Activity Limitation Stages Are Associated With Risk of Hospitalization Among Medicare Beneficiaries.

BACKGROUND

Activity limitation stages based on activities of daily living (ADLs) and instrumental activities of daily living (IADLs) are associated with 3-year mortality in elderly Medicare beneficiaries, yet their associations with hospitalization risk in this population have not been studied.

OBJECTIVE

To examine the independent association of activity limitation stages with risk of hospitalization within a year among Medicare beneficiaries aged 65 years and older.

DESIGN

Cohort study.

SETTING

Community.

PARTICIPANTS

A total of 9447 community-dwelling elderly Medicare beneficiaries from the Medicare Current Beneficiary Survey for years 2005-2009.

METHODS

Stages were derived for ADLs and IADLs separately. Associations of stages with time to first hospitalization and time to recurrent hospitalizations within a year were assessed with Cox proportional hazards models, with which we accounted for baseline sociodemographics, smoking status, comorbidities, and the year of survey entry.

MAIN OUTCOMES: Time to first hospitalization and time to recurrent hospitalizations within 1 year.

PRINCIPLE FINDINGS: The adjusted risk of first hospitalization increased with greater activity limitation stages (except stage III). The hazard ratios (95% confidence intervals) for ADL stages I-IV compared with stage 0 (no limitations) were 1.49 (1.36-1.63), 1.61 (1.44-1.80), 1.54 (1.35-1.76), and 2.06 (1.61-2.63), respectively. The pattern for IADL stages was similar. For recurrent hospitalizations, activity limitation stages were associated with the risk of the first hospitalization but not with subsequent hospitalizations.

CONCLUSION

Activity limitation stages are associated with the risk of first hospitalization in the subsequent year among elderly Medicare beneficiaries. Stages capture clinically interpretable profiles of ADL and IADL functionality and describe preserved functions and activity limitation in an aggregated measure. Stage can inform interventions to ameliorate disability and thus reduce the risk of a subsequent hospitalization in this population.

LEVEL OF EVIDENCE: IV.