[Treatment persistence with brand-name vs. generic metformin in monotherapy for type 2 diabetes: real-life retrospective study using the propensity matching score].

OBJECTIVE

To evaluate treatment persistence in patients with polymedicated type 2 diabetes (DM2) receiving new treatment with brand-name vs. generic metformin 850mg in usual clinical practice.

PATIENTS AND METHODS

Observational, retrospective study based on the medical records of patients aged ≥50 years who initiated metformin treatment (brand-name vs. generic) between 01/01/2016 and 31/12/2017. The follow up was two years.

MAIN MEASURES

treatment persistence and clinical consequences (metabolic control [HbA1c] and hospital admissions). Each patient in the brand-name group (reference) was paired with a patient from the generic group using propensity score matching. A Cox proportional risk model was constructed (p<0.05).

RESULTS

863 patients receiving brand-name metformin were matched (ratio 1:1) with patients receiving generic metformin. The median age was 60.8 years (SD: 8.8) years and 52.6% were female. Persistence at 24 months was 8.6% higher for brand-name vs. generic metformin (63.2% vs. 58.2%; p=0.034). The hazard ratio for brand-name metformin was 0.83 (95% CI: 0.71-0.96, p=0.013). During the follow-up there was a greater percentage reduction of HbA1c in the brand-name vs. generic group (-6.8% vs. -4.1%; p=0.013). There was a non-significant 19.1% reduction in hospital admissions in the brand-name vs. generic group (8.9% vs. 11.0%; p=0.148).

CONCLUSIONS

Polymedicated patients who initiated new brand-name metformin treatment for DM2 had greater treatment persistence than those who initiated it with generic metformin and had better metabolic control (percentage reduction in HbA1c).