Delay of first voiding episode is associated with longer reported sleep duration

Time to first void is a common outcome in nocturia clinical trials, but its relationship to other conventional self-reported sleep measures is uncertain. We examined associations between change in time to first void and change in sleep duration over the course of such a trial.

Secondary data analyses were based on a previously published study of a medication treating nocturia in 757 adult patients studied for periods up to 5 months. We used repeated-measures logistic regression models with generalized estimating equations (GEE) to examine the odds ratios (ORs) for achieving 6.0, 6.5, or 7.0 hours of total sleep duration based on increases of time to first void of 1, 2, or 3 hours.

Increases in time to first void were associated with longer sleep durations from beginning to end of study. A 1-hour increment in time to first void was associated with a higher likelihood of obtaining a total sleep duration of e6 (OR = 1.43; 95% confidence interval [CI], 1.19-1.73), e6.5 (OR = 1.30; 95% CI, 1.16-1.47), or e7 (OR = 1.24; 95% CI, 1.12-1.37) hours, after controlling for baseline time to first void, baseline sleep duration, time, and age (all Ps < .0001). Similar results were seen for 2- and 3-hour increments in time to first void.

Time to first void may be an important supplementary variable about which to inquire in population-based studies.