Original Article Characteristics of insomnia in a primary care setting: EQUINOX survey of 5293 insomniacs from 10 countries Damien Léger a,⇑ , Markku Partinen b , Max Hirshkowitz c , Sudhansu Chokroverty d , Jan Hedner e on behalf of the EQUINOX (Evaluation of daytime QUality Impairment by Nocturnal awakenings in Outpatient’s eXperience) Survey Investigators a Université Paris Descartes, APHP, Centre du Sommeil et de la Vigilance, Hôtel Dieu de Paris, 75004 Paris, France b Skogby Sleep Clinic, Rinnekoti Research Centre, Espoo, Finland c Sleep Disorders and Research Center, VA Medical Center, Houston, TX, USA d New Jersey Neuroscience Institute, JFK Medical Center, Edison, NJ, USA e Sleep Laboratory Unit, Department of Respiratory Medicine and Allergology, Sahlgrenska University Hospital, Göteborg, Sweden article info Article history: Received 8 December 2009 Received in revised form 2 April 2010 Accepted 30 April 2010 Keywords: Insomnia Epidemiology Difficulties initiating sleep Difficulties maintaining sleep Nocturnal awakenings Non restorative sleep Primary care abstract Objective: To describe the characteristics of insomnia in primary care physicians’ (PCPs’) practices in 10 countries and to understand how the difficulty of maintaining sleep (DMS) was or was not associated with other insomnia symptoms such as difficulty initiating sleep (DIS), early morning awakenings (EMA) or nonrestorative sleep (NRS) in PCPs patients with insomnia. Methods: International, noninterventional, cross-sectional, observational survey conducted in a primary care setting in subjects complaining of sleep disturbances in 10 countries. A questionnaire based on DSM- IV and ICSD criteria was administered. Results: Thirteen thousand one hundred twenty-four subjects were enrolled by 647 physicians; 5293 of them (32.6%) had insomnia and were surveyed. The population was predominantly female (63.9%) with a mean age of 47.8 ± 15.3 years; 39.9% of these patients have already been treated for sleep difficulties. Combination of all types of insomnia symptoms (DIS + DMS + EMA + NRS) was the most frequently reported combination (38.6% of the subjects), while the percentage of subjects presenting with only one type of insomnia symptom (DIS, DMS, EMA or NRS) was very low: 3%, 1.8%, 0.9% and 1.4% respec- tively. DMS was on average the most commonly reported insomnia symptom (80.2%). Multiple logistic regression showed that DMS, EMA and NRS symptoms were significantly linked with each other and also to other insomnia criteria (sleep satisfaction, sleep quality, sleep duration, number of hours of sleep, fre- quency of insomnia symptoms, wake up rested / unrested and non restorative sleep). Conclusions: Patients visiting PCPs with insomnia are likely to present with severe and poly-symptomatic insomnia. Ó 2010 Elsevier B.V. All rights reserved. 1. Introduction Insomnia is a common complaint that can impair patient’s qual- ity of life and daytime functioning. The prevalence of insomnia in the general population of adults has been widely studied in many countries [1–5]. A recent review of the literature covering more than 50 studies of insomnia showed that when consensus defini- tions of insomnia are used (DSM-IV [6] and ICSD-2 [7]) estimates of prevalence in the general population vary widely, from less than 15% to 25% [8,9], depending on the definition of the characteristics of the population sampled, the regional perceptions and practices regarding sleep disorders. Consensus definitions are based on subjective assessment made by subjects with complaints of difficulty initiating sleep (DIS), dif- ficulty maintaining sleep (DMS), early morning awakenings (EMA), nonrestorative sleep (NRS) occurring despite adequate opportunity and circumstances for sleep and with daytime impairment re- ported by the patient [6,7]. These definitions which are used clin- ically for the diagnosis of insomnia have also been recommended in research by several sleep research groups [10–12]. Several questions regarding the characteristics of insomniacs remain unresolved. One major issue is why even severe insomniacs do not seek professional help to cope with their poor sleep [13] and who does seek help for their insomnia. Surprisingly, few studies have addressed insomnia in general practice [14–17]. 1389-9457/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.sleep.2010.04.019 ⇑ Corresponding author. Address: Université Paris Descartes, Place du Parvis Notre Dame, 75181 Paris Cedex 04, France. Tel.: +33 1 42 34 82 43; fax: +33 1 42 34 82 27. E-mail address: damien.leger@htd.aphp.fr (D. Léger). Sleep Medicine 11 (2010) 987–998 Contents lists available at ScienceDirect Sleep Medicine journal homepage: www.elsevier.com/locate/sleep