Factors associated with insomnia in older adult outpatients vary by gender: a cross-sectional study

Background Insomnia is a common sleep disturbance in older adults and is associated with many poor health outcomes. This study aimed to explore factors associated with insomnia in older adult outpatient clinics, and to further analyze the influence of gender on factors associated with insomnia. Methods This cross-sectional study was conducted in the outpatient clinics of a tertiary hospital in Southern Taiwan from July to September 2018. A total of 400 consecutive subjects aged 60 years or older were recruited. Insomnia was defined as a score of ≥ 6 points on the Athens Insomnia Scale (AIS). Socio-demographics, health behaviors and clinical data were collected by face-to-face interview. Multivariable logistic regression was adopted for statistical analysis of the entire sample and stratified by gender. Results Participants’ mean age was 74.74 ± 8.54 years, and the majority (93%) had more than one chronic disease. The prevalence of insomnia accounted for 30% (120/400) of all subjects, with males 22.9% (46/201) and females 37.2% (74/199). Gender, appetite, exercise, depressive symptoms, and sleep-related conditions such as short sleep duration, sleeping pills usage, medium-high risk of obstructive sleep apnea (OSA) and restless leg syndrome (RLS) were factors associated with insomnia in older adults. Exercise, sleeping pills usage, and RLS were independently associated with insomnia only in men, while appetite and medium-high risk of OSA were associated with insomnia in women only. In addition, after further adjusting for covariates, prevalence of the insomnia-related symptoms such as sleep induction, total sleep duration, sleep quality and sleepiness during the day was significantly higher in females than in males. Conclusions Insomnia symptoms are highly prevalent among older adults, predominantly females. Significant differences are found between genders in factors associated with insomnia and insomnia-related symptoms. Understanding gender differences may help clinicians to modify associated factors when managing older adults with insomnia.