Table 4.

Effects of the LIRE intervention on utilization of lumbar, sacral, or thoracic spine surgery over 18-month follow-up

	Any
	Adjusted Proportions
	Control (n = 117,455)	Intervention (n = 121,431)	OR‖ (95% CI)	P
Primary outcome (Aim 2)
Any spine surgery*	3.2%	3.1%	0.99 (0.91–1.07)	0.74†
Secondary outcomes (Aim 2)
Fusion‡	1.1%	1.1%	1.01 (0.89–1.14)	0.85§
Decompression	2.9%	2.8%	0.97 (0.88–1.06)	0.47§

^*Any spine surgery includes decompression surgery, spinal fusion or proxies for spine fusion, or other surgeries involving the lumbar, sacral, or thoracic spine.

^†Statistical significance defined as P < 0.05.

^‡Spinal fusion or proxies for spinal fusion (e.g., disc arthroplasty). Fusion may or may not have also involved decompression.

^§Statistical significance defined as P < 0.025 (with Bonferroni correction accounting for two individual surgical spine procedures).

^‖Models adjusting for fixed effects (site, clinic size tertile, computed tomography vs. magnetic resonance imaging, Charlson Comorbidity category [0, 1, 2, 3+], site-specific time [linear], gender, age range [<40, 40–60, >60]) and random effects (clinic [intercept and treatment] and provider [intercept only]).