Firstly through review process the clinical findings and laboratory results can be accurately found. 

If there's any questions about the laboratory findings (for example, if the laboratory tests are inconsistent with the clinical and epidemiologic findings), can ask a qualified laboratorian to review the laboratory techniques being used. 

Secondly through review process investigators — clinicians and non-clinicians —can find it useful to visit one or more patients with the disease. If we do not have the clinical background to verify the diagnosis, bring a qualified clinician in team. Talking directly with some patients gives  a better understanding of the clinical features, and helps to develop a mental image of the disease and the patients affected by it. In addition, conversations with patients are very useful in generating hypotheses about disease etiology and spread. They may be able to answer some critical questions: What were their exposures before becoming ill?