Occupational injury is a major public health problem resulting in significant morbidity and mortality and a heavy economic burden. The goal of this grant was to address serious non-fatal work-related trauma by developing a surveillance system, which might provide ongoing information of adequate quality and completeness to provide a basis for preventive efforts. The original objectives or aims of the Surveillance of Serious Work- Related Trauma grant were to: 1. Develop, test, and refine a definition for serious work-related trauma; 2. Determine the feasibility of establishing a surveillance system for serious work-related trauma by linking existing sources of information, such as workers' compensation data, the existing Minnesota Department of Health (MDH) Trauma Registry, and hospital discharge records; 3. Determine reporting biases found in data compiled from different reporting sources; and. 4. Determine the magnitude, distribution, etiology, and outcome of serious work-related trauma. Aims 2,3,4 were revised and submitted to NIOSH on June 21, 2002 after the CDC Site Visit on June 18-19, 2002. The Advisory Work Group reviewed a variety of methods for developing an operational definition of "Serious Work-Related Injury" and also a sampling frame of hospital and trauma centers throughout Minnesota for a population-based study of serious injury. However, the final source of cases was 20 hospitals and medical centers that yielded more than 80 % of cases meeting study criteria during a previous calendar year. The final case definition included Minnesota residents age 2: 14 to S 65 years who were admitted for a non-fatal serious injury from January 1 through December 31, 2000 who had: a length of stay in the hospital or trauma center 2: 1 day or a UB-92 code identifying anesthesia (for outpatients); no V code as a primary diagnosis; and specific ICD-9 Codes and ICD-9 E Codes for inclusion criteria. The Association of Vital Records and Health Statistics (A VRHS) definition of work-relatedness was used. Hospital and trauma center staff of participating institutions identified subjects meeting study eligibility criteria and transferred two separate datasets of eligible cases to the MDH, one from the hospital administrative database and the other from the trauma center registry. Then a random sample of subjects from the hospital database was drawn, and subjects were contacted to determine if the injuries were work-related. Cases with work-related injuries were interviewed by telephone to determine the type of work, nature of injuries and injury event and any change in work and daily living due to the injury. Trauma center data were collected for use as a comparison dataset to assess whether data collection from trauma centers alone could provide a representative sample of serious work-related trauma in Minnesota. The study required IRB approval from all separate institutions participating in this effort, often with variations in the protocol for data collection and contact of study subjects. Conduct of this study was hindered, redirected and completely stopped by a series of events. By December of the study's final year, the Co-Principal Investigator had assumed other responsibilities within the MDH, and the Principal Investigator had absented himself from the study, ultimately resigning from the MDH. NIOSH directed the MDH to stop all study activities in February of the final year, and total study cessation occurred in May at the most critical time of data collection. A CDC Site Visit occurred in June, and approval for both study continuation and the new Principal Investigator did not occur until late August. Without IRE approval, the study could not start again until September. Although a one-year no-cost extension was obtained, no additional funding was secured and key analytic staff reduced effort in the winter and left in the spring. At the time of study cessation, participating institutions had reported 12,501 inpatient, 3,015 outpatient, and 3,889 trauma center cases meeting the study criteria. Of these cases, a random sample of 7,498 was drawn to contact for determining if injuries were work-related. Although a total of 231 interviews had been completed, the 1682 study subjects remaining could not be contacted according to IRB stipulations, therefore, interviewers were dismissed. When the study restarted four months later all outstanding data were entered and cleaned. Available interview data were double coded and entered. Due to the incomplete set of interviews designed to address the nature and outcomes of serious work-related trauma, and the loss of key personnel to complete the analysis of existing questionnaire data, hospital and trauma center data, and other study data, the results focus on basic distributions and issues speaking to the adequacy of the proposed methods and suggestions for future studies of serious work -related injury. Hospital and trauma center cases known to have work-related trauma from interview data, were screened for possible data elements consistently identifying those with serious work-related trauma. Although this effort did not produce algorithms for identifying work injuries without labor intensive interviewing, information on payer (e.g. Workers' Compensation) in hospital databases, work for income in trauma registry databases, and specific E Codes relating to workplace occurrence of injury in both hospital and trauma center data appeared useful. In addition, combining information on cases appearing in both the hospital and trauma center databases of the same institution added further information. These sources produced work-related estimates of 6.8% for the hospital database and 9.0% for the trauma center of one major medical center. In spite of the disappointment of not being able to take full advantage of the incredible amount of work represented by this effort, methodologic information of use for future research was obtained. The case definition of work-related injury or some variation would seem useful for future efforts. Obtaining outpatient data was too labor intensive for a surveillance system. Also, the demands of separate IRBs from several medical centers were time consuming and unduly complex due to institutional variations in the protocol for contacting study subjects. Based on our experience, a validation study is being discussed with the MDH's Trauma Data Bank, which has ongoing access to data from all trauma centers in Minnesota. The effort would assess the accuracy of using existing data elements such as E codes, "work for income", and Workers' Compensation and other payer information to identify work-related serious trauma.
Center for Occupational Health and Safety, Chronic Disease and Environmental Epidemiology, Health Promotion and Chronic Disease, Minnesota Department of Health, 717 Delaware Street S.E., Minneapolis, MN 55414