Service evaluation is designed and conducted solely to define or judge current care and should answer the question: "What standard does this service achieve?"
It should measure current service without reference to a standard and involve an intervention in use only. (The choice of treatment is that of the clinician and patient according to guidance, professional standards and/or patient preference and this should happen before service evaluation).
Service evaluation usually involves analysis of existing data but may include administration of interview or questionnaire. There should be no randomisation and service evaluation does not require NHS REC review.