The prevalence and workplace costs of adult attention deficit hyperactivity disorder in a large manufacturing firm.

Little is known about the effects of adult attention deficit hyperactivity disorder (ADHD) on work performance or accidents-injuries.MethodA survey was administered in 2005 and 2006 to employees of a large manufacturing firm to assess the prevalence and correlates of adult ADHD. Respondents (4,140 in 2005, 4,423 in 2006, including 2,656 in both surveys) represented 35-38% of the workforce. ADHD was assessed with the World Health Organization (WHO) Adult ADHD Self-Report Scale (ASRS), a validated screening scale for DSM-IV adult ADHD. Sickness absence, work performance and workplace accidents-injuries were assessed with the WHO Health and Work Performance Questionnaire (HPQ). The estimated current prevalence (standard error) of DSM-IV ADHD was 1.9% (0.4). ADHD was associated with a 4-5% reduction in work performance (chi12=9.1, p=0.001), a 2.1 relative-odds of sickness absence (chi12=6.2, p=0.013), and a 2.0 relative-odds of workplace accidents-injuries (chi12=5.1, p=0.024). The human capital value (standard error) of the lost work performance associated with ADHD totaled USD 4,336 (676) per worker with ADHD in the year before interview. No data were available to monetize other workplace costs of accidents-injuries (e.g. destruction of equipment). Only a small minority of workers with ADHD were in treatment. Adult ADHD is a significantly impairing condition among workers. Given the low rate of treatment and high human capital costs, in conjunction with evidence from controlled trials that treatment can reduce ADHD-related impairments, ADHD would seem to be a good candidate for workplace trials that evaluate treatment cost-effectiveness from the employer's perspective.