Occurrence and Characteristics of Hospitalizations During First-Line Chemotherapy Among Individuals with Metastatic Colorectal Cancer.

Objective: Choosing chemotherapy for metastatic colorectal cancer (mCRC) requires balancing clinical effectiveness and risk of complications. This study characterized real-world inpatient/emergency department (ED) hospitalizations during first-line chemotherapy among individuals with mCRC.

Methods: This retrospective cohort study used data from medical and pharmacy claims. All patients had mCRC with ≥1 claim for ≥1 of the 5 most frequently utilized first-line chemotherapy agents (fluorouracil, oxaliplatin, bevacizumab, irinotecan, capecitabine). The main outcome was all-cause hospitalizations (inpatient or ED setting) identified from claims via ICD-9/10-CM coding from index date until 30 days after the end of first-line chemotherapy or last available data.

Results: A total of 717 individuals (mean age 55 years; 58% male; ECOG 0/1/2+/missing in 44%/39%/6%/11%; median follow-up 116 days) met study criteria. Thirty-four distinct chemotherapy regimens were used. Overall, 40% of patients had ≥1 hospitalization (n=285; total 415 hospitalizations); 12% (n=85) had ≥2 hospitalizations. The median time to first hospitalization was 52 days; median inpatient length of stay was 4 days; infections/neutropenia (21%) and bowel-related complications (17%) were the most common issues associated with inpatient hospitalizations. In univariate analyses, insurance plan type, geographical location, ECOG, and renal disease were associated with hospitalization. In multivariable analyses, ECOG ≥1 was associated with a 67% increase (p<0.01) in the odds of hospitalization vs ECOG= 0.

Conclusion: Approximately 40% of patients with mCRC were hospitalized during the study period. Hospital stays were typically short. Further research is needed to determine how many of these hospitalizations may be avoidable. We also observed a large amount of variation in regimens used in the first-line setting.