Complexity of the Therapeutic Regimen in Older Adults with Cancer: Associated Factors

Population aging is a worldwide phenomenon and is often associated with multimorbidity and polypharmacy. Complex medication regimens are common among older adults and contribute to the occurrence of harmful health outcomes. Age is one of the main risk factors for cancer. This study aimed to determine and characterize the therapeutic complexity in older patients with cancer, and analyze the factors associated with high complexity and the impact of the oncological context.

A cross-sectional study with patients aged ≥65 years with cancer was conducted in three hospitals in northern Portugal. Data collection was obtained using self-reports. The medication regimen complexity was assessed using the Medication Regimen Complexity Index (MRCI). Descriptive and association statistical analysis were performed. Logistic, linear, simple and multiple regression analysis were conducted, with and without automatic variable selection.

A total of 552 patients were included (median age, 71; IQR, 68-76). The mean MRCI before the oncological context was 18.67 (SD 12.60) and 27.39 (SD 16.67) after the oncological context, presenting a statistically significant difference in the values obtained (p < 0.001). An elevated complexity was significantly associated with polypharmacy, chronic diseases and with the administration of high-risk medications (p < 0.05). High MRCI values showed a relationship with the occurrence of potential drug interactions (p < 0.001). There was no relationship with the existence of cardiac risk comorbidity.

This study demonstrated the existence of high therapeutic complexity in older patients with cancer, suggesting the need for intervention to prevent medication-related problems in this vulnerable population.