Assessment of clinical trial safety data for industry, regulatory agencies, medical practitioners and patients requires definition and measurement, monitoring, and overall analysis. Prospective 'safety' definitions and reliable measurement tools reduce inefficient data collection and improve the validity of resulting analyses. Statistical tools can help investigators monitor safety data from controlled clinical trials and help improve post-marketing surveillance. Also, when evaluating overall safety, one needs to assess all available information by combining information from many trials and other sources. Planning for this combined assessment, incorporating flexibility to assess unanticipated yet important nuances in individual trials, may be more important than the actual statistical analysis method used. A keen awareness of the future needs of consumers of this information is quite important. Some current proposals to combine safety information will be discussed.