducted by deleting each study individually to evaluate the quality and consistency of the results. Visual inspection of the Begg’s test was done to assess publication bias. Stata 14.0 (Stata Corp LLC, Texas, USA) was used for statistical analysis.
3. Results 3.1. Selected studies
Among 661 retrieved searched articles, 27 articles were finally eligible with a total of 462 included patients, 23 single arm studies and 4 comparative studies were identified which included a total of 329 and 133 patients respectively. These articles were published from 1998[9] to 2018[10-11]. The mean age was 68.5±2.3 years (n=403; median:68.0), 52.4% are males(196/373).