Economic Evaluation in Lumbar Spinal Fusion

The optimal choice of treatment for chronic low back pain (pain for more than three to six months) has been subject to many scientific disputes. After decades of targeted research, including several high-quality randomised controlled trials, the gathered knowledge indicates that lumbar fusion has a place in evidence-based medicine as a relevant therapeutic option for selected patients.¹ At the same time, it represents a field that automatically attracts political focus due to the complexity of the disease, the life-time consequences to the individual and to society if treatment is unsuccessful, and the recent rise in the number of spine surgeries together with the introduction of increasingly sophisticated and more costly surgical techniques.² This is even further incentivised by the broader political challenge of health costs exceeding budgets in most publicly funded healthcare systems, thus making prioritisation a necessity. Economic evaluation is a rational approach for informing such decisions about what technologies or interventions should be prioritised over others to maximise the value for money in healthcare (and elsewhere).

The discipline of health economic evaluation evolved during the 1970s and was first adopted by the spine society in the late 1990s.^3–5 It refers to a branch of analytic tools that systematically assesses both costs and outcomes in order to inform rational decision-making about resource allocation, which is increasingly requested by healthcare managements.⁶ Health economic evaluations can thus be seen as a common language where it is possible for clinicians, administrators, politicians and patients to communicate over issues such as where resources should be spent in order to maximise the health gain at the population level, given that resources are scarce and insufficient to satisfy all demands in a publicly financed healthcare system. In order to do this one should realise that it is important not only to measure clinical outcome, but also to measure the costs spent to achieve this outcome.

In 2005, a systematic literature review identified seven studies on economic evaluations in lumbar spinal fusion.⁷ Six of the studies were from the US and one was from Sweden, and they all compared alternative surgical techniques. A quality assessment of the studies pointed at some general methodological problems and no conclusion about the cost effectiveness of individual techniques could be made due to study heterogeneity, poor convergent validity and, for some studies, also poor reporting standards. It should be noted that the quality problems were most severe for the earliest studies for which reason they could be considered teething troubles. Nevertheless, the need to maintain focus on methodological quality was underlined by the authors and commentators.^7,8

The purpose of this article is to give a briefing on the state of the art of economic evaluations applied in lumbar spinal fusion using European studies as examples in order to identify needs and opportunities for future research priorities. The paper is not a result of a systematic literature search, nor will quality assessment of the identified literature be conducted. It should also be noted that the title of the paper is more popular than precise; ‘lumbar spinal fusion’ does not include conservative treatment and motion-preservation surgeries per se, although the scope of these treatment modalities overlap the scope of spinal fusion. Therefore, such comparators are relevant in an evaluation context and accordingly they were considered in this article. This article proceeds with a brief synopsis of the health economic methodology, a presentation of recent applied work, including a few worked examples, and a section on limitations. It recapitulates with a discussion of the status and challenges for future research.