# A Systematic Review of Methods to Measure Adherence to Oral Anticancer Medications in African Women With Breast Cancer at Initiation, Implementation, and Discontinuation of Therapy

## TL;DR

This paper reviews methods used to measure how well African women with breast cancer follow oral cancer medication at different stages of treatment.

## Contribution

The study systematically evaluates adherence measurement methods specific to African women with breast cancer across medication phases.

## Key findings

- Most studies focused on the implementation phase of medication adherence.
- Self-report measures were most common but lacked reliability and validity data.
- Few studies assessed adherence at the initiation or discontinuation phases.

## Abstract

This systematic review was aimed at assessing methods used to measure oral anticancer medication (OAM) adherence at its three phases (initiation, implementation, and discontinuation) in women with breast cancer (BC) in Africa.

This review followed the Joanna Briggs Institute guidelines. Four databases were searched from 1990 to 2025 using keywords representing medication adherence, oral anticancer agents, breast cancer, measures, women, and Africa. The reporting followed the updated PRISMA guidelines.

All 13 studies (100%) reviewed assessed OAM adherence at the implementation phase, four studies (30.8%) at the discontinuation phase, and one study (7.7%) at the initiation phase. Persistence was also assessed in four studies (30.8%). Prescription refill records were used to measure adherence at the initiation phase. Drug assays in blood, prescription refills, pill counts, medical records reviews, and self‐report measures were used during the implementation phase. Prescription refills, medical records, and self‐report measures were used at the discontinuation phase. Overall, self‐report measures (46.2%; n = 6) were the most frequently used during the implementation phase. However, most studies that employed these measures did not report the psychometric properties, including reliability and validity.

The implementation phase was the most commonly assessed. Initiation and discontinuation phases were relatively less assessed. Self‐report measures were the most frequently used, but the reliability and validity of these measures are lacking, hence limiting the evidence to guide practice. Thus, measures with sound psychometric properties, including reliability and validity, that can assess OAM adherence across its three phases are needed to improve adherence measurement and patient outcomes, particularly in Africa.