Job-Related Musculoskeletal Injuries and Illnesses as Reported in the BLS Survey of Occupational Injuries and Illnesses

William L. Weber

Bureau of Labor Statistics
2 Massachusetts Avenue N. E.
Room 3180 Washington, D. C. 20212

ABSTRACT

The Bureau of Labor Statistics (BLS) Survey of Occupational Injuries and Illnesses gathers data annually on the number and incidence of non-fatal occupational injuries and illnesses affecting workers in private industry. Since 1992, the survey also has provided information on the demographic characteristics of injured and ill workers who required recuperation away from work and on the circumstances of their injuries and illnesses. The worker demographics include: industry, occupation, gender, age, length of service, and race or ethnicity. The injury and illness circumstances include: the nature of the injury or illness, the part of body affected, the event or exposure leading to the injury or illness, and the primary and secondary sources of the injury or illness. The survey also provides the median days away from work resulting from job-related injuries and illnesses by worker characteristic and injury and illness circumstance.

This paper profiles ten categories of musculoskeletal injuries and illnesses reported by the 1995 survey. The characteristics of workers who experienced musculoskeletal injuries and illnesses during the four year period are described. The events and exposures that led to these injuries and illnesses are identified. The materials, tools, equipment, and substances that directly inflicted the injury or illnesses, that is, the sources of the injuries and illnesses are described. When meaningful, cross-tabulations of the worker characteristics and injury/illness circumstances are presented.

INTRODUCTION

The 1995 Survey of Occupational Injuries and Illnesses sampled approximately 250,000 private industry establishments nationwide. Survey data are gathered from employers with 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). The Mine Safety and Health Administration of the Department of Labor and the Federal Railroad Administration of the Department of Transportation provide information for establishments covered under corresponding federal safety and health legislation.

Two stages of sampling are employed for the survey: selection of establishments and selection of cases involving days away from work. The total number of lost workday injuries and illnesses is used as the sample design variable for the establishment sample. Establishments are stratified by State, Standard Industrial Classification (SIC), and employment size class. The Neyman allocation procedure is used to allocate the total sample by strata. A systematic random sampling technique is used to select samples within each strata. The establishment sample is designed to produce national data at the 2 digit SIC level in agriculture, forestry and fishing; at the 3 digit SIC level in oil and gas extraction; construction; transportation and public utilities; wholesale and retail trade; finance, insurance, and real estate; and services; and at the 4 digit SIC level in manufacturing.

The sampling of injury and illness cases involving days away from work varies by establishment. The expected number of cases involving days away from work is computed for each sampled establishment based on its industry and size class. If the expected number of cases involving days away from work exceeds 20, the establishment is asked to provide detailed case information for only those cases that occurred during a specified time period (certain months or days of the month). Time periods are sampled across the entire year and randomly assigned to the establishments. Thus, the survey estimates represent injuries and illnesses that occur throughout the reference year. For establishments with an expected case load of 20 or fewer injuries and illnesses involving days away from work, the employer is asked to provide detailed case information for all injuries and illnesses that involve recuperation away from work. About 96 percent of the sample is asked to provide data for all cases involving days away from work.

The survey is collected by BLS and participating State agencies who fund 50 percent of the collection costs. State specific estimates are available for the participating States for the same industry levels described above for the national program. Thirty-eight States participated in the 1995 survey. BLS collects the national sample units in the non-participating States and the District of Columbia. State specific data are not available for the non-participating States.

METHODS and RESULTS

The survey is collected by mail. Sample establishments receive a two part questionnaire. In Part 1, they are asked to report their average employment for the year, the total hours worked by all workers during the year, and the totals for the year from their Occupational Safety and Health Administration Log and Summary of Occupational Injuries and Illnesses (OSHA form 200). The reported hours worked are the exposure base for estimating incidence rates. The reported employment is used to ratio adjust the survey estimates to reflect differences in the universe between the survey reference period and the time period for which the sample was selected.

