PT - JOURNAL ARTICLE AU - Bruce Arroll AU - Antonio Fernando III AU - Karen Falloon AU - Felicity Goodyear-Smith AU - Chinthaka Samaranayake AU - Guy Warman TI - Prevalence of causes of insomnia in primary care: a cross-sectional study AID - 10.3399/bjgp12X625157 DP - 2012 Feb 01 TA - British Journal of General Practice PG - e99--e103 VI - 62 IP - 595 4099 - http://bjgp.org/content/62/595/e99.short 4100 - http://bjgp.org/content/62/595/e99.full SO - Br J Gen Pract2012 Feb 01; 62 AB - Background As a result of a research interest in primary insomnia, the prevalence of other causes of insomnia in primary care must be ascertained. No source was found in the literature. It is also essential to know the epidemiology of the common causes of a condition to make an accurate diagnosis in primary care.Aim To determine the prevalence of causes of insomnia in primary care, as part of a method of identifying patients with primary insomnia.Design and setting Cross-sectional study in three general practices in Auckland, New Zealand.Method Consecutive patients from the waiting room were asked to complete a nine-page questionnaire on possible causes of insomnia.Results In total, 1517 patients were approached and 955 completed the nine-page questionnaire (63%). Of the 41% (388) who reported difficulty with sleeping, primary insomnia occurred in 12% (45) of the population (95% confidence interval = 9% to 15%); 50% (195) had depression, 48% (185) had anxiety and 43% (165) had general (physical) health problems. Obstructive sleep apnoea occurred in 9% (34) and delayed sleep phase disorder in 2% (7). Only primary insomnia and delayed sleep phase disorder are mutually exclusive; the others can co-exist.Conclusion This is the first description of the prevalence of causes of insomnia in primary care. It is hoped that the focus on primary insomnia will result in more behavioural treatments and lower the use of hypnotics in primary care; it should also assist in the appropriate detection and treatment of other causes of insomnia in primary care.