Potentially inappropriate medications defined by STOPP criteria in older patients with breast and colorectal cancer.

purposeScreening for potentially inappropriate medications (PIM) is recommended in older patients with cancer receiving chemotherapy, given the concern for adverse drug reactions, drug-drug interactions and non-adherence. Our objective was to determine the impact of PIM on outcomes in patients with breast and colorectal cancers receiving chemotherapy.

methodsWe used data from the SEER-Medicare database, including patients >/= 66 years old with a diagnosis of Stage II/III breast and colorectal cancer made between 7/1/2007-12/31/2009. We used modified STOPP criteria to define baseline PIM as a dichotomous variable in the 4 months prior to diagnosis. STOPP criteria was used based on its performance as a robust measure of PIM. Outcomes measures included ER visits, hospitalizations, and death within 3 months from the last chemotherapy, and a composite of the three. We used Chi-square or Fisher's exact test to determine associations of PIM with covariates and outcomes, and Cox proportional hazards (PH) model for the time-to-event analysis.

resultsFinal analysis included 1,595 patients with breast cancer and 1,528 patients with colorectal cancer. Frequency of baseline PIM by STOPP was 31.5% in the breast and 30.9% in the colorectal cohort. In the breast cohort, associations with the composite outcome in the Cox PH model included disease stage, comorbidity, medication number and baseline ER visits/hospitalization. Age, gender, race, comorbidity and baseline ER visits/hospitalization were associated in the colorectal cohort. PIM was not associated with outcomes in either cohort, aside from hospitalization in the breast.

conclusionsWe found no consistent association between pre-chemotherapy PIM defined by STOPP and outcomes.