This investigation focused on alternative methods for evaluating the impact of Chevron Corporation's Health Quest Fitness Center program on medical expenditures, comparing descriptive and multivariate research designs. Many uncontrolled studies of corporate health management programs base estimates of program effectiveness on descriptive analyses such as Student's t tests. Unlike more sophisticated multivariate analyses, descriptive analyses often produce biased estimates of program cost savings. To test alternative research design methods, the investigators compared inpatient and pharmacy expenditures for program participants and non-participants over a 2.5-year period, using descriptive and multivariate regression analyses. Results showed that compared with non-participants, expenditures for participants were significantly lower for subjects who used a Health Quest fitness center at least twice weekly. Previous descriptive studies suggested a much broader impact. The results underscore the need to use multivariate analyses when evaluating the financial impact of corporate health management programs, especially when randomization cannot be used to assign participation status.