Background: Congenital heart disease (CHD) is the commonest birth defect. Studies estimating the prevalence of CHD in school-age children could therefore contribute to quantifying unmet health needs for diagnosis and treatment, particularly in lower-income countries. Data at school age are considerably sparser, and individual studies have generally been of small size. We conducted a literature-based meta-analysis to investigate global trends over a 40-year period.
Methods and results: Studies reporting on CHD prevalence in school-age children (4-18 years old) from 1970 to 2017 were identified from PubMed, EMBASE, Web of Science and Google Scholar. According to the inclusion criteria, 42 studies including 2,638,475 children, reporting the prevalence of unrepaired CHDs (both pre-school diagnoses and first-time school-age diagnoses), and nine studies including 395,571 children, specifically reporting the prevalence of CHD first diagnosed at school ages, were included. Data were combined using random-effects models. The prevalence of unrepaired CHD in school children during the entire period of study was 3.809 (95% confidence intervals 3.075-4.621)/1000. A lower proportion of male than female school children had unrepaired CHD (OR = 0.84 [95% CI 0.74-0.95]; p = 0.001). Between 1970-1974 and 1995-1999, there was no significant change in the prevalence of unrepaired CHD at school age; subsequently there was an approximately 2.5-fold increase from 1.985 (95% CI 1.074-3.173)/1000 in 1995-1999 to 4.832 (95% CI 3.425-6.480)/1000 in 2010-2014, (p = 0.009). Among all CHD conditions, atrial septal defects and ventricular septal defects chiefly accounted for this increasing trend. The summarised prevalence (1970-2017) of CHD diagnoses first made in childhood was 1.384 (0.955, 1.891)/1000; during this time there was a fall from 2.050 [1.362, 2.877]/1000 pre-1995 to 0.848 [0.626, 1.104]/1000 in 1995-2014 (p = 0.04).
Conclusions: Globally, these data show an increased prevalence of CHD (mainly mild CHD conditions) recognised at birth/infancy or early childhood, but remaining unrepaired at school-age. In parallel there has been a decrease of first-time CHD diagnoses in school-age children. These together imply a favourable shift of CHD recognition time to earlier in the life course. Despite this, substantial inequalities between higher and lower income countries remain. Increased healthcare resources for people born with CHD, particularly in poorer countries, are required.
Keywords: Congenital heart disease; Meta-analysis; National income; Prevalence; School children.