A clinical prediction model to assess risk for chemotherapy-related hospitalization in patients initiating palliative chemotherapy

IMPORTANCE: Chemotherapy-related hospitalizations in patients with advanced cancer are common, distressing, and costly. Methods to identify patients at high risk of chemotherapy toxic effects will permit development of targeted strategies to prevent chemotherapy-related hospitalizations. OBJECTIVE: To demonstrate the feasibility of using readily available clinical data to assess patient-specific risk of chemotherapy-related hospitalization. DESIGN, SETTING, AND PARTICIPANTS: Nested case-control study conducted from January 2003 through December 2011 at the Mass General/North Shore Cancer Center, a community-based cancer center in northeastern Massachusetts. The parent cohort included 1579 consecutive patients with advanced solid-tumor cancer receiving palliative-intent chemotherapy. Case patients (n = 146) included all patients from the parent cohort who experienced a chemotherapy-related hospitalization. Controls (n = 292) were randomly selected from 1433 patients who did not experience a chemotherapy-related hospitalization. EXPOSURES: Putative risk factors for chemotherapy-related hospitalization - including patient characteristics, treatment characteristics, and pretreatment laboratory values - were abstracted from medical records. Multivariable logistic regression was used to model the patient-specific risk of chemotherapy-related hospitalization. MAIN OUTCOMES AND MEASURES: Chemotherapy-related hospitalization, as adjudicated by the oncology clinical care team within a systematic quality-assessment program. RESULTS: A total of 146 (9.2%) of 1579 patients from the parent cohort experienced a chemotherapy-related hospitalization. In multivariate regression, 7 variables were significantly associated with chemotherapy-related hospitalization: age, Charlson comorbidity score, creatinine clearance, calcium level, below-normal white blood cell and/or platelet count, polychemotherapy (vs monotherapy), and receipt of camptothecin chemotherapy. The median predicted risk of chemotherapy-related hospitalization was 6.0% (interquartile range [IQR], 3.6%-11.4%) in control patients and 14.7% (IQR, 6.8%-22.5%) in case patients. The bootstrap-adjusted C statistic was 0.71 (95% CI, 0.66-0.75). At a risk threshold of 15%, the model exhibited a sensitivity of 49% (95% CI, 41%-57%) and a specificity of 85% (95% CI, 81%-89%) for predicting chemotherapy-related hospitalization. CONCLUSIONS AND RELEVANCE: In patients initiating palliative chemotherapy for cancer, readily available clinical data were associated with the patient-specific risk of chemotherapy-related hospitalization. External validation and evaluation in the context of a clinical decision support tool are warranted.