The role of biologic agents in damage progression in rheumatoid arthritis: indirect comparison of data coming from randomized clinical trials
Therapeutic Advances in Musculoskeletal Disease, 06/22/2012
Favalli EG et al. – All biologic agents provide a favourable effect on disease progression both in early and late rheumatoid arthritis (RA). The significant heterogeneity among various randomized clinical trials (RCTs) did not allow an effective comparison of the performance of biologic agents in each study.Methods
- A systematic review of literature from 1988 to 2011 was conducted.
- Only randomized, double–blind, controlled, comparative trials, with evaluation of radiographic progression were included.
- The radiographic score was standardized and mean difference in the percentage of the annual radiographic progression rate was used as the effect measure.
- Heterogeneity between studies was estimated by I2 test.
- For each trial, the effect was plotted according to its standard error in a funnel plot.
- Of 44 potentially relevant trials, 12 RCTs were included in the study.
- In order to optimize RCTs comparison, studies were stratified in early and late RA group.
- Main population characteristics were similar in both early and late RA groups, whereas the standardized baseline radiographic score value significantly differs among trials in both early (range 2.7–21.9) and late (range 23.46–75) RA groups.
- The standardized annual estimated progression is similar across the late RA group.
- Strong evidence of heterogeneity (I2 = 97%, p = 0.00001) but no asymmetry of the funnel plot was observed in the early RA group.
- Total mean difference was –16.28 (95% confidence interval [CI] –24.42 to –8.14).
- For the late RA group a random model was used (I2 = 99%, p = 0.00001) and a total mean difference of –39.25 (95% CI –53.77 to –24.73) was found.