Abstract
It is unknown if comorbid conditions account for the association between migraines and work performance. This issue was investigated in the National Comorbidity Survey Replication (n = 9282). Twelve-month severe or persistent migraines and other headaches were assessed with comorbid 12-month mental and physical disorders using the WHO Composite International Diagnostic Interview. Work performance was assessed using the WHO Health and Work Performance Questionnaire. Significant associations of these conditions with work disability disappeared with controls for comorbid disorders, but severe or persistent migraines continued to predict work loss days even with controls. Individual-level and societal-level annual human capital values were $1165 and $9.3 billion for this subset of migraines. Roughly 20% of these associations were due to comorbidity, 60% to direct effects and 20% to indirect effects through temporally secondary comorbidities. These strong associations suggest that workplace interventions for severe or persistent migraines might have a positive return-on-investment for employers.