Utilization and cost of drugs for diabetes and its comorbidities and complications in Kuwait.

Background: Diabetes imposes a large burden on countries' healthcare expenditures. In Kuwait, diabetes prevalence in adults is estimated at 22.0%%-double the worldwide prevalence (9.3%). There is little current data on pharmaceutical costs in Kuwait of managing diabetes and diabetes-related complications and comorbidities.

Objectives: Estimate the utilization and cost of drugs for diabetes and diabetes-related complications and comorbidities in Kuwait for year 2018, as well determinants of costs.

Methods: This cross-sectional study used a multi-stage stratified sampling method. Patients were Kuwaiti citizens with diabetes, aged 18-80, recruited from all six governorates. Physicians collected demographic data, clinical data, and current drug prescription for each patient which was extrapolated for the full year of 2018. A prevalence-based approach and bottom-up costing were used. Data were described according to facility type (primary care vs. hospital). A generalized linear model with log function and normal distribution compared drug costs for patients with and without comorbidities/complications after adjustments for demographic and health confounders (gender, age group, disease duration, and obesity).

Results: Of 1182 diabetes patients, 64.0% had dyslipidemia and 57.7% had hypertension. Additionally, 40.7% had diabetes-related complications, most commonly neuropathy (19.7%). Of all diabetes patients, 85.9% used oral antidiabetics (alone or in combinations), 49.5% used insulin alone or in combinations, and 29.3% used both oral antidiabetics and insulin. The most frequently used oral drug was metformin (75.7%), followed by DPP4 inhibitors (40.2%) and SGLT2 inhibitors (23.8%). The most frequently used injectables were insulin glargine (36.6%), followed by GLP-1 receptor agonists (15.4%). Total annual drug cost for Kuwait's diabetic population for year 2018 was US$201 million (US$1,236.30 per patient for antidiabetics plus drugs for comorbidities/complications).

Conclusions: Drug costs for treating diabetes and comorbidities/complications accounted for an estimated 22.8% of Kuwait's 2018 drug expenditures. Comorbidities and complications add 44.7% to the average drug cost per diabetes patient.