Results of sensitivity analysis, in which 58 linear mixed models regressed ln(Apnea-Hypopnea Index+1) on hormone therapy use before and after a cutoff date, among 228 subjects in the Sleep in Midlife Women Study, Madison, WI, 1990–2009. Each model used a different date. Each data point is the estimated difference between the effect of hormone therapy use before and after the date shown. Models were adjusted for menopausal stage and age. In-home visits only were used (N=1,519 observations).