DATOS investigators measured treatment outcomes by using a random sample of approximately 3,000 patients. The researchers compared patients' weekly and daily drug use for the 12 months before they entered treatment with their weekly and daily drug use 12 months after they stopped treatment. Patients in outpatient methadone treatment who were still in treatment were interviewed approximately 24 months after admission. Other outcomes the researchers measured included whether patients reported fewer illegal acts, whether patients were working full- time, and whether patients reported fewer attempts or thoughts of suicide. For the four treatment types, the study found reductions almost without exception in the use of all drugs, including cocaine, heroin, and marijuana. Even people in short-term inpatient treatment for 30 days or less improved significantly. These results verify the effectiveness of drug abuse treatment no matter what its form. 4 listed sources and 8 figures