Comparison and prediction of sleep quality in users of bed or hammock as sleeping device.

Objectives: To compare and predict sleep quality between bed and hammock users .

Design: Cross-sectional pilot study.

Setting: Habitual hammock and bed users of southern Mexico.

Participants: Sixty-eight college students (53% female, mean age 21 ± 1.6 years); 33 usually sleep in bed and 35 in hammock.

Intervention: Not applicable.

Measurements: Objective sleep measures were obtained using an actigraphy device on 7 consecutive days. Questionnaires about sleep habits and sleepiness (Epworth scale) were completed. Body mass index (BMI) was obtained with a weighing machine and altimeter.

Results: Subjective sleep measures between habitual hammock and bed users were not significant (P > .05). Differences were found on 2 objective sleep measures: (1) activity index, on which hammock users obtained 7.62 minutes more than bed users (M = 36.72, standard deviation [SD] = 10.86 vs. M = 44.34, SD = 13.08, P = .018) and (2) mean sleep episodes, on which hammock users had 19.67 minutes less than bed users (M = 71.52, SD = 34.37 vs. M = 51.85, SD = 24.29, P = .014). Hammock users had a higher BMI than bed users (M = 23.38, SD = 3.45 vs. M = 26.20, SD = 4.86, P = .010). Sex and BMI were included in the predictive model of linear regression (P < .05) of the sleep actigraphy parameters, the sleeping device was excluded of final model.

Conclusions: Hammock users show increased BMI, higher activity index and shorter mean sleep episodes than bed users. However, sex and BMI were stronger predictors of actigraphy parameters than bed type.