Convergent Validity of Parent-Reported Attention-Deficit/Hyperactivity Disorder Diagnosis: A Cross-Study Comparison

Getahun et al recently published a study titled “Recent Trends in Childhood Attention-Deficit/Hyperactivity Disorder”¹ in which they used medical records and well-defined criteria to generate the prevalence of diagnosed attention-deficit/hyperactivity disorder (ADHD) in a large southern California administrative sample. Their study contributes important geographically based estimates of ADHD and draws conclusions about increasing ADHD prevalence within southern California. However, the authors cited our previous research² to support a commonly held assertion that parent and teacher reports of ADHD “overestimate true prevalence.”¹ To date, parent-reported ADHD diagnosis on national health surveys has not been directly validated against a clinical standard and thus needs further study before conclusions related to validity can be made. However, studies like that by Getahun and colleagues may inform the evidence base for the validity of using survey data for monitoring ADHD over time. Our research estimated that the parent-reported prevalence of ADHD for children aged 4 to 17 years in California was 6.2% (in 2007),² which may appear high compared with the estimate by Getahun and colleagues of 4.9% among children aged 5 to 11 years in California (in 2001-2010). Herein, we replicate our previous analyses of parent-reported ADHD with a sample more comparable to the study population analyzed by Getahun and colleagues.

To allow for descriptive comparison, we revisited our previous analyses of data from the 2007 National Survey of Children’s Health (NSCH),² further restricting the sample (73 123 children aged 4-17 years) to one more closely reflecting that used by Getahun and colleagues: specifically, children in California aged 5 to 11 years who were covered by health insurance (n = 590). The NSCH has 2 ADHD diagnostic indicators: one for having ever been told by a health care provider that a child had ADHD and the other for having current ADHD. The ADHD case definition by Getahun and colleagues was more reflective of a period prevalence rate than a point prevalence rate, suggesting that the “ever” diagnostic indicator was more appropriate for cross-study comparison. Prevalence estimates of the national, state-based, and age- and insurance-restricted NSCH survey estimates and 95% CIs of parent-reported ADHD were calculated using SUDAAN version 10.0.1 statistical software (RTI International) to account for the complex sampling design.

Based on NSCH data, nationally, 9.5% (95% CI, 9.0%-10.0%) of children aged 4 to 17 years had ever received a parent-reported ADHD diagnosis (Figure). This estimate was only slightly lower than, but statistically indistinguishable from, that of children with health insurance (9.8%; 95% CI, 9.2%-10.3%). Restricting the data to insured children aged 5 to 11 years, the national prevalence of children with a history of ADHD diagnosis decreased by 14.3%, to 8.4% (95% CI, 7.7%-9.1%). Further subsetting the age- and insurance-restricted analysis to children in California reduced the prevalence by 44.3% of the national rate, to 4.7% (95% CI, 2.5%-8.4%) of insured California children aged 5 to 11 years with a history of ADHD.

On initial inspection, the ADHD rate reported by Getahun and colleagues (4.9%) appears lower than previous² national (9.5%) and California-based (6.2%) estimates of parent-reported ADHD. However, the analyses presented here confirm previous reports of the sensitivity of these estimates to insurance status, geography, and age.^3-5 When considering these factors, the estimated prevalence of parent-reported ADHD in California closely approximates the rate of documented ADHD diagnosis in medical records of a southern California population, with the rate found by Getahun and colleagues falling within the 95% CI of the NSCH estimate of ADHD among children in California, regardless of age. Therefore, in contrast to the authors’ statements that studies relying on parent-reported cases of ADHD “overestimate true prevalence,”¹ an alternative conclusion may be drawn from this study. Specifically, the study by Getahun and colleagues provides evidence of convergent validity that demonstrates the appropriateness of parent report for monitoring state-based and national prevalence of ADHD.

Corresponding Author: Ms Visser, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Mailstop E-88, 1600 Clifton Rd, Atlanta, GA 30333 (svisser@cdc.gov).

Published Online: May 13, 2013. doi:10.1001/jamapediatrics.2013.2364

Author Contributions: Ms Visser had full access to all the data in the study and takes full responsibility for the integrity of the data and accuracy of the data analysis.

Study concept and design: Visser, Danielson, and Perou.

Acquisition of data: Blumberg.

Analysis and interpretation of data: Visser, Danielson, Bitsko, and Blumberg.

Drafting of the manuscript: Visser and Danielson.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Visser and Danielson.

Administrative, technical, and material support: Visser and Bitsko.

Study supervision: Visser and Perou.

Conflict of Interest Disclosures: None reported.