Trends of prescribing adherence of antiplatelet agents in Hong Kong patients with acute coronary syndrome: a 10-year retrospective observational cohort study.

OBJECTIVES: The objective of this study is to examine the temporal trend of antiplatelet prescribing pattern during index hospitalisation discharge in Hong Kong (HK) acute coronary syndrome (ACS) population. DESIGN: The study is a retrospective observational cohort study. SETTING: The study retrieved data from electronic health record from Hospital Authority (HA), HK. PARTICIPANTS: The study included patients aged 18 years old or above, who were admitted to seven institutions under HA with diagnosis of ACS during 2008-2017. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the frequency of antiplatelet therapy prescription at the point of index hospitalisation discharge each year during 2008-2017. Association between demographics, baseline comorbidities, procedures and antiplatelet prescription were examined as secondary outcome using multivariate logistic regression model, with commonly used antiplatelet groups selected for comparison. RESULTS: Among the included 14 716 patients, 5888 (40.0%) discharged with aspirin alone, 6888 (46.8%) discharged with dual antiplatelet therapy (DAPT) with clopidogrel, and 973 (6.6%) discharged with DAPT with prasugrel/ticagrelor. Prescribing rate of aspirin alone decreased substantially from 56.8% in 2008 to 27.5% in 2017. Utilisation of DAPT with clopidogrel increased from 33.7% in 2008 to 52.7% in 2017. Use of DAPT with prasugrel/ticagrelor increased from 0.3% in 2010 to 15.3% in 2017. Compared with those prescribed with DAPT with clopidogrel, male patients (adjusted OR (aOR) 1.34, 95% CI 1.09 to 1.65), patients with non-ST-elevation myocardial infarction (aOR 2.50, 1.98 to 3.16) or ST-elevation myocardial infarction (aOR 3.26, 2.59 to 4.09), use of glycoprotein IIb/IIIa (aOR 3.03, 2.48 to 3.68) or undergoing percutaneous coronary intervention (aOR 3.85, 3.24 to 4.58) or coronary artery bypass graft (aOR 6.52, 4.63 to 9.18) during index hospitalisation, concurrent use of histamine-2 receptor antagonists (aOR 1.35, 1.10 to 1.65) or proton pump inhibitors (aOR 3.57, 2.93 to 4.36) during index hospitalisation discharge were more likely to be prescribed with DAPT with prasugrel/ticagrelor. Patients with older age (aOR 0.97, 0.96 to 0.97), diabetes (aOR 0.68, 0.52 to 0.88), chronic kidney disease (aOR 0.43, 0.22 to 0.85) or concurrent use of oral anticoagulant (aOR 0.16, 0.07 to 0.42) were more likely to received DAPT with clopidogrel. CONCLUSIONS: Use of DAPT with prasugrel/ticagrelor was suboptimal yet improving during 2008-2017 in HK patients with ACS. Considering DAPT, predictors for clopidogrel prescription, compared with prasugrel/ticagrelor, were consistent with identified risk factors of bleeding.

Use of metformin and aspirin is associated with delayed cancer incidence.

BACKGROUND: While the chemoprevention effect of aspirin is well-established, the effects of metformin in cancer prevention is still controversial. This study is to investigate the use of aspirin, metformin, or the combination of both is associated with delayed cancer incidence. METHOD: This dataset is based on the electronic medical record of public hospitals in Hong Kong. Patients were classified into 1. aspirin user, 2. metformin user, 3. both aspirin and metformin user and 4. control group with neither aspirin nor metformin used. Aspirin and/or metformin must have been taken for over 6 months in the treatment group and cancer incidences was counted at least 6 months after exposure to such medications. The primary outcome of this study was overall incidence of cancer during the follow-up period. The secondary outcomes were cancer incidences of specific sites, including colon/rectum, liver, oesophagus, pancreas, stomach, lung, breast, kidney, bladder and prostate. Cox proportional hazards regression models were fitted to estimate hazard ratios of cancer risks. Inverse probability of treatment weighting was used to control for the medication effects. RESULTS: A total of 120,971 aspirin users, 11,365 metformin users, and 6630 aspirin plus metformin users, were identified. Compare to the control groups, those who used aspirin alone demonstrated a significant reduction in overall cancer risk (HR 0.80, 95% CI 0.73-0.87). Similarly, those who used metformin alone also showed an overall reduction in cancer risk (HR 0.79, 95% CI 0.71-0.88). Patients who received both aspirin and metformin showed the most significant reduction in overall cancer risk (HR 0.53, 95% CI 0.45-0.63). Metformin showed a significant reduction in cancer risk of lung, oesophagus and bladder. CONCLUSION: There is a similar decrease in overall cancer rate with the use of aspirin or metformin alone. A more significant reduction in overall cancer risk was found with the use of both agents.