Cost-utility of lumbar interbody fusion surgery: A systematic review.

Background Context: Lumbar interbody fusion (LIF) is a common surgical intervention for treating lumbar degenerative disorders. Increasing demand has contributed to ever-increasing healthcare expenditure and economic burden. To address this, cost-utility analyses (CUAs) compare value in the context of patient outcomes. CUAs quantify health improvements using quality-adjusted life years (QALYs), allowing decision-makers to determine procedure value.

Purpose: While there is a growing body of literature assessing LIF value, a comprehensive synthesis of LIF CUAs is lacking. This systematic review aims to address this gap by assessing all available CUAs of LIF techniques, to support evidence-based practices that improve outcomes and promote efficient resource use.

Study Design: Systematic review.

Study Sample: This study sample consisted of adult patients with lumbar degenerative conditions specifically treated with lumbar interbody fusion, including grade I or II degenerative spondylolisthesis, lumbar spinal stenosis, disc degeneration, and spondylosis, with or without low back and/or leg pain.

Outcome Measures: Direct (healthcare) and indirect (non-healthcare) costs, cost sources and calculation methods, utility scores, QALY gain, cost-utility, incremental cost-effectiveness ratios, and willingness-to-pay thresholds. Outcomes were reported as median and interquartile ranges (IQR).

Methods: A systematic review was conducted following PRISMA guidelines. PubMed, Web of Science, and Embase were searched from inception to October 23, 2023, for CUAs reporting QALYs and costs of LIF procedures. Relevant studies were selected and data extracted. Subgroup analyses compared minimally invasive versus open surgery and anterior versus posterior approaches. Study quality was assessed using the CHEC-Extended tool. Quantitative meta-analysis was not performed due to methodological heterogeneity.

Results: Out of 2047 identified studies, 14 met inclusion criteria. The mean CHEC-Extended score was 72.1%. Most studies reported on TLIF (n=11) and utilized EQ-5D questionnaire to calculate utility (n=9). Direct costs were sourced from institutional databases, Medicare, DRGs, Redbook, and a variety of other sources. Most indirect costs were estimated from productivity loss. TLIF demonstrated the highest median QALY gain over 1 year (0.43, IQR 0.121-0.705), while PLIF was highest over 2 years (1.33). ALIF was most favorable over 1 year ($30901/QALY) and OLIF was most favorable over 2 years ($11187/QALY). PLIF, TLIF, and LLIF exhibited similar cost-utility over 2 years ($44383, $45628, $48576/QALY). MIS was substantially favorable to OS at 1 year ($42635 vs. $226304), though similar at 2 years ($48576 vs. $45628/QALY). Anterior approach was favorable to posterior approach at 1 year ($30901.5 vs. $81038) and 2 years ($29881.9 vs. $44383). Cost-utility comparisons substantially varied and were sensitive to utility measures, study methodology, cost sourcing, and follow-up duration.

Conclusions: This is the first systematic review to comprehensively assess CUAs of all LIF approaches in the existing literature. While certain approaches, such as ALIF and OLIF, may demonstrate favorable outcomes, these conclusions are limited by high methodological heterogeneity and a limited study pool. By addressing existing gaps in study design and reporting, future comparative cost-utility research can better inform evidence-based decision-making and optimize the value of spinal surgical care.