Table 2.

Interfacility variation in mineral metabolism treatment strategies presented as median odds ratio (95% confidence interval)

Treatment Strategies	Median Odds Ratio (95% Confidence Interval) by Cohort Year
	All	2006–2008	2009–2011	2012–2015
Vitamin D alone	1.8 (1.6 to 2.0)	2.0 (1.8 to 2.5)	1.5 (1.3 to 1.9)	1.9 (1.6 to 2.8)
No mineral metabolism medication	2.0 (1.8 to 2.3)	1.7 (1.5 to 2.0)	1.8 (1.6 to 2.2)	3.2 (2.7 to 4.0)
Cinacalcet-containing	1.9 (1.7 to 2.1)	1.7 (1.5 to 2.1)	2.0 (1.8 to 2.5)	2.6 (2.2 to 3.2)
Phosphate binder alone	1.9 (1.8 to 2.1)	1.6 (1.5 to 1.8)	1.9 (1.7 to 2.1)	3.5 (3.0 to 4.2)
Number of groups (facilities)	359	253	257	265
Number of patients	15,591	5399	5225	4967

The reference strategy is vitamin D sterol and phosphate binder. Model is adjusted for age (linear and quadratic term), comorbidity, sex, race (Black, White, and other), and insurance status. The median odds ratio for a specified strategy describes the effect of the facility on receiving that strategy, rather than the reference strategy, for two otherwise similar patients. A median odds ratio near one implies facility variation plays a minor role in the probability of receiving the specified strategy; larger values indicate greater discrepancies across facilities, after controlling for patient characteristics. A median odds ratio of 1.8 implies a median increase of 80% in the odds of using that strategy (relative to the reference strategy) when a patient is switched from a facility with lower odds to one with greater odds, holding all other predictors constant.