Interest and properties of the Sexual Activity Questionnaire (SAQ) for the measurement of sexual function in the therapeutic management of patients suffering from endometriosis

Endometriosis is a benign chronic pathology affecting 5 to 10% of women during their genital period. It is responsible of painful symptoms and impaired quality of sexual life. The evaluation of the sexual function of these women is a key element of the management. It requires the use of Patient Reported Outcome (PRO), such as questionnaires. Sexual function questionnaires usually used are heterogeneous and have not been validated in this specific population. This thesis focused on the Sexual Activity Questionnaire (SAQ), a questionnaire originally developed to assess the effect of antihormonal treatment in patients at risk of developing breast cancer. The SAQ had subsequently been used to evaluate the efficacy of endometriosis surgery but had not been validated in this specific population.We assessed the psychometric properties of the SAQ according to COSMIN criteria such as construct validity, internal consistency, and responsiveness. The psychometric validity of the SAQ was confirmed in an observational cohort of patients with endometriosis managed by medical and/or surgical treatment. The unidimensional nature of the SAQ in this population made it possible to calculate an SAQ score by summing the 10 items (score from 0 to 30, 30 being the best sexual function). The responsiveness of the SAQ was good in the context of surgical treatments. Finally, we determined a minimal clinical important difference (MCID) for the SAQ score of 2.2.We then used the SAQ in a study evaluating the influence of high dose progestins treatments on sexual function in women with endometriosis. The SAQ score was significantly lower after treatment in the group of patients receiving high dose progestins, indicating an impairment of sexual function in thesepatients before adjustment (mean: 15.5±6.3 versus 18.3±6.2; p=0.03) and after adjustment (adjusted effect size -0.44 (95% confidence interval -0.86, -0.02), p=0.04) despite an improvement of dyspareunia after treatment (mean: 45±29 versus 28±29, P<0.001).High dose progestins treatments were associated with lower sub-scores for 2 items: pleasure (1.8±0.8 vs 2.2±0.9, p=0.02) and satisfaction with frequency of intercourse (1.2±1.2 vs 1.8±1.1, p=0.02).Finally, we performed a systematic review over 20 years to assess a detailed description, using COSMIN criteria, of the psychometric properties of all sexual questionnaires used in the field of endometriosis. This rigorous evaluation of the qualities and shortcomings of the different PROs available will allow for a better choice of tools for measuring sexual function in future research in this field. The results show that the SAQ is a great tool for the evaluation of surgical treatment, one of the major axes of endometriosis management. The FSFI is multidimensional and allows to study more precisely some sub-areas such as desire, arousal, lubrication, orgasm and satisfaction.In conclusion, the SAQ is now validated for the evaluation of sexual function in patients with endometriosis. The determination of a MCID makes it very useful for clinical practice and for research. Its use has made it possible to show alteration of sexual function associated to the use of high dose progestins. Among different questionnaires available, the SAQ stands out with high quality measurement properties that make it a potential candidate to be integrated in a core outcomes measures recommended for care and research.