Many different designs of total hip arthroplasty
(THA) with varying performance and cost are available. The identification
of those which are the most cost-effective could allow significant
cost-savings. We used an established Markov model to examine the
cost effectiveness of five frequently used categories of THA which differed
according to bearing surface and mode of fixation, using data from
the National Joint Registry for England and Wales. Kaplan–Meier
analyses of rates of revision for men and women were modelled with
parametric distributions. Costs of devices were provided by the
NHS Supply Chain and associated costs were taken from existing studies.
Lifetime costs, lifetime quality-adjusted-life-years (QALYs) and
the probability of a device being cost effective at a willingness
to pay £20 000/QALY were included in the models. The differences in QALYs between different categories of implant
were extremely small (<
0.0039 QALYs for men or women over the
patient’s lifetime) and differences in cost were also marginal (£2500
to £3000 in the same time period). As a result, the probability
of any particular device being the most cost effective was very
sensitive to small, plausible changes in quality of life estimates
and cost. Our results suggest that available evidence does not support
recommending a particular device on cost effectiveness grounds alone.
We would recommend that the choice of prosthesis should be determined
by the rate of revision, local costs and the preferences of the
surgeon and patient. Cite this article:
To review systematically review literature on the early diagnosis of spinal metastases and prediction of spinal cord compression (SCC) due to spinal metastases From 13 electronic bibliographic databases were searched we identified 2,425 potentially relevant articles of which 31 met the inclusion criteria. These were quality appraised. Seventeen studies reported retrospective data, 10 were prospective studies, and three were other study designs. There was one systematic review. There were no randomised controlled trials. There were approximately 7,900 participants in the included studies and 5,782 participants were analysed. The sample sizes ranged from 41 to 859. Cancers reported were: lung alone (n=3); prostate alone (n=6); breast alone (n=7); mixed cancers (n=13); and unclear (n=1). Ninety-three prognostic factors were identified as potentially significant in predicting risk of SCC or collapse. Many of the included studies provided limited information about patient population and selection criteria and they varied in methodological quality, rigour and transparency. Several studies with mixed case populations identified type of cancer (e.g. breast, lung or prostate cancer) as a significant factor in predicting SCC, but determining the risk differential is difficult because of residual bias in studies. Overall the quality of the research was poor. The only predictors identified for SCC were number of spinal metastases, duration of disease, total disease burden and immediate symptomatology of cord involvement.Study Purpose
Methods and results
