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Mild Traumatic Brain Injury as Function of Workplace Violence: Implications for the U.S. Workers’ Compensation System

December 12, 2024 (8 min read)

By Christopher Mahon, LexisNexis Legal Insights Contributing Author

A study published in July 2024 by Occupational and Environmental Medicine analyzed U.S. workers’ compensation claims for mild traumatic brain injuries (mTBI) caused by workplace violence (WPV).

There were two main objectives of the study:

1. To determine the incidence of mTBI as a function of workplace violence (WPV).

2. To analyze the factors that determine return-to-work (RTW) outcomes for those who suffer mTBI injuries in the workplace as a result of workplace violence.

The study, “Mild Traumatic Brain Injury Caused by Workplace Violence in a U.S. Workers’ Compensation System,” was authored by Kerri Wizner of MDGuidelines, Lincolnshire, Illinois; W. Shane Journeay of Dalhousie University’s Department of Medicine; Daniel Jolivet of The Standard, Portland, Oregon; and Justine Ahle of MDGuidelines, Lincolnshire, Illinois.

According to the authors, their study is the first to examine U.S. workers’ compensation claims for mild traumatic brain injuries caused by workplace violence. The study focused on 2015-2019 data available from the California Workers’ Compensation Information System (WCIS).

Background

Every year in the United States two to three million people sustain a traumatic brain injury (TBI). Approximately 81% of those injuries are mild traumatic brain injuries (mTBI).  

About 18% of all TBI cases are work-related. In the workplace, such injuries can be categorized as being caused by workplace violence (WPV) or not being caused by workplace violence (non-WPV).

The International Classification of Disease (ICD) codes provide categorization for mild, moderate, and severe traumatic brain injury. ICD-9 claims classified TBI as mild if the injured person suffered no loss of consciousness or loss of consciousness for less than 60 minutes. ICD-10 claims classified TBI as mild if the injured person suffered no loss of consciousness or loss of consciousness for less than 30 minutes.

Workers who experience mTBI can suffer from fatigue, headaches, and behavioral issues. For three to twelve months after the injury, they may not be able to work at levels established before the injury. Mild traumatic brain injuries are a concern for employers due to the resultant time away from work, cost of care, and volume of injuries.

Workplace mTBI injuries most commonly occur in education, healthcare, public administration (especially as it relates to correctional facilities), construction, manufacturing, and transportation industries. Such injuries are caused by a variety of events including falls, being hit by a moving object, vehicle crashes, and assaults. Resultant psychological injuries may correlate to longer absence from work and may require specialized psychological care.

Traumatic brain injuries and workplace violence exist, of course, in a larger field of all workplace injuries. In the United States during 2022, 108 million workdays were lost due to injuries and the resultant total cost including medical care, wage and productivity loss, and administrative expenses was $167 billion.

In 2021, to address the significance of workplace violence, the U.S. Congress passed legislation that required WPV prevention training. Also, the Occupational Safety and Health Administration (OSHA) provides such training to nurses.

Research Methodology

Claims data from the California WCIS was used for this study. Data was for the years 2015-2019 and covered workers whose ages ranged from 18 to 65. Data included information about the injury, worker demographics, employer information, and claim-related medical care information. Specific job information was also included. For example, job class, as defined by physical demands of the work, was included. Light, medium, heavy, or very heavy work are defined according to how many pounds, in increments from 10 to 100, are required to be lifted occasionally or frequently in the work setting.

The Occupational Safety and Health Administration (OSHA) definition of occupational violence was used for this study. The OSHA definition of such violence is “any act or threat of physical violence, harassment, intimidation, or other threatening disruptive behavior that occurs at the work site.” Recovery duration refers to the time from the date of injury until the date the worker is released back to work.

If demographic was missing, the claim was not included in the study model.

Both workplace violence and non-workplace violence injuries were compared according to categories and variables that included sex, age, income, industry, job class, location, and coexisting conditions.

Results of the Study

Statistical Information

Many of the results of this study can be reported and understood quantitatively. For example:

Regarding claims:

  • The study identified 27,307 mTBI claims.
  • 14,089 claims had release-to-work dates.

Types of injuries:

  • 83% were mild concussions.
  • 7% were mild focal TBI.
  • 8% were mild diffuse TBI.

Gender, age, income, and geographical demographics:

  • 1% workers in the study were men.
  • Median age for cohort was 43 years.
  • Median income was $38,500.
  • 92% resided in an urban setting.

