WASHINGTON—Workplace injury and illness data that the Occupational Safety and Health Administration collects from employers is inadequate, according to a Tuesday report by the Government Accountability Office.

Workplace injuries and illnesses often are underreported, the nonpartisan arm of Congress said.

The GAO said some employers avoid reporting workplace injuries and illnesses to save money on workers compensation costs and out of fear of jeopardizing rewards based on having low injury and illness rates.

Additionally, the report found that workers did not report job-related injuries because they feared being fired or did not want to let their co-workers down and risk losing rewards for maintaining safety.

The report said OSHA's audits of employers' records are inadequate and noted that OSHA does not routinely interview workers as part of its records audits.

According to the GAO, OSHA annually audits records of a representative sample of about 250 of approximately 130,000 worksites in the high-hazard industries to verify the accuracy of workplace injury and illness data. While OSHA is not required to interview workers, the GAO report said taking that step could assist evaluating the accuracy of employer records.

“Accurate injury and illness records are vital to protect workers' health and safety,” Labor Secretary Hilda L. Solis said in a statement. “They not only enable OSHA to better target its resources and determine the effectiveness of its efforts, accurate numbers are also an important tool that workers and employers can use to identify hazards in their workplaces.”

The GAO recommends that OSHA inspectors: