Table 3.
Change in predicted utilization and expenditures (amount as modeled in the post period vs. amount as expected had the pre period trend continued) for Treatment (ACC assignees) vs. Comparator (other large practice assignees), 18 months after ACC activation
| Treatment Predictions | Comparator Predictions | Difference at 18 months: Treatment vs. Comparator, Post vs. Pre | ||||||
|---|---|---|---|---|---|---|---|---|
| A | B | C | D | Difference = (A-B) - (C-D) | ||||
| Enrollment | Predicted Outcome | Under Post Trend | Under Pre Trend | Under Post Trend | Under Pre Trend | Difference | 95% Confidence Interval | P-Value |
| TANF | Plan Expenditures | $393.76 | $389.69 | $386.97 | $423.65 | $40.74 | (−$75.99, $157.48) | 0.492 |
| Any Hospitalization | 1.49% | 1.25% | 1.45% | 1.50% | 0.29% | (−0.23%, 0.81%) | 0.278 | |
| Any ED Visit | 8.85% | 8.07% | 8.29% | 8.29% | 0.79% | (−0.32%, 1.89%) | 0.162 | |
| SSI (Without Medicare) | Plan Expenditures | $852.01 | $972.92 | $800.77 | $870.81 | −$50.87 | (−$202.09, $100.36) | 0.508 |
| Any Hospitalization | 4.01% | 4.13% | 3.72% | 3.77% | −0.07% | (−0.92%, 0.77%) | 0.862 | |
| Any ED Visit | 12.47% | 11.79% | 10.95% | 10.99% | 0.72% | (−0.46%, 1.90%) | 0.233 | |
| Expansion | Plan Expenditures | $511.62 | $243.02 | $469.07 | $573.49 | $373.02 | ($−100.26, $846.30) | 0.121 |
| Any Hospitalization | 1.66% | 1.71% | 1.37% | 1.01% | −0.41% | (−2.64%, 1.83%) | 0.723 | |
| Any ED Visit | 7.56% | 8.21% | 6.79% | 10.82% | 3.37% | (−1.89%, 8.64%) | 0.209 | |
| UHC Medicare-Medicaid Dual | Plan Expenditures | $416.19 | $403.27 | $446.12 | $499.16 | $65.96 | (−$121.81, $253.73) | 0.488 |
| Any Hospitalization | 1.49% | 1.26% | 1.71% | 2.00% | 0.52% | (−0.53%, 1.58%) | 0.332 | |
| Any ED Visit | 4.16% | 4.45% | 4.17% | 3.90% | −0.55% | (−2.38%, 1.27%) | 0.551 | |
Notes: Predictions made using interrupted time series segmented regression analysis. Change in outcome at 18 months estimated by comparing (1) the 18-month outcome amount in the post period with (2) what the outcome amount would have been at 18 months after ACC activation (real or proxy) if pre period trends had continued. Linear regression used for expenditures; logistic regression used for utilization outcomes. Sample is person-months from 2010–2016.
denotes significance at p < .05. Regression covariates of interest were study Group (treatment [ACC assignees] vs. comparator [other large practice assignees]); a linear monthly time trend counting months before and after ACC activation (real or proxy; ACC activation defined as time zero), indicators and splines for the post period (months 0 and after); and the interactions between these variables and Group. Other covariates included sex, age group, race, language, 17 comorbidity indicators arthritis, asthma, atrial fibrillation, autism, cancer, chronic obstructive pulmonary disease, congestive heart failure, dementia, depression, HIV, hyperlipidemia, liver disease, myocardial infarction, osteoporosis, schizophrenia, stroke, and substance abuse), state-by-year fixed effects, an indicator for whether a state had adopted the Medicaid Expansion in the given month, and seasonality. Repeated measures adjusted for using generalized estimating equations (GEE), clustering by practice.