Early Impact of the State Innovation Models Initiative on Diagnosed Diabetes Prevalence Among Adults and Hospitalizations Among Diagnosed Adults

Effect of State-Led Delivery System and Payment Reforms on Population-Level Detection and Management of Diabetes

OBJECTIVE

The Centers for Medicare and Medicaid Services State Innovation Models (SIM) initiative has invested more than $1 billion to test state-led delivery system and payment reforms that can affect diabetes care management. We examined whether SIM implementation between 2013 and 2017 was associated with diagnosed diabetes prevalence or with hospitalization or 30-day readmission rate among diagnosed adults.

RESEARCH DESIGN AND METHODS

The quasiexperimental design compared study outcomes before and after the SIM initiative in 12 SIM states versus five comparison states using difference-in-differences (DiD) regression models of 21,055,714 hospitalizations for adults age ≥18 years diagnosed with diabetes in 889 counties from 2010 to 2017 across the 17 states. For readmission analyses, comparative interrupted time series (CITS) models included 11,812,993 hospitalizations from a subset of nine states.

RESULTS

Diagnosed diabetes prevalence changes were not significantly different between SIM states and comparison states. Hospitalization rates were inconsistent across models, with DiD estimates ranging from -5.34 to -0.37 and from -13.16 to 0.92, respectively. CITS results indicate that SIM states had greater increases in odds of 30-day readmission during SIM implementation compared with comparison states (round 1: adjusted odds ratio [AOR] 1.07; 95% CI 1.04, 1.11; P < 0.001; round 2: AOR 1.06; 95% CI 1.03, 1.10; P = 0.001).

CONCLUSIONS

The SIM initiative was not sufficiently focused to have a population-level effect on diabetes detection or management. SIM states had greater increases in 30-day readmission for adults with diabetes than comparison states, highlighting potential unintended effects of engaging in the multipayer alignment efforts required of state-led delivery system and payment reforms.

The impact of the State Innovation Models Initiative on population health

In this paper, we examine the effects of the State Innovation Models Initiative (SIM) on population-level health status. SIM provided $250 million to six states in 2013 for broad delivery system reforms. We use data from the Behavioral Risk Factor Surveillance System for the years 2010-2016. Our sample is restricted to individuals ages 45 and older residing in 6 SIM and 15 control states. Treatment effects in a difference-in-difference design are estimated using a latent factor model for multiple indicators of health status. In addition to estimates for the primary sample, we obtain estimates for six subsamples based on strata of age, education, income, race and urban/rural status. We find that individuals in states that implemented SIM show significant improvements in health status. The effects of SIM are greater among older, Medicare eligible individuals, including those living in rural areas. The State Innovation Models Initiative, which provided financial incentives for states to implement health care delivery system reforms, led to population-level improvements in health status.

The Early Impact of the Centers for Medicare & Medicaid Services State Innovation Models Initiative on 30-Day Hospital Readmissions Among Adults With Diabetes

BACKGROUND

The Centers for Medicare & Medicaid Services (CMS) State Innovation Models (SIM) Initiative funds states to accelerate delivery system and payment reforms. All SIM states focus on improving diabetes care, but SIM's effect on 30-day readmissions among adults with diabetes remains unclear.

METHODS

A quasi-experimental research design estimated the impact of SIM on 30-day hospital readmissions among adults with diabetes in 3 round 1 SIM states (N=671,996) and 3 comparison states (N=2,719,603) from 2010 to 2015. Difference-in-differences multivariable logistic regression models that incorporated 4-group propensity score weighting were estimated. Heterogeneity of SIM effects by grantee state and for CMS populations were assessed.

RESULTS

In adjusted difference-in-difference analyses, SIM was associated with an increase in odds of 30-day hospital readmission among patients in SIM states in the post-SIM versus pre-SIM period relative to the ratio in odds of readmission among patients in the comparison states post-SIM versus pre-SIM (ratio of adjusted odds ratio=1.057, P=0.01). Restricting the analyses to CMS populations (Medicare and Medicaid beneficiaries), resulted in consistent findings (ratio of adjusted odds ratio=1.057, P=0.034). SIM did not have different effects on 30-day readmissions by state.

CONCLUSIONS

We found no evidence that SIM reduced 30-day readmission rates among adults with diabetes during the first 2 years of round 1 implementation, even among CMS beneficiaries. It may be difficult to reduce readmissions statewide without greater investment in health information exchange and more intensive use of payment models that promote interorganizational coordination.