Self-evaluations of factors promoting and disturbing sleep: An epidemiological survey in Finland

The purpose of this epidemiological survey ( N = 1600) was to describe the factors which middle-aged urban people in Finland perceived as promoting or disturbing sleep. The response rate was 75%. The results suggested that quality of sleep is determined by numerous factors; social and psychological factors, health status, external sleeping conditions, life style and living habits. Every third respondent felt that exercise had a positive impact on sleep. Second in importance were reading and listening to music. Furthermore, sauna, shower and bath, stability in life, psychological factors, positive experience in work, satisfactory sexual life and good and quiet sleeping environment were reported to have positive effects on sleep. Men considered work-related pressure and fatigue (20%) as the most important factor disturbing falling asleep or quality of sleep. In women's ranking work problems appeared no sooner than in the third place. Women reported worries, interpersonal problems, and marital and family discord as the most disturbing factors to sleep (37%). Coffee in the evening had a negative effect on falling asleep. Although a ‘nightcap’ was considered to improve relaxation on falling asleep, men ranked alcohol as the fourth disturbing factor. Other disturbing factors were stress, irregularities in everyday life because of social events, travelling or atypical catnaps. Eating and exercising too heavily or too late in the evening were found to disturb sleep. On the other hand, temporary lack of exercise seemed to impair the quality of sleep. As external factors disturbing sleep the subjects considered noise, light, too high room temperature, tight clothing, unfamiliar sleeping environment and restless children. Health-related symptoms were also listed as disturbing factors, especially by women and with advancing age. We classified the subjects into good and poor sleepers by an index from nine items describing quality of sleep. The three factors best promoting sleep were mentioned more often by the poor sleepers than by the good sleepers. The poor sleepers also reported psychological factors to promote sleep (24%) significantly more often ( P < 0.01) than the good sleepers (9%). In general, the poor sleepers described many more disturbing factors than the good sleepers.