Factors associated with insomnia in older people with a mild to moderate degree of poor cognitive ability in Thailand

Aim: To examine the prevalence and risk factors of insomnia among older adults with a mild to moderate degree of poor cognitive ability.Methods: A total of 18 634 people aged 60 years old or more who had been included in a multistage National Health Examination survey III (NHES III), 4138 of whom had a mild to moderate degree of poor cognitive ability, were identified. Prevalence and associated factors of self-reported insomnia and daytime tiredness due to inadequate sleep (DTIS) were analyzed.Results: The prevalence of older people with a mild to moderate degree of poor cognitive ability was 22.2%. The prevalence of insomnia and DTIS among older people with poor cognitive ability was 63.7% and 53.2%, respectively. The independent factors associated with insomnia within this particular group were: female sex, aged of 80 years or more, no formal education, financially poor, poor self-care, joint pain, feeling depressed, and poor self-perceived health. The odds of insomnia increased with increased severity of self-perceived health. Interestingly, nearly all independent factors associated with insomnia were also significantly associated with DTIS, and with both conditions combined.Conclusion: Modifiable risk factors, such as depressive symptom, poor health status and joint pain, should be managed to primarily prevent the occurrence of insomnia in older people with poor cognitive ability. © 2010 Japan Geriatrics Society.