Number Needed to Screen for Tuberculosis Disease Among Children: A Systematic Review

CONTEXT: Improving detection of pediatric tuberculosis (TB) is critical to reducing morbidity and mortality among children. OBJECTIVE: We conducted a systematic review to estimate the number of children needed to screen (NNS) to detect a single case of active TB using different active case finding (ACF) screening approaches and across different settings. DATA SOURCES: We searched 4 databases (PubMed, Embase, Scopus, and the Cochrane Library) for articles published from November 2010 to February 2020. STUDY SELECTION: We included studies of TB ACF in children using symptom-based screening, clinical indicators, chest x-ray, and Xpert. DATA EXTRACTION: We indirectly estimated the weighted mean NNS for a given modality, location, and population using the inverse of the weighted prevalence. We assessed risk of bias using a modified AXIS tool. RESULTS: We screened 27 221 titles and abstracts, of which we included 31 studies of ACF in children < 15 years old. Symptom-based screening was the most common screening modality (weighted mean NNS: 257 [range, 5–undefined], 19 studies). The weighted mean NNS was lower in both inpatient (216 [18–241]) and outpatient (67 [5–undefined]) settings (107 [5–undefined]) compared with community (1117 [28–5146]) and school settings (464 [118–665]). Risk of bias was low. LIMITATIONS: Heterogeneity in the screening modalities and populations make it difficult to draw conclusions. CONCLUSIONS: We identified a potential opportunity to increase TB detection by screening children presenting in health care settings. Pediatric TB case finding interventions should incorporate evidence-based interventions and local contextual information in an effort to detect as many children with TB as possible.