Trends In Acute Pulmonary Embolism Admission Rates And Mortality Outcomes In Australia, 2002-2003 To 2017-2018: A Retrospective Cohort Study

Background Contemporary Australian epidemiological data on acute pulmonary embolism (PE) are lacking.Objectives To determine the admission rates of acute PE in Australia, and to assess the temporal trends in short- and medium-term mortality following acute PE.Methods Retrospective population-linkage study of all New South Wales residents admitted with a primary diagnosis of PE between January 1, 2002 and December 31, 2018 using data from the Centre for Health Record Linkage databases. Main outcome measures included temporal trends in total PE admissions and all-cause mortality at prespecified time points up to 1 year, stratified by gender.Results There were 61,607 total PE admissions between 2002 and 2018 (meanstandard deviation: 3,624 +/- 429 admissions per annum; 50.42 +/- 3.70 admissions per 100,000 persons per annum). The mean admission rate per annum was higher for females than for males (54.85 +/- 3.65 vs. 44.91 +/- 4.34 admissions per 100,000 persons per annum, respectively) and remained relatively stable for both genders throughout the study period. The main study cohort, limited to index PE admission only, comprised 46,382 persons (mean age: 64.6 +/- 17.3 years; 44.4% males). The cumulative in-hospital, 30-day, 3-month, and 1-year mortality rates were 3.7, 5.6, 9.6, and 16.8%, respectively. When compared with 2002 as the reference year, there was a significant reduction in in-hospital (odds ratio [OR]=0.34; 95% confidence interval [CI]=0.25-0.46), 30-day (OR=0.58, 95% CI=0.46-0.73), and 1-year (hazard ratio=0.74, 95% CI=0.66-0.84) (all p <0.001) mortality risk by 2017 after adjusting for age, gender, and relevant confounders. The survival improvements were seen in both genders and were greater for females than for males.Conclusion Mortality following PE has improved with reductions observed in both short- and medium-term follow-ups between 2002 and 2018 with greater reductions in females despite their higher admission rates over time.