Abstract

Empirical research in psychotherapy, especially outcome research, has become essential in today's society with its ethical and scientific imperatives. The OQ-45.2, an instrument designed by M. Lambert to assess psychotherapy outcomes, has been validated and widely applied in the United States. It is sensitive to change in the therapeutic process and can distinguish among different populations. This paper reports preliminary data on the application of the OQ-45.2 among various populations in Santiago, Chile in order to test its validity in our context. The OQ was used among three populations within the Psychiatric Institute: outpatients beginning psychotherapy (n=173), acute inpatients (n=14), and Emergency Room patients (n=30). The control group was a population of adult students in technical education programs (n=202). We administered the OQ repeatedly to the control group in order to study the instrument's stability and reliability (test-retest). Its sensitivity to change was also assessed by applying the instrument before and after the therapeutic process. We describe the initial difficulties in applying the instrument in our context, and the formal changes we made to the test. The OQ proved to be able to distinguish between the clinical and control groups, as well as among the different subgroups within each main group. It also displayed sensitivity to change in the patient sample as a response to psychotherapy. We believe that the OQ-45.2 has not only demonstrated its validity, but is already making a contribution to psychotherapeutic reflection