Assessment and validation of diagnostic interviewing skills for the mental health professions

A behavioral test was developed to assess the quality of diagnostic interviewing skills of (future) mental health professionals. Two aspects of diagnostic interviewing ability are distinguished: process skills, reflecting the interpersonal and communication skills; and content skills, referring to the information-gathering ability of the interviewer. It was found that diagnostic interviewing can be reliably measured with respect to interrater reliability. However, interviewer performance on one case proved to be a poor predictor of performance on other cases. It was concluded that a large number of cases is required to obtain reliable scores of general diagnostic interviewing ability. Validity was supported by the correlational analyses. Process skills were strongly related to patient satisfaction, whereas content skills were related to the amount of relevant information given by the patient and the accuracy of the diagnostic formulation and treatment plan.