A clinical index to stratify hospitalized older adults according to risk for new-onset disability

Abstract

Background: Many older adults who are independent prior to hospitalization develop a new disability by hospital discharge. Early risk stratification for new-onset disability may improve care. Thus, this study's objective was to develop and validate a clinical index to determine, at admission, risk for new-onset disability among older, hospitalized adults at discharge.

Design: Data analyses derived from two prospective studies.

Setting: Two teaching hospitals in Ohio.

Participants: Eight hundred eighty-five patients aged 70 years and older were discharged from a general medical service at a tertiary care hospital (mean age 78, 59% female) and 753 patients discharged from a separate community teaching hospital (mean age 79, 63% female). All participants reported being independent in five activities of daily living (ADLs: bathing, dressing, transferring, toileting, and eating) 2 weeks before admission.

Measurements: New-onset disability, defined as a new need for personal assistance in one or more ADLs at discharge in participants who were independent 2 weeks before hospital admission.

Results: Seven independent risk factors known on admission were identified and weighted using logistic regression: age (80-89, 1 point; ≥90, 2 points); dependence in three or more instrumental ADLs at baseline (2 points); impaired mobility at baseline (unable to run, 1 point; unable to climb stairs, 2 points); dependence in ADLs at admission (2-3 ADLs, 1 point; 4-5 ADLs, 3 points); acute stroke or metastatic cancer (2 points); severe cognitive impairment (1 point); and albumin less than 3.0 g/dL (2 points). New-onset disability occurred in 6%, 13%, 18%, 34%, 35%, 45%, 50%, and 87% of participants with 0, 1, 2, 3, 4, 5, 6, and 7 or more points, respectively, in the derivation cohort (area under the receiver operating characteristic curve (AUC)=0.784), and in 8%, 10%, 27%, 38%, 44%, 45%, 58%, and 83%, respectively, in the validation cohort (AUC=0.784). The risk score also predicted (P<.001) disability severity, nursing home placement, and long-term survival.

Conclusion: This clinical index determines risk for new-onset disability in hospitalized older adults and may inform clinical care.

Figure 1

Proportion of participants with different numbers of activity of daily living (ADL) dependencies at discharge, according to the risk score. The number of ADLs participants were dependent in is shown in different colors, according to the key. Catastrophic disability is indicated by dependence in three or more ADLs. In this figure, the derivation and validation cohorts are combined. Areas under the receiver operating characteristic curve were 0.760 for participants aged 70 to 79 and 0.763 for participants aged 80 and older; 0.781 for women and 0.786 for men; 0.787 for participants with severe cognitive impairment and 0.725 for those without severe cognitive impairment; and 0.723 for participants independent in zero to one ADLs at admission and 0.767 for those dependent in two to five ADLS at admission.

Appendix 1

Disability or Death at Discharge, According to Risk Score in Patient Subgroups