Home-Based Primary Care and the Risk of Ambulatory Care-Sensitive Condition Hospitalization Among Older Veterans With Diabetes Mellitus

IMPORTANCE Primary care services based at home have the potential to reduce the likelihood of hospitalization among older adults with multiple chronic diseases. OBJECTIVE To characterize the association between enrollment in Home-Based Primary Care (HBPC), a national home care program operated by the US Department of Veterans Affairs (VA), and hospitalizations owing to an ambulatory care-sensitive condition among older veterans with diabetes mellitus. DESIGN AND SETTING Retrospective cohort study. Patients admitted to VA and non-VA hospitals were followed up from January 1, 2006, through December 31, 2010. PARTICIPANTS Veterans 67 years or older who were fee-for-service Medicare beneficiaries, were diagnosed as having diabetes mellitus and at least 1 other chronic disease, and had at least 1 admission to a VA or non-VA hospital in 2005 or 2006. EXPOSURES Enrollment in HBPC, defined as a minimum of 2 HBPC encounters during the study period. MAIN OUTCOMES AND MEASURES Admission to VA and non-VA hospitals owing to an ambulatory care-sensitive condition, as measured by the Agency for Healthcare Research and Quality's Prevention Quality Indicators in VA medical records and Medicare claims. Outcomes were analyzed using distance from the veteran's residence to a VA facility that provides HBPC as an instrumental variable. RESULTS Among 56 608 veterans, 1978 enrolled in HBPC. These patients were older (mean age, 79.1 vs 77.1 years) and had more chronic diseases (eg, 59.2% vs 53.5% had congestive heart failure). Multivariable predictors for HBPC enrollment included paralysis (odds ratio [ OR], 2.11; 95% CI, 1.63-2.74), depression (OR, 1.99; 95% CI, 1.70-2.34), congestive heart failure (OR, 1.36; 95% CI, 1.17-1.58), and distance from the nearest HBPC-providing VA facility (OR, 0.59; 95% CI, 0.50-0.70 for >10-30 vs <5 miles). After controlling for selection using an instrumental variable analysis, HBPC was associated with a significant reduction in the probability of experiencing a hospitalization owing to an ambulatory care-sensitive condition (hazard ratio, 0.71; 95% CI, 0.57-0.89), with an absolute reduction in the probability of hospitalization of 5.8% in 1 year. CONCLUSIONS AND RELEVANCE Home-Based Primary Care is associated with a decreased probability of ambulatory care-sensitive condition hospitalization among elderly veterans with diabetes mellitus. In accountable care models, HBPCmay have an important role in the management of older adults with multiple chronic diseases.