MEASURING ACTIVITIES IN CLINICAL-TRIALS USING RANDOM WORK SAMPLING - IMPLICATIONS FOR COST-EFFECTIVENESS ANALYSIS AND MEASUREMENT OF THE INTERVENTION

Determining research-related costs from intervention-related costs is important for both clinical and health services research. Often this t ask involves estimating what proportion of the workday personnel spend on a variety of activities. We used a portable random reminder beeper to measure the daily work activities and contacts of study nurses wit hin the context of a multi-site randomized trial designed to assess th e effectiveness of primary care. Nurses recorded 4920 work activities over 140 consecutive workdays. Research-related activities consumed th e largest proportion of the workday, 42.5% (95% CI, 38.1-46.7) followe d by patient care, 28.8% (24.1-33.2), personal time 16.4% (12.0-20.7), and time spent in transit 12.5% (9.1-15.9). Because this research-rel ated time is spent performing tasks specific to the enrollment of pati ents and measurement of outcome variables, we will use an adjusted ann ual salary for these nurses (from $56,392-$32,425) when attributing co sts of the intervention in cost-effectiveness analyses and for future management projections. Work sampling is a flexible, inexpensive metho d that was well accepted by the nurses in this study. Our results prov ide important insights into the costs analysis of complex intervention s involving health professionals and may allow us to explore why the i ntervention worked or did not work at individual sites.