IDENTIFYING THRESHOLDS FOR CLASSIFYING CHILDHOOD PSYCHIATRIC-DISORDER- ISSUES AND PROSPECTS

Objective: To evaluate empirically the implications of choosing differ ent thresholds to classify conduct disorder and attention-deficit hype ractivity disorder for estimating prevalence, test-retest reliability of measurement, and informant (parent/teacher) agreement and for evalu ating comorbidity and associated features of disorder. Method: Data fo r the study came from problem checklist assessments done by parents an d teachers of children aged 6 to 16 years (N = 1,229) selected with kn own probability from a general population sample and from structured i nterviews obtained in a stratified, random subsample (n = 251). Result s: Estimates varied widely depending on the rationale used to set thre sholds. Percent prevalence went from 0.1 to 39.2; kappa estimates of t est-retest reliability went from .19 to .82. Parent-teacher agreement based on kappa went from .0 to .38. Relative odds between disorder and associated features varied twofold. Conclusion: Use of different rati onales to set thresholds for classifying childhood psychiatric disorde r in the general population has profound implications for what we lear n about the epidemiology of childhood disorder.