6ER-031 Relationship between price of purchase and quality of oral antidiabetic drugs in Sub-Saharan Africa: the diabdaf study

<h3>Background and Importance</h3> Falsified and substandard medicines remain a major challenge in sub-Saharan Africa (SSA), affecting the quality of care for non-communicable diseases such as diabetes. While medicine pricing is often used as a proxy for quality, the actual relationship between the cost and quality of oral antidiabetic drugs (OAD) in SSA remains poorly explored. <h3>Aim and Objectives</h3> We conducted a post hoc analysis of the DIABDAF study to examine the relationship between OAD prices of purchase and their quality in Africa. <h3>Material and Methods</h3> OAD were chosen by investigators as those frequently prescribed in SSA: one biguanide (metformin) and three sulfonylureas (glyburide, gliclazide, glimepiride). Drugs were collected from licensed pharmacies and street markets in capital and border cities of seven countries. Prices of purchase were converted into international dollars (int$) using purchasing power parity to ensure comparability across countries. Quality of drugs was assessed based on active pharmaceutical ingredient content (APIC), impurity level, or both (composite quality criteria). A multivariate analysis using a mixed-effects linear model was fitted, with two random effects (pharmaceutical batch and country of purchase), using R (v4.4.3). <h3>Results</h3> Overall, 610 samples with a price of purchase were collected from seven countries. Prices ranged from 0.06 int$ to 1.92 int$. Mean prices were 0.43±0.26 int$ for metformin (n=220, 36%), 0.40±0.39 int$ for glyburide (n=80,13%), 0.91±0.33 int$ for glimepiride (n=180, 30%) and 1.25±0.54 int$ for gliclazide (n=130, 21%). Branded medicines had a mean price of 0.92±0.54 int$, and 0.57±0.40 for generics. In univariate analysis price was significantly associated with quality according to APIC (p=0.004) and composite quality criteria (p=0.003): poor-quality drugs were less expensive than good-quality drugs, but not quality according to impurity level (p=0.869). In multivariate analysis, drug status (generics being less expensive, p=0.001) and INN (p&lt;0.001) remained significantly associated with price. There was a significant interaction between drug quality and place of manufacture (p=0.002). Specifically, poor-quality drugs produced in Asia were about 4.6% less expensive than good-quality ones (p=0.001), whereas no significant difference was observed for drugs produced in Europe or Africa. <h3>Conclusion and Relevance</h3> This large study of 610 samples supports a price–quality association of OADs in SSA, influenced by drug, status and manufacturing origin. <h3>References and/or Acknowledgements</h3> 1. https://pubmed.ncbi.nlm.nih.gov/40823495/ <h3>Conflict of Interest</h3> No conflict of interest