The epidemiology of heart failure in the general Australian community - Study of Heart failure in the Australian Primary carE setting (SHAPE): methods
Abstract Background: There is a paucity of information on the epidemiology of heart failure (HF) in Australia. The Study of Heart failure in the Australian Primary carE setting (SHAPE) study aims to estimate the prevalence and annual incidence of HF in the general Australian community and to describe the demographic and key clinical profile of Australians with HF. Methods: We undertook a retrospective cohort study based on analysis of non-identifiable medical records of adult patients cared for at 43 general practices between 1 July 2013 and 30 June 2018. Data were extracted from coded (diagnosis, pathology and prescription fields) and uncoded fields (clinical notes) in the medical records. The latter searches of free text looked for common synonyms relevant to HF. The population was stratified into three groups based on a hierarchy of selection criteria: (1) definite HF, (2) probable HF and (3) possible HF. The prevalence and annual incidence of HF were calculated, along with 95% confidence intervals. Results: The practices provided care to 2.3 million individual patients over the five-year study period, of whom 1.93 million were aged 18 years and above. Of these patients 16,930 were classified as having ‘definite HF’, 4873 as having ‘probable HF’ and 36,517 as having ‘possible HF’. A further 40,992 were identified as having an aetiological condition associated with HF. These estimates accord with findings in similar populations from other countries. Among ‘active patients’ (regular attenders of a practice), the crude prevalence of HF was 1.813% (95%CI:1.79–1.84%), and the age-standardised prevalence was 2.199% (95%CI:2.168-2.23%). The annual incidence was 0.291% (95%CI:0.286–0.296%), and the age-standardised annual incidence was 0.348% (95%CI:0.342–0.354%). The estimates of prevalence and incidence suggest that almost 420,000 people were living with HF in Australia in 2017, and over 66,000 new cases of HF occurred that year. Conclusions: This novel approach to undertaking retrospective research of primary care data successfully analysed a combination of coded and uncoded data from the electronic medical records of patients routinely managed in the GP setting. SHAPE is the first real-world study of the epidemiology of HF in the general Australian community setting.