Introduction: The purpose of this retrospective study was to examine the prevalence of comorbidities, resource use, direct medical costs, and the costs associated with missed work for adults diagnosed with attention-deficit hyperactivity disorder (ADHD).
Study design: From a large claims database that captures inpatient, outpatient and prescription drug services, individuals diagnosed with ADHD between the years 1999 and 2001 were retrospectively identified. The ADHD cohort (n = 2252) were matched with a non-ADHD cohort (n = 2252) on a 1: 1 ratio, based upon age, gender, metropolitan statistical area and type of insurance coverage. The ADHD cohort was compared with the non-ADHD cohort for differences in comorbidities and direct medical costs (inpatient, outpatient and prescription drug costs) using year 2001 prices.
Using data from six Fortune 200 employers, time missed from work and costs associated with absenteeism, short-term disability and worker’s compensation was examined for a subsample (n = 354) of the employees diagnosed with ADHD.
Chi-square and t-statistics were used to compare the ADHD population with the control group with regards to comorbidites and service use. Analysis of covariance and multivariate regressions were used to examine differences in days missed from work, direct medical costs and costs associated with missed work.
Results: Adults diagnosed with ADHD were significantly more likely to have a comorbid diagnosis of asthma (p = 0.0014), anxiety (p < 0.0001), bipolar disorder (p < 0.0001), depression (p < 0.0001), drug or alcohol abuse (p < 0.0001), antisocial disorder (p = 0.0081) or oppositional disorder (p = 0.0022) compared with the control group. Controlling for the impact of comorbidities, adults diagnosed with ADHD had significantly higher outpatient costs ($US3009 vs $US1492; p < 0.0001), inpatient costs ($US1259 vs $US514; p < 0.0001), prescription drug costs ($US1673 vs $US1008; p < 0.0001), and total medical costs ($US5651 vs $US2771; p < 0.0001) compared with the non-ADHD cohort. Employees diagnosed with ADHD missed significantly more days due to ‘unofficial’ absences (4.33 days vs 1.13 days; p < 0.0001).
Conclusions: The results demonstrate that adults diagnosed with ADHD have a higher prevalence of comorbidities, higher medical costs and more absences than matched individuals without ADHD. These findings suggest that there may be an opportunity for the effective treatment of ADHD to lead to cost-offsets.
Irritable Bowel Syndrome Direct Medical Cost Prescription Drug Cost Medical Claim Data Mental Illness Diagnosis
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Funding for this project was provided by Eli Lilly and Company. Kristina Secnik and Andrine Swensen are salaried employees of Lilly Research Laboratories. Maureen J. Lage is a consultant to Eli Lilly and Company. The authors have no other potential conflicts of interest. All three authors contributed equally to study design and construction of the manuscript. MJL had primary responsibility for the analyses. We would like to thank the editor and five anonymous referees for helpful comments.
American Psychiatric Association, Diagnostic and statistical manual of mental disorders. 4th ed. Washington, DC: American Psychiatric Association, 1994Google Scholar
Hill JC, Schoener EP. Age-dependent decline in attention deficit hyperactivity disorder. Am J Psychiatry 1997 Sep; 154 (9): 1323–5Google Scholar
Leibson CL, Katusic SK, Barbaresi WJ, et al. Use and costs of medical care for children and adolescents with and without attention-deficit/hyperactivity disorder. JAMA 2001 Jan 3; 285 (1): 60–6PubMedCrossRefGoogle Scholar
Zeitlin H. Continuities of childhood disorders into adulthood. In: Reder P, McClure M, Jolley A, editors. Family matters: interfaces between child and adult mental health. London: Routledge, 2000Google Scholar
Curran S, Fitzgerald M. Attention deficit hyperactivity disorder in the prison population. Am J Psychiatry 1999; 156 (10): 1664–5PubMedGoogle Scholar
Muslow MIL O’Neal KK, Murry VM. Adult attention deficit hyperactivity disorder, the family, and child maltreatment. Trauma Violence Abuse 2001; 2 (1): 36–50CrossRefGoogle Scholar
Seidman LJ, Biederman J, Weber W, et al. Neuropsychological function in adults with attention deficit hyperactivity disorder. Biol Psychiatry 1998; 44 (4): 260–8PubMedCrossRefGoogle Scholar
Selke JH. Adults with ADHD in the workplace: a descriptive analysis and evaluation of the workplace and job satisfaction [dissertation]. Berkeley (CA): University of California, 2000Google Scholar
Biederman J, Faraone SV, Lapey K. Comorbidity of diagnosis in attention deficit hyperactivity disorder. Child Adolesc Psychiatr Clin N Am 1992; 2: 335–61Google Scholar
Biederman J, Famone SV, Spencer T, et al. Patterns of psychiatric comorbidity, cognition, and psychosocial functioning in adults with attention deficit hyperactivity disorder. Am J Psychiatry 1993; 150 (12): 1792–8PubMedGoogle Scholar
Tannock R, Ickowicz A, Schachar R. Differential effects of methylphenidate on working memory in ADH/HD children with and without comorbid anxiety. J Am Acad Child Adolesc Psychiatry 1995; 34: 886–95PubMedCrossRefGoogle Scholar
