Andrew J Kerr1,2,3, Tom Kai Ming Wang1, Yannan Jiang4, Corina Grey2, Sue Wells2, Katrina K Poppe2. 1. Department of Cardiology, Middlemore Hospital, 100 Hospital Road, Otahuhu, Auckland 2025, New Zealand. 2. Section of Epidemiology and Biostatistics, School of Population Health, Faculty of Medical and Health Sciences, School of Population Health, Grafton Campus, 22-30 Park Ave, Grafton, Auckland 1023, New Zealand. 3. School of Medicine, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand. 4. National Institute for Health Innovation, School of Population Health, University of Auckland, 22 Park Avenue, Grafton, Auckland 1023, New Zealand.
Abstract
AIMS: Routinely collected health administrative data have become an important data source for investigators assessing disease epidemiology. Our aim was to investigate the implications of identifying acute coronary syndrome (ACS) events in New Zealand (NZ) national hospitalization data using either the first (primary) or subsequent (secondary) codes. METHODS AND RESULTS: Using national health datasets, we identified all NZ hospitalizations (2014-16) for patients ≥20 years with a primary or secondary International Classification of Diseases 10th Revision, Australian Modification (ICD10-AM) ACS code. Outcomes included 1-year all-cause and cause-specific mortality, hospitalized non-fatal myocardial infarction, heart failure, stroke, or major bleeding, and a composite comprising these outcomes. Of 35 646 ACS hospitalizations, 78.5% were primary and 21.5% secondary diagnoses. Compared to primary coding, patients with a secondary diagnosis were older (mean 77 vs. 69 years), more likely to be females (48% vs. 36%), had more comorbidity, and were less likely to receive coronary angiography or revascularization. Higher adverse event rates were observed for the secondary diagnosis group including a three-fold higher 1-year mortality (40% vs. 13%) and two-fold higher composite adverse outcome (54% vs. 26%). The use of primary codes alone, rather than combined primary and secondary codes, resulted in overestimation of coronary angiography and revascularization rates, and underestimation of the 1-year case fatality (13.1% vs. 19.0%) and composite adverse event rate (26% vs. 32%). CONCLUSION: Patient characteristics and outcomes of ACS events recorded as primary vs. secondary codes are very different. These findings have important implications for designing studies utilizing ICD10-AM codes. Published on behalf of the European Society of Cardiology. All rights reserved.
AIMS: Routinely collected health administrative data have become an important data source for investigators assessing disease epidemiology. Our aim was to investigate the implications of identifying acute coronary syndrome (ACS) events in New Zealand (NZ) national hospitalization data using either the first (primary) or subsequent (secondary) codes. METHODS AND RESULTS: Using national health datasets, we identified all NZ hospitalizations (2014-16) for patients ≥20 years with a primary or secondary International Classification of Diseases 10th Revision, Australian Modification (ICD10-AM) ACS code. Outcomes included 1-year all-cause and cause-specific mortality, hospitalized non-fatal myocardial infarction, heart failure, stroke, or major bleeding, and a composite comprising these outcomes. Of 35 646 ACS hospitalizations, 78.5% were primary and 21.5% secondary diagnoses. Compared to primary coding, patients with a secondary diagnosis were older (mean 77 vs. 69 years), more likely to be females (48% vs. 36%), had more comorbidity, and were less likely to receive coronary angiography or revascularization. Higher adverse event rates were observed for the secondary diagnosis group including a three-fold higher 1-year mortality (40% vs. 13%) and two-fold higher composite adverse outcome (54% vs. 26%). The use of primary codes alone, rather than combined primary and secondary codes, resulted in overestimation of coronary angiography and revascularization rates, and underestimation of the 1-year case fatality (13.1% vs. 19.0%) and composite adverse event rate (26% vs. 32%). CONCLUSION: Patient characteristics and outcomes of ACS events recorded as primary vs. secondary codes are very different. These findings have important implications for designing studies utilizing ICD10-AM codes. Published on behalf of the European Society of Cardiology. All rights reserved.
Authors: Wanyanhan Jiang; Han Chen; Jiaqiang Liao; Xi Yang; Biao Yang; Yuqin Zhang; Xiaoqi Pan; Lulu Lian; Lian Yang Journal: Environ Health Date: 2022-01-19 Impact factor: 5.984