Data collection
Schedule of collection
The recruitment of patients was started in 1994. The first treatments were started in 1995 and the last should be finished in 2006. The follow-up of patients continues to the end of 2009.
Ways of collection
Patients were initially assessed before being randomly assigned to the different treatments. After this, the assessments were repeated during treatment and at follow-up, a total of 11 times. Information was collected using questionnaires, videotaped interviews, psychological tests, and laboratory measurements.
Additional information regarding health and service utilization was annually collected from nationwide population registers from the start of the study to the end of the follow-up. Register data consisted of prescription medication, periods of hospital treatment, use of rehabilitation services, causes of death, and income taxes. Therapists filled in questionnaires concerning their professional education and experience (Development of Psychotherapists Common Core Questionnaire, DPCCQ) and about the treatment process (Working Alliance Inventory, WAI).
Extent of measurements
The assessments were completed at the baseline examination and during the follow-up after 3, 7, and 9 months and 1, 1.5, 2, 3, 4, 5, 6, and 7 years. Questionnaires were administered on each of these occasions. The questionnaires administered after 3 and 9 months, and 1.5, 2, 4, and 6 years were brief. Interviews were completed at baseline and repeated twice during the first year, i.e. at 7 months and 1 year, and were thereafter carried out every second year. Psychological tests were carried out at baseline and repeated after 3 and 5 years of follow-up.
Distribution of assessments by time
| Assessment | |||
|---|---|---|---|
| Time | |||
| Questionnaire | Interview | Psychological test | |
| 0 months | X | X | X |
| 3 months | X | ||
| 7 months | X | X | |
| 9 months | X | ||
| 1 year | X | X | |
| 1½ years | X | ||
| 2 years | X | ||
| 3 years | X | X | X |
| 4 years | X | ||
| 5 years | X | X | X |
| 6 years | X | ||
| 7 years | X | X | |
Implementation of measurements
Prior to the start of therapy
The assessment process started with an evaluation of the referral in regard to the inclusion criteria. A screening questionnaire was also applied to estimate the need for treatment and eligibility to the study. The decision on eligibility was made by a psychiatrist on the basis of a questionnaire and interview. Patients completed an extensive questionnaire package, attended interviews, and participated in psychological and laboratory tests. The baseline interview was carried out in three sessions and was videotaped for quality control assessment and qualitative research. Psychological and laboratory tests were usually carried out after the second interview. A psychiatric evaluation concluded the baseline assessment. Randomization and assignment to therapy were also carried out. Patients assigned to psychoanalysis were subject to a similar assessment procedure, except for self-selection to the specific treatment and analyst.
After the start of therapy
The follow-up was started at the beginning of the therapy. Measurement with either a brief or extended protocol, as described above, was carried out at pre-determined points of time during the follow-up. Each follow-up interview comprised one interview session. The conduction of the therapies and the working alliance were monitored using questionnaires (patient and therapist versions) at all points of measurement during the therapy and on the first measurement occasion after the end of the therapy.