Do patients with prediabetes managed with metformin achieve better glycaemic control? A national study using primary care medical records.

AIMS: To estimate the effectiveness of metformin on glycaemic parameters among participants with incident prediabetes attending Australian general practices. METHODS: This retrospective cohort study used electronic health records of regular participants (3+ visits in two consecutive years) attending 383 Australian general practices (MedicineInsight). Participants with 'incident' prediabetes (newly recorded diagnosis between 2012 and 2017) and their glycaemic parameters (haemoglobin A1c [HbA1c] or fasting blood glucose [FBG]) at 6-, 12-, and 18-24 months post diagnosis (unexposed) or post-management with metformin (treatment) were identified from the database. We estimated the average treatment effect (ATE) of metformin management on glycaemic parameters using both linear regression and augmented inverse probability weighting. RESULTS: Of the 4770 investigated participants with 'incident' prediabetes, 10.2% were managed with metformin. Participants on metformin had higher HbA1c levels at the baseline than those unexposed (mean 45 mmol/mol [6.2%] and 41 mmol/mol [5.9%], respectively), but no differences were observed at 6-12 months (mmol/mol ATE 0.0, 95% CI -0.4; 0.7) or 12-18 months (ATE -0.3, 95% CI -1.2; 0.3). However, participants on metformin had lower mean HbA1c mmol/mol at 18-24 months (ATE -1.1, 95% CI -2.0; 0.1) than those unexposed. Consistent results were observed for FBG (ATE at 6-12 months -0.14 [95% CI -0.25; -0.04], 12-18 months 0.02 [95% CI -0.08; 0.13] and 18-24 months -0.07 [95% CI -0.25; 0.12]). CONCLUSION: The higher HbA1c and FBG baseline levels among participants with 'incident' prediabetes managed with metformin improved after 6-12 months of starting pharmacological management, and the effect persisted for up to 24 months. Management with metformin could prevent further deterioration of glycaemic levels.

General practice management of depression among patients with coronary heart disease in Australia.

BACKGROUND: Incident depression is associated with coronary heart disease (CHD) and increased morbidity and mortality. Treatment of depression with antidepressants and psychotherapy can be beneficial for these patients to reduce the risk of further CHD events. Ongoing management of CHD and depression mainly occurs in the community, but little is known about the identification and care of patients with comorbid CHD and depression in general practice. This study explores the prescription of antidepressants for these patients by sociodemographic variables. METHODS: This is an open cohort study with de-identified data based on electronic medical records of 880,900 regular patients aged 40 + years from a national general practice database in Australia (MedicineInsight). Data from 2011-2018 was used to classify patients as newly recorded CHD (CHD recorded in 2018 but not in previous years), previously recorded CHD (CHD recorded between 2011-2017) or no recorded history of CHD. Antidepressant prescribing in 2018 considered active ingredients and commercial brand names. The association between sociodemographic variables and antidepressant prescribing was tabulated according to the CHD status. RESULTS: The proportion of current depression among patients with newly recorded CHD was 11.4% (95%CI 10.3-12.6), 10.5% among those with previously recorded CHD (95%CI 10.0-11.1) and 9.6% among those with no recorded history of CHD (95%CI 9.2-10.1). Antidepressant prescribing was slightly higher among those with newly recorded CHD (76.4%; 95%CI 72.1-80.6) than among those with previously recorded CHD (71.6%; 95%CI 69.9-73.2) or no history of CHD (69.5%; 95%CI 68.6-70.4). Among males with newly recorded CHD and depression, antidepressant prescribing was more frequent in major cities or inner regional areas (~ 81%) than in outer/remote Australia (66.6%; 95% CI 52.8-80.4%). CONCLUSIONS: Although antidepressant prescribing was slightly greater in those with newly recorded CHD compared to those with depression alone, its clinical significance is uncertain. Much larger differences in prescribing were seen by geographic location and could be addressed by innovations in clinical practice.