Association of Patient Social, Cognitive, and Functional Risk Factors with Preventable Hospitalizations: Implications for Physician Value-Based Payment.

BACKGROUND: Ambulatory care-sensitive condition (ACSC) hospitalizations are used to evaluate physicians' performance in Medicare value-based payment programs. However, these measures may disadvantage physicians caring for vulnerable populations because they omit social, cognitive, and functional factors that may be important determinants of hospitalization.
OBJECTIVE: To determine whether social, cognitive, and functional risk factors are associated with ACSC hospitalization rates and whether adjusting for them changes outpatient safety-net providers' performance.
DESIGN: Using data from the Medicare Current Beneficiary Survey, we conducted patient-level multivariable regression to estimate the association (as incidence rate ratios (IRRs)) between patient-reported social, cognitive, and functional risk factors and ACSC hospitalizations. We compared outpatient safety-net and non-safety-net providers' performance after adjusting for clinical comorbidities alone and after additional adjustment for social, cognitive, and functional factors captured in survey data.
SETTING: Safety-net and non-safety-net clinics. PARTICIPANTS: Community-dwelling Medicare beneficiaries contributing 38,616 person-years from 2006 to 2013. MEASUREMENTS: Acute and chronic ACSC hospitalizations.
RESULTS: After adjusting for clinical comorbidities, Alzheimer's/dementia (IRR 1.30, 95% CI 1.02-1.65), difficulty with 3-6 activities of daily living (ADLs) (IRR 1.43, 95% CI 1.05-1.94), difficulty with 1-2 instrumental ADLs (IADLs, IRR 1.54, 95% CI 1.26-1.90), and 3-6 IADLs (IRR 1.90, 95% CI 1.49-2.43) were associated with acute ACSC hospitalization. Low income (IRR 1.28, 95% CI 1.03-1.58), lack of educational attainment (IRR 1.33, 95% CI 1.04-1.69), being unmarried (IRR 1.18, 95% CI 1.01-1.36), difficulty with 1-2 IADLs (IRR 1.30, 95% CI 1.05-1.60), and 3-6 IADLs (IRR 1.44, 95% CI 1.16-1.80) were associated with chronic ACSC hospitalization. Adding these factors to standard Medicare risk adjustment eliminated outpatient safety-net providers' performance gap (p < .05) on ACSC hospitalization rates relative to non-safety-net providers.
CONCLUSIONS: Social, cognitive, and functional risk factors are independently associated with ACSC hospitalizations. Failure to account for them may penalize outpatient safety-net providers for factors that are beyond their control.