The prevalence of ADHD: its diagnosis and treatment in four school districts across two states.

OBJECTIVE: To describe the epidemiology of ADHD in communities using a DSM-IVTR case definition. METHOD: This community-based study used multiple informants to develop and apply a DSM -IVTR-based case definition of ADHD to screening and diagnostic interview data collected for children 5-13 years of age. Teachers screened 10,427 children (66.4%) in four school districts across two states (SC and OK). ADHD ratings by teachers and parent reports of diagnosis and medication treatment were used to stratify children into high and low risk for ADHD. Parents (n = 855) of high risk and gender frequency-matched low risk children completed structured diagnostic interviews. The case definition was applied to generate community prevalence estimates, weighted to reflect the complex sampling design. RESULTS: ADHD prevalence was 8.7% in SC and 10.6% in OK. The prevalence of ADHD medication use was 10.1% (SC) and 7.4% (OK). Of those medicated, 39.5% (SC) and 28.3% (OK) met the case definition. Comparison children taking medication had higher mean symptom counts than other comparison children. CONCLUSIONS: Our ADHD estimates are at the upper end of those from previous studies. The identification of a large proportion of comparison children taking ADHD medication suggests that our estimates may be conservative; these children were not included as cases in the case definition, although some might be effectively treated.

The psychometric properties of the Vanderbilt attention-deficit hyperactivity disorder diagnostic parent rating scale in a community population.

OBJECTIVE: To examine the psychometric properties of the Vanderbilt ADHD Diagnostic Parent Rating Scale (VADPRS) using a community-based sample of primarily elementary and middle school-aged children. METHOD: Participants were initially recruited from 41 elementary schools in 5 Oklahoma school districts including urban, suburban, and rural students. Vanderbilt rating scales were obtained from all teachers (n = 601) and sampled parents (n = 587) of the participating children. Construct validity was assessed by confirmatory factor analysis of the 45 items that made up the 4 scales of inattention, hyperactivity, conduct/oppositional problems, and anxiety/depression problems. Reliability was evaluated from internal consistency, test-retest, and interrater agreement perspectives. Criterion validity was evaluated via comparisons to a structured psychiatric interview with the parents using the Diagnostic Interview Schedule for Children-IV. RESULTS: A 4-factor model (inattention, hyperactivity, conduct/oppositional problems, and anxiety/depression problems) fit the data well once discarding conduct items that were infrequently endorsed. The estimates of coefficient alpha ranged from .91 to .94 and the analogous KR20 coefficient for a binary item version of the scale ranged from .88 to .91. Test-retest reliability exceeded .80 for all summed scale scores. The VADPRS produced a sensitivity of .80, specificity of .75, positive predictive value of .19, and negative predictive value of .98 when predicting an attention-deficit hyperactivity disorder (ADHD) case definition that combined teacher's Vanderbilt ADHD Diagnostic Teacher Rating Scale and parent diagnostic interview responses. CONCLUSION: The confirmation of the construct and concurrent criterion validities found in this study further support the utility of the VADPRS as a diagnostic rating scale for ADHD.

The psychometric properties of the Vanderbilt attention-deficit hyperactivity disorder diagnostic teacher rating scale in a community population.

OBJECTIVE: This study examined the psychometric properties of the Vanderbilt AD/HD Diagnostic Teacher Rating Scale (VADTRS). METHODS: Information was collected from teachers and parents in 5 school districts (urban, suburban, and rural). All teachers in participating schools were asked to complete the VADTRS on all their students. Construct validity was evaluated through an exploratory factor analysis investigation of the 35 items that made up the 4 scales of inattention, hyperactivity, conduct/oppositional problems, and anxiety/depression problems. Convergent validity was assessed among a subsample of participants whose teachers completed the Strengths and Difficulties Questionnaire (SDQ). Finally, predictive validity was examined for another subsample of high- and low-risk children whose parents completed a structured psychiatric interview, the Diagnostic Interview Schedule for Children-IV. RESULTS: For construct validity, a 4-factor model (inattention, hyperactivity, conduct/oppositional, and anxiety/depression problems) fits the data well. The estimates of the KR20 coefficient for a binary item version of the scale ranged from .85 to .94. Convergent validity with the SDQ was high (Pearson's correlations > .72) for these 4 factors. For predictive validity, the VADTRS produced a sensitivity of .69, specificity of .84, positive predictive value of .32, and negative predictive value of .96 when predicting future case definitions among children whose parents completed a diagnostic interview. CONCLUSION: The confirmation of the construct and convergent validity and acceptable scale reliabilities found in this study further supports the utility of the VADTRS as a diagnostic rating scale for attention-deficit hyperactivity disorder. The low predictive validity further demonstrates the need for multiple observers in establishing the diagnosis.