The impact of comorbidity of mental and physical conditions on role disability in the US adult household population.

CONTEXT: There is limited information that accounts for comorbidity on the impact of role disability associated with a wide range of mental and physical disorders in population-based samples. OBJECTIVE: To estimate the comparative effects of common mental and physical conditions on role disability in the general population using a novel method that accounts for comorbidity. DESIGN: Direct interviews about physical and mental conditions during the past year. SETTING: The National Comorbidity Survey Replication, a nationally representative series of face-to-face interviews. PATIENTS: A nationally representative sample of adults living in households (N = 5962 respondents, 18 years and older). MAIN OUTCOME MEASURE: Disability in major life roles was assessed with the World Health Organization Disability Assessment Schedule. Simulations that allow for complex interactions among conditions were used to estimate the conditions' effects on disability days, when respondents were completely unable to carry out their usual daily activities because of problems with mental or physical health, in the past 12 months. RESULTS: An estimated 53.4% of US adults have 1 or more of the mental or physical conditions assessed in the survey. These respondents report an average 32.1 more role-disability days in the past year than demographically matched controls, equivalent to nearly 3.6 billion days of role disability in the population. Musculoskeletal disorders and major depression had the greatest effects on disability days. Mental conditions accounted for more than half as many disability days as all physical conditions at the population level. Associations of specific conditions with disability decreased substantially after controlling for comorbidity, suggesting that prior studies, which generally did not control for comorbidity, overestimated disease-specific effects. CONCLUSION: The staggering amount of health-related disability associated with mental and physical conditions should be considered in establishing priorities for the allocation of health care and research resources.

Prevalence and effects of mood disorders on work performance in a nationally representative sample of U.S. workers.

OBJECTIVE: Research on the workplace costs of mood disorders has focused largely on major depressive episodes. Bipolar disorder has been overlooked both because of the failure to distinguish between major depressive disorder and bipolar disorder and by the failure to evaluate the workplace costs of mania/hypomania. METHOD: The National Comorbidity Survey Replication assessed major depressive disorder and bipolar disorder with the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI) and work impairment with the WHO Health and Work Performance Questionnaire. A regression analysis of major depressive disorder and bipolar disorder predicting Health and Work Performance Questionnaire scores among 3,378 workers was used to estimate the workplace costs of mood disorders. RESULTS: A total of 1.1% of the workers met CIDI criteria for 12-month bipolar disorder (I or II), and 6.4% meet criteria for 12-month major depressive disorder. Bipolar disorder was associated with 65.5 and major depressive disorder with 27.2 lost workdays per ill worker per year. Subgroup analysis showed that the higher work loss associated with bipolar disorder than with major depressive disorder was due to more severe and persistent depressive episodes in those with bipolar disorder than in those with major depressive disorder rather than to stronger effects of mania/hypomania than depression. CONCLUSIONS: Employer interest in workplace costs of mood disorders should be broadened beyond major depressive disorder to include bipolar disorder. Effectiveness trials are needed to study the return on employer investment of coordinated programs for workplace screening and treatment of bipolar disorder and major depressive disorder.

The prevalence and effects of adult attention deficit/hyperactivity disorder on work performance in a nationally representative sample of workers.

OBJECTIVE: The prevalence and workplace consequences of adult attention deficit/hyperactivity disorder (ADHD) are unknown. METHODS: An ADHD screen was included in a national household survey (n = 3198, ages 18-44). Clinical re-interviews calibrated the screen to diagnoses of Diagnostic and Statistical Manual of Mental Disorders, 4th edition ADHD. Diagnoses among workers were compared with responses to the WHO Health and Work Performance Questionnaire (HPQ). RESULTS: A total of 4.2% of workers had ADHD. ADHD was associated with 35.0 days of annual lost work performance, with higher associations among blue collar (55.8 days) than professional (12.2 days), technical (19.8 days), or service (32.6 days) workers. These associations represent 120 million days of annual lost work in the U.S. labor force, equivalent to dollar 19.5 billion lost human capital. CONCLUSIONS: ADHD is a common and costly workplace condition. Effectiveness trials are needed to estimate the region of interest of workplace ADHD screening and treatment programs.

Using the World Health Organization Health and Work Performance Questionnaire (HPQ) to evaluate the indirect workplace costs of illness.

This report presents an overview of methodological issues in estimating the indirect workplace costs of illness from data obtained in employee surveys using the World Health Organization Health and Work Performance Questionnaire (HPQ). The HPQ is a brief self-report questionnaire that obtains three types of information: screening information about the prevalence and treatment of commonly occurring health problems; information about three types of workplace consequences (sickness absence, presenteeism, and critical incidents); and basic demographic information. The report considers two sets of methodological issues. The first set deals with measurement. The rationale for the HPQ approach to measurement is described in this section. In addition, data are presented regarding the accuracy of HPQ measures, documenting that the HPQ has excellent reliability, validity, and sensitivity to change. The second set of methodological issues deals with data analysis. A number of analysis problems are reviewed that arise in using self-report nonexperimental survey data to estimate the workplace costs of illness and the cost-effectiveness of treatment. Innovative data analysis strategies are described to address these problems.

The World Health Organization Adult ADHD Self-Report Scale (ASRS): a short screening scale for use in the general population.

BACKGROUND: A self-report screening scale of adult attention-deficit/hyperactivity disorder (ADHD), the World Health Organization (WHO) Adult ADHD Self-Report Scale (ASRS) was developed in conjunction with revision of the WHO Composite International Diagnostic Interview (CIDI). The current report presents data on concordance of the ASRS and of a short-form ASRS screener with blind clinical diagnoses in a community sample. METHOD: The ASRS includes 18 questions about frequency of recent DSM-IV Criterion A symptoms of adult ADHD. The ASRS screener consists of six out of these 18 questions that were selected based on stepwise logistic regression to optimize concordance with the clinical classification. ASRS responses were compared to blind clinical ratings of DSM-IV adult ADHD in a sample of 154 respondents who previously participated in the US National Comorbidity Survey Replication (NCS-R), oversampling those who reported childhood ADHD and adult persistence. RESULTS: Each ASRS symptom measure was significantly related to the comparable clinical symptom rating, but varied substantially in concordance (Cohen's kappa in the range 0.16-0.81). Optimal scoring to predict clinical syndrome classifications was to sum unweighted dichotomous responses across all 18 ASRS questions. However, because of the wide variation in symptom-level concordance, the unweighted six-question ASRS screener outperformed the unweighted 18-question ASRS in sensitivity (68.7% v. 56.3%), specificity (99.5% v. 98.3%), total classification accuracy (97.9% v. 96.2%), and kappa (0.76 v. 0.58). CONCLUSIONS: Clinical calibration in larger samples might show that a weighted version of the 18-question ASRS outperforms the six-question ASRS screener. Until that time, however, the unweighted screener should be preferred to the full ASRS, both in community surveys and in clinical outreach and case-finding initiatives.