Multiple measures of sexual function best identify therapy outcomes


Thorp et al. (BJOG 2014; DOI: 10.1111/1471-0528.12878) argue strongly that the sexual lives of women should be accorded an intrinsic value equal to those of men and the need for a safe and effective product to treat the number of women with low sexual desire is unmet. This is undisputable; however, the pharmacology for the treatment of sexual desire and orgasmic disorder in women is ‘a somewhat barren field’, mainly because the definitions rely on describing the observable reported physical changes of sexual arousal where the biology and physiology remain controversial and poorly researched (Levin Pharmacol Biochem Behav 2014;121:62–70). This is unsurprising given that it is the limbic system and prefrontal lobe that are considered essential for the initiation of sexual desire and the initiation of the cascade of neurovascular events triggering somatic and genital responses of sexual function and behaviour (Graziottin and Giraldi 2006, ISSM (International Society of Sexual Medicine) Standard Committee Book, Standard practice in Sexual Medicine Oxford: Blackwell).

Recent paradigm changes in the definition of sexual dysfunction have integrated sexual interest/arousal disorder (DSM-5) as research identifies a significant overlap. This inherently obfuscates attempts to delineate improvements to sexual drive or desire regardless of how the problem is measured. Where exactly constitutes desire on a continuum and how does desire become ‘lost’ or considered ‘low’? For many women desire is strongly context dependent and the association with sexual arousal either concurrent or subsequently (or even as the initiator of desire) remains challenging to both define and measure.

Some caution is required about labelling problems for women describing sexual symptoms. Mitchell et al. (Lancet 2013;382:1817–29) in the Natsal3 studies show that sexual response problems lasting at least 3 months in the preceding year are common, even in young people. More than 40% of men and 50% of women report one or more problems, but the proportion of sexually active individuals reporting distress about their sex life is much lower (about 10%). The authors note that their estimates of individual problems including infrequent and frequent symptoms as well as mild and bothersome problems should be interpreted accordingly.

Forbes et al. (J Sex Res 2014;51: 485–91) argue that standard measures like the female sexual function index are inappropriate for use among individuals who are not sexually active and that supplementary measures of sexual function may be more appropriate. Specific concerns of the desire domain of the FSFI have been voiced. Multimodal measures are encouraged in new studies assessing sexual function. Tabatabaie (Sex Relation Ther 2014;29:269–79) recommends that the outcome of sex therapy be conceptualised on sexual satisfaction, quality of life and confidence, which are distinct from direct measurement of function. This approach may offer favourable results in measuring change in response to any intervention using the bio-psychosocial treatment model (McCabe et al. J Sex Med 2010;7:327–36). The applicability to the biomedical model is less clear but a multimodal approach to assessment and outcome is a contemporary standard operating procedure (Bitzer et al. J Sex Med 2013;10:36–49). Reduction in sexually related distress, for example feeling less bothered by low sexual desire, with new agents in development such as bremelanotide (Kingsberg et al. Obstet Gynecol 2014;123:29S–30S) and concurrent improvements in the number of satisfying sexual events and level of sexual desire (measured on the FSFI) reported with flibanserin offer hope to women impacted by sexual desire problems.

Disclosure of interest

The author has no conflict of interest to disclose.