Insomnia Can Be an Acute Experience or a Chronic Disorder, Characterized by Difficulty in Falling Asleep And/or Remaining

INSOMNIA CAN BE AN ACUTE EXPERIENCE OR A CHRONIC DISORDER, CHARACTERIZED BY DIFFICULTY IN FALLING ASLEEP AND/OR REMAINING ASLEEP or by poor quality of sleep.1 The sleep difficulty is associated with daytime distress, such as tiredness, negative mood, or difficulty with memory or concentration. The estimated prevalence of chronic insomnia in the US is about 10% (about 25 million people), but prevalence varies a great deal across studies.2 For approximately 20%-25% of chronically affected persons, insomnia appears as a primary disorder.3, 4 For the majority, insomnia occurs in the presence of medical and psychiatric conditions, such as depression,5 anxiety, restless leg syndrome, or painful illnesses, although the nature of the relationship between insomnia and those conditions has not been established.6,7 For that reason a recent National Institutes of Health State of the Science conference8 concluded that the term “comorbid insomnia” was preferable to “secondary insomnia.” Risk factors for chronic insomnia include female sex and increasing age, although the latter appears due to the increase in various illnesses with age, rather than age per se.9 Chronic insomnia generally lasts for at least several years6,10 and can be associated with reduced quality of life11, 12 and an increased risk of a major depressive disorder.13, 14 Other correlates of insomnia may include fatigue, reduced physical ability, impaired social performance, and higher rates of absenteeism from work, accidents at work, and presenteeism (i.e., lower productivity while at the workstation).15 Several studies have examined the health care utilization and cost burden associated with insomnia. Hatoum and colleagues16 reviewed the experience of 5 American Medical Group Association clinics and found that insomnia patients had more emergency room visits, more calls to the doctor, and more use of over-thecounter drugs than noninsomnia patients. Health-related quality of life was also lower for insomnia patients. Similarly, Simon and VonKorff17 surveyed 1,962 patients at primary health clinics and conducted face-to-face interviews with a stratified random subsample (n = 373), in order to estimate the prevalence and costburden of chronic insomnia. They found the prevalence of chronic insomnia was 10%, and they found that chronic insomnia patients had higher health care costs and significantly greater physical and social disability than good sleepers. Leger et al.18 also found higher rates of absenteeism, more trouble concentrating at work, and more medical problems (resulting in more physician office visits) among insomnia patients, compared with good sleepers. Other studies have attempted to estimate the cost burden of insomnia from a public health perspective. While methods have The Direct and Indirect Costs of Untreated Insomnia in Adults in the United States