[Key factors in design of case report form].

Case report form (CRF) is a key document for data collection in clinical trials. A well-designed CRF is required for database construction, data accuracy, data query/cleaning, CRF completion and statistical analysis. A well-defined process or SOP should be in place for CRF design. Data collection should fully meet the demand of study protocol. The layout of CRF should be clear with well-structured fields and standard coding for fields.