Two-fold Increased Risk for Unsatisfactory Spine Surgery Outcome Found in Workers’ Compensation Patients
Commentary by Thomas Cheriyan MD and Brook I. Martin, PhD
Patients with workers’ compensation have a 2-fold increased risk of an unsatisfactory outcome compared to patients without workers’ compensation after spine surgery, according to a meta-analysis published online ahead of print in The Spine Journal.
“This association was consistent when studies were grouped by country or procedure,” said lead author Thomas Cheriyan MD, Hospital for Joint Diseases, New York Langone Medical Center, New York, NY. “The results of this study underline the importance of taking into consideration compensation status when interpreting results, especially with regard to patient reported outcomes. Compensation status must be considered in all surgical intervention studies,” Dr. Cheriyan said.
“The study nicely summarizes the large body of evidence showing that patients undergoing spine surgery paid through the workers’ compensation system tend to have worse outcomes compared to those with commercial insurance,” commented Brook I. Martin, PhD, Assistant Professor of Health Service Research and Orthopedic Surgery at the Geisel School of Medicine at Dartmouth, Hanover, NH.
Studies Clarify Impact of Workers Compensations on Spinal Surgery Outcomes
The impact of workers’ compensation status on outcomes of spinal surgery has varied widely in previous studies, making it difficult to assess the impact of compensations status on clinical outcomes, according to the study background.
“Numerous studies have shown that compensation status results in poorer outcomes when compared to patients without worker’s compensation,” said lead author Thomas Cheriyan MD. “However, the strength of association has varied considerably from 1.3 to 7.2. This study quantifies the average strength of association between compensation status and outcomes in patients undergoing spine surgery,” Dr. Cheriyan explained.
The meta-analysis included 13 prospective and 18 retrospective studies; a total of that compare outcomes between compensated and noncompensated patients who underwent spine surgery. A total of 3,567 patients were included in the analysis, and the average followup was 4 months to 10 years. Of the 31 studies, 12 involved only decompression and 19 involved fusion.
Significantly Greater Risk of Unsatisfactory Outcomes Linked to Workers’ Compensation Status
Patients with workers’ compensation had a significantly greater relative risk for unsatisfactory outcome (2.12; P<0.001). The relative risk was similarly elevated when the authors assessed the studies by country of origin: 2.09 for studies from Europe and Australia and 2.14 for studies from the United States; P<0.01 for both. The relative risk of unsatisfactory outcome among patients receiving workers’ compensation was slightly higher for decompression-only procedures compared with fusion (2.53 and 1.79; P<0.01 for both).
A significantly greater proportion of patients with workers’ compensation did not return to work compared to those without workers’ compensation, at last follow up (43% vs 17%; P<0.001).
“While the results give us an approximate estimate of the strength of association between compensation status and unsatisfactory outcome after spine surgery, it does not provide the etiology of these findings. Further studies and efforts should be done to determine the cause of this association,” Dr. Cheriyan concluded.
Possible Mechanisms Behind the Relationship
There is a lot of debate about the possible reasons for the poorer outcomes found among patients receiving workers’ compensation, explained Dr. Martin. Some unanswered question are whether patients with workers’ compensation sustain back injuries that are substantially different from those with commercial insurers, and whether they have different comorbidities, health habits, or psychological profiles, Dr. Martin commented.
Also, it is important to consider the patients’ satisfaction with work as “we know from some studies that work satisfaction is a predictor of what patient outcomes will be following surgery,” Dr. Martin said. “Alternatively, are the [outcomes worse] because compensation systems create an adversarial environment that patients have to navigate through, struggle to sustain benefits, and maintaining their rights in?,” Dr. Martin said.
“One interesting piece in this study is that Cheriyan et al looked at whether there were different rates of successful fusion, based on x-rays, among the subset of patients who underwent a fusion surgery,” Dr. Martin noted. “There was a slight trend for a higher rate of nonunion, an undesirable outcome, among the workers’ compensation patients, but the finding was not statistically significant. That finding suggests that the higher rate of unsatisfactory outcome is not due to a worse surgical treatment,” Dr Martin said.
A related study by Dr. Martin and colleagues compared outcomes of lumbar fusion in patients covered by workers’ compensation in Washington State (which had limited coverage policies) versus in California (which had broader coverage policies) and found that the broader lumbar fusion coverage policy was associated with greater use of lumbar fusion, use of more invasive operations, more reoperations, higher rates of complications, and greater inpatient costs.
“We believe that the differences are partly due to the design of the compensation system itself. Broader coverage in reimbursement policies are associated with higher rates of use and higher rates of complications that stem from doing more complicated types of procedures,” Dr. Martin said.
“We need more research on how we can redesign workers’ compensation systems that eliminate some of the adversarial situations that patients get into. Limited studies are emerging from other countries showing that if some of the no-fault regulations are removed, it may lead to better outcomes. I think we need to study some of these mechanisms in this country,” Dr. Martin concluded.