An article published in the September 2014 issue of Spinal Deformity, the official journal of the Scoliosis Research Society, examines the factors predicting cost-effectiveness of adult spinal deformity surgery two years after the procedure.
The researchers conducted a prospective, consecutive, multicenter database including 514 patients who underwent spinal deformity surgery. The patients were followed for two years after surgery. The researchers performed an analysis to determine which factors were associated with a cost per quality-adjusted life year less than $100,000 — the threshold for a cost-effective procedure.
The researchers found:
1. QALY change for all patients in the study was 0.15 on average and the cost per QALY was $243,761. There were around 10.4 percent of the patients who had a cost per QALY of less than $100,000 after two years.
2. The patients who had less than $100,000 cost per QALY were predominantly female and older than 60 years old. The breakdown for diagnoses in this category is:
• Adult idiopathic scoliosis: 32.1 percent
• Adult de novo scoliosis: 35.7 percent
• Sagittal imbalance: 14.3 percent
• Other scoliosis: 17.9 percent
3. All life Oswestry Disability Index and Scoliosis Research Society instruments were associated with cost-effectiveness, except for the SRS-Mental. The patients with Preoperative ODI scores between 60 and 70, and SRS Pain and Activity subscores of more than four minimally clinically important difference points between the normative values, had the highest percentage of cost-effective patients, according to the study abstract.
4. The biggest factors associated with cost-effectiveness for surgical scoliosis correction were:
• Patients older than 55 years
• Adult de novo scoliosis
• Prior surgery
• Higher preoperative sagittal vertical axis
• Lower maximum Cobb angles
• Eight or fewer levels fused
• Lower blood loss
• Worse global alignment classification
• Global sagittal mal-alignment
5. There was a negative association with cost-effectiveness for combined anterior-posterior surgeries. "Patients with higher preoperative morbidity are more likely to be cost-effective with a cost/QALY less than $100,000," concluded the study authors.