Conduct an economic evaluation based on best currently available evidence comparing alternative treatments levonorgestrel-releasing intrauterine system, depot-medroxyprogesterone acetate, combined oral contraceptive pill (COCP) and ‘no treatment’ to prevent recurrence of endometriosis after conservative surgery in primary care, and to inform the design of a planned trial-based economic evaluation.
We developed a state transition (Markov) model with a 36-month follow-up. The model structure was informed by a pragmatic review and clinical experts. The economic evaluation adopted a UK National Health Service perspective and was based on an outcome of incremental cost per quality-adjusted life year (QALY). As available data were limited, intentionally wide distributions were assigned around model inputs, and the average costs and outcome of the probabilistic sensitivity analyses were reported.
On average, all strategies were more expensive and generated fewer QALYs compared to no treatment. However, uncertainty attributing to the transition probabilities affected the results. Inputs relating to effectiveness, changes in treatment and the time at which the change is made were the main causes of uncertainty, illustrating areas where robust and specific data collection is required.
There is currently no evidence to support any treatment being recommended to prevent the recurrence of endometriosis following conservative surgery. The study highlights the importance of developing decision models at the outset of a trial to identify data requirements to conduct a robust post-trial analysis.
Citation: Sabina Sanghera, Pelham Barton, Siladitya Bhattacharya, Andrew W Horne Pharmaceutical treatments to prevent recurrence of endometriosis following surgery: a model-based economic evaluation BMJ Open 2016;6:e010580 doi:10.1136/bmjopen-2015-010580
Received: 17 November 2015 Revised: 10 March 2016 Accepted: 17 March 2016 Published: 15 April 2016
Copyright: This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
The authors would like to thank the other clinicians involved in the PRE-EMPT study who assisted us with the assumptions; Hilary Critchley, Andrew Prentice, Kevin Cooper.
Contributors SB, AWH and TER contributed to the design of the whole project and obtained funding. TER designed the economic component of the project to include a pretrial analysis. SS under the supervision of PB and TER conducted the pretrial analysis with advice from SB and AWH. SS prepared the manuscript as lead writer and TER edited the manuscript. All authors have commented on and approved the submitted manuscript.
Funding This work was supported by NIHR HTA grant number 11/114/01.
Competing interests None declared.