Home Time as a Patient-Centered Outcome in Administrative Claims Data

BACKGROUND: Home time, the number of days alive and spent out of hospital and skilled nursing facility, has been proposed as a patient-centered outcome that can be readily calculated in administrative claims data. OBJECTIVES: To compare home time against existing patient-centered outcome measures. DESIGN: Retrospective cohort study. SETTING: Community. PARTICIPANTS: A total of 4594 Medicare beneficiaries 65 years or older with complete survey and claims data in the Medicare Current Beneficiary Survey 2010 to 2011. MEASUREMENTS: Home time was calculated from the 2011 claims data (range, 0-365 days). The 1-year incidence of patient-centered outcomes (poor self-rated health, mobility impairment, depression, limited social activity, and difficulty in self-care) was measured. The minimum clinically important difference (MCID) was derived by contrasting the mean home time between those who experienced functional decline or death and those who did not. RESULTS: The mean home time was 355.8 days (SD, 42.1 days); 84.1% had a home time of 365 days, and 5.7% had a home time of 336 days or fewer. The incidence of poor self-rated health ranged from 2% (home time, 365 days) to 21% (home time, less than 337 days). Similarly, the corresponding incidence risks were 11% to 59% for mobility impairment, 5% to 19% for depression, 17% to 67% for limited social activity, and 13% to 68% for difficulty in self-care. The risk of mobility impairment, depression, and difficulty in self-care increased steeply after home time loss of 15 days or greater. The MCID of home time was 18.6 days. CONCLUSION: A loss in home time is associated with decline in several patient-centered outcome measures in community-dwelling Medicare beneficiaries. These results provide empirical evidence to promote adoption of home time and its clinical interpretation for database studies of medical interventions.