Retrospective cohort analysis of prescription patterns of cancer medications during periods of drug stockouts in Botswana

Objective: Cancer drug stockouts occur at high frequencies globally, however, their effects on treatment are understudied in sub-Saharan Africa (SSA). We aimed to determine whether causes of suboptimal cancer treatment prescriptions differed between periods of stockout and full treatment supply.

Design: A retrospective cohort study of systemic therapy prescriptions for patients diagnosed with the twelve most common solid tumour cancers treated in 2016.

Setting: Princess Marina Hospital in Gaborone, Botswana.

Participants: Patients in the retrospective cohort who experienced any suboptimal treatment events, defined as ≥7 days delay or switch from guideline-concordant initiated therapy.

Primary and secondary outcome measures: Frequency of delays and patterns of prescription changes for specific regimens and cancer types.

Results: 167/378 patients contributed to 320 suboptimal events (115 therapy switches, 167 delays and 38 events with both), over 1452 total chemotherapy cycles received. Events during stockout were 43% delays, 43% switches and 14% both during stockout periods and 67.2% delays, 24.4% switches and 8.4% both during non-stockout periods (p<0.001). Majority of switches involved de-escalation of initially prescribed guideline-recommended regimens in patients with breast cancer, Kaposi sarcoma and patients with colorectal cancer, which occurred more frequently during periods of drug stockouts. Among patients with breast cancer, substitution of docetaxel for paclitaxel event occurred exclusively during paclitaxel drug stockout. Delays of ≥7 days events were most frequent in breast cancer patients receiving paclitaxel during stockout, and combination doxorubicin and cyclophosphamide even during periods of non-stockout.

Conclusions: The aetiology of suboptimal events differed during stockout and non-stockout periods. Prescription patterns that involved de-escalation of initiated therapy and substitution of paclitaxel with docetaxel occurred frequently during periods of drug stockout. Further research needs to be conducted to understand the impact of stockout on survival and barriers to maintaining essential cancer medicines supplies in SSA, and the factors driving frequent delays in therapy delivery.