Data collection and management for research studies.

All research studies, be they randomised clinical trials or epidemiological or observational studies, require appropriate, accurate, and complete data. The most important step in research (not covered in this paper), is study design. Unless there has been careful definition of the hypothesis to be tested, outcomes to be measured, and calculation of required sample size, time and resources will be wasted.l1 Researchers should consult a statistician or epidemiologist for help with this crucial stage. There are already a number of excellent articles on the design of data collection forms.5-7 This paper is based on 12 years of personal experience of designing and using data recording systems for randomised trials (including thousands of children8 9) and observational studies and is applicable to studies conducted by research personnel or health professionals. Design of questionnaires for completion by patients or parents (covered in a recent article10) is not discussed here.