Journal Club Notes

Outcomes of Term Induction in Trial of Labor After Cesarean Delivery

Primary Outcomes Most important Most clinically significant Easiest to measure Sample size is usually based on primary outcomes Choose 1 to 2 primary outcomes

Secondary outcomes Other outcomes of interest Clinical, patient satisfaction, economic Unintended or unexpected side effects Adverse events

Composite outcomes Used for adverse but rare events Increases statistical power for rare events Power is the ability of the study to detect a true difference If a study is underpowered, then there may be a true difference but the study cannot detect it – result is not statistically TOLAC study used composite maternal morbidity and composite neonatal morbidity to increase power

Outcomes of Term Induction in TOLAC Study was underpowered to detect differences in individual maternal morbidities by weeks of gestation Severe maternal morbidity and uterine rupture are rare events Results may be statistically insignificant because there are too few cases in the sample Review Table 4 E.g. 37 weeks gestation OR 4.22; 95% CI (0.97-18.43)