An example of self-selection bias in follow-up research.
D000041:Absenteeism; D002648:Child; D002653:Child Behavior Disorders / Q000628:therapy; D003156:Community Mental Health Services; D003258:Consumer Behavior; D005500:Follow-Up Studies; D006801:Humans; D008722:Methods; D012106:Research; D012917:Social Adjustment; D011795:Surveys and Questionnaires