Access and Adherence to Treatments

Several retrospective cohort studies have evaluated the effect of prescription copayment amounts for cancer drugs on patient compliance with therapy.[1,2]

A cross-sectional study using data from the 2011 to 2014 National Health Interview Survey found that individuals aged 18 to 64 years with a recent or previous cancer diagnosis were more likely to report changing their prescription drug use (e.g., not filling prescriptions or skipping doses) for financial reasons than individuals without a history of cancer.[3] Another study examined the association between imatinib copayment and medication adherence among patients with chronic myeloid leukemia, from 2002 to 2011, using MarketScan health plan claims.[1] Over the study period, monthly copayments for imatinib ranged from $0 to $4,792, with a mean and median of $108 and $30, respectively. Patients in the highest quantile of monthly copayments for imatinib (mean, $53) compared with patients in the lowest quantile (mean, $17) had a statistically significant adjusted risk ratio (RR) of 1.70 (95% confidence interval [CI], 1.30–2.22) for discontinuing imatinib during the first 180 days of treatment.[1] Similarly, patients with higher copayments for imatinib (vs. the lower copayment group) had an adjusted RR of 1.42 (95% CI, 1.19–1.69) for nonadherence to their imatinib therapy.[1]

Other studies examined the association between copayment amounts for adjuvant endocrine therapy, aromatase inhibitors, and tamoxifen and noncompliance in women with breast cancer.[2,4,5] Studies have been relatively consistent in showing that at the highest levels of copayment, cancer patients become less likely to take cancer-related medications on a daily basis (nonadherence), or they discontinue their medications over the long term (nonpersistence of use). Reduced adherence to cancer medications may be worse when the total out-of-pocket cost of all prescription drugs taken by the patient is considered.[5]

A cross-sectional survey study of adult patients (N = 300) receiving cancer therapy at Duke Cancer Institute found that 16% of patients reported high or overwhelming financial distress, 27% reported medication nonadherence, and 4.67% reported chemotherapy nonadherence.[6] Among patients reporting medication nonadherence, 14% specified skipping medication doses to make the prescription last longer, 11% stated they took less medication than prescribed to make the prescription last longer, and 22% indicated that they did not fill a prescription because of cost.[6] Among the patients reporting chemotherapy nonadherence, 1% skipped chemotherapy doses to make the prescription last longer, 1.67% took less chemotherapy to make the prescription last longer, and 3.33% did not fill a chemotherapy prescription because of cost.

This study also found that an increased likelihood of nonadherence was associated with the following characteristics:

A statistically significant decreased risk of nonadherence was associated with having private insurance (adjusted OR, 0.31; 95% CI, 0.14–0.72).

A cross-sectional cohort study of 10,508 patients who started oral chemotherapy between 2007 and 2009 examined the association between prescription abandonment rates and cost sharing.[7] Abandonment was defined as a paid prescription claim gap of more than 90 days. An adjusted analysis found that claims with cost sharing of $251 to $350 had 2.3 times the likelihood of abandonment (95% CI, 1.59–3.36); $351 to $500 had 3.28 times the likelihood of abandonment (95% CI, 2.20–4.88); and more than $500 had 4.46 times the likelihood of abandonment (95% CI, 3.80–5.22) when compared with cost sharing of $100 or less.[7] Additionally, the study identified a substantially higher proportion of patients who paid more than $500 out of pocket for their first oral chemotherapy claim in the Medicare group compared with the commercially insured group (45.5% vs. 10.7%; P < .001).[7]

Anecdotal reports also suggest that terminally ill cancer patients are foregoing the opportunity to obtain lethal doses of barbiturates in states with death-with-dignity laws because the price of these generic medications has increased to approximately $3,000 for a typical prescription.[8]