Perceived control and sleep in hospitalized older adults: a sound hypothesis?

Abstract

Background/objectives: To examine the associations between perceived control over sleep, noise levels, sleep duration, and noise complaints in a cohort of hospitalized adults.

Design: Prospective cohort study.

Setting: General medicine ward in an academic medical center.

Participants: One hundred eighteen hospitalized patients age 50 years and over (mean age, 65 years; 57% female; 67% African American).

Measurements: Sleep duration was measured via wrist actigraphy, and noise levels in patient rooms were measured via sound monitors. Validated questionnaires were used to assess sleep characteristics at baseline and sleep quality for each night. Perceived control over sleep was measured at baseline using the Sleep Self-Efficacy (SSE) scale (range 9-45).

Results: The mean SSE score was 32.1 (standard deviation, 9.4), and the median score was 34 (interquartile range, 24-41). Average sleep duration for patients in the hospital was 333 minutes (5.5 hours). Forty-two percent of patients complained of noise disrupting their sleep. Linear regression clustered by subject showed that above median SSE was associated with longer sleep duration (+55 minutes 95% confidence interval [CI]: 14, 97; P = 0.010). This association remained significant after controlling for objective noise levels and patient demographics (+50 minutes 95% CI: 11, 90; P = 0.014). In logistic regression controlling for noise level and patient demographics, those patients with high SSE were 51% less likely to complain of noise disruptions (odds ratio: 0.49; 95% CI: 0.25, 0.96; P = 0.039).

Conclusion: Higher perceived control over sleep is associated with longer sleep duration, better sleep quality, and fewer reports of noise disruptions. In addition to noise control, interventions to boost perceived control may improve in-hospital sleep.

Figure 1

Flow of Patients through the Study. Abbreviations: ICU, intensive care unit

Figure 2

Association between sleep self-efficacy (SSE) and sleep duration. Baseline levels of SSE were measured using the Sleep Self-Efficacy Scale where a higher score indicates a greater degree of confidence in one’s ability to sleep. Patients were considered to have high SSE if they scored above the median score of 35 on the Sleep Self-Efficacy Scale and low SSE if they scored below the median. Sleep duration was measured in minutes via wrist- watch actigraphy. A 2-sample t test with equal variances showed that those with high SSE had longer sleep duration than those with low SSE.

Figure 3

Association between sleep self-efficacy (SSE) and complaints of noise. Baseline levels of SSE were measured using the Sleep Self-Efficacy Scale where a higher score indicates a greater degree of confidence in one’s ability to sleep. Patients were considered to have high SSE if they scored above the median score of 35 on the Sleep Self-Efficacy Scale and low SSE if they scored below the median. Patient complaints of noise were measured on a 5-point scale, where a higher score indicates greater disruptiveness of noise. Scores >1 were considered to be noise complaints. Patients with high SSE had significantly fewer complaints of noise compared to those with low SSE.