Study objectives: To estimate the prevalence and associations of broadly defined (i.e., meeting full ICD-10, DSM-IV, or RDC/ICSD-2 inclusion criteria) insomnia with work performance net of comorbid conditions in the America Insomnia Survey (AIS).
Design/setting: Cross-sectional telephone survey.
Participants: National sample of 7,428 employed health plan subscribers (ages 18+).
Measurements and results: Broadly defined insomnia was assessed with the Brief Insomnia Questionnaire (BIQ). Work absenteeism and presenteeism (low on-the-job work performance defined in the metric of lost workday equivalents) were assessed with the WHO Health and Work Performance Questionnaire (HPQ). Regression analysis examined associations between insomnia and HPQ scores controlling 26 comorbid conditions based on self-report and medical/pharmacy claims records. The estimated prevalence of insomnia was 23.2%. Insomnia was significantly associated with lost work performance due to presenteeism (χ² (1) = 39.5, P < 0.001) but not absenteeism (χ² (1) = 3.2, P = 0.07), with an annualized individual-level association of insomnia with presenteeism equivalent to 11.3 days of lost work performance. This estimate decreased to 7.8 days when controls were introduced for comorbid conditions. The individual-level human capital value of this net estimate was $2,280. If we provisionally assume these estimates generalize to the total US workforce, they are equivalent to annualized population-level estimates of 252.7 days and $63.2 billion.
Conclusions: Insomnia is associated with substantial workplace costs. Although experimental studies suggest some of these costs could be recovered with insomnia disease management programs, effectiveness trials are needed to obtain precise estimates of return-on-investment of such interventions from the employer perspective.
Keywords: Insomnia; absenteeism; comorbidity; employment; epidemiology; presenteeism.