A team of researchers from Rothman Orthopaedic Institute and Washington University School of Medicine, St. Louis asked a simple question: Do threshold cutoffs using patient-reported outcomes (PROMs) for insurer reimbursement pre-approvals deny spine fusion surgery to patients who need it?
To objectively answer that question, the team designed a study to calibrate how closely the insurer pre-approval process, using PROMs, aligned with the patient’s quantified and validated need for surgery.
Their conclusions? Denying spine fusion surgery based on a preoperative PROM can and does result in denying surgery to many patients who would be helped with surgery. According to study co-author, Alan Hilibrand, M.D., M.B.A., “We hope that this illustrates for payors that these preop parameters are not useful as a screen for surgery.”
Their work, “Preoperative Oswestry Disability Index Should not be Utilized to Determine Surgical Eligibility for Patients Requiring Lumbar Fusion for Degenerative Lumbar Spine Disease,” appears in the July 15, 2024, edition of Spine.
“There were two things to know about the study,” Dr. Hilibrand, co-chief of spinal surgery at Sidney Kimmel Medical College/The Rothman Orthopaedic Institute, told OTW. “One was that we applied a concept used in a recent joints study about denying joint replacements based on preoperative patient assessments. The other was we hypothesized that imposing these restrictions may affect access to care for underrepresented groups.”
The researchers looked at patients who underwent one to three-level primary lumbar fusion at an academic center from 2014 to 2020, with Oswestry Disability Index (ODIs) collected preoperatively and one year postoperatively.
Dr. Hilibrand and his colleagues designed their study using the well-known and validated ODI to establish a theoretical threshold cutoff for surgery approval or denial at ODI scale increments of 10. The minimal clinically important difference was set at 14.3.
The research team then measured the percentages of patients who met minimal clinically important thresholds for approval or denial of spine surgery treatment. At each threshold, the researchers calculated the positive predictive value for minimal clinically important difference attainment.
In all, 1,368 patients were included in the study.
All told, 62.4% (N=364) achieved a minimal clinically important difference. As the ODI thresholds increased, the percent of patients who reached minimal clinically important differences rose.
At the lowest ODI threshold, 6.58% (N=90) of patients would be denied, rising to 20.2%, 39.5%, 58.4%, 79.9%, and 91.4% at ODI thresholds of 30, 40, 50, 60, and 70, respectively.
The positive predictive value increased from 7.2% for patients with ODI>20 to 91.9% for patients with ODI>70. The number of patients denied a clinical improvement in the denied category per patient achieving the minimal clinically important difference increased at each threshold (ODI>20: 1.96; ODI>30: 2.40; ODI>40: 2.75; ODI>50: 3.03; ODI>60: 3.54; ODI>70: 3.75).
“This study illustrates that denying surgery based on a preoperative PROM might increase the likelihood of achieving minimal clinically important difference but would result in denying surgery to many patients who would be helped with surgery,” explained Dr. Hilibrand to OTW. “We hope that this illustrates for payors that these preop parameters are not useful as a screen for surgery.”
