<p>Median annual costs by category and subgroup.</p>

Background The rising prevalence of diabetes is increasing the healthcare costs especially when associated with infection. We aimed to assess the antibiotic consumption and medication costs in diabetes. Methods We performed a retrospective claims-based study using Iranian Health Insurance Organization (IHIO) dataset from 24 provinces during 2014–2017. Systemic antibacterials were quantified in defined daily doses and diabetic patients were stratified into “No antibiotic” (NAb) and quartiles of cumulative antibiotic exposure (Q1–Q4). A dominant antidiabetic regimen was assigned when ≥80% of a patient’s diabetes prescriptions came from one drug class or combination. Inflation-adjusted annual medication costs were modelled with log-link Gamma generalized linear models. Results The study comprised 1,704,182 individuals (62.0% women). Biguanides alone were most common dominant diabetes regimen (40%), whereas penicillin accounted for 35.8% of all antibiotic dispensing. Mean annual medication costs were 93 USD for women and 138 USD for men; however, after adjustment men incurred slightly lower costs than women. Compared with the NAb group, costs rose progressively with antibiotic exposure, reaching an adjusted mean ratio (MR) 3.17 (95%CI 3.09–3.25) in Q4. Relative to biguanide monotherapy, costs were markedly higher for regimens biguanides + insulins (MR 5.75, 5.54–5.97) or insulins alone (MR 5.53, 5.38–5.68). Conclusion Quantifying the joint impact of antidiabetic regimens and antibiotic use on treatment costs highlights key factors driving healthcare expenditures. These findings can inform targeted antibiotic stewardship strategies and guide reimbursement policy to optimize resource allocation and reduce the financial burden on both patients and insurers.研究背景 糖尿病患病率持续上升，正不断推高医疗成本，在合并感染的情况下尤为显著。本研究旨在评估糖尿病患者的抗生素使用量与药物成本。 研究方法 本研究采用回顾性医保索赔研究设计，使用2014年至2017年伊朗健康保险组织（Iranian Health Insurance Organization, IHIO）覆盖24个省份的数据集。以限定日剂量（defined daily doses）量化全身用抗菌药物的使用量，并将糖尿病患者分为无抗生素暴露组（No antibiotic, NAb）以及按累积抗生素暴露量划分的四分位数组（Q1~Q4）。若患者≥80%的糖尿病处方来自同一药物类别或联合用药方案，则将其归类为该类主要降糖治疗方案（dominant antidiabetic regimen）。采用对数连接Gamma广义线性模型（log-link Gamma generalized linear models）对经通胀调整的年度药物成本进行建模分析。 研究结果 本研究共纳入1704182名受试者，其中女性占62.0%。单用双胍类药物是最常见的主要降糖治疗方案（占比40%），而青霉素类药物占所有抗生素配药量的35.8%。女性患者的平均年度药物成本为93美元，男性为138美元；但经校正后，男性的花费略低于女性。与无抗生素暴露组相比，患者的药物成本随抗生素暴露量增加而逐步升高，在Q4组校正后均数比（adjusted mean ratio, MR）达3.17（95%CI：3.09~3.25）。相较于单用双胍类药物治疗方案，双胍类联合胰岛素（MR 5.75，95%CI：5.54~5.97）或单用胰岛素（MR 5.53，95%CI：5.38~5.68）的治疗成本显著更高。 研究结论 量化降糖治疗方案与抗生素使用对治疗成本的联合影响，可明确推动医疗支出的关键因素。本研究结果可为针对性抗生素管理策略的制定提供参考，并指导报销政策优化，以实现资源配置的最优化，同时减轻患者与保险机构的经济负担。