The Bureau of Labor Statistics (BLS), Injuries, Illnesses, and Fatalities (IIF) program, provides annual information on the rate and number of work-related injuries, illnesses, and fatal injuries, and how these statistics vary by incident, industry, geography, occupation, and other characteristics. These data are collected through the Survey of Occupational Injuries and Illnesses (SOII) and the Census of Fatal Occupational Injuries (CFOI).
The Survey of Occupational Injuries and Illnesses (SOII) is a Federal/State program in which employer’s reports are collected annually from approximately 200,000 private industry and public sector (State and local government) establishments and processed by State agencies in cooperation with the Bureau of Labor Statistics. 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 to report data in a given survey year. Summary information on the number of injuries and illnesses is transcribed by these employers directly from their recordkeeping logs to the survey questionnaire.
Injuries and illnesses logged by employers conform to definitions and recordkeeping guidelines set by the Occupational Safety and Health Administration (OSHA), U.S. Department of Labor. Under OSHA guidelines, non-fatal cases are recordable if they are occupational injuries or illnesses which involve lost work time, medical treatment other than first aid, restriction of work or motion, loss of consciousness, or transfer to another job. Employers record 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 calendar year. Overwhelmingly, reported illnesses are more often acute cases that are easier to directly relate to workplace activity (e.g., contact dermatitis or carpal tunnel syndrome), as opposed to long-term latent illnesses, such as cancers. The latter illnesses that generally would not be known until well after survey data for a particular year have been collected are believed to be under-recorded and, thus, understated in the BLS survey.
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 estimates across all possible samples that could have been drawn is measured via the sampling error, which is presented for the SOII as the percent Relative Standard Error (RSE). To calculate the 95-percent confidence interval given the percent RSE from a SOII estimate:
– Divide the percent RSE by 100 and multiply the result by the SOII estimate to determine the standard error
– Multiply the standard error by 1.96 to determine the Margin Of Error (MOE)
– The SOII estimate plus or minus the MOE is the 95-percent confidence interval
The 95-percent confidence interval is the interval centered on the sample-based estimate and includes all values within 1.96 times the estimate’s standard error. If several different samples were selected to estimate the population value (such as an injury and illness incidence rate), the 95-percent confidence interval would mean that one would be 95-percent certain that the range of these sample-based estimates would include the true population value.
The dataset contains four measures used to assess the phenomenon of occurrences of injuries and illnesses among workers by industry. Below is listed the four measures:
– Percent relative standard errors for rates of non-fatal occupational injuries and illnesses by industry
– Percent relative standard errors for numbers of non-fatal occupational injuries and illnesses by industry
– Incidence rates of non-fatal occupational injuries and illnesses by industry and case types
– Numbers of non-fatal occupational injuries and illnesses by industry and case type (thousands)
It is necessary to mention that days-away-from-work cases include those that result in days away from work with or without job transfer or restriction.
Data for Mining (Sector 21 in the North American Industry Classification System — United States, 2012) include establishments not governed by the Mine Safety and Health Administration rules and reporting, such as those in Oil and Gas Extraction and related support activities. Data for mining operators in coal, metal, and nonmetal mining are provided to BLS by the Mine Safety and Health Administration, U.S. Department of Labor. Independent mining contractors are excluded from the coal, metal, and nonmetal mining industries. These data do not reflect the changes the Occupational Safety and Health Administration made to its recordkeeping requirements effective January 1, 2002; therefore, estimates for these industries are not comparable to estimates in other industries.
Data for employers in railroad transportation are provided to BLS by the Federal Railroad Administration, U.S. Department of Transportation.
Relative standard errors were not calculated for mining, except oil and gas (NAICS 212), and rail transportation (NAICS 482).
The incidence rates represent the number of injuries and illnesses per 100 full-time workers.
