Factors that are relevant to the decision regarding the use of surgical treatment for degenerative spondylolisthesis include disease-state severity and patient quality-of-life expectations. Some factors may not be easily appraised by the surgeon. In prospective trials involving patients undergoing nonoperative and operative treatment, there are instances of crossover in which patients from the nonoperative group undergo surgery. Identifying and understanding patient characteristics that may influence crossover from nonoperative to operative treatment will aid understanding of what motivates patients toward pursuing surgery.
Patients with degenerative spondylolisthesis who were randomized to nonoperative care in a prospective, multicenter study were evaluated over 8 years of enrollment. Two cohorts were defined: (1) the surgery cohort (patients who underwent surgery at any point) and (2) the nonoperative cohort (patients who did not undergo surgery). A Cox proportional hazards model, modeling time to surgery, was used to explore demographic data, clinical diagnoses, and patient expectations and attitudes after adjusting for other variables. A subanalysis was performed on surgery within 6 months after enrollment and surgery >6 months after enrollment.
One hundred and forty-five patients who had been randomized to nonoperative treatment, 80 of whom crossed over to surgery, were included. In analyzing baseline differences between the 2 cohorts, patients who underwent surgery were younger; however, there were no significant difference between the cohorts in terms of race, sex, or comorbidities. Treatment preference, greater Oswestry Disability Index score, marital status, and no joint problems were predictors of crossover to surgery. Clinical factors, including stenosis, neurological deficits, and listhesis levels, did not show a significant relationship with crossover. At the time of long-term follow-up, the surgery cohort showed significantly greater long-term improvement in health-related quality of life (p < 0.001). The difference was maintained throughout follow-up.
Neurological symptoms and diagnoses, including listhesis and stenosis severity, did not predict crossover from nonoperative care to surgery. Attitudes toward surgery, greater Oswestry Disability Index score, marital status, and no joint problems were independent predictors of crossover from nonoperative to operative care. Certain demographic characteristics were associated with higher rates of crossover, although they were connected to patient attitudes toward surgery.
Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
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1New York Spine Institute, NYU Langone Orthopedic Hospital, New York, NY
2The Dartmouth Institute for Health Policy and Clinical Practice (J.L. and T.M.), and Department of Biomedical Data Sciences (W.Z.), Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
3Rocky Mountain Hospital for Children, Denver, Colorado
4Spine Service, Hospital for Special Surgery, New York, NY
E-mail address for P.G. Passias: Peter.Passias@nyumc.org
Investigation performed at New York Spine Institute, NYU Langone Orthopedic Hospital, New York, NY, and The Dartmouth Institute for Health Policy and Clinical Practice, and Department of Biomedical Data Sciences, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
Disclosure: Funding for SPORT (Spine Patient Outcomes Research Trial) was awarded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) (U01-AR45444) and the Office of Research on Women’s Health, the National Institutes of Health, the National Institute of Occupational Safety and Health, and the Centers for Disease Control and Prevention. The Multidisciplinary Clinical Research Center in Musculoskeletal Diseases is funded by NIAMS (P60-AR048094 and P60-AR062799). On the Disclosure of Potential Conflicts of Interest forms, which are provided with the online version of the article, one or more of the authors checked “yes” to indicate that the author had a relevant financial relationship in the biomedical arena outside the submitted work and “yes” to indicate that the author had a patent and/or copyright, planned, pending, or issued, broadly relevant to this work (http://links.lww.com/JBJSOA/A43).