Function, injury severity early after back injury are predictors of chronic disability

Study finds patients who initially visited a chiropractor had reduced odds of chronic disability.

Patients who had high scores on the Roland-Morris Disability Questionnaire in the first few weeks after a work-related back injury were at high risk for not having returned to work 1 year later, according to a prospective population-based cohort study conducted at the University of Washington, Seattle.

Judith A. Turner, PhD, and colleagues interviewed 1,885 injured workers 3 weeks after they filed a claim for a job-related back injury, identifying several key risk factors that were early predictors of long-term disability. None, she said, was as strong a predictor as having a Roland-Morris score between 18 and 24 on a scale of 0 to 24, representing individuals with the most functional disability.

“Those in the highest category of scores had 26 times the odds of still being disabled at 1 year,” she told Orthopedics Today. “That is pretty strong, and even after adjusting for all other baseline factors that might explain disability, they still have over seven times the odds of being disabled at 1 year.”

Turner presented the findings at Spine Week 2008, where the investigators received the International Society for the Study of the Lumbar Spine prize for best clinical paper.

Injury severity

Among other factors the study identified as strong early predictors of long-term disability after work-related back injuries: radiculopathy at baseline.

“Patients with radiculopathy had between four and eight times the odds of still being disabled at 1 year when you don’t consider other factors that might be important,” she said. However, even after adjusting for other factors, the odds remained two to four times as great for them to not return to work (RTW), Turner explained.

Investigators used an injury severity scoring system they previously developed and validated from a medical records review.

Job factors

Another predictor for chronic disability was having an employer who did not offer the injured worker a job accommodation to facilitate early RTW, such as reduced hours or lighter duty work, Turner noted.

Having widespread pain early after injury also was a risk factor for chronic disability. Turner explained that other studies have also found that patients who have widespread pain are more likely to have worse outcomes in other settings such as primary care.

Patients who viewed their job as hectic were also were more likely to be out of work at 1 year.

Investigators initially looked at baseline variables believed to be associated with chronic disability in this population as individual predictors. They then grouped them into eight related domains from sociodemographic to job-related factors to establish the group or domain’s ability to predict disability.

When investigators analyzed which health care providers patients saw first after their injury vs. disability at 1 year, “Clearly, patients whose first visit for the injury was to a chiropractor had reduced odds of chronic disability,” Turner said. “That at least raises the possibility that chiropractic care was more effective in improving pain and disability or promoting RTW.”

Twenty-nine percent initially saw a chiropractor, compared to 36% who saw a primary care physician.

Older workers

The finding concerning chiropractors surprised the researchers who expected to see the best outcomes in the 7% of patients who initially saw an occupational medicine physician. “In fact, if anything, they had somewhat worse outcomes,” Turner said.

While other studies found a clear connection between older patients and chronic disability, this one did not. Older workers were no more likely than middle-aged workers to become chronically disabled.

“The final thing that was a little bit of a surprise is we would have predicted that a history of episodes of back pain in the past would be associated with worse outcomes. … That in itself was not a predictor,” but if previous back pain resulted in being out of work 1 month or more, it was a risk factor, she explained.

A red flag

Turner urged physicians to consider radiculopathy a red flag for chronic disability and not only look for early signs of physical disability in these patients, but see them regularly in the days after their injury. At each visit, ask about their activity level.

“Give them a strong message that early activity is good, that bed rest and avoiding activity are not helpful,” and encourage them to RTW as soon as possible, Turner said.

The investigators developed a disability risk screening questionnaire based on their findings and expect to start a pilot program in Washington to determine if screening and early intervention for those at high risk can prevent chronic disability after on-the-job back injuries.

For more information:
Judith A. Turner, PhD, can be reached in the Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Box 356560, Seattle, WA 98195-6560; 206-543-3997; e-mail: jturner@u.washington.edu. The study was funded by the Centers for Disease Control and Prevention National Institute for Occupational Safety and Health grant no. 1 R01 OHO4069.

Reference:
Turner JA, Franklin G, Fulton-Kehoe D, et al. Early predictors of chronic work disability: A prospective, population-based study of workers with back injuries. Presented at Spine Week 2008. May 26-31, 2008. Geneva.