Purpose: Optimal adherence to antidiabetics among patients with type 2 diabetes mellitus has been associated with positive health outcomes; however, studies to assess this adherence in Saudi Arabia are scarce. We aimed to evaluate adherence to antidiabetics using a Saudi population. Methods: This was a multicenter, retrospective cohort study of patients (≥ 18 years old) with type 2 diabetes mellitus who received ≥ 1 antidiabetic between 2015 and 2020. Adherence was estimated using the continuous multiple-interval measure of medication availability (CMA7). A CMA7 cutoff point of ≥ 80% was chosen to define optimal adherence, and the odds of not achieving therapeutic annual HbA1c levels (i.e. ≥ 7%) in the optimal vs. suboptimal adherence groups was assessed using a logistic regression model adjusting for the measured confounders. Results: A total of 36,789 patients were included in the study. The most commonly prescribed regimens were metformin single treatment (n=15,025 [41.6%]) and gliclazide-metformin combination treatment (n=5,667 [15.7%]). The median CMA7 was 70.4%, and only 13,552 (36.9%) patients were adherent to their antidiabetics (CMA7 ≥ 80%). The odds of not achieving therapeutic HbA1c levels one year after the index date were comparable in the optimal vs. suboptimal adherence groups (odds ratio = 0.99, 95% confidence interval 0.92 to 1.05). Conclusions: This study showed that a large proportion of a Saudi population with type 2 diabetes mellitus were non-adherent to their antidiabetic treatments. Future Saudi and regional studies are needed to assess the impact of adherence on HbA1c levels and on cardiovascular outcomes.

Purpose: Studies suggested that drug pricing might be a risk factor for drug shortage; however, a few provided a quantitative assessment of this possible causal association. This study aimed to assess whether drug prices are associated with drug shortage incidents. Methods: This was a retrospective database analysis study. Drugs with shortage notifications (one drug per notification) that were sent to the Saudi Food and Drug Authority (SFDA) from Jan/2017 to Dec/2020 by different stakeholders were included in the study. For each drug, the foreign-to-Saudi-price ratio (FTSPR) was calculated (FTSPR= mean international price/Saudi price). Accordingly, drugs were split into three groups: Group 1 (FTSPR >1]), Group 2 (FTSPR =1]), and Group 3 (FTSPR <1]). The primary outcomes were the ratio of mean counts (mCR) between the three groups with Group 3 chosen as a control group. The study outcomes were analyzed using a negative binomial regression model adjusting for the measured confounders. All study analyses were conducted using RSudio Version 1.2.5033. Results: A total of 900 drugs were included (Group 1=348, Group 2=345, Group 3=209). The mean count of Group 1 higher was higher than Group 3 (mCR: 1.88; 95% confidence interval [CI] 1.24 to 2.83), while and mean counts of Group 2 vs. Group 3 were comparable (mCR: 1.39; 95%CI 0.92 to 2.09). Conclusions: The results of our study showed that shortage was associated with drugs that are more expensive outside Saudi Arabia. Additional international studies are needed to explore this causal association.