Table 2.

Incremental costs, life and quality-adjusted life years, and cost-effectiveness ratios

Benefits measured in life year (LYs)
Strategy	Time Horizon	Total Cost	Incremental Cost	Total LYs	Incremental LYs	ICER
Payer Perspective
SLNB	10 years	$14,141	$11,504	8.91	0.02	$652,636
Observation		$2,637		8.89
SLNB	15 years	$15,503	$11,248	12.08	0.08	$138,374
Observation		$4,255		12.00
SLNB	20 years	$16,402	$11,033	14.20	0.17	$63,161
Observation		$5,368		14.02
Societal Perspective
SLNB	15 years	$17,285	$10,552	12.08	0.08	$131,900
Observation		$6,733		12.00
Benefits measured in quality-adjusted life years (QALYs)
Strategy	Time Horizon	Total Cost	Incremental Cost	Total QALYs	Incremental QALYs	ICER
Payer Perspective
SLNB	15 years	$15,845	$11,825	10.33	−0.20	−$60,025
Observation		$4,020		10.53
SLNB	20 years	$17,065	$11,727	12.66	−0.18	−$65,657
Observation		$5,339		12.84
SLNB	25 years	$17,888	$11,642	14.27	−0.13	−91,701
Observation		$6,246		14.39
Structural sensitivity analysis assuming 25% probability of anxiety and an associated disutility of 0.20 associated with axillary observation.
Payer Perspective
SLNB	15 years	$15,845	$11,533	10.33	0.30	$39,417
Observation		$4,020		10.03
Structural sensitivity analysis assuming 25% probability of anxiety, an associated disutility of 0.20 associated with axillary observation, and a 10% reduction in the annual probability of all-cause mortality
Payer Perspective
SLNB	15 years	$15,546	$11,206	9.70	0.29	$38,658
Observation		$4,340		9.41

SLNB = sentinel lymph node biopsy