The OSHA log totals for the establishment include the number of: injuries with days away from work or restricted workdays or both; injuries with days away from work; total days away from work; total days of restricted work activity; injuries without lost workdays; six specific illness types; illnesses with days away from work, or restricted workdays or both; illnesses with days away from work; total days away from work; total days of restricted work activity; and illnesses without lost workdays. The six illness types for which totals are gathered are: skin diseases or disorders, dust diseases of the lungs, respiratory conditions due to toxic agents, poisoning, disorders due to physical agents, and disorders associated with repeated trauma. All injury and illness information gathered by the survey has been maintain by the employer under OSHA record keeping requirements.

In Part 2, employers are asked to report demographic information about workers with injuries and illnesses involving days away from work and to provide details about the incident. The worker demographic information that is requested includes: approximate length of service with the employer, race or ethnic background, age, gender, and occupation. The data about the incident includes: date of the injury or illness, number of days away from work, number of days of restricted work activity, the activity the employee was engaged in at the time of the injury or illness exposure, how the injury or illness occurred, the nature of the injury or illness, and the object or substance that directly harmed the worker.

The information reported in Part 2 of the survey for injuries and illnesses involving days away from work is coded by trained coders in the participating States and at BLS using standardized classification systems. The worker's occupation is classified using the Bureau of the Census occupational coding system. The nature of the injury or illness, the part of body affected, the primary and secondary source of the injury or illness, and the event or exposure leading to the injury or illness is coded using the BLS Occupational Injury and Illness Classification system. This injury and illness coding system has been adopted by the American National Standards Institute as a national standard for classifying work related injuries and illnesses.

The BLS estimates the number and incidence of job-related injuries and illnesses by SIC for each variable reported under Part 1 of the survey as described above. From Part 2 of the survey, the number of injuries and illnesses involving days away from work is estimated by SIC, occupation, age of worker, gender, length of service, and race/ethnic origin. Because the survey does not gather hours worked by occupation, age, gender, length of service, or race/ethnic origin, incidence rates for these variables are not available. The number and incidence of occupational injuries and illnesses that require recuperation away from work are estimated by SIC, nature of the injury/illness, part of body affected, source, and event or exposure. BLS also estimates the number and incidence (except for occupation, age, gender, length of service, and race/ethnic origin combinations) of injuries and illnesses for all two-way cross tabulations of SIC, worker demographics and case circumstances. All estimates that meet BLS release criteria are available on the INTERNET. The BLS maintains a query capability to generate estimates for cross tabulations of more than two variables, for example SIC by occupation by nature.

The percent distribution of injuries and illnesses involving days away from work is estimated by the duration of time away from work, that is 1, 2, 3 to 5, 6 to 10, 11 to 20, 21 to 30, and 31 days or more. The median days away from work is also estimated. These measures of time away from work are available by SIC, occupation, age of worker, gender, length of service, race or ethnic origin, nature of injury or illness, part of body, source, and event or exposure and for all two-way cross tabulations of these variables. The distribution of days away from work and medians for additional cross tabulations may be obtained through queries.

CONCLUSIONS

This report profiles ten disabling conditions that are commonly considered musculoskeletal disorders out of the several hundred categories of work injuries and illnesses experienced by American workers during 1995. These 10 conditions are:

• Sprains, strains, tears
• Sprains and bruises
• Fractures
• Fractures and other non-burn injuries
• Dislocations
• Back pain, hurt back
• Soreness, pain, hurt, except the back
• Carpal tunnel syndrome
• Tendonitis and other rheumatisms, except the back
• Sciatica, lumbago, and other dorsopathies

The ten conditions are selected from a larger group that might be considered disorders affecting the musculoskeletal system and connective tissue. Two views of each condition are presented: A distribution of the number of injuries or illnesses by occupation of the injured and ill workers and a distribution by the major events or exposures that led to the condition.