This 3-year collaborative research project was designed to provide empirical evidence to substantiate the impact of various employer policies and practices on the prevention and management of workplace disability. It studied a random sample of 220 Michigan establishments with more than 100 employees from seven different industries who responded to a mail survey in the first half of 1991. The study correlates differences in employer-reported levels of achievement on policy and practice dimensions with performance on disability outcome measures, while controlling for a set of establishment characteristics in a multivariate regression analysis. There are three sets of policy and practice interventions evaluated here. First is safety intervention, that is, the attempt to prevent injuries from happening at all (measured as Safety Diligence, Ergonomic Solutions, and Safety Training). Second is disability management, the set of strategies to minimize the disability consequences of a given injury or disease arising from the workplace (measured as Disability Case Monitoring and Proactive Return-to-Work Program). Third is health promotion, which represents an attempt to intervene directly with individuals to encourage more healthy lifestyles, in the expectation that this will reduce the likelihood of a workplace accident or disease, or reduce the lost worktime resulting from a given injury or disease (measured as Wellness Orientation). In addition, a fourth dimension was included to capture the general environment of the firm and the orientation of its management in areas relevant to the study (measured as People Oriented Culture and Active Safety Leadership). These interventions and the general environment of the firm were scored on this set of eight variables which represent self-rated firm achievement of the policy and practice dimensions. The marginal effect of these interventions is determined by comparing firm performance on the incidence of work-related disability (Lost Workday Cases and Workers' Compensation Wage-Loss Claims), the duration of disability (Lost Workdays per Case), and overall disability prevention and management performance (Total Lost Workdays). Our results show that a higher self-rating on Safety Diligence is strongly associated with better performance on disability outcomes, varying with the specific measure. Higher self-rating on Proactive Return-to-Work Programs is also strongly associated with better performance outcomes. Safety Training and Active Safety Leadership is shown to have significant effects on the number of Lost Workday Cases. For example, on the summary measure of total Lost Workdays per 100 Employees, 10 percent better self-rating on Safety Diligence translates into 17 percent fewer lost workdays, and 10 percent better self-rating on Proactive Return-to-Work Programs translates into 7 percent fewer lost workdays. Thus, the twin strategies of trying to prevent injuries in the first place, and working to ameliorate their disability effects through disability management techniques, are both shown to be productive in reducing workplace disability in those establishments that have implemented them rigorously. Disability Case Monitoring could not be shown to have significant effects; in fact, Disability Case Monitoring had negative impacts in some cases. This probably reflects the controlling aspects of Disability Case Monitoring, as we speculate that these practices can be viewed by the employees as negative and interfering if they do not emanate from a supportive company human resource climate. Ergonomic Solutions and Wellness Orientation generally do not perform significantly, and this is attributed to their indirect connection to the performance outcomes used here or ineffective measurement of these dimensions in the study. Site visits were made to a subsample of 32 firms selected from the larger, random sample in order to confirm the quantitative survey findings and gain operational understanding of successful policies and practices contributing to low disability rates. Companies were generally found to be most advanced in their safety efforts, very active in injury management, and had implemented at least some form of return-to-work. Health promotion strategies to prevent specific work injuries have not yet been fully developed. The disability prevention efforts of successful firms use data effectively to measure performance, identify problems, guide actions taken, and motivate active support and participation of management, supervisors and line employees. Successful firms rigorously investigate injuries and communicate their commitment by immediately responding to risks when they are identified. In these low-disability firms, safety and disability management are viewed as components of quality, productivity and financial stability. Working relationships have been developed with responsive health care providers to assure effective injury management, but firms also maintain an active role in case management themselves. Their return-to-work process is systematic, yet flexible to respond to individual needs. Innovative firms have also implemented ergonomic principles to prevent risks. Nearly all companies visited reported increasing incidence and costs due to cumulative trauma and repetitive motion disorders. Additional strategies are needed to resolve and prevent these disabilities. This study demonstrates that many employers have moved aggressively to policies and practices designed to reduce the incidence and the costs of disability in their workplace. The project concludes that disability can be prevented and managed; and those who do it well can expect to be rewarded with lower disability costs, more satisfied workers, higher productivity and, ultimately, higher profits.