Patients respond differently to different treatment procedures.
Patients with different backgrounds and drug abuse histories may respond differently to the same treatment procedure. Differences in backgrounds between therapists and patients may influence the response to treatment. What is needed is a record, for each patient separately, of the patient's characteristics, types and amounts of outcomes achieved, treatment procedures used, and resources expended. These individual findings can then be combined to show the effectiveness of the program as a whole and of its individual parts. To understand whether and how a treatment procedure is responsible for outcomes observed, it is also useful to collect data on psychological, social, and possibly biological processes that occur within individual patients.