Intent-to-Treat Outcome Rates by Selection Group (Selected n = 13,219; Not Selected n = 21,630)
| Unadjusted | ||||
|---|---|---|---|---|
| Outcome in Postselection Period | Rate per 1,000 Patients/Month (SE) | Absolute Difference in Rate | Rate Ratio (95% CI) | Adjusted Rate Ratio (95% CI) |
| Total primary care office visitsa | ||||
| Selectedb | 235 (12) | −1 | 1.00 (0.93–1.08) | 1.01 (0.94–1.09) |
| Not selected (ref) | 236 (17) | – | 1.00 | 1.00 |
| Total behavioral/mental health visitsc | ||||
| Selected | 201 (28) | −31d | 0.87 (0.79–0.94)d | 0.89 (0.81–0.99)d |
| Not selected (ref) | 232 (29) | – | 1.00 | 1.00 |
| Total laboratory testse | ||||
| Selected | 342 (28) | −13 | 0.96 (0.88–1.05) | 0.97 (0.89–1.05) |
| Not selected (ref) | 355 (39) | – | 1.00 | 1.00 |
| Total referralsf | ||||
| Selected | 45 (9) | +5 | 1.14 (0.95–1.37) | 1.18 (1.02–1.35)d |
| Not selected (ref) | 40 (6) | – | 1.00 | 1.00 |
| Total immunizationsg | ||||
| Selected | 57 (4) | −2 | 0.97 (0.93–1.01) | 0.98 (0.94–1.03) |
| Not selected (ref) | 59 (4) | – | 1.00 | 1.00 |
| Total imaging studiesh | ||||
| Selected | 43 (3) | +2 | 1.06 (0.99–1.13) | 1.08 (1.01–1.16)d |
| Not selected (ref) | 41 (2) | – | 1.00 | 1.00 |
CHC = community health center; CPT = Current Procedural Terminology; EHR = electronic health record; HCPCS = Healthcare Common Procedure Coding System; ref = reference group; SE = standard error.
Notes: (1) Rates are zero-inflated Poisson regression estimates. Adjusted estimates controlled for categorical age and race/ethnicity as these variables differed significantly between the selection groups at baseline. (2) All models accounted for clustering of patients by primary CHC through a robust sandwich variance estimator. (3) Postselection period was the 36 months after an applicant was notified of selection to apply for insurance coverage (the selection date) through the Oregon Experiment or, for those not selected, a randomly assigned selection date based on the distribution of selection dates for the selected group. (4) SE denotes robust standard error estimate of the use rate that accounts for clustering of patients within primary CHC.
↵a Face-to-face office visits in a primary care setting and/or with a primary care clinician.
↵b Oregon OCHIN patients selected to apply for health insurance coverage via the Oregon Experiment vs not selected.
↵c Face-to-face encounters designated as behavioral or mental health in the EHR; limited to 11,571 patients seen at 1 or more of the 33 clinics with the behavioral/mental health visit indicator.
↵d Statistically significant difference compared with reference group.
↵e CPT and HCPCS codes grouped as laboratory tests in the EHR.
↵f CPT and HCPCS codes grouped as referrals in the EHR.
↵g CPT and HCPCS codes grouped as immunizations in the EHR.
↵h CPT and HCPCS codes grouped as imaging studies in the EHR.