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Table 1 Characteristics of the six studies

From: The impact of childhood diagnosed ADHD versus controls without ADHD diagnoses on later labour market attachment—a systematic review of longitudinal studies

Study, country Number of subjects Age at first assessment Mean age at follow up Participants (eligible, included, completed follow-up) (%) Study age range Collection of outcomes at last follow-up Outcome measures Results
Roy et al. [16], USA, Canada, Germany 579 children with ADHD and 258 controls 7–10 years 24.7 years 476 (82%) with ADHD and 241 (93%) controls 16 years after baseline Questionnaire performed by participants and parents Occupation:Job changes (total number of times fired or quit)
Earnings: Public assistance (yes/no)
Income levels (measured on a scale of 1–10)
Education:Bachelor’s degree (yes/no)
ADHD severity predicted an increased likelihood of more job changes (number of times fired or quit) and receiving public assistance
ADHD severity predicted reduced likelihood of receiving a bachelor´s degree
Owens et al. [13], USA 140 girls with ADHD and 88 controls 6–12 years 25.6 years 123 (88%) with ADHD and 85 (97%) controls 16 years after baseline Clinic-based assessment, structured interview. Parents completed questionnaires Occupation: Life-RIFT, Problems at work, Current employment status, hours worked per week
Earnings: Receiving public assistance, current monthly salary
Education: Highest degree, years of education
No statistically significant differences among any groups on current employment, hours worked per week, receiving public assistance or current salary
Persisters (participants who met ADHD criteria in all study waves) showed significantly more problems at work. Comparisons reported significantly better functioning at work than girls with persistent ADHD. Overall, employment outcomes among comparisons were slightly better than desisters and partials (participants who met the criteria for ADHD at baseline (W1) and at third (W3) or forth (W4) study wave), but much better than persisters
Probands had finished 2 less years schooling
Hechtman et al. [8], Canada, USA 579 individuals with ADHD and 258 controls 7–10 years 24.7 years 476 (82%) with ADHD and 241 (93%) controls 16 years after baseline Questionnaire performed by participants and parents Occupation: Number of jobs, average job length, number of times fired or quit
Earnings: Current income, receiving public assistance (yes/no)
Education: Bachelor´s degree (yes/no)
Significant difference in average job length, number of times fired or quit, current income and public assistance
16.0% of ADHD participants vs. 3.2% of controls received public assistance. Persisters showed the worst outcomes and the controls the best. 22.2% of persisters and 9.6% of desisters received public assistance
Majority of ADHD group (61.7%) had a high school degree or less. Majority of control (60.8%) group had completed at least some college. 8.0% of persisters had a Bachelor´s degree, 17.8% of desisters and 37.1% of controls
Klein et al. [10], USA 207 boys with ADHD and 178 controls 6–12 years 41.4 years 135 (65%) with ADHD and 136 (76%) controls 33 years after baseline Interviews performed of trained and closely supervised doctoral level clinical psychology candidates Occupation: Hollingshead (scaled 1–8) (jobs held, job satisfaction, work relationships, latenesses, job changes, firings), Occupational function scaled 1–6)
Earnings: Annual salary
SES: 5-point scale (high score = low SES)
Education: Years of education, highest degree
ADHD group had significantly lower occupational attainment levels, but 84% of them were holding jobs. Employed probands had an annual salary $40,000 beyond the controls
Employed probands had "average" to "good work" performance. Comparisons were significantly superior (good-very good)
Probands had 2.5 fewer years of schooling then controls. Significant fewer probands had a Bachelor´s degree (16%) vs. controls (35%)
Biederman et al. [3], USA 140 with ADHD and 120 controls 6–17 years 27.1 years 79 (56%) with ADHD and 90 (75%) controls 16 years after baseline Structured clinical interviews performed of interviewers that had undergraduate degrees in psychology and were extensively trained
Interviewed all subjects and their mothers
Occupation: Hollingshead, Occupational rankings 1–9
Earnings: Financially dependent on their parents
SES: Hollingshead 5-point scale. High score = Low SES
Education: Educational level Hollingshead scale 1–7 , College graduate yes/no
Significantly lower occupational level in the ADHD group compared to controls
Men how had ADHD as boys were significantly more likely to be financially dependent on their parents and had lower social class. Boys with ADHD had significantly lower personal socioeconomic status vs. their family of origin socioeconomic status
They were also less likely to graduate from college
Mannuzza et al. [11], USA 103 boys with ADHD and 100 controls 6–12 years 25.5 years 91 (88%) with ADHD and 95 (95%) controls 13–19 years after baseline Semi-structured psychiatric interviews performed of a doctor-level clinical psychologist and a psychiatric social worker Occupation: Hollingshead Occupational rankings 1–7. Owners of small business
Education: Years of formal schooling completed, Highest degree completed, Bachelor’s degree (yes/no)
90% of both probands and controls were employed at follow-up, but probands significantly lower occupational rankings. 18% of probands and 5% of controls were owners of small businesses
Probands had significantly 2.5 fewer years of schooling then controls. Significant fewer probands had a Bachelor´s degree or higher (12%) vs. controls (49%)