MsFLASH network vaginal health trial: absence of evidence is NOT evidence of absence

Approximately 50% of postmenopausal women experience vulvovaginal symptoms associated with genitourinary syndrome of menopause (GSM). GSM is a chronic and progressive condition with a well-defined treatment algorithm. Analysis of the MsFLASH Vaginal Health Trial data produced two main conclusions, which were that prescribed vaginal 10 μg estradiol tablet and over-the-counter (OTC) vaginal moisturizer did not provide additional benefit over placebo vaginal tablet and placebo gel in reducing postmenopausal vulvovaginal symptoms; or increasing the proportions of women reporting sexual activity or improving pain scores with sexual activity. These treatment conclusions are contrary to all prior robust clinical trial data for dyspareunia and vaginal dryness, and not in line with the good clinical practice for GSM management presented by the American College of Obstetricians and Gynecologists, The North American Menopause Society, and the Endocrine Society. Overall, the flaws of the MsFLASH Vaginal Health Trial were to incorrectly identify the therapeutic outcomes of most interest using metrics that exhibit high degrees of placebo bias; and to utilize low statistical power with which to appreciate any significant differences between groups.