86 Incidence of Pulmonary Thromboembolism in Canadian Children: A 3-Year National Surveillance Study

Abstract

Abstract Introduction/Background Pulmonary thromboembolism (PTE) is a rare but life-threatening event for which adequate epidemiological data in paediatrics are lacking. Best estimates regarding the epidemiology of PTE in Canadian children were published over two decades ago, using information obtained from a national registry of paediatric thromboembolic disease which only examined pulmonary embolism as a related complication. It is likely that the true rates of pulmonary thromboembolism in Canadian children are higher. Objectives To determine the minimum national incidence of PTE in children (neonate up to <18 years) by age, gender, and province / territory of residence using an existing national surveillance system. Design/Methods Through the Canadian Paediatric Surveillance program, over 2,800 paediatricians and subspecialists practicing in Canada were contacted monthly from January 2020 to December 2022. Using a standardized definition of PTE and pre-specified diagnostic criteria, clinicians were requested to report all new suspected or confirmed cases. Results During the 3-year study period, 58 cases of PTE were reported, documenting a minimum average annual national incidence of 2.4 per million Canadian children. Females accounted for 77.6% (n=45) cases. Patients ranged in age from 2 months to 17.9 years (median age 15.8 years; interquartile rate 13.3 to 16.7 years). Incidence rates (reported as average annual per million children) varied by age: 0-4 years, 0.7; 5-9 years, 0.2; 10-14 years, 2.0; 15-18 years, 6.6; and also by province: Newfoundland, 21.3; Saskatchewan, 4.6; British Columbia, 4.5; New Brunswick, 4.4; Alberta, 3.5; Nova Scotia, 1.8; Ontario, 1.6; Manitoba, 1.0; Quebec, 0.9. Conclusion Although the overall minimum average annual national incidence of PTE in Canada is 2.4 per million children, adolescents, particularly females, appear to be at highest risk of disease. It is not clear whether geographic distribution of cases disproportionate to provincial census may be related to regional differences in diagnostic practices, population-related risk factors (e.g., obesity, genetic thrombophilias, OCP prescribing), or reporting of cases.