Spinal surgery has a well-recognized failure rate, with a substantial minority of patients failing to improve post-operatively. This rate varies depending on the underlying diagnosis, patient characteristics, magnitude of surgery, and definition of failure. Regardless of the cause of failure, many patients who do not improve continue to use healthcare resources and fail to return to work. In order to get a better sense of the association between patient-reported outcomes (PROs) and post-operative costs, Amanda Hansson-Hedblom and colleagues from Sweden analyzed the Swedish Spine Registry and the Swedish Board of Health and Welfare's patient register. They included over 12,000 patients who had undergone lumbar spine surgery between 2000 and 2012 and who had data recorded in the registries. Based on their responses to a global assessment question, the patients were classified as successful ("pain has disappeared" or "pain is much improved"), undetermined ("pain somewhat improved") or unsuccessful ("no change in pain" or "pain has worsened"). They also compared changes in VAS leg and back pain, ODI, and EQ-5D to their global outcome classification and found that the successful group had change scores that exceeded the MCIDs in the literature for these outcomes, the undetermined group had changes scores at or below MCIDs, and the unsuccessful group had scores that were well below the MCIDs. Overall, 67% of patients were classified as successful, 16% as undetermined, and 17% as unsuccessful. The successful group was younger (52 vs. 60 in the unsuccessful group), included a slightly lower proportion of females (49% vs. 54%), had a higher rate of tertiary schooling (30% vs. 19%), a somewhat higher income (€207/day vs. €173/day), were more likely to be born in Sweden (79% vs. 67%), had a lower comorbidity index (0.26 vs. 0.49), and were less likely to be taking antidepressants (12% vs. 18%). They were less likely to be treated with a decompression alone (31% vs. 53%) and more likely to undergo discectomy (42% vs. 19%). The authors did not stratify outcomes by underlying diagnosis, though the distribution of procedures among the outcome groups suggests that the successful group included more disc herniation patients, and the unsuccessful group included more spinal stenosis patients. Not surprisingly, both direct medical costs and indirect social costs (i.e. missed work) were much higher for the unsuccessful group, with the indirect costs totaling about 80% of total costs. At 2-3 years after surgery, total costs were €1517/month for the unsuccessful group compared to €525/month for the successful group. Compared to the baseline 3 years prior to surgery, this represents a €716/month increase for the unsuccessful group and a €53/month increase for the successful group.
This is a well-done registry study evaluating the costs to society of failed spine surgery. Fortunately, about 2/3 of patients had a successful outcome with relatively low post-operative costs. The undetermined and unsuccessful groups continued to have high costs to society, predominantly in missed work and social insurance payments. While the authors did not specifically evaluate predictors of failure, the data suggested that the usual suspects of demographic and psychosocial characteristics likely played a major role. Older, less educated, lower socioeconomic status patients with higher levels of medical and psychological comorbidities were more likely to fail. This result has been shown time and time again throughout both the spine and general medical literature. However, this paper, like most others on the topic, did not include a non-operative group to which surgical outcomes could be compared. The Spine Patient Outcomes Research Trial demonstrated that patients with characteristics predicting worse surgical outcomes also had worse non-operative outcomes, and that the magnitude of improvement with surgery compared to non-operative treatment was similar for patients with and without these characteristics.1-3 This paper and others make it clear that certain demographic, psychosocial, and medical characteristics are associated with higher rates of failed surgery and increased costs. However, patients with these characteristics should not be denied surgery if they meet clear-cut indications for surgery for conditions that are known to improve with surgical treatment (i.e. spinal stenosis and disc herniation). These patients are likely to cost society more both in direct medical and indirect social costs whether or not they undergo surgery. The spine surgeon's goal should be to use surgery appropriately to maximize outcomes on an individual patient level, not to ration care in order to save society money.
Please read Ms. Hansson-Hedblom's article in the September 15 issue. Does this change how you consider patient and disease characteristics when making surgical treatment decisions? Let us know by leaving a comment on The Spine Blog.
Adam Pearson, MD, MS
Associate Web Editor
1. Pearson A, Lurie J, Tosteson T, et al. Who should have surgery for an intervertebral disc herniation? Comparative effectiveness evidence from the spine patient outcomes research trial. Spine 2012;37:140-9.
2. Pearson A, Lurie J, Tosteson T, Zhao W, Abdu W, Weinstein JN. Who should have surgery for spinal stenosis? Treatment effect predictors in SPORT. Spine 2012;37:1791-802.
3. Pearson AM, Lurie JD, Tosteson TD, Zhao W, Abdu WA, Weinstein JN. Who should undergo surgery for degenerative spondylolisthesis? Treatment effect predictors in SPORT. Spine (Phila Pa 1976) 2013;38:1799-811.