Many studies have shown that patients hurt on-the-job and covered under Workers’ Compensation (WC) have worse results after rotator cuff repair compared to those who do not have WC claims. The reasons for this difference still aren’t clear.
A recent study from Brown University in Rhode Island may help shed some light on this. Researchers tested individual factors to see if they could find a specific cause for the worse results in WC patients. The research method they used was a multivariable analysis. This statistical analysis helps show the effect of each factor studied while controlling for other factors that could confuse the results.
They did this by just studying patients treated by one single surgeon. This approach helps eliminate differences from one surgeon to another. Each patient had a full-thickness tear with symptoms lasting for more than three months despite conservative care.
Several other measures were taken before and after surgery to help identify factors that could explain the differences in results between WC patients and non-WC patients. Each patient was examined and gave the surgeon a complete medical history. They also completed a series of questionnaires to assess pain level, function, expectations, general health, and psychosocial status.
After all the data was collected and carefully analyzed, the Workers’ Compensation group did have worse performance and worse improvement in all areas (compared to the non-WC group). When all other things were equal, the main difference was whether or not the patient had a WC claim. To put this in research terms, we would say that Workers’ Compensation status is an independent predictor of worse outcomes.
Sex, duration of symptoms, size of the rotator cuff tear, and number of other health problems did not seem to make a difference between the two groups. Everyone in both groups improved from before surgery to after surgery. But the general trend was for WC patients to have lower function on the SST and DASH tests. Level of pain and quality of life were worse for the WC patients. And they showed overall less improvement.
Why is this? Well, we still don’t know. There is always the possibility that secondary gain is the underlying factor. Secondary gain refers to the patient’s hope of receiving a financial reward for his or her injury. This study did not assess that factor directly. Measuring results before and after the claim has been settled may help shed some light on the effect of secondary gain.
For now, the authors could only say that a WC claim has a negative effect on the short-term results of a rotator cuff repair. And they pointed out that there are other variables they didn’t test for. Further studies are needed to assess the effect of anatomic factors (tendon quality, repair strength). Long-term results of this study (five to 10 years later) may show that when it’s all said and done, outcomes are equal.