Prescription trends and costs of diabetes medications in Australia between 2003 and 2019: an analysis and review of the literature

Comparing the Effect of Early Versus Delayed Metformin Treatment on Glycaemic Parameters Among Australian Adults With Incident Diabetes: Evidence Using a National General Practice Database

PURPOSE

To compare the effect of early vs delayed metformin treatment for glycaemic management among patients with incident diabetes.

METHODS

Cohort study using electronic health records of regular patients (1+ visits per year in 3 consecutive years) aged 40+ years with 'incident' diabetes attending Australian general practices (MedicineInsight, 2011-2018). Patients with incident diabetes were defined as those who had a) 12+ months of medical data before the first recording of a diabetes diagnosis AND b) a diagnosis of 'diabetes' recorded at least twice in their electronic medical records or a diagnosis of 'diabetes' recorded only once combined with at least 1 abnormal glycaemic result (i.e., HbA1c ≥6.5%, fasting blood glucose [FBG] ≥7.0 mmol/L, or oral glucose tolerance test ≥11.1mmol/L) in the preceding 3 months. The effect of early (<3 months), timely (3-6 months), or delayed (6-12 months) initiation of metformin treatment vs no metformin treatment within 12 months of diagnosis on HbA1c and FBG levels 3 to 24 months after diagnosis was compared using linear regression and augmented inverse probability weighted models. Patients initially managed with other antidiabetic medications (alone or combined with metformin) were excluded.

FINDINGS

Of 18,856 patients with incident diabetes, 38.8% were prescribed metformin within 3 months, 3.9% between 3 and 6 months, and 6.2% between 6 and 12 months after diagnosis. The untreated group had the lowest baseline parameters (mean HbA1c 6.4%; FBG 6.9mmol/L) and maintained steady levels throughout follow-up. Baseline glycaemic parameters for those on early treatment with metformin (<3 months since diagnosis) were the highest among all groups (mean HbA1c 7.6%; FBG 8.8mmol/L), reaching controlled levels at 3 to 6 months (mean HbA1c 6.5%; FBG 6.9mmol/L) with sustained improvement until the end of follow-up (mean HbA1c 6.4%; FBG 6.9mmol/L at 18-24 months). Patients with timely and delayed treatment also improved their glycaemic parameters after initiating treatment (timely treatment: mean HbA1c 7.3% and FBG 8.3mmol/L at 3-6 months; 6.6% and 6.9mmol/L at 6-12 months; delayed treatment: mean HbA1c 7.2% and FBG 8.4mmol/L at 6-12 months; 6.7% and 7.1mmol/L at 12-18 months). Compared to those not managed with metformin, the corresponding average treatment effect for HbA1c at 18-24 months was +0.04% (95%CI -0.05;0.10) for early, +0.24% (95%CI 0.11;0.37) for timely, and +0.29% (95%CI 0.20;0.39) for delayed treatment.

IMPLICATIONS

Early metformin therapy (<3 months) for patients recently diagnosed with diabetes consistently improved HbA1c and FBG levels in the first 24 months of diagnosis.

Patterns of metformin use and glycated haemoglobin trends among patients with newly diagnosed type 2 diabetes in Alberta, Canada

AIM

Canadian guidelines recommend metformin as first-line therapy for incident uncomplicated type 2 diabetes and the vast majority of patients are treated accordingly. However, only 54% 65% remain on treatment after 1 year, with the highest discontinuation rates within the first 3 months. The purpose of this study was: (a) to identify individual and clinical factors associated with metformin discontinuation among patients with newly diagnosed uncomplicated type 2 diabetes in Alberta, Canada, and (b) describe glycated haemoglobin (HbA1c) trajectories in the first 12 months after initiation of pharmacotherapy, stratified by metformin usage pattern.

MATERIALS AND METHODS

We conducted a retrospective cohort study using linked administrative datasets from 2012 to 2017 to define a cohort of individuals with uncomplicated incident type 2 diabetes. Using logistic regression, we determined individual and clinical characteristics associated with metformin discontinuation. We categorized individuals based on patterns of metformin use and then used mean HbA1c measurements over a 12-month follow-up period to determine glycaemic trajectories for each pattern.

RESULTS

Characteristics associated with metformin discontinuation were younger age, lower baseline HbA1c and having fewer comorbidities. Sex, income and location (urban/rural) were not significantly associated with metformin discontinuation. Individuals who continued metformin with higher adherence and individuals who discontinued metformin entirely had lowest HbA1c values at 12 months from treatment initiation. Those who changed therapy or had additional therapies added had higher HbA1c values at 12 months.

CONCLUSION

Identifying characteristics associated with discontinuation of metformin and individuals' medication usage patterns provide an opportunity for targeted interventions to support patients' glycaemic management.

