Patient-reported outcomes following surgery for degenerative spondylolitshtesis: comparison of a universal and multitier health care system

Study design: Retrospective review of results from a prospectively collected Canadian cohort in comparison to published literature.

Objectives: (1) To investigate whether patients in a universal health care system have different outcomes than those in a multitier health care system in surgical management of degenerative spondylolisthesis (DS). (2) To identify independent factors predictive of outcome in surgical DS patients.

Summary of background data: Canada has a national health insurance program with unique properties. It is a single-payer system, coverage is universal, and access to specialist care requires referral by the primary care physician. The United States on the other hand is a multitier public/private payer system with more rapid access for insured patients to specialist care.

Methods: Surgical DS patients treated between 2013 and 2016 in Canada were identified through the Canadian Spine Outcome Research Network (CSORN) database, a national registry that prospectively enrolls consecutive patients with spinal pathology from 16 tertiary care academic hospitals. This population was compared with the surgical DS arm of patients treated in the Spine Patients Outcome Research Trial (SPORT) study. We compared baseline demographics, spine-related, and health-related quality of life (HRQOL) outcomes at 3 months and 1 year. Multivariate analysis was used to identify factors predictive of outcome in surgical DS patients.

Results: The CSORN cohort of 213 patients was compared with the SPORT cohort of 248 patients. Patients in the CSORN cohort were younger (mean age 60.1 vs. 65.2; p<.001), comprised fewer females (60.1% vs. 67.7%; p=.09), and had a higher proportion of smokers (23.3% vs. 8.9%; p<.001). The SPORT cohort had more patients receiving compensation (14.6% vs. 7.7%; p<.001). The CSORN cohort consisted of patients with slightly greater baseline disability (Oswestry disability index scores: 47.7 vs. 44.0; p=.008) and had more patients with symptom duration of greater than 6 months (93.7% vs. 62.1%; p<.001). The CSORN cohort showed greater satisfaction with surgical results at 3 months (91.1% vs. 66.1% somewhat or very satisfied; p<.01) and 1 year (88.2% vs. 71.0%, p<.01). Improvements in back and leg pain were similar comparing the two cohorts. On multivariate analysis, duration of symptoms, treatment group (CSORN vs. SPORT) or insurance type (public/Medicare/Medicaid vs. Private/Employer) predicted higher level of postoperative satisfaction. Baseline depression was also associated with worse Oswestry disability index at 1-year postoperative follow-up in both cohorts.

Conclusions: Surgical DS patients treated in Canada (CSORN cohort) reported higher levels of satisfaction than those treated in the United States (SPORT cohort) despite similar to slightly worse baseline HRQOL measures. Symptom duration and insurance type appeared to impact satisfaction levels. Improvements in other patient-reported health-related quality of life measures were similar between the cohorts.