Impact of Oncology Drug Shortages on Chemotherapy Treatment

Abstract

Prescription drug shortages began to increase markedly in the mid-2000s, including sterile injectable products such as chemotherapy drugs. Using Medicare claims linked to Surveillance Epidemiology and End Results (SEER), we examined outpatient chemotherapy use during shortage periods relative to the months before and after a shortage for newly diagnosed patients with breast, colorectal, leukemia, lung, lymphoma, ovarian, or pancreatic cancer (N = 182,470). For most drugs, we found little impact of shortages on either the fraction of patients receiving that drug or the quantity provided. In some cases, we found declines in utilization: 4% for doxorubicin and fluorouracil; 2.9% for oxaliplatin; and about 1% for cytarabine, dacarbazine, and leuprolide. Although shortages for a few drugs resulted in substantial reductions in use, in most cases, they resulted in little to no reduction. We discuss potential explanations for these counterintuitive findings, including potential limitations of current drug shortage reporting methods.

Figure 1.

Frequency of Oncology Drug Shortages: 2001–2012 Data Source: UUDIS

Figure 2.

Percentage Change in Utilization During a Shortage Panel A: Fraction of Patients Treated Panel B: Units Per Patient Notes: Shortages are defined using UUDIS coding. The points represent the coefficient estimate for the shortage effect from the interrupted time series regression using a linear model with IHS transformation (see shortage indicator in Equation 1 of the Supplementary Materials). The bars are 95% confidence intervals for each coefficient. Points highlighted in orange represent the most commonly used drugs (i.e., they are among the top 25 chemotherapy drugs in the Medicare claims). Four drugs (capecitabine, dactinomycin, denileukin, interferon alfa 2A) are not included in the figure because units are missing during shortage months. Missing units occur when the drug is given in an outpatient hospital setting rather than a physician’s office.

Figure 2.

Percentage Change in Utilization During a Shortage Panel A: Fraction of Patients Treated Panel B: Units Per Patient Notes: Shortages are defined using UUDIS coding. The points represent the coefficient estimate for the shortage effect from the interrupted time series regression using a linear model with IHS transformation (see shortage indicator in Equation 1 of the Supplementary Materials). The bars are 95% confidence intervals for each coefficient. Points highlighted in orange represent the most commonly used drugs (i.e., they are among the top 25 chemotherapy drugs in the Medicare claims). Four drugs (capecitabine, dactinomycin, denileukin, interferon alfa 2A) are not included in the figure because units are missing during shortage months. Missing units occur when the drug is given in an outpatient hospital setting rather than a physician’s office.

Figure 3.

Percentage Changes in Utilization During a Shortage Using FDA Shortage Definitions Panel A: Fraction of Patients Treated Panel B: Units Per Patient Notes: Shortages are defined using FDA coding. The points represent the coefficient estimate for the shortage effect from the interrupted time series regression using a linear model with IHS transformation (see shortage indicator in Equation 1 of the Supplementary Materials). The bars are 95% confidence intervals for each coefficient. Points highlighted in orange represent the most commonly used drugs (i.e., they are among the top 25 chemotherapy drugs in the Medicare claims). Three drugs (asparaginase, capecitabine and daunorubicin) are not included in Panel B because units are missing during FDA shortage months. Missing units occur when a drug is in an outpatient hospital setting rather than a physician’s office.

Figure 3.

Percentage Changes in Utilization During a Shortage Using FDA Shortage Definitions Panel A: Fraction of Patients Treated Panel B: Units Per Patient Notes: Shortages are defined using FDA coding. The points represent the coefficient estimate for the shortage effect from the interrupted time series regression using a linear model with IHS transformation (see shortage indicator in Equation 1 of the Supplementary Materials). The bars are 95% confidence intervals for each coefficient. Points highlighted in orange represent the most commonly used drugs (i.e., they are among the top 25 chemotherapy drugs in the Medicare claims). Three drugs (asparaginase, capecitabine and daunorubicin) are not included in Panel B because units are missing during FDA shortage months. Missing units occur when a drug is in an outpatient hospital setting rather than a physician’s office.