6. Limitations of the mental health data base.

Mental health research illustrates the value and limitations of data derived from the records of long-term care institutions. Social and other nondisease factors like distance have been shown to play a significant role in determining who gets care; however, patient-related data are not sufficient to measure the prevalence, distribution, and outcome of psychiatric conditions. Rapid changes in treatment over the past 25 years have far outstripped the ability of mental health data systems to inform decision makers or evaluate new approaches. It is recommended that the long-term care basic data set include 1) adequate descriptors of the reasons other than diagnoses that explain the use of services; 2) recording of the increasingly prevalent adverse reactions resulting from treatment; and 3) sufficient identification data to link patient records from different sources and to permit follow-up studies.