The Economic Burden of Insomnia: Direct and Indirect Costs for Individuals with Insomnia Syndrome, Insomnia Symptoms, and Good Sleepers

TLDR: The economic burden of insomnia is very high, with the largest proportion of all expenses attributable to insomnia-related work absences and reduced productivity.

Abstract: INSOMNIA IS A PREVALENT PUBLIC HEALTH PROBLEM, WITH BETWEEN 6% AND 10% OF THE POPULATION MEETING DIAGNOSTIC CRITERIA FOR INSOMNIA syndrome1–3 and about a third of the population experiencing insomnia symptoms at any given moment.2 Despite its high prevalence, there is little information on the economic burden of insomnia. Information on the costs of illnesses, an indicator of their burden to society, is increasingly driving policy decisions about the funding and development of health care and research programs and priorities. Insurance companies are also concerned with the costs of illnesses and the impact that interventions may have in reducing symptoms and health care system utilization. Economic evaluations of the cost of illnesses or the cost effectiveness of treatments consider 2 broad categories of costs. These include direct costs associated with the consumption of resources (e.g., consultations, products, and testing), and indirect costs associated with the loss of resources (e.g., absenteeism, reduced productivity).4 While studies show a relationship between insomnia severity and the use of health-care service and product utilization,5–9 quantification of the associated costs is scarce. Similarly, some studies have reported a relationship between insomnia, increased absenteeism, and decreased productivity,10–13 yet the economic burden of this has been less frequently measured. The National Commission on Sleep Disorders Research estimated the direct costs of insomnia in the United States at $13.9 billion for the year 1995,14 whereas Leger et al.15 estimated the total cost of insomnia in France at about 10 million francs (or $2 billion US). The indirect costs associated with insomnia have received less attention in the literature, primarily because these costs are more difficult to estimate and quantify, there is no single database from which to draw, and measurement of these variables is more subject to interpretation and memory bias. Stoller16 attempted to quantify work-related deficits by combining data obtained in a study of workplace performance in Navy servicemen17 with her own insomnia prevalence estimate of 33% and a performance decrement estimate of 4%. The monetary value of absenteeism and lost productivity was estimated at $41.1 billion annually (1995 US$). A per person estimate was attempted by Chilcott and Shapiro,5 who suggest a decrease in work productivity due to insomnia of 10%. This amounts to $3,000 per insomnia sufferer per year. Stoller16 also looked at a number of other indirect costs, including insomnia-related accidents, alcoholism, and depression, estimating their costs at between $77.05 and $92.13 billion. Although these estimates have been criticized because they are based on liberal prevalence rates and relied on some questionable assumptions,9 they are still frequently used to describe the indirect economic consequences of insomnia. A French study18 concluded that insomnia is associated with increased absenteeism and reduced productivity, with associated costs about twice as high for insomnia patients as for good sleepers. The methods of costing did not allow, however, for an analysis of the proportional contribution of insomnia. There was also a methodological problem associated with double-counting costs that may have inflated cost estimates. Using existing data banks, Hillman et al.19 estimated the financial costs of all sleep disorders combined (e.g., insomnia, sleep apnea, periodic limb movements) for Australia at about $1,524 million, or 0.8% of the Australian gross domestic product. While an innovative approach was used to estimate fractions of other health impacts attributable to sleep disorders, this study did not permit the identification of costs associated with individual sleep disorders. A recent study by Ozminkowski et al.20 used medical claims data for health-care services, and absenteeism and short-term disability records to assess costs of insomnia occurring in adults in the US. After matching adult (aged 18–64) subsamples on variables determined by propensity score analysis, indirect costs combined were $1,253 higher in individuals with insomnia as compared to those without insomnia. The matching procedure and use of objective data lend strength to this study. However, costs related to reduced productivity, transportation, use of alcohol, and use of over-the-counter products were excluded from the analysis, suggesting that the results may underestimate the real cost of insomnia. Despite recent progress in documenting the economic burden of insomnia, some methodological weaknesses limit the current state of knowledge on this topic. The use of large administrative databases precludes analysis of potential confounding variables such as the reasons for consultations, use of OTC products, actual consumption of prescribed medications and, for some medications, the target ailment for which it was prescribed. When workplace records are used to obtain absenteeism data, reasons for absences are rarely provided and productivity data are not available. Similarly, the use of official accident records precludes identification of the contributing role of insomnia to these events. Studies typically use 2 groups—individuals with and without insomnia; the inclusion of an intermediate category would allow analysis of a linear relationship between costs and insomnia severity. The purpose of this study was to estimate, from the societal perspective, direct and indirect costs of insomnia. Costs were compared across three groups of participants classified as being good sleepers, having insomnia symptoms or having insomnia syndrome. The proportional contribution of insomnia to overall consultation costs and three indirect dependent cost variables, absenteeism, productivity and accidents, was also calculated.