The Survey of Occupational Injuries and Illnesses is a Federal/State program in which employer's reports are collected annually from about 176,000 private industry establishments and processed by State agencies cooperating with the Bureau of Labor Statistics. Summary information on the number of injuries and illnesses is copied by these employers directly from their recordkeeping logs to the survey questionnaire. The questionnaire also asks for the number of employee hours worked (needed in the calculation of incidence rates) as well as its average employment (needed to verify the unit's employment-size class).
Occupational injury and illness data for coal, metal, and nonmetal mining and for railroad activities were provided by the Department of Labor's Mine Safety and Health Administration and the Department of Transportation's Federal Railroad Administration. The survey excludes all work-related fatalities as well as nonfatal work injuries and illnesses to the self employed; to workers on farms with 10 or fewer employees; to private household workers; and, nationally, to federal, state, and local government workers.
Injuries and illnesses logged by employers conform with definitions and recordkeeping guidelines set by the Occupational Safety and Health Administration, U.S. Department of Labor. Under those guidelines, nonfatal cases are recordable if they are occupational illnesses or if they are occupational injuries which involve lost worktime, medical treatment other than first aid, restriction of work or motion, loss of consciousness, or transfer to another job. Employers keep counts of injuries separate from illnesses and also identify for each whether a case involved any days away from work or days of restricted work activity, or both, beyond the day of injury or onset of illness.
Occupational injuries, such as sprains, cuts, and fractures, account for the vast majority of all cases that employers log and report to the BLS survey. Occupational illnesses are new cases recognized, diagnosed, and reported during the year. Overwhelmingly, those reported are easier to directly relate to workplace activity (e.g., contact dermatitis or carpal tunnel syndrome) than are long-term latent illnesses, such as cancers. The latter illnesses are believed to be underrecorded and, thus, understated in the BLS survey.
Survey estimates are based on a scientifically selected sample of establishments, some of which represent only themselves but most of which also represent other employers of like industry and workforce size that were not chosen in a given survey year.
For each survey, the sample used is one of many possible samples, each of which could have produced different estimates. The variation in the sample across all possible samples that could have been drawn is measured by the standard error, for which a range is shown in most tabulations requested by survey users. The data also are subject to nonsampling errors which are not measured. They include characteristic data unavailable for some cases, mistakes in recording or coding the data, and definitional difficulties. To minimize nonsampling errors, the Bureau conducts a rigorous training program for survey coders and continues to encourage survey participants to respond fully and accurately to all survey elements.
Data collected or maintained by the Bureau of Labor Statistics under a pledge of confidentiality shall be treated in a manner that will assure that individually identifiable data will be accessible only to authorized persons and will be used only for statistical purposes.
Last Modified Date: February 05, 2002