Validation Study of Cardiovascular International Statistical Classification of Diseases and Related Health Problems, Tenth Edition, Australian Modification (ICD-10-AM) Codes in Administrative Healthcare Databases (ANZACS-QI 77).

BACKGROUND: Administrative healthcare databases can be utilised for research. The accuracy of the International Statistical Classification of Diseases and Related Health Problems, Tenth Edition, Australian Modification (ICD-10-AM) coding of cardiovascular conditions in New Zealand is not known and requires validation. METHOD: International Statistical Classification of Diseases and Related Health Problems, Tenth Edition, Australian Modification coded discharges for acute coronary syndrome (ACS), heart failure (HF) and atrial fibrillation (AF), in both primary and secondary diagnostic positions, were identified from four district health boards between 1 January 2019 and 31 June 2019. A sample was randomly selected for retrospective clinician review for evidence of the coded diagnosis according to contemporary diagnostic criteria. Positive predictive values (PPVs) for ICD-10-AM coding vs clinician review were calculated. This study is also known as All of New Zealand, Acute Coronary Syndrome-Quality Improvement (ANZACS-QI) 77. RESULTS: A total of 600 cases (200 for each diagnosis, 5.0% of total identified cases) were reviewed. The PPV of ACS was 93% (95% confidence interval [CI] 89%-96%), HF was 93% (95% CI 89%-96%) and AF was 96% (95% CI 92%-98%). There were no differences in PPV between district health boards. PPV for ACS were lower in Maori vs non-Maori (72% vs 96%; p=0.004), discharge from non-Cardiology vs Cardiology services (89% vs 96%; p=0.048) and ICD-10-AM coding for unstable angina vs myocardial infarction (81% vs 95%; p=0.011). PPV for HF were higher in the primary vs secondary diagnostic position (100% vs 89%; p=0.001). CONCLUSIONS: The PPVs of ICD-10-AM coding for ACS, HF, and AF were high in this validation study. ICD-10-AM coding can be used to identify these diagnoses in administrative databases for the purposes of healthcare evaluation and research.

What is the Statin Possession Ratio Cut-Off Which Identifies Those at Increased Risk Following Acute Coronary Syndrome (ANZACS-QI 68)?

AIMS: More optimal dispensing of statins is associated with greater cholesterol lowering; however, it is not known whether this translates to improved outcomes following acute coronary syndrome (ACS). The aim of this study was to assess the association between various levels of statin adherence and outcomes following ACS. METHODS: Patients hospitalised with ACS who underwent coronary angiography between 2014-2018 were identified from the All New Zealand ACS Quality Improvement (ANZACS-QI) registry. Medication possession ratio (MPR) was used to assess statin adherence and calculated over 1 year post-discharge using linked pharmaceutical dispensing datasets. Optimal, adequate and suboptimal adherence was defined as an MPR of ≥1.0, 0.8-0.99 and 0-0.79, respectively. A combined outcome of all-cause mortality and rehospitalisation for atherosclerotic disease was identified from 1 year post-discharge through September 2021. Cox proportional hazard models were used to adjust for confounding variables. RESULTS: Of the 30,452 patients, 68% had optimal adherence, 15% adequate adherence and 16% had suboptimal adherence to statins. Mean follow-up was 3.6 years. Those with suboptimal adherence had a higher adjusted risk of the combined outcome compared with those with optimal adherence (HR 1.18, 95% CI 1.11-1.26). There was no significant difference in adjusted outcome between those with optimal and adequate adherence (HR 0.99, 95% CI 0.92-1.06). CONCLUSIONS: Suboptimal statin adherence following ACS is associated with an increased risk of mortality and rehospitalisation. An MPR cut-off of 0.8 seems reasonable to identify those at higher risk of cardiovascular events that could benefit the most from interventions to improve statin adherence and is appropriate as a target for quality improvement programs.

Contrasting trends in heart failure incidence in younger and older New Zealanders, 2006-2018.

OBJECTIVE: Studies indicate that age-standardised heart failure (HF) incidence has been decreasing internationally; however, contrasting trends in different age groups have been reported, with rates increasing in younger people and decreasing in the elderly. We aimed to describe age-specific trends in HF incidence in New Zealand (NZ). METHODS: In this nationwide data linkage study, we used routinely collected hospitalisation data to identify incident HF hospitalisations in NZ residents aged ≥20 years between 2006 and 2018. Age-specific and age-standardised incidence rates were calculated for each calendar year. Joinpoint regression was used to compare incidence trends. RESULTS: 116 113 incident HF hospitalisations were identified over the 13-year study period. Between 2006 and 2013, age-standardised incidence decreased from 403 to 323 per 100 000 (annual percentage change (APC) -2.6%, 95% CI -3.6 to -1.6%). This reduction then plateaued between 2013 and 2018 (APC 0.8%, 95% CI -0.8 to 2.5%). Between 2006 and 2018, rates in individuals aged 20-49 years old increased by 1.5% per year (95% CI 0.3 to 2.7%) and decreased in those aged ≥80 years old by 1.2% per year (95% CI -1.7 to -0.7%). Rates in individuals aged 50-79 years old initially declined from 2006 to 2013, and then remained stable or increased from 2013 to 2018. The proportion of HF hospitalisations associated with ischaemic heart disease decreased from 35.1% in 2006 to 28.0% in 2018. CONCLUSION: HF remains an important problem in NZ. The decline in overall incidence has plateaued since 2013 due to increasing rates of HF in younger age groups despite an ongoing decline in the elderly.

Temporal trends in the burden of heart failure.

Heart failure is a common healthcare problem associated with high morbidity and mortality. The burden of heart failure is changing; increases secondary to an ageing population may be offset by improved primary cardiovascular prevention and advances in heart failure therapies. In this review, we evaluate recent international trends in heart failure incidence, morbidity and mortality. Although the age-standardised incidence of heart failure has been decreasing since 2000, the incidence in those age groups <55 years is increasing with patients being diagnosed at younger ages. Despite improvements in therapies for heart failure, prognosis still remains poor with up to one-third of patients not surviving beyond 1 year following diagnosis and no improvements in mortality over the past 10 years. The case-mix of heart failure patients is changing with a greater proportion having non-ischaemic aetiology and preserved ejection fraction, and a higher prevalence of non-cardiovascular comorbidity and mortality.