TY - JOUR
T1 - Major medical outcomes with spinal augmentation vs conservative therapy
AU - McCullough, Brendan J.
AU - Comstock, Bryan A.
AU - Deyo, Richard A.
AU - Kreuter, William
AU - Jarvik, Jeffrey G.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2013/9/9
Y1 - 2013/9/9
N2 - IMPORTANCE: The symptomatic benefits of spinal augmentation (vertebroplasty or kyphoplasty) for the treatment of osteoporotic vertebral compression fractures are controversial. Recent population-based studies using medical billing claims have reported significant reductions in mortality with spinal augmentation compared with conservative therapy, but in nonrandomized settings such as these, there is the potential for selection bias to influence results. OBJECTIVE: To compare major medical outcomes following treatment of osteoporotic vertebral fractures with spinal augmentation or conservative therapy. Additionally, we evaluate the role of selection bias using preprocedure outcomes and propensity score analysis. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort analysis of Medicare claims for the 2002-2006 period. We compared 30-day and 1-year outcomes in patients with newly diagnosed vertebral fractures treated with spinal augmentation (n = 10 541) or conservative therapy (control group, n = 115 851). Outcomes were compared using traditional multivariate analyses adjusted for patient demographics and comorbid conditions. We also used propensity score matching to select 9017 pairs from the initial groups to compare the same outcomes. EXPOSURES: Spinal augmentation (vertebroplasty or kyphoplasty) or conservative therapy. MAIN OUTCOMES AND MEASURES: Mortality, major complications, and health care utilization. RESULTS: Using traditional covariate adjustments, mortality was significantly lower in the augmented group than among controls (5.2%vs 6.7%at 1 year; hazard ratio, 0.83; 95%CI, 0.75-0.92). However, patients in the augmented group who had not yet undergone augmentation (preprocedure subgroup) had lower rates of medical complications 30 days post fracture than did controls (6.5%vs 9.5%; odds ratio, 0.66; 95%CI, 0.57-0.78), suggesting that the augmented group was less medically ill. After propensity score matching to better account for selection bias, 1-year mortality was not significantly different between the groups. Furthermore, 1-year major medical complications were also similar between the groups, and the augmented group had higher rates of health care utilization, including hospital and intensive care unit admissions and discharges to skilled nursing facilities. CONCLUSIONS AND RELEVANCE: After accounting for selection bias, spinal augmentation did not improve mortality or major medical outcomes and was associated with greater health care utilization than conservative therapy. Our results also highlight how analyses of claims-based data that do not adequately account for unrecognized confounding can arrive at misleading conclusions.
AB - IMPORTANCE: The symptomatic benefits of spinal augmentation (vertebroplasty or kyphoplasty) for the treatment of osteoporotic vertebral compression fractures are controversial. Recent population-based studies using medical billing claims have reported significant reductions in mortality with spinal augmentation compared with conservative therapy, but in nonrandomized settings such as these, there is the potential for selection bias to influence results. OBJECTIVE: To compare major medical outcomes following treatment of osteoporotic vertebral fractures with spinal augmentation or conservative therapy. Additionally, we evaluate the role of selection bias using preprocedure outcomes and propensity score analysis. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort analysis of Medicare claims for the 2002-2006 period. We compared 30-day and 1-year outcomes in patients with newly diagnosed vertebral fractures treated with spinal augmentation (n = 10 541) or conservative therapy (control group, n = 115 851). Outcomes were compared using traditional multivariate analyses adjusted for patient demographics and comorbid conditions. We also used propensity score matching to select 9017 pairs from the initial groups to compare the same outcomes. EXPOSURES: Spinal augmentation (vertebroplasty or kyphoplasty) or conservative therapy. MAIN OUTCOMES AND MEASURES: Mortality, major complications, and health care utilization. RESULTS: Using traditional covariate adjustments, mortality was significantly lower in the augmented group than among controls (5.2%vs 6.7%at 1 year; hazard ratio, 0.83; 95%CI, 0.75-0.92). However, patients in the augmented group who had not yet undergone augmentation (preprocedure subgroup) had lower rates of medical complications 30 days post fracture than did controls (6.5%vs 9.5%; odds ratio, 0.66; 95%CI, 0.57-0.78), suggesting that the augmented group was less medically ill. After propensity score matching to better account for selection bias, 1-year mortality was not significantly different between the groups. Furthermore, 1-year major medical complications were also similar between the groups, and the augmented group had higher rates of health care utilization, including hospital and intensive care unit admissions and discharges to skilled nursing facilities. CONCLUSIONS AND RELEVANCE: After accounting for selection bias, spinal augmentation did not improve mortality or major medical outcomes and was associated with greater health care utilization than conservative therapy. Our results also highlight how analyses of claims-based data that do not adequately account for unrecognized confounding can arrive at misleading conclusions.
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U2 - 10.1001/jamainternmed.2013.8725
DO - 10.1001/jamainternmed.2013.8725
M3 - Article
C2 - 23836009
AN - SCOPUS:84883769814
SN - 2168-6106
VL - 173
SP - 1514
EP - 1521
JO - JAMA internal medicine
JF - JAMA internal medicine
IS - 16
ER -