The Client Outcomes report lists the data that client outcomes are based on, not actual client outcomes. For actual client outcomes use the Client Outcomes Summary report.
The process for generating client outcomes is based on capturing the data your organization wants to base client outcomes on, and that is accomplished in different ways based on what kind of data is needed. By default data is pulled from treatment plans and discharge summaries, and consists mainly of various scores like ACE, CAR, and CATS. Capturing outcome data entails some overhead, so it is disabled by default.