Differences between objective and subjective sleep quality in chronic primary insomniacs and the correlated factors

Background The severity of difficulty it fatling asleep and the insufficiency of the steeping time in the primary insomniacs always were overestimated, even after medication and improving the objective sleep quality. Moreover, remarkable psychosomatic symptoms were found in patients and the symptoms were significantly linked to the self-reported sleep quality. So in this study, it was designed to explore the differences between objective and subjective sleep quality and its correlative factors in chronic insomniacs. Methods A total of 55 chronic primary insomniac cases diagnosed by DSM-IV diagnostic criteria for primary insomnia and 15 normal controls were rated with Pittsburgh sleep quality index (PSQI), State-Trait Anxiety Inventory (STAI), and the Subjective General Condition Form All cases and the controls were then examined by the whole-night polysomnography (PSG) records. Results Compared with the objective parameters of PSG, the subjective parametersiu chronic insomniacs had significantly longer sleep latency and lower total sleep time and sleep efficiency [(80.3±73.7) min vs. (23.2±25.4) min, (157.8±141.7) min v.s (332.2±154.7) min, (0.52±0.27) min v.s. (0.67±0.28)min, respectively, P＜0.001]. The difference between subjective and objective sleep latency was related to the total scores of STAI. TAI and SAI (r=0.402, 0.374 and 0.397, respectively, P＜0.05). Conclusions There were significant differences between objective and subjective estimations of steep quality in chronic insomniacs, and they might result in the overestimation of the severity of insomnia. The differences between subjective and objective sleep quality in the chronic insomniacs were significantly correlated with the levels of anxiety.