Prognostic studies examine the effect of variables, like surgical Intervention, on disease progression. When posed with a Clinical question around Outcomes and Prognosis, clinicians need to know how to best answer it by Searching the literature. Prognostic studies can have a variety of designs; the optimal design depends on the question posed. Generally, Observational studies provide the highest confidence in estimates for prognosis. The Evaluation of a prognostic study hinges on six questions: (1) Is the sample representative of my patient? (2) Is the follow-up sufficiently long and complete? (3) Are the assessed outcomes objective and unbiased? (4) How likely are the outcomes to occur over time? (5) How precise are the estimates? and (6) Can I apply the results to my practice or patient? Using a clinical example, this chapter demonstrates how to identify and Appraise prognostic literature by answering each question.