Data collection and complication rates in clinical audit

Audit data were collected continuously between February 1988 and July 1991. For the initial period (February 1988-June 1990) data were collected by monitoring of ward admission and discharge records and by collecting data from operating theatre records whilst complications were noted in a 'complications book' which was kept on the notes trolley. In July 1991, when a computerized system for storing and processing audit data was introduced into the department, the methods of data collection changed. For each patient a proforma was attached to the clinical notes which was filled in at each stage of the hospital stay. On this proforma was a list of possible complications which were ticked, as appropriate, at the time of discharge from hospital. We have reviewed the results of clinical audit during these two periods. The number of operations performed per month fell slightly in the latter period (p = 0.005). However, there was a significant increase in both the number of complications (p < 0.0001) and in the complication rate (p < 0.0001). Further analysis showed that there was a similar increase in the number of recorded major and minor complications, and that this increase was also seen even when changes in medical personnel were accounted for. We suggest that the increased complication rate recorded in the latter period reflects the change in the method of data collection. This has important implications when comparing outcome measures for clinical departments.