RELATIONSHIP BETWEEN SLEEPINESS AND GENERAL HEALTH-STATUS

One commonly used instrument for evaluating general health and functio nal status is the medical outcomes survey short form 36 (MOS). Scores obtained from this instrument are known to vary with chronic diseases and depression. However, the degree to which these health dimensions m ay be influenced by sleep quality or sleepiness is not well understood . A cross-sectional study was performed on the association between gen eral health status, as determined by the MOS, with sleepiness, assesse d using a standardized questionnaire [the Epworth sleepiness scale (ES S)] and the multiple sleep latency test (MSLT). One hundred twenty-nin e subjects (68 women), aged 25-65 years, without severe chronic medica l or psychiatric illnesses, underwent an overnight sleep study, follow ed by an MSLT (consisting of a series of four attempts at napping at 2 -hour intervals), and completed the MOS and the ESS. The mean MSLT sco re was 11 +/- 2 minutes, (range 2-20) and the mean ESS score was 10 +/ - 5 (range 0-24). Scores for the MOS dimensions ''general health perce ptions'', ''energy/fatigue'', and ''role limitations due to emotional problems'' were correlated significantly with ESS scores (r = -0.30, - 0.41, and -0.30, respectively; p values were all <0.001). The MSLT was also significantly correlated with ''energy/fatigue'' (r = -0.19; p < 0.05). After considering the effects of chronic illness and/or body m ass index in a multiple hierarchical regression analysis, sleepiness, as assessed by the ESS score, explained 8% of the variance in general health perceptions, 17% of the variance in energy/fatigue, 6% of the v ariance in the summary measure of well-being, and 3% of the variance i n the summary measure of functional status. The variation of MOS score s with sleepiness, unrelated to age or chronic disease, suggests that measures of general health status may be broadly influenced by sleepin ess and sleep quality. These data suggest that 1) sleepiness has an im portant impact on general health and functional status, specifically i nfluencing self-perceptions regarding energy/fatigue; 2) a more specif ic assessment of sleepiness in general health evaluations may help exp lain some of the observed variability in these measures across subject s; and 3) general health measures may be useful in the evaluations of patients with sleep disorders.