BLS Handbook of Methods

Chapter 9.
Occupational Safety and Health Statistics

Data Collection
State agencies mail report forms to selected employers in February to cover the previous calendar year's experience. For those States not participating in the program, reporting forms are mailed by BLS. Each employer completes a single report form which is used for both national and State estimates of occupational injuries and illnesses. This procedure eliminates duplicate reporting by respondents and, together with the use of identical survey techniques at the national and State levels, insures maximum comparability of estimates. (A copy of the reporting form and instructions is included in the print edition of the BLS Handbook of Methods.)

Summary information on the number of injuries and illnesses by type of case is copied directly from employer logs and entered in part 1 of the form. Part 1 also contains questions about the number of employee hours worked (needed in the calculation of incidence rates), the reporting unit's principal products or activity, and average employment to insure that the establishment is classified in the correct industry and employment-size class. Part 2 of the form requests detailed information on the worker and the injury or illness incident that resulted in the employee being away from work. State agency and BLS personnel edit the summary data (part 1) and code the characteristics of cases with days away from work (part 2), verifying apparent inconsistencies through phone calls, correspondence, or visits. The data are keypunched and mechanically edited. Reports which do not meet the computer screening criteria or senior staff review are verified with the employer.

By early fall, the active collection phase of the survey is completed and the preparation of data for both national and State estimates of occupational injuries and illnesses begins. Priority goes to processing the summary information on injury and illness counts by type of case, so that initial estimates of those data can be issued in mid-December. Coding and related processing of the characteristics of days-away-from-work cases continues through the following February, with initial estimates of injury and illness characteristics published in late April-early May.

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