Refill adherence to repeat prescriptions of cancer drugs to ambulatory patients

The objective was to study the refill adherence among ambulatory patients with prescribed cancer drugs. The study was based on copies of repeat prescriptions, which were collected at three large Swedish pharmacies during the last 3 months of 2004. Copies of 141 repeat prescriptions were analysed. There was no statistical significant difference between the number of patients with undersupply of cancer drugs (i.e. <80% of prescribed cancer drugs) and that of patients with undersupply of all other drugs, or between the number of patients with oversupply of cancer drugs (>120% of prescribed cancer drugs) and that of patients with oversupply of all other drugs. Undersupply of drugs was found among 14% of the patients. The median treatment gap for these patients was 39 (range 29-49 days) per 98-100 days of prescribed treatment time, meaning that the undersupply leads to treatment gaps that may jeopardize their therapeutic outcome. It is reasonable to expect that more seriously ill patients would be adherent to prescribed medication, and consequently that cancer patients would have high adherence. However, our data show that cancer patients on oral long-term treatment have a non-adherence similar to that of patients in general.