Table 4.

Incident Rate Ratios from Generalized Linear Model Regressions of Costs in VA Patients with Heart Failure in FY2010, N=117,882

	Model (1) Patient factors only	Model (2) Facility only	Model (3) Patient and facility factors
R-squared	0.116	0.018	0.132
Root Mean Squared Error	46245	48739	45824
Age in years	0.991		0.990
Gender
Female	Ref		Ref
Male	0.942		0.941
Race/ethnicity
White	Ref		Ref
Black	1.015		1.048
Hispanic	1.135		1.032
Other	0.975		0.995
Unknown	0.761		0.769
Marital status
Single	Ref		Ref
Married	0.801		0.821
Separated/divorced/widowed	0.933		0.945
Service connected percent
0 or none	Ref		Ref
1–49	0.930		0.933
50+	1.163		1.172
Insurance coverage
None	Ref		Ref
Major medical/private/CHAMPUS	0.751		0.755
Medicare	0.902		0.915
All other	0.852		0.853
Eligibility for VA
Above means test	Ref		Ref
Below means test, not service connected	1.542		1.524
Service connected	1.615		1.594
Other eligibility	1.376		1.357
Chronic conditions
Diabetes	1.115		1.117
Hypertension	1.344		1.338
Ischemic heart disease	1.393		1.385
Chronic renal failure	1.901		1.868
Alzheimer’s disease	1.377		1.363
Depression	1.207		1.207
Post-traumatic stress disorder	1.030		1.031
Alcohol use disorder	1.280		1.282
Drug use disorder	1.266		1.242
Other psychiatric conditions	1.404		1.390

All parameters in the table were statistically significant at p<0.001

Incident rate ratios were obtained from generalized linear regression models with a Poisson family distribution and log-link function. IRRs represent percent change in costs associated with a one-unit change in continuous variable or the percent change in costs relative to the reference category for categorical variables. Coefficients from facility dummies in models 2 and 3 are not shown in table.