Do 3-day courses of methylprednisolone (MP) treatment decrease the re-exacerbation risk in patients with severe chronic obstructive pulmonary disease (COPD) when compared to 10-day treatment?

Objective: To test whether selection bias has affected the reported effect estimate for 3-day courses MP treatment in comparison to 10-day courses MP treatment (RD 0.06. 95%CI: -0.26 to 0.37), regarding the re-exacerbation risk in patients with COPD. Method: Trial adjusted, simulated comparator trial (SCT) based I2 test for single randomised controlled trials Result: The estimated selection bias level (B%) of 30% suggests that 21-30% (8 – 11 of 34) of the total trial subjects were non-randomly allocated in favour of one treatment group above the other. This level appears not high enough in order to have affected the reported effect estimate. Conclusion: The effect estimate reported by the tested trial suggests a non-significantly higher re-exacerbation risk in the 3-day MP treatment group in comparison to 10-day treatment. The selection bias level, estimated by use of the trial adjusted, simulated comparator trial (SCT) based I2 test for single RCTs, B% = 30%, appears not high enough in order to have affected the reported estimate.