Noncardiac Pain Prevalence, Pain Intensity, Pain Interference, Sleep, and Cardiopulmonary Function in Outpatient Cardiac Rehabilitation.

Abstract

Objectives: To examine relationships between noncardiac pain, cardiopulmonary function, and sleep quality in the context of outpatient cardiac rehabilitation (CR). A secondary purpose was to determine whether sleep quality was predictive of pain and cardiopulmonary function.

Design: A cross-sectional cohort study.

Setting: Outpatient cardiac rehabilitation program.

Participants: A total of 100 participants (N=100) were enrolled.

Interventions: Not applicable.

Main outcome measures: Participants completed the Brief Pain Inventory, Pittsburgh Sleep Quality Index (PSQI), and 6-Minute Walk Test (6MWT) near CR admission. The 6MWT was completed again near CR discharge (11wk).

Results: Of the 72% of participants who reported the presence of noncardiac pain, the mean (±SD) Brief Pain Inventory pain intensity was 5.04 (±2.69) at its worst, 2.06 (±2.00) at its least, and 3.67 (±1.90) on average. The mean total PSQI score was 8.81 (±4.57), and significantly greater (poorer) for those with the presence of pain (9.54±4.57) than those with the absence of pain (6.81±3.88). Those with poor sleep (total PSQI score >5; "sleeper status") had greater pain intensity on all pain scales (P<.05), more pain interference on all interference items (P<.02), and a trend toward poorer 6MWT scores at baseline (P=.06). Total PSQI score and sleeper status each independently predicted the presence versus absence of pain (χ²=4.11; P=.04; χ²=7.09; P<.01, respectively). Additionally, total PSQI score predicted pain intensity (R²=0.09-0.22; P<.01 for all pain scales) and 6MWT scores at baseline (R²=0.07; P<.01) but not at follow-up (R²≤0.01; P=.61).

Conclusions: Poor sleep and noncardiac pain are highly prevalent in CR and are therefore targets for therapeutic intervention. Poor sleep, as assessed by the PSQI, is predictive of pain and cardiopulmonary function at the initiation of CR.