IJPDS International Journal of Population Data Science IJPDS 2399-4908 Swansea University 10.23889/ijpds.v11i5.3546 11:5:3546 S2399490821035461 Population Data Science Cross-Country Comparison of Medication Adherence After Stroke Using Standardised Methods: A Pilot Distributed Network Analysis for INSPIRE-STROKE L. DalliLachlan1 F. KilkennyMonique2 ChuAnna3 IlomakiJenni4 A. JackeviciusCynthia5 K. KapralMoira6 V. VyasManav3 T. OlaiyaMuideen1 A. CadilhacDominique2 C. LivoriAdam7 Stroke and Ageing Research, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia Stroke and Ageing Research, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia; Stroke and Critical Care Research Theme, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Heidelberg, Victoria, Australia ICES, Toronto, Ontario, Canada Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia ICES, Toronto, Ontario, Canada; College of Pharmacy, Western University of Health Sciences, Pomona, USA; Institute of Health Policy, Management, and Evaluation, University of Toronto, Toronto, Ontario, Canada ICES, Toronto, Ontario, Canada; Institute of Health Policy, Management, and Evaluation, University of Toronto, Toronto, Ontario, Canada; Department of Medicine (General Internal Medicine), University of Toronto, Toronto, Ontario, Canada Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; Pharmacy Department, Grampians Health, Ballarat, Victoria, Australia; Clinical Diabetes and Epidemiology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia 11 5 3546 This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. This article is available from the IJPDS website at: https://ijpds.org/article/view/3546 Background

Post-stroke medication adherence can be assessed using dispensing data; however, variations in methods hinder reliable comparisons across regions. We developed and implemented standardised methods to compare post-stroke medication adherence between countries.

 Methods

Australia and Canada, with population-based data and universal healthcare systems, were selected for this INSPIRE-STROKE proof-of-concept distributed network analysis (www.inspire-stroke.bigdatacvd.com). Metadata were shared to harmonise data variables and structure. Patients admitted with incident ischaemic stroke and atrial fibrillation (Victoria, Australia [July 2014–June 2017]; Ontario, Canada; [July 2014–March 2022]), aged 66–105 years, who survived ≥90 days post-discharge were included. The proportion of days covered (PDC) of direct oral anticoagulants (DOACs) was measured from initiation to 1-year post-discharge. Adherence was measured in 8 simulations, using standardised code, to adjust for different PDC measurement parameters from the TEN-SPIDERS framework (www.tenspiders.adherencelab.com). Aggregated outputs were compared between countries.

 Results

Among 2471 Australians (50% female; 36% aged 85+ years) and 16622 Canadians (51% female; 34% aged 85+ years), 50% and 65% initiated a DOAC within 90 days post-stroke, respectively. Among initiators, median 1-year DOAC PDC was 86.8% (interquartile range [IQR]: 75.9%–92.6%) in Australia vs 96.2% (IQR: 89.6%–98.6%) in Canada. Adjustment for pre-supply, early refills, and switching increased median PDC by +10.3% in Australia and +3.5% in Canada. Further adjustment for in-hospital stays had negligible impacts on PDC in both countries.

 Conclusions

Standardised methods were successfully implemented to facilitate cross-country comparisons of post-stroke medication adherence. Use of standardised methods in other countries will enable reliable global surveillance of post-stroke medication adherence.