Health-related quality of life and sleep disorders in Taiwanese people with heart failure
The purposes of this cross-sectional, descriptive, correlational study were to describe the characteristics of sleep disorders and HRQOL; to explore the relationships between individual characteristics (age, gender, education, living arrangement, marital status, financial status, employment status, and type of language), HF characteristics (body mass index, comorbidity, and perceived health), sleep disorders (nocturnal sleep quality, daytime sleepiness, and daytime napping), and HRQOL; and to identify predictors of HRQOL. A nonprobability sample of 125 participants with HF was recruited from the outpatient departments of a large medical center and an affiliated hospital located in southern Taiwan. All participants were individually interviewed by the principal investigator in either a private area within a clinic or in their homes, except for two participants who completed the questionnaires by themselves at locations of their choice. Overall, the study findings indicated that insomnia (difficulty initiating sleep, maintaining sleep, or both) may be common among the participants. Approximately 72.8% of the participants reported poor nocturnal sleep quality, however, only 30 (24%) of them had excessive daytime sleepiness. Additionally, the majority (81.6%) of the participants reported they were prone to habitual daytime napping after lunch. Except for the significant relationship between daytime sleepiness and the component of daytime dysfunction, daytime sleepiness and daytime napping were not significantly correlated with the global and componential variables of nocturnal sleep quality. By using a hierarchical multiple regression model analysis, six predictors were identified from 14 predictor variables, and those six accounted for 58.5% (p<.001) of the variance in HRQOL. After controlling for age, education, financial status, comorbidity, perceived health, and NYHA Class, the analyses showed that sleep variables (subjective sleep quality, sleep disturbances, and sleep latency) accounted for 7% of the variance in HRQOL. The study found that the Taiwanese persons with HF who experienced better HRQOL were those who had higher level of education, lower NYHA Classes, and small numbers of comorbid conditions, and reported better subjective sleep quality, fewer sleep disturbances, and shorter sleep latency.