For a study, researchers sought to determine the prevalence of secondary hypertension in otherwise healthy children with an outpatient hypertension diagnosis. The databases MEDLINE, PubMed Central, Embase, Web of Science, and the Cochrane Library were systematically searched for observational studies reporting the prevalence of secondary hypertension in children who had hypertension evaluated and had no known comorbidities associated with hypertension at the time of diagnosis. The study-specific prevalence of secondary hypertension in children examined for hypertension was derived independently by two authors. A random-effects meta-analysis was used to aggregate prevalence estimates for secondary hypertension.

There were 2,575 children with hypertension in 19 prospective studies and 7 retrospective investigations, with a median of 65 participants (range, 9-486) in each research. When compared to research done in referral clinics, studies conducted in primary care or school settings indicated a reduced prevalence of secondary hypertension (3.7%; 95% CI, 1.2% -7.2%) compared with studies conducted in referral clinics (20.1%; 95% CI, 11.5% -30.3%). There were no significant subgroup differences based on research design, nation, participant age range, hypertension definition, blood pressure device, or study quality when stratified by study environment. Despite the fact that the studies used varied methodologies to identify secondary hypertension, the diagnostic evaluations were at least as extensive as the restricted tests indicated by current guidelines. The low frequency of secondary hypertension among children with a new diagnosis of hypertension obtained on screening validates clinical practice advice to avoid intensive testing for secondary causes in most children with hypertension in the primary care environment.