Effects of home-based primary care on Medicare costs in high-risk elders.

Objectives: To determine the effect of home-based primary care (HBPC) on Medicare costs and mortality in frail elders.

Design: Case-control concurrent study using Medicare administrative data.

Setting: HBPC practice in Washington, District of Columbia.

Participants: HBPC cases (n = 722) and controls (n = 2,161) matched for sex, age bands, race, Medicare buy-in status (whether Medicaid covers Part B premiums), long-term nursing home status, cognitive impairment, and frailty. Cases were eligible if enrolled in MedStar Washington Hospital Center's HBPC program during 2004 to 2008. Controls were selected from Washington, District of Columbia, and urban counties in Virginia, Maryland, and Pennsylvania.

Intervention: HBPC clinical service.

Measurements: Medicare costs, utilization events, mortality.

Results: Mean age was 83.7 for cases and 82.0 for controls (P < .001). A majority of both groups was female (77%) and African American (90%). During a mean 2-year follow-up, in univariate analysis, cases had lower Medicare ($44,455 vs $50,977, P = .01), hospital ($17,805 vs $22,096, P = .003), and skilled nursing facility care ($4,821 vs $6,098, P = .001) costs, and higher home health ($6,579 vs $4,169; P < .001) and hospice ($3,144 vs. $1,505; P = .005) costs. Cases had 23% fewer subspecialist visits (P = .001) and 105% more generalist visits (P < .001). In a multivariate model, cases had 17% lower Medicare costs, averaging $8,477 less per beneficiary (P = .003) over 2 years of follow-up. There was no difference between cases and controls in mortality (40% vs 36%, hazard ratio = 1.06, P = .44) or in average time to death (16.2 vs 16.8 months, P = .30).

Conclusion: HBPC reduces Medicare costs for ill elders, with similar survival outcomes in cases and controls.