Effect of frailty on hospital outcomes among patients with cancer in the United States: Results from the National Inpatient Sample

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Introduction: To understand the effects of frailty on hospital outcomes such as in-hospital mortality, length of stay, and healthcare cost among patients with cancer using a nationally representative database. Materials and Methods: This study was a retrospective observational analysis of Nationwide Inpatient Sample (NIS) data collected during 2005–2014. Participants included adult patients with cancer ≥45 years identified by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. ‘Frail’ versus ‘non-frail’ hospitalizations were determined using the Johns Hopkins Adjusted Clinical Groups (ACG) frailty-defining diagnosis indicator. Main outcome measures were in-hospital mortality, hospital length of stay, and hospitalization cost. We defined prolonged length of stay as hospital stay ≥75th percentile of the study sample. Propensity score match analysis was done to examine whether frailty was associated with length of stay and in-hospital mortality. Results: There were 10,463,083 cancer hospitalizations during 2005–2014, of which 1,022,777 (9.8%) were frail. Patients having length of stay ≥8 days were significantly higher among frail group, compared to non-frail group (53.3% versus 25.3%, P < 0.001). Similarly, unadjusted mortality (12.0% versus 5.3%, P < 0.001) and hospitalization costs ($29,726 versus $18,595, P < 0.001) were significantly higher for frail patients. Nearly $28 billion was expended on hospitalization of frail patients with cancer during the study period. In propensity score match analysis, the odds of in-hospital mortality (odds ratio [OR], 1.54; 95% confidence interval [CI], 1.50–1.58) and length of stay (OR, 2.23; 95% CI, 2.18–2.27) were significantly greater for frail patients. Discussion: Frailty was associated with adverse hospital outcomes such as increased length of stay, mortality, and hospitalization cost among all cancer types. Our findings could be valuable for frailty-based risk stratification of patients with cancer. Concerted efforts by the physiatrists, oncologists, and surgeons towards identifying frailty and incorporating it in risk estimation measures could help in optimizing management strategies for cancer.