TABLE 6.

Adjusted Results from Multivariable Regression Model Estimating the Relationship Between Risk Factors and Number of Drug Therapy Problems per Patient Using the Overall Study Population (N = 2,578,336)

Variable	Estimated Parameter	Incident Rate Ratio	95% Confidence Interval	P Value
Drug count
≥ 8	0.72	2.06	2.05-2.07	< 0.001
< 8 (reference group)
Disease count
≥ 3	0.58	1.79	1.78-1.80	< 0.001
< 3 (reference group)
Annual drug spend
≥ $3,144	0.17	1.18	1.18-1.19	< 0.001
< $3,144 (reference group)
Age group, years				< 0.001
> 70	0.22	1.24	1.24-1.25
65-70	0.29	1.33	1.33-1.34
< 65 (reference group)
Gender				< 0.001
Female	0.07	1.08	1.07-1.08
Male (reference group)
Region				< 0.001
Midwest	0.01	1.01	1.00-1.01
Northeast	0.02	1.02	1.02-1.03
South	0.20	1.22	1.21-1.22
West (reference group)
Race				< 0.001
African American	0.21	1.23	1.22-1.24
Asian	-0.02	0.98	0.97-0.99
Hispanic	0.10	1.11	1.09-1.12
Native American	0.12	1.13	1.10-1.17
Other	0.02	1.02	1.01-1.03
White (reference group)
Household income				< 0.001
> $52,565	-0.06	0.94	0.94-0.95
Missing	-0.03	0.97	0.96-0.99
≤ $52,565 (reference group)
Prior outpatient visit(s)	0.36	1.44	1.43-1.45	< 0.001
Prior emergency room visit(s), all-cause	0.25	1.28	1.27-1.28	< 0.001
Prior acute inpatient stay, all-cause	0.21	1.23	1.22-1.24	< 0.001

Deviance value = 2532321; Degrees of Freedom (DF) = 2578316; Value/DF = 0.9822; Akaike Information Criterion = 6149537.