The study determined the cost-effectiveness of cementless versus cemented total hip arthroplasty (THA), using a decision modelling framework, in a hypothetical cohort of 70-year-old patients with fracture of the femoral neck or arthritis involving the hip. The authors concluded that none of the strategies was preferred over the others given the similar benefits and a non significant difference in costs. However, the quality of the study methodology appears to have been limited by poor reporting and unclear presentation of the results.

Cost-utility analysis

The objective of the study was to determine the cost-effectiveness of cementless versus cemented total hip arthroplasty (THA), using a decision modelling framework, in a hypothetical cohort of 70-year-old patients with fracture of the femoral neck or arthritis involving the hip.

The interventions under examination were cemented THA and cementless THA.

Italy/hospital.

Analytical approach: The economic evaluation used a Markov model to simulate the management of THA. The time horizon of the analysis appears to have been 5 years, although this was not explicitly stated. The authors stated that the a payer perspective was adopted.

Effectiveness data: The clinical data appear to have been derived from published sources that might have been identified selectively. Key data on implant revision rates came from the Regional Orthopaedic Prosthesis register, in which 23,966 THAs were recorded. The probability of infection and perioperative mortality were taken from a published study conducted in the USA. The age-specific probability of death from causes unrelated to THA was assumed to be equal to the age-specific death in the general population, based on a US study.

Monetary benefit and utility valuations: The utility estimates were based on published well-being index scores that differentiated between patients with and without arthritis.

Measure of benefit: The summary benefit measure was the quality-adjusted life-years (QALYs). These were estimated using the decision model. Future QALYs were discounted at an annual rate of 3%. 

Cost data: A breakdown of the cost items was not given. The macro-category of implant cost (cemented and cementless devices, revision THAs) was reported. The costs were derived from the database of the authors’ institution. The resource use data were presumably based on hospital average estimates.  The costs were in euros (EUR). The price year was 2006. An annual discount rate of 3% was applied to future costs.

Analysis of uncertainty: A sensitivity analysis was performed on the revision rates, implant costs, perioperative mortality, infection rates and utility values.

Cementless THAs resulted in a mean additional cost of EUR 2,066 per patient. The authors stated that the expected QALYs were similar with the two strategies. However, the meaning of the reported "effectiveness" and, consequently, the "cost-effectiveness ratios" was unclear. nevertheless, these are the findings of the analysis: the average cost-effectiveness ratio was EUR 2,353 with cemented THA and EUR 112 with cementless THA. The incremental analysis showed that the incremental cost-effectiveness ratio with cementless THA was EUR 61. 

The authors stated that the model was sensitive to variation in the revision rates, implant costs, perioperative mortality, infection rates and utility values, but did not report clearly the results of the sensitivity analysis.

The authors concluded that the risk of early revision was similar between treatment groups, resulting in similar QALYs and a cost-difference that was not significant. Thus, the authors stated that no one strategy was preferred over the others.  It was noted that further studies should investigate not only the relationship between quality of life and the effect of different devices, but also the impact of the devices on societal costs.

Interventions: The selection of the comparators reflected the two general typologies of implants used for THA. They are also likely to be valid in other settings.

Effectiveness/benefits:  The approach used to derive the clinical estimates was not clear. The primary published sources were presumably identified selectively. Data on revision rates were appropriately taken from a regional registry, with a very large sample of THAs, that reflected the Italian context. However, except for this regional database, details of the other sources of data were not given. This limits the possibility of judging the validity of the primary data.

Costs: The analysis of the costs was limited to the health services of device implantation. A breakdown of the cost items involved in this macro-category was not provided. The costs reflected hospital prices, which was consistent with the perspective adopted in the study. The price year was reported, together with the use of discounting.

Analysis and results: The synthesis of the costs and benefits was not clear because contrasting results were reported in a table and in the text. For example, if cemented THA was less costly and equally effective as cementless THA, it is not clear why the authors stated that the two options were similar. The results of the sensitivity analysis were only partially reported and were not clearly justified. The authors noted some potential limitations of the analysis, such as the use of 5-year prosthesis survival data and the restriction of the cost analysis only to implant costs.

Concluding remarks: The quality of the study methodology was not clear because of the limited reporting of some sources used. Furthermore, the limited cost analysis and the unclear presentation of the study results make the authors’ conclusions hard to assess.

None stated.

Chang RW, Pellisier JM, Hazes GB. Cost-effectiveness analysis of total hip arthroplasty for osteoarthritis of the hip. JAMA, 1996;275:858-65.

Slover J, Espehaug B, Havelin LI, et al. Cost-effectiveness of unicompartmental and total knee arthroplasty in elderly low-demand patients. A Markov decision analysis. J Bone Joint Surg Am 2006;88:2348-55.

This record was compiled by CRD commissioned reviewers according to a set of guidelines developed in collaboration with a group of leading health economists.