Bioequivalence Evaluation in Healthy Volunteers: New Generic Formulations of Sitagliptin and Sitagliptin-Metformin Fixed-Dose Combination Compared with the Originator Products

INTRODUCTION

Three studies compared the bioequivalence (BE) of new generic tablet formulations of sitagliptin (100 mg; fasting) and the fixed-dose combination (FDC) of sitagliptin/metformin (50/850 mg, 50/1000 mg; both fed) in healthy volunteers with the same tablet strengths of the reference products Januvia and Janumet.

METHODS

The study design was open-label, single-dose, randomized with two-way crossover periods. Blood sampling was performed for 72/48 h in the sitagliptin/FDC studies, respectively. Primary pharmacokinetic (PK) parameters for sitagliptin and metformin were area under the plasma concentration-time curve from time 0 to last timepoint of measurable concentration (AUC_0-t) and maximum plasma concentration (C_max). Test (T) and reference (R) formulations proved bioequivalent if 90% confidence interval (CI) of geometric least-squares mean ratio for AUC_0-t and C_max were within BE acceptance range of 80.00-125.00%. Safety evaluations included vital signs, clinical laboratory tests, and adverse events (AEs).

RESULTS

Treated/evaluable volunteers for BE per study were: 30/28 (sitagliptin 100 mg), 26/25 (FDC 50/850 mg), and 26/24 (FDC 50/1000 mg). The 90% CI of the geometric means of T/R ratios for primary PK parameters were within predefined BE limits: CI for AUC_0-t and C_max were 95.83-100.37% and 91.85-109.56% (sitagliptin 100 mg); 100.84-103.69% and 93.44-105.10% (FDC 50/850 mg), and 101.26-105.20% and 98.71-112.89% (FDC 50/1000 mg); respective values for metformin were 94.23-101.89% and 91.66-99.38% (FDC 50/850 mg) and 98.45-104.89% and 96.79-105.62% (FDC 50/1000 mg). All AEs were nonserious, transient, and mostly mild. Safety evaluations did not reveal any relevant difference between T and R formulations.

CONCLUSIONS

The new generic tablet formulations of sitagliptin 100 mg and the FDCs sitagliptin/metformin 50/850 mg and 50/1000 mg demonstrated bioequivalence to originator reference products. Therefore, the new products are expected to provide efficacy and tolerability similar to those of the reference products in the treatment of patients with type 2 diabetes (T2D).

TRIAL REGISTRATION

EudraCT EU Clinical Trials Registry (2014-005437-31); ClinicalTrials.gov Registry (NCT05549570 and NCT05549583, both retrospectively registered on 20 September 2022).

Testing the Feasibility and Dietary Impact of a "Produce Prescription" Program for Adults with Undermanaged Type 2 Diabetes and Food Insecurity in Australia

BACKGROUND

There is growing interest in Food is Medicine programs that incorporate food-based interventions into health care for patients with diet-related conditions.

OBJECTIVES

We aimed to test the feasibility of a "produce prescription" program and its impact on diet quality for people with type 2 diabetes (T2D) experiencing food insecurity in Australia.

METHODS

We conducted a pre-post intervention study in n = 50 adults experiencing food insecurity with T2D and glycated hemoglobin (HbA1c) ≥8%. Once enrolled, participants received healthy food boxes weekly free of charge, with the contents sufficient to create 2 meals/d, 5 d/wk for the entire household, over 12 wk. Participants were also provided with tailored recipes and behavioral change support. The primary outcome was change in diet quality assessed by 24-h diet recalls. Secondary outcomes included differences in cardiovascular disease risk factors; blood micronutrients; and feasibility indicators. Differences in the baseline and 12-wk mean primary and secondary outcomes were assessed by paired t tests.

RESULTS

Participants were older adults with mean ± SD age 63 ± 9 y (range: 40-87 y), HbA1c 9.8% ± 1.5%, and 46% were female. Overall, 92% completed the final study follow-up for the primary outcome. Compared with baseline, diet quality improved at week 12, with an increase in the mean overall diet quality (Alternate Healthy Eating Index score) of 12.9 (95% CI: 8.7, 17.1; P < 0.001), driven by significant improvements in vegetables, fruits, whole grains, red/processed meat, trans fat, sodium, and alcohol consumption. Blood lipids also improved (total:HDL cholesterol: -0.48; 95% CI: -0.72, -0.24; P < 0.001), and there was significant weight loss (-1.74 kg; 95% CI: -2.80, -0.68 kg, P = 0.002), but no changes in other clinical outcomes. Participants reported high levels of satisfaction with the program.

CONCLUSIONS

These findings provide strong support for an adequately powered randomized trial to assess effects of produce prescription as an innovative approach to improve clinical management among individuals with T2D experiencing food insecurity. This trial was registered at https://anzctr.org.au/ as ACTRN12621000404820.