[Value of telephone interview for quality assurance and therapy evaluation in child and adolescent psychiatry. Review of the literature and empirical results of participation quota and possible sampling bias].

OBJECTIVE: The incurred costs of telephone interviews are lower than those of other methods. Thus the question arises whether this method affords the necessary quality for therapy evaluation in child and adolescent psychiatry and psychopathology. A review of the literature shows higher rates of participation for telephone and personal interviews as opposed to those for questionnaires sent by mail. Results of investigations within the social sciences are inconsistent with regard to the quality of the data collected in telephone interviews. The few results available from samples from psychiatry permit no clear-cut conclusions as to the quality of such data.
METHOD: The results of two follow-up studies of former inpatients of a hospital for child and adolescent psychiatry are presented with regard to the rate of participation and the sample bias.
RESULTS: The empirical data show a higher rate of participation for telephone interviews (85%) than for either personal interviews or questionnaires sent by mail. Sample bias in telephone interviews is smaller than in the other assessment approaches.
CONCLUSIONS: Since the advantages of telephone interviews outweigh those of other methods, this method of interviewing should be used as a matter of routine for quality assurance and therapy evaluation.