Most common co-occurring codes:

  • Disease of the musculoskeletal system (30.8%).
  • Other unclassified symptoms such as headache or migraine (18.9%).
  • Mental, behavioral, and neurodevelopmental disorders (9.8%).
  • Diseases of the nervous system (9.6%) such as pain.

Leave Duration

Leave duration and costs:

  • Median leave duration: 40 days.
  • Median cost of medical services and indemnity: $16,500.

The study analyzed leave duration according to the variables of WPV, sex, age, income, job class (involving light to very heavy physical work), rural or urban work settings, and coexisting conditions.

The study found that an increase in numerical values for variables would create an increase in leave duration. For example, a male worker of older age with a higher income involved in heavy work would have an expected higher leave duration. (In this study, for comparative purposes, females were assigned a numerical value of 0 and males a numerical value of 1.)

The authors concluded that “only age and coexisting conditions were statistically important across these variables.” No significant difference was found for leave duration between WPV and non-WPV mTBI injuries.

Workplace Violence vs. Non-Workplace Violence

Days away from work:

  • WPV: 36 days away from work.
  • Non-WPV: 40 days away from work.

Associated costs:

  • Costs related to WPV: $15,228
  • Costs related to non-WPV: $16,737

Those with WPV claims tended to be younger, have higher income, and be in the education, public administration, or healthcare industries with sedentary or light physical demands at work.

In this study, 11.2% of mTBI claims were caused by WPV. This rate of 11.2% is higher than the rates found in Canada (6.6%) and Australia (9%) for similar claims.

Industries with High Amount of WPV mTBI Workers’ Compensation Claims

The industries with the highest amount of WPV mTBI workers’ compensation claims in this study were educational services, public administration, healthcare, and social services.

According to the study, “The three industries with the highest WPV mTBI claims had the largest proportion in the following locations: educational services—elementary and secondary schools (71.1%); public administration—correctional institutions (22.8%); and healthcare and social assistance— general medical and surgical hospitals (29.3%).”

Study Limitations

Systems of measurement may not be perfectly accurate for a number of reasons. Workers’ compensation claims may not represent the total amount of injuries and disorders. Certain injury-specific trends cannot be measured or inferred from this data set. There are varying definitions of TBI, which creates difficulties when comparing international rates and severity of injury, which also affects comparisons regarding medical care, research, and preventive efforts.

In this study, removing claims that had no release-to-work date may have created bias in the data for either less severe or more severe injuries. Less severe injuries may not have required a release-to-work date; more severe injuries may not have included a date due to medical necessity. However, one analysis was conducted for claims that had no release-to-work date, and results from that study showed no significant change in the “direction or magnitude of the findings.”

Key Takeaways

  • The two industries with the most WPV-related mTBI claims in this study were public administration and educational services, which accounted for 20.1% and 15.8% of the claims, respectively. Industries with the next highest amount of claims were health care and social services.
  • There is no significant difference for recovery duration for WPV mTBI claims and non-WPV mTBI claims, which was contrary to the hypothesis of the authors, who originally thought WPV would result in longer recovery times for mTBI.
  • Age of worker and coexisting conditions did statistically affect RTW outcomes. Other factors that may affect RTW are job class, income, education level, sex, and number of coexisting conditions.
  • Return-to-work (RTW) outcomes may be improved when there is a supportive employer and medical care teams focused on RTW. According to one study, work environment was more important for RTW success than the worker’s sociodemographic status and the predictors related to the worker’s injury.
  • Measuring the amount of time necessary for an employee to return to work is an important means by which successful care can be measured.
  • There is no significant difference for U.S. dollar costs associated with WPV mTBI claims and non-WPV mTBI claims.
  • The invisible nature of brain injuries suggest recovering workers need positive validation, gradual RTW, and modified work expectations following the injury.
  • 11.2% of the mTBI claims in this study were caused by workplace violence.

Future Research

Future research on workplace violence, especially as it relates to mTBI, may be conducted in three specific areas:

  • Identifying the specific source of workplace violence, and then determining which prevention strategies can best reduce the possibilities of such violence.
  • How job class affects workplace violence workers’ compensation claims.
  • How other types of conditions related to workplace violence, such as post-traumatic stress, affect worker recovery and workers’ compensation claims.

The research of this study and all future relevant research can help to improve worker recovery and reduce the possibility of workplace violence. 

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