Background context:

The number of performed instrumented lumbar spine surgeries and associated healthcare-related costs have increased over the last decades, and will increase further in the future. With the consistent growth of healthcare-related costs, cost-effectiveness of surgical techniques is of major relevance. Common indications for instrumented lumbar spine surgery are spondylolisthesis and degenerative disease. A commonly used technique is the open transforaminal lumbar interbody fusion (OTLIF). Nowadays, there is an increasing interest in the minimally invasive variation of this technique (MITLIF). Currently available literature describes that MITLIF has comparable or even better clinical results compared to OTLIF. Cost-effectiveness of MITLIF and OTLIF is important considering the growing health-care related costs, although no consensus has been reached regarding the most cost-effectivene technique. In this systematic review, previous literature concerning costs and cost-effectiveness of OTLIF was compared with MITLIF in patients with lumbar spondylolisthesis or degenerative disease. Furthermore, methodological quality of included studies was assessed.

Purpose:

This study aims to evaluate the current literature on cost-effectiveness of open transforaminal lumbar interbody fusion (OTLIF) compared minimally invasive transforaminal lumbar interbody fusion (MITLIF) to in patients with lumbar spondylolisthesis or degenerative disease.

Study design:

This study is a systematic literature review and meta-analysis.

Study sample:

Clinical studies reporting costs or cost effectiveness for either OTLIF or MITLIF in patients with spondylolisthesis, lumbar instability, or degenerative disease were included.

Outcome measures:

The following data items were evaluated: study design, study population, utility measurement tool, gained Quality Adjusted Life Years (QALYs), cost sources, health care and societal perspective costs, total costs, costs per QALY (cost-effectiveness) and incremental cost-effectiveness ratio (ICER).

Methods:

A systematic search was conducted using databases PubMed, CINAHL, EMBASE, Cochrane, Clinical Trials, Current Controlled Trials, ClinicalTrials.gov, NHS Centre for Review and Dissemination, Econlit and Web of Science on studies reporting OTLIF or MITLIF, spondylolisthesis or lumbar instability or degenerative disease, and costs. Relevant studies were selected and reviewed independently by two authors. For comparison, all costs were converted to American Dollars with the reference year 2018.

Results:

After duplicate removal, a total of 892 studies were identified. Eventually, 32 studies were included. Nine studies compared OTLIF and MITLIF directly. All studies mentioned healthcare perspective costs. Seven studies mentioned societal perspective costs. Cost-effectiveness of OTLIF was mentioned in five studies, ranging from $47,303/QALY to $218,766/QALY. Cost-effectiveness of MITLIF was mentioned in one study, $121,105/QALY. Meta-analysis of hospital perspective costs showed a significant overall effect in favour of MITLIF, with a mean difference of $2,650. There was great heterogeneity in health care and societal perspective costs due to different in-, and exclusion factors, baseline characteristics, and calculation methods. Overall quality of studies was low.

Conclusions:

OTLIF and MITLIF appear to be expensive interventions when using a threshold of $50,000/QALY. Results of this study and previous literature suggest that MITLIF is more cost-effective compared to OTLIF. Considering the increase in healthcare costs of instrumented spine surgery, cost-effectiveness could be one of the factors in surgical decision-making. Prospective randomized studies directly comparing cost-effectiveness of OTLIF and MITLIF from both hospital and societal perspectives are needed to obtain higher level of evidence.