Middleton, L J, Daniels, J P, Weckesser, A, Bhattacharya, S, Roberts, T, Critchley, H O D, Becker, C, Cooper, K, Gupta, J, Saridogan, E, Horne, A, Clark, J, Prentice, A, Jones, G, Denny, E & Whittall, C 2017, ' Preventing recurrence of endometriosis by means of long-Acting progestogen therapy (PRE-EMPT) : Report of an internal pilot, multi-arm, randomised controlled trial incorporating flexible entry design and adaption of design based on feasibility of recruitment ', Trials, vol. 18, no. 1, 121 . https://doi.org/10.1186/s13063-017-1864-0