The "monitoring model" and the mortality X treatment interaction threat to validity in mental health outcome evaluation.
Symptom improvement rates among three cohorts of adult outpatients generated by a base-line monitoring model approach to outcome evaluation are presented. Follow-up questionnaire data were collected by mail. The cohorts represented approximately 40% self-selected samples from the parent populations of clients admitted for service. Efforts to interpret significant cohort improvement rate differences led to the conclusion that differences may have been the result of severely symptomatic clients differentially selecting themselves in/out of follow-up data collection. This Mortality X Treatment interaction threat to the validity of conclusions about service effectiveness is discussed in the context of Campbell and Stanley's recurrent institutional cycle design, with particular emphasis placed on reducing posttreatment data loss.
D003155:Community Mental Health Centers; D006801:Humans; D001523:Mental Disorders / Q000523:psychology / Q000628:therapy*; D010043:Outcome and Process Assessment, Health Care / Q000379:methods*; D011581:Psychological Tests