Appendix 1.

Regression Results for All Outcomes in Full Cohort, FY2019-2021

	In-Person Primary Care Visits	Virtual Primary Care Visits	Adherence (Proportion of days covered) to Diabetes Medications	All-Cause Emergency Department Visits	All-Cause Medical/ Surgical Hospitalization	Hospitalization for Ambulatory Care Sensitive Condition	Hospitalization for Diabetes Domplications
	Coefficient	Coefficient	Coefficient	IRR	IRR	IRR	OR
Quarter	−0.05^*	−0.02^*	0.003^*	0.97^*	0.99	0.99	0.98
	(0.002)	(0.002)	(0.000)	(0.002)	(0.011)	(0.029)	(0.006)
Pandemic phase
Prepandemic phase	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Early pandemic phase	−0.68^*	0.88^*	0.001	0.80^*	0.79^*	0.77^*	0.77^*
	(0.011)	(0.021)	(0.0001)	(0.006)	(0.018)	(0.023)	(0.027)
Midpandemic phase	0.08^*	0.49^*	−0.003	0.97^*	0.98	0.95	0.99
	(0.015)	(0.019)	(0.002)	(0.014)	(0.019)	(0.034)	(0.048)
Patient factors
Age group
<65 years	Ref	Ref	Ref	Ref	Ref	Ref	Ref
65 to 70 years	0.07^*	0.06^*	0.02^*	0.85^*	0.85^*	0.79	0.62^*
	(0.007)	(0.008)	(0.001)	(0.034)	(0.021)	(0.332)	(0.016)
71+ years	0.19^*	0.10^*	0.03^*	0.83^*	0.82^*	0.75	0.49^*
	(0.008)	(0.009)	(0.001)	(0.013)	(0.025)	(0.372)	(0.013)
Gender
Female	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Male	0.23^*	−0.24^*	0.01^*	0.92	1.17	1.36	1.53^*
	(0.016)	(0.022)	(0.002)	(0.033)	(0.083)	(0.314)	(0.081)
Race/ethnicity
White	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Black	−0.07^*	−0.15^*	−0.05^*	1.20^*	0.95	1.13	1.07
	(0.019)	(0.022)	(0.002)	(0.066)	(0.048)	(0.079)	(0.032)
Hispanic	0.01	−0.10^*	−0.03^*	1.26^*	1.09	1.04	1.10
	(0.028)	(0.025)	(0.004)	(0.077)	(0.050)	(0.279)	(0.047)
Other	0.01	−0.004	−0.02^*	1.01	1.00	1.03	1.02
	(0.014)	(0.020)	(0.002)	(0.024)	(0.056)	(0.107)	(0.049)
Drive time to primary care (in miles)	−0.004^*	−0.002^*	<0.001	1.00	1.00	1.00	1.00
	(0.0003	(0.0005)	<0.001	(0.001)	(0.001)	(0.002)	(0.001)
Rural/urban residence
Urban	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Rural	0.051^*	0.10^*	0.01^*	0.77^*	0.90^*	0.89	0.83^*
	(0.019)	(0.026)	(0.002)	(0.041)	(0.041)	(0.142)	(0.026)
Marital status
Currently married	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Divorced/separated	−0.001	−0.05^*	−0.02^*	0.97	1.03	1.13^*	1.22^*
	(0.007)	(0.008)	(0.001)	(0.020)	(0.031)	(0.037)	(0.028)
Single, never married	0.020	−0.10^*	−0.02^*	0.99	1.06	1.17	1.39^*
	(0.011)	(0.013)	(0.002)	(0.019)	(0.028)	(0.252)	(0.044)
Widowed	0.12^*	0.02	−0.01^*	1.00	1.05	1.12	1.25^*
	(0.015)	(0.016)	(0.002)	(0.039)	(0.040)	(0.083)	(0.048)
VA enrollment priority
Group 1 to 2	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Group 3 to 4	0.12^*	0.10^*	−0.01^*	1.05	1.12	1.16	1.20^*
	(0.012)	(0.013)	(0.002)	(0.021)	(0.089)	(0.139)	(0.039)
Group 5 to 6	−0.005	−0.09^*	−0.02^*	1.07	1.17	1.31	1.33^*
	(0.007)	(0.009)	(0.001)	(0.027)	(0.109)	(0.459)	(0.033)
Group 7 to 8	−0.04	−0.05	−0.01^*	1.01	1.10	1.29	1.23^*
	(0.016)	(0.020)	(0.003)	(0.028)	(0.072)	(0.246)	(0.072)
Elixhauser comorbidity score	0.11^*	0.10^*	−0.001^*	1.16^*	1.36	1.42	1.35^*
	(0.005)	(0.003)	(<0.001)	(0.028)	(0.179)	(0.751)	(0.005)
Comorbid depression	0.09^*	0.10^*	−0.02^*	0.96	0.75	0.69	0.81^*
	(0.008)	(0.009)	(0.001)	(0.020)	(0.139)	(0.339)	(0.019)
Clinic factors
Clinic appointment wait time	−0.004	0.013	<−0.001	1.01	0.98^*	0.98	0.99
	(0.014)	(0.016)	(0.001)	(0.002)	(0.007)	(0.034)	(0.020)
Clinic ratio of telephone encounters	−0.03^*	0.28^*	0.001	1.04	1.01	1.03	1.04^*
	(0.011)	(0.018)	(0.001)	(0.016)	(0.026)	(0.075)	(0.017)
Clinic use of telehealth	0.014	−0.042^*	<−0.001	0.98	0.99^*	0.99	0.98
	(0.013)	(0.015)	(0.001)	(0.009)	(0.004)	(0.019)	(0.018)
County rate of COVID-19	0.06^*	−0.05^*	−0.003^*	1.02^*	1.02	1.00	1.01
	(0.003)	(0.005)	(0.0003)	(0.005)	(0.013)	(0.041)	(0.009)

Outcomes for primary care use and adherence were estimated from linear regression models adjusting for quarter, patients’ sociodemographic characteristics, Elixhauser comorbidity, comorbid depression, distance to primary care site, rurality, clinic factors, and community rate of COVID infections. A Poisson model was used to estimate emergency department visits, all-cause, and ambulatory care-sensitive condition hospitalizations, whereas a logistic model was used to estimate hospitalization for diabetes complications. All results have standard errors reported in parentheses.
*P < .01.
Abbreviations: IRR, incidence rate ratio; VA, veterans affairs; OR, odds ratio.