title: Validation of a screening tool to identify older children living with HIV in primary care facilities in high HIV prevalence settings.
abstract: OBJECTIVE
  We previously proposed a simple tool consisting of five items to screen for risk of HIV infection in adolescents (10-19 years) in Zimbabwe. The objective of this study is to validate the performance of this screening tool in children aged 6-15 years attending primary healthcare facilities in Zimbabwe.
  
  
  METHODS
  Children who had not been previously tested for HIV underwent testing with caregiver consent. The screening tool was modified to include four of the original five items to be appropriate for the younger age range, and was administered. A receiver operator characteristic analysis was conducted to determine a suitable cut-off score. The sensitivity, specificity and predictive value of the modified tool were assessed against the HIV test result.
  
  
  RESULTS
  A total of 9568 children, median age 9 (interquartile, IQR: 7-11) years and 4971 (52%) men, underwent HIV testing. HIV prevalence was 4.7% (95% confidence interval, CI:4.2-5.1%) and increased from 1.4% among those scoring zero on the tool to 63.6% among those scoring four (P < 0.001). Using a score of not less than one as the cut-off for HIV testing, the tool had a sensitivity of 80.4% (95% CI:76.5-84.0%), specificity of 66.3% (95% CI:65.3-67.2%), positive predictive value of 10.4% and a negative predictive value of 98.6%. The number needed to screen to identify one child living with HIV would drop from 22 to 10 if this screening tool was used.
  
  
  CONCLUSIONS
  The screening tool is a simple and sensitive method to identify children living with HIV in this setting. It can be used by lay healthcare workers and help prioritize limited resources.
authors.affiliation: aBiomedical Research and Training Institute, Harare bHarare City Health, Harare, Zimbabwe cDepartment of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK dDepartment of Paediatrics, University of Zimbabwe, Harare, Zimbabwe eClinical Research Department, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Tsitsi
authors.initials: T
authors.lastname: Bandason
authors.forename: Grace
authors.initials: G
authors.lastname: McHugh
authors.forename: Ethel
authors.initials: E
authors.lastname: Dauya
authors.forename: Stanley
authors.initials: S
authors.lastname: Mungofa
authors.forename: Shungu M
authors.initials: SM
authors.lastname: Munyati
authors.forename: Helen A
authors.initials: HA
authors.lastname: Weiss
authors.forename: Hilda
authors.initials: H
authors.lastname: Mujuru
authors.forename: Katharina
authors.initials: K
authors.lastname: Kranzer
authors.forename: Rashida A
authors.initials: RA
authors.lastname: Ferrand
mesh_terms: D000293:Adolescent; D002648:Child; D003661:Decision Support Techniques; D005260:Female; D015658:HIV Infections / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D011320:Primary Health Care; D012372:ROC Curve; D012680:Sensitivity and Specificity; D015030:Zimbabwe