We would like to respond to the comments of Pittrof and colleagues1 regarding our paper ‘Is it worth paying more for emergency contraception?’ The cost effectiveness of ulipristal acetate versus levonorgestrel 1.5 mg'.2

1. Pittrof et al. claim incorrectly that the two comparative randomised controlled trials (RCTs) of ulipristal acetate (UPA) and levonorgestrel (LNG) were underpowered. Both studies were designed as non-inferiority studies (to show that UPA was no less effective than LNG) and were adequately powered to do this.3 4

2. Pittrof et al. do not accept that a meta-analysis using different drug regimens in the RCTs is acceptable. The scientific peer reviewers/statisticians of the Lancet considered this meta-analysis to be appropriate, as did National and European regulatory authorities including the Scottish Medicines Consortium and the European Medicines Authority. A detailed explanation of the rationale for the drug regimes used and their comparability is contained within the original Lancet article.4

3. Pittrof et al. postulate that UPA for emergency contraception (EC) could predipose to placenta praevia. The scientific rationale behind this is flawed and there is no reported association between …