title: Performance of point-of-care CD4 testing technologies in resource-constrained settings: a systematic review and meta-analysis.
abstract: BACKGROUND
  Point-of-care (POC) CD4 testing increases patient accessibility to assessment of antiretroviral therapy eligibility. This review evaluates field performance in low and middle-income countries (LMICs) of currently available POC CD4 technologies.
  
  
  METHODS
  Eight electronic databases were searched for field studies published between January 2005 and January 2015 of six POC CD4 platforms: PointCare NOW™, Alere Pima™ CD4, Daktari™ CD4 Counter, CyFlow® CD4 miniPOC, BD FACSPresto™, and MyT4™ CD4. Due to limited data availability, meta-analysis was conducted only for diagnostic performance of Pima at a threshold of 350 cells/μl, applying a bivariate multi-level random-effects modelling approach. A covariate extended model was also explored to test for difference in diagnostic performance between capillary and venous blood.
  
  
  RESULTS
  Twenty seven studies were included. