Do nicotine inhaler increase smoking cessation during pregnancy?

Objective: To test whether selection bias has affected the reported effect estimate for the use of nicotine inhalers (RD 0.01. 95%CI: -0.05 to 0.08), regarding smoking cessation during pregnancy. Method: Trial adjusted, simulated comparator trial (SCT) based I2 test for single randomised controlled trials Result: The estimated selection bias level (B%) of 40% suggests that 31-40% (43 – 55 of 137) of the total trial subjects were non-randomly allocated in favour of one treatment group above the other. This level appears 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 smoking cessation rate in the nicotine inhaler group during pregnancy in comparison to placebo. The selection bias level, estimated by use of the trial adjusted, simulated comparator trial (SCT) based I2 test for single RCTs, B% = 40%, appears high enough in order to have affected the reported estimate.