CONTEXT AND QUESTION ASKED: In patients with metastatic cancer, chemotherapy may provide symptom control, prevent complications, prolong life, or improve quality of life. Except in rare cases, however, patients with metastatic disease will not be cured. In older patients with metastatic cancer, hospitalization for treatment toxicity may reduce the quality of an already limited life expectancy. We evaluated the association between chemotherapy for metastatic cancer and risk of hospitalization. MAIN CONCLUSION: Hospitalizations are common in patients with incurable advanced malignancies and are more likely among those who receive chemotherapy. APPROACH: In the linked SEER-Medicare dataset, we identified Medicare beneficiaries aged 66 years or older with a primary diagnosis of metastatic breast, colorectal, ovarian, bladder, lung, pancreas, esophageal, stomach, or prostate cancer between 2001 and 2009 who died by the end of 2010. Chemotherapy recipients and nonrecipients were pair-matched by age, sex, race, comorbidity, geographic region and survival duration. The primary endpoint was hospital admission, identified in inpatient claims between cancer diagnosis and the first of hospice admission or death. We also identified the subset of admissions associated with a primary or secondary diagnosis code suggestive of an adverse effect of chemotherapy. The association between chemotherapy and hospitalization was estimated in separate multivariable Cox proportional-hazards regression models for each cancer site, accounting for the matched-pairs design and controlling for unmatched demographic and disease characteristics. RESULTS: Of 18,486 patients who received chemotherapy for metastatic cancer, 92% were hospitalized at least once for any reason, including 51% hospitalized for a likely toxicity. The corresponding rates among matched non-recipients were 83% and 34% (Figure). In nearly all cancers, chemotherapy recipients had a greater risk of hospitalization for a likely toxicity or for any cause. Chemotherapy recipients had substantially higher hospitalization for infection or fever (21% v 15%), hematologic complications (11% v 3%), dehydration (13% v 6%), and PE or DVT (9% v 4%) compared with nonrecepients. Chemotherapy was associated with a significantly increased risk of likely toxicity-related hospitalization in nearly all cancers, controlling for sociodemographic characteristics and other treatment. The association was greatest in patients with metastatic esophageal cancer (adjusted hazard ratio, 2.00; 95% CI, 1.11 to 3.60) and smallest in patients with metastatic prostate cancer (adjusted hazard ratio, 1.22; 95% CI, 1.01 to 1.47). INTERPRETATION: Older patients receiving chemotherapy for incurable advanced cancers are at high risk of hospitalization, of which a non-negligible proportion is likely attributable to adverse effects of treatment. Infection, fever, dehydration, and hematologic complications constitute a large proportion of these events, some of which may be preventable through evidence-based patient management, prophylactic interventions, and effective outpatient care. Our findings might be limited to older patients with advanced cancer who have a generally poor prognosis or limited expected survival. SIGNIFICANCE OF FINDINGS: Understanding the common reasons for hospital admissions and developing toxicity management programs and educational resources may help patients and their families make informed treatment decisions, minimize adverse effects and reduce hospitalizations in this population with limited life expectancy. [Figure: see text]
Methodological Challenges for Epidemiologic Studies of Deprescribing at the End of Life
