Data Considerations: Sources, Availability, and Constraints

Preliminary data searches for safety and health-related information identified the US Department of Labor (USDL), Bureau of Labor Statistics (BLS) as the primary source for the baseline measures. The BLS data are primary in that BLS collects data via survey, analyzes the data, and publishes the results of their analyses annually. BLS data are the most comprehensive national data available to the public.

The Center to Protect Workers’ Rights (CPWR) was identified as an additional, secondary data source. CPWR focuses on safety and health in construction and related economics issues. CPWR is the research and development arm of the Building and Trades Department of the AFL-CIO. CPWR publishes The Construction Chart Book.15 The Chart Book is designed to summarize statistics on construction industry and employment trends. The intent of the Chart Book is to define key characteristics of the industry, while providing information about sources of data. The Chart Book was helpful in identifying ways to summarize and present health-related information.

This report provides a sampling of the type of data available from the BLS on fatal and nonfatal injuries and illnesses. The BLS disseminates data in a continuous series of annual releases from the BLS safety and health statistical series. These releases cover • Workplace Injuries and Illnesses and Characteristics of Injuries and Illnesses

Resulting in Absences from Work, from the Survey of Occupational Injuries and

Illnesses.

• Fatal Occupational Injuries, from the National Census of Fatal Occupational Injuries. The Survey of Occupational Injuries and Illnesses provides data on injuries and illnesses that are derived from a two-stage sample selection process. The first stage involves selecting establishments. The second stage involves selecting the sample of cases involving days away from work which is derived from the sample establishments. The

15

The Center to Protect Workers’ Rights. 1997. The Construction Chart Book: The US Construction Industry and Its Workers. Report D1-97. Washington, DC: The Center to Protect Workers’ Rights.

National Census of Fatal Occupational Injuries provides actual, verifiable data on

fatalities.

Survey of Occupational Injuries and Illnesses

The sample data on nonfatal occupational injuries and illnesses used in this report came from the 1994 Survey of Occupational Injuries and Illnesses of the BLS.16 In cooperation with State agencies, BLS collects information from employers17 on the number and incidence18,19 of nonfatal work-related injuries and illnesses. The survey sample selected by BLS consists of approximately 250,000 establishments in private industry. Survey data are solicited from employers having 11 employees or more in agricultural production, and from all employers in agricultural services, forestry, and fishing; oil and gas extraction; construction; manufacturing; transportation and public utilities; wholesale trade; retail trade; finance, insurance and real estate; and services (except private households). Data for employees covered by other Federal safety and health legislation are provided by the Mine Safety and Health Administration of the U.S. Department of Labor.

Each year the Survey provides estimates by industry and by State of the number of workplace injuries and illnesses, and also by the number of injuries and illnesses that involve lost work time. The average number of days away from work and the percent distribution of days away from work by industry are also given.

By recording the days away from work, the Survey provides a measure of the “seriousness” of injuries and illnesses. The majority of recorded illness cases are new illness cases that are recognized, diagnosed, and reported during the year. Long-term latent illnesses are believed to be understated in the Survey’s illness measures because they are difficult to relate directly to workplace activity.

For workers with injuries and illnesses involving time away from work, the Survey estimates the number and percent distribution of injuries and illnesses by occupation, sex, age, race, and length of service. Numbers, percent distributions, and incidence rates are also calculated by detailed nature of injury and illness, part of body affected, source of the injury or illness, and type of event or exposure leading to the incident. Cross tabulations of the worker characteristics and injury/illness circumstances are also

16

US Department of Labor. 1997. Occupational Injuries and Illnesses: Counts, Rates, and Characteristics, 1994. Bulletin 2485. Washington, DC: Bureau of Labor Statistics.

17

Construction establishments with no employees (i.e., self-employed construction workers) are not covered by the Survey.

18

Three broad categories—the recordable incidence rate (RIR), the lost workday case incidence rate (LWCIR), and the illness incidence rate (IIR)—are used to specify the incident rate.

19

The incidence rates for the RIR and the LWCIR represent the number of injuries and illnesses per 100 full-time equivalent workers and were calculated as: (N/EH) x 200,000, where N = the number of injuries and illnesses, EH = the total hours worked by all employees during the calendar year, and 200,000 = the base for 100 equivalent full-time workers (working 40 hours per week, 50 weeks per year). The incidence rate for the IIR represents the number of illnesses per 10,000 full-time equivalent workers.

available. The median and percent distribution of days away from work are estimated for each worker and case characteristic.

National Census of Fatal Occupational Injuries

The National Census of Fatal Occupational Injuries collects a systematic, verifiable count of all fatal work injuries as well as detailed information on how these events occurred. Multiple data sources are used to identify, verify, and profile fatal work