%0 Journal Article %T Timing of surgical antibiotic prophylaxis administration: Complexities of analysis %A Carrie Cartmill %A Lorelei Lingard %A Glenn Regehr %A Sherry Espin %A John Bohnen %A Ross Baker %A Lorne Rotstein %J BMC Medical Research Methodology %D 2009 %I BioMed Central %R 10.1186/1471-2288-9-43 %X Two clear challenges manifested during the data extraction process: the actual classification of antibiotic timing, and the additional complication of multiple antibiotic regimens with different timing classifications in a single case. A formalized protocol was developed for dealing with incomplete, ambiguous and unclear documentation. A hierarchical coding system was implemented for managing cases with multiple antibiotic regimens.Researchers who are tracking prophylactic antibiotic timing as an outcome measure should be aware that documentation of antibiotic timing in the patient chart is frequently incomplete and unclear, and these inconsistencies should be accounted for in analyses. We have developed a systematic method for dealing with specific problematic patterns encountered in the data. We propose that the general adoption of a systematic approach to analysis of this type of data will allow for cross-study comparisons and ensure that interpretation of results is on the basis of timing practices rather than documentation practices.The timing of prophylactic antibiotic administration is a patient safety outcome that is recurrently tracked and reported. Compliance to antibiotic prophylaxis guidelines [1-9], the effect of interventions on antibiotic prophylaxis timing [10-20], and the relationship between prophylaxis timing and the incidence of surgical site infection [21-24] are quality measures that are described in the literature. The results of the published work are unanimous in suggesting an association between properly timed antibiotic prophylaxis and a decreased rate of surgical site infections [21-30]. It is apparent that these timing data are worthwhile data to collect and the interpretation of these data has important implications for patient safety practices. However, diverse data collection methods and approaches to analysis make comparisons across studies difficult and impede knowledge building in this field. This paper describes several challenges %U http://www.biomedcentral.com/1471-2288/9/43