Weiss M, Hechtman LT, Weiss G. ADHD in adulthood: a guide to current theory, diagnosis and treatment. Baltimore (MD): John Hopkins University Press, 1999Google Scholar
Biederman J, Wilens TE, Mick EA, et al. Psychoactive substance use disorders in adults with attention deficit hyperactivity disorder (ADHD): effects of ADHD and comorbidity. Am J Psychiatry 1995; 152: 1652–8PubMedGoogle Scholar
Biederman J, Wilens T, Mick E, et al. Pharmacotherapy of attention-deficit/hyperactivity disorder reduces risk for substance use disorder. Pediatrics 1999; 104 (2): E20PubMedCrossRefGoogle Scholar
US Census Bureau. Metropolitan and micropolitan statistical area definitions [online]. Available from URL: http://www.census.gov/population/www/estimates/metrodef.html [Accessed 2004 Oct 6]Google Scholar
Marks DJ, Newcorn JH, Halperin JM. Comorbidity in adults with attention-deficit/hyperactivity disorder. Ann N Y Acad Sci 2001; 931: 216–38PubMedCrossRefGoogle Scholar
Barr WB. Schizophrenia and attention deficit disorder: two complex disorders of attention. Ann N Y Acad Sci 2001; 931: 239–50PubMedCrossRefGoogle Scholar
Alpert JE, Maddocks A, Nierenberg AA, et al. Attention deficit hyperactivity disorder in childhood among adults with major depression. Psychiatry Res 1996; 62 (3): 213–9PubMedCrossRefGoogle Scholar
Biederman J, Faraone SV, Mick E, et al. Attention deficit hyperactivity disorder and juvenile mania: an overlooked comorbidity? J Am Acad Child Adolesc Psychiatry 1996; 35 (8): 997–1007PubMedCrossRefGoogle Scholar
Bellak L. The schizophrenic syndrome and attention deficit disorder: thesis, antithesis, and synthesis? Am Psychol 1994; 49 (1): 25–9PubMedCrossRefGoogle Scholar
Raley JJ, Greenberg MS, Bemporad JR, et al. Unrecognized attention-deficit hyperactivity disorder in adults presenting for outpatient psychotherapy. J Child Adolesc Psychopharmacol 1992; 2: 267–75CrossRefGoogle Scholar
Shekim W, Asarnow RE Hess E, et al. A clinical and demographic profile of a sample of adults with attention deficit hyperactivity disorder, residual state. Compr Psychiatry 1990; 31 (5): 533–44CrossRefGoogle Scholar
Barkley RA, Murphy KR, Dupaul GI, et al. Driving in young adults with attention deficit hyperactivity disorder: knowledge, performance, adverse outcomes, and the role of executive functioning. J Int Neuropsychol Soc 2002; 8 (5): 655–72PubMedCrossRefGoogle Scholar
Leibson CL, Katusic SK, Barberesi WJ, et al. Use and costs of medical care for children and adolescents with and without attention deficit / hyperactivity disorder. JAMA 2001; 285 (1): 60–6PubMedCrossRefGoogle Scholar
Biederman J, Milberger S, Famone SV, et al. Associations between childhood asthma and ADHD: issues of psychiatric comorbidity and familiality. J Am Acad Child Adolesc Psychiatry 1994; 33 (6: 842–8PubMedCrossRefGoogle Scholar
Biederman J, Faraone SV, Spencer T, et al. Gender differences in a sample of adults with attention deficit hyperactivity disorder. Psychiatry Res 1994 Jul; 53 (1): 13–29PubMedCrossRefGoogle Scholar
Osterberg E, Blomquist L, Krakau I, et al. A population study on irritable bowel syndrome and mental health. J Gastroenterol 2000 Mar; 35 (3): 264–8Google Scholar
Trikas P, Vlachonikolis I, Fragkiadukis N. Core mental state in irritable bowel syndrome. Psychosom Med 1999 Nov-Dec; 61 (6): 781–8PubMedGoogle Scholar
Ramsey S, Summers KH, Leong SA, et al. Productivity and medical costs of diabetes in a large employer population. Diabetes Care 2002; 25 (1): 23–9PubMedCrossRefGoogle Scholar
Birnbaum HG, Cremieux PY, Greenberg PE, et al. Using healthcare claims data for outcomes research and pharmacoeconomic analyses. Pharmacoeconomics 1999; 16 (1): 1–8PubMedCrossRefGoogle Scholar
Goetzel RZ, Hawkins K, Ozminkowski RJ, et al. The health and productivity cost burden of the “top 10” physical and mental health conditions affecting six large U.S. employers in 1999. J Occup Environ Med. 2003; 45: 5–14PubMedCrossRefGoogle Scholar
SAS User’s Guide. SAS/STAT User’s Guide: version 8. Cary (NC): SAS Institute, 1999Google Scholar
Duan, N. Smearing estimate: a nonparametric retransformation method. J Am Statist Assoc (JASA) 1983; 78 (383): 605–10CrossRefGoogle Scholar
American Academy of Pediatrics. Treatment of the school-aged child with attention-deficit/hyperactivity disorder. Pediatrics 2001; 108 (4): 1033–44CrossRefGoogle Scholar
Famone SV, Biederman J, Spencer T, et al. Attention-deficit/hyperactivity disorder in adults: an overview. Biol Psychiatry 2000; 48 (1): 9–20CrossRefGoogle Scholar
Barkley RA. Accidents and attention-deficit/hyperactivity disorder. Trends in Evidence-Based Neuropsychiatry (TEN) 2001; 3 (4): 64–8Google Scholar
Friedman SR. Emotion recognition, social skills and adult attention-deficit/hyperactivity disorder [dissertation]. Detroit (MI): Wayne State University, 2001Google Scholar
Chan E, Zhan C, Homer CJ. Health care use and costs for children with attention-deficit/hyperactivity disorder: National estimates from the Medical Expenditure Panel Survey. Arch Pediatr Adolesc Med 2002; 156 (5): 504–11PubMedGoogle Scholar