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Cost-effectiveness of balloon kyphoplasty in patients with symptomatic vertebral compression fractures in a UK setting |
Strom O, Leonard C, Marsh D, Cooper C |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. CRD summary This study examined the cost-effectiveness of balloon kyphoplasty, compared with nonsurgical management, for vertebral compression fractures in osteoporotic patients. The authors concluded that balloon kyphoplasty was a cost-effective alternative to nonsurgical management for hospitalised patients with a vertebral compression fracture, from the perspective of the health care payer. The study followed conventional recommendations and guidelines for cost-effectiveness analysis and this should ensure the validity of the authors’ conclusions. Type of economic evaluation Study objective This study examined the cost-effectiveness of balloon kyphoplasty, compared with nonsurgical management, for vertebral compression fractures in osteoporotic patients, with a T-score of -2.5 and one vertebral fracture. Interventions Balloon kyphoplasty was a minimally invasive surgical procedure and it was compared against nonsurgical management. Methods Analytical approach:The analysis was based on a Markov model with a lifetime horizon. The authors stated that the study was conducted from a health care perspective, namely that of the UK National Health Service (NHS).
Effectiveness data:The clinical evidence was selected from published sources. The baseline patients’ characteristics and clinical efficacy data were from a randomised controlled trial, called the Fracture Reduction Evaluation (FREE) trial (Wardlaw, et al. 2009, see ‘Other Publications of Related Interest’ below for bibliographic details). This trial enrolled 300 patients and compared balloon kyphoplasty against nonsurgical management. The epidemiological data were from UK-specific sources, wherever possible; Swedish data were used for the fracture incidence due to a lack of UK data. The key input was the impact of balloon kyphoplasty on vertebral fracture incidence, which was from the FREE trial, and the quality-of-life consequences for these patients. An important assumption was made for the long-term effect of balloon kyphoplasty.
Monetary benefit and utility valuations:The utility values were from the FREE trial, where a visual analogue scale was used to assess the impact of a painful fracture on a patient's health. European Quality of life (EQ-5D) questionnaire scores were then derived, using the UK utility algorithm.
Measure of benefit:Quality-adjusted life-years (QALYs) were the summary benefit measure and they were discounted at an annual rate of 3.5%.
Cost data:The economic analysis included the costs of hospitalisation for vertebral compression fractures, which were from a published study, and the costs of balloon kyphoplasty, which were from three NHS hospitals that provided this procedure. The differences in the length of hospital stay were a key part of cost assessment and were based on estimates reported in published studies and on authors’ assumptions. The costs were in UK pounds sterling (£) and were discounted at an annual rate of 3.5%. The price year was 2008.
Analysis of uncertainty:A deterministic one-way sensitivity analysis was carried out on selected inputs including the persistence of quality-of-life effects, length of stay, and patient age. A probabilistic analysis was conducted by assigning probability distributions to the key inputs and using a bootstrapping method. Results The lifetime costs were £10,420 with balloon kyphoplasty and £8,926 with nonsurgical management. The QALYs were 3,842 with balloon kyphoplasty and 3,673 with nonsurgical management. The incremental cost per QALY gained with balloon kyphoplasty over nonsurgical management was £8,840.
The sensitivity analysis suggested that, in a worst-case scenario, in which the efficacy of balloon kyphoplasty deteriorated after one year (three years in the base case), the incremental cost per QALY gained rose to £14,500. When length of hospital stay was reduced by at least nine days with balloon kyphoplasty, over nonsurgical management (six days in the base case), balloon kyphoplasty was dominant, as it was more effective and less expensive. Higher cost-utility ratios were observed in older patients. In the probabilistic sensitivity analysis, balloon kyphoplasty dominated nonsurgical management in nearly 13% of simulations. Authors' conclusions The authors concluded that, from the perspective of the health care payer, balloon kyphoplasty was a cost-effective alternative to nonsurgical management in hospitalised patients with a vertebral compression fracture. CRD commentary Interventions:The selection of the comparators was appropriate. The proposed invasive procedure was compared against the conventional conservative approach for patients with vertebral compression fractures. No information was given on the nonsurgical management strategy. The authors stated that vertebroplasty would have been a more appropriate comparator, but it was not selected because there was a lack of data on this procedure.
Effectiveness/benefits:The authors selected known sources of evidence for the clinical inputs, focusing on morbidity and mortality associated with vertebral compression fractures and the impact of these fractures on a patient's quality of life. The use of a clinical trial for the treatment effect was appropriate, but some assumptions were needed to extrapolate the short-term data to a longer time horizon. These assumptions were extensively investigated in the sensitivity analysis. Extensive information was provided on the derivation of the quality of life scores and the instrument used to assess the utility values. QALYs were an appropriate benefit measure, given the impact of the disease on survival and quality of life.
Costs:The cost categories were consistent with the perspective. The cost of hospital stay was reported as a total category, while a list of items, their unit costs, and resource quantities were presented for the balloon kyphoplasty procedure. The costs that were common to both strategies, such as analgesics and rehabilitation, were not considered. This was a conservative assumption as the nonsurgical management patients might have used more health care resources in clinical practice. The price year and the use of discounting were clearly reported. The hospital costs were from conventional UK sources, while the cost of balloon kyphoplasty was from a previous study, but its methods were not reported. Other details, such as the price year and the discount rate, were provided.
Analysis and results:An incremental approach was appropriately used to synthesise the costs and benefits of the two strategies. The issue of uncertainty was satisfactorily investigated, using a variety of methods. The results were clearly reported and discussed. Some limitations were acknowledged and related to the lack of long-term data on the effects of balloon kyphoplasty and of information on the length of stay associated with this procedure. Generally, the authors used conservative assumptions and assessed the impact of changes in these variables in the sensitivity analysis.
Concluding remarks:The study followed conventional recommendations and guidelines for cost-effectiveness analysis and this should ensure the validity of the authors’ conclusions. Funding Supported by a grant from Medtronic. Bibliographic details Strom O, Leonard C, Marsh D, Cooper C. Cost-effectiveness of balloon kyphoplasty in patients with symptomatic vertebral compression fractures in a UK setting. Osteoporosis International 2010; 21(9): 1599-1608 Other publications of related interest Wardlaw D, Cummings SR, Van Meirhaeghe J, Bastian L, Tillman JB, Ranstam J, Eastell R, Shabe P, Talmadge K, Boonen S. Efficacy and safety of balloon kyphoplasty compared with nonsurgical care for vertebral compression fracture (FREE): a randomised controlled trial. Lancet 2009; 373: 1016-1024. Indexing Status Subject indexing assigned by NLM MeSH Aged; Catheterization /economics; Cost-Benefit Analysis; Female; Fractures, Compression /economics /mortality /surgery; Great Britain /epidemiology; Health Care Costs /statistics & Humans; Kyphoplasty /economics /methods; Length of Stay /statistics & Male; Models, Econometric; Osteoporotic Fractures /economics /mortality /surgery; Quality of Life; Spinal Fractures /economics /mortality /surgery; numerical data; numerical data AccessionNumber 22010001642 Date bibliographic record published 24/11/2010 Date abstract record published 08/12/2010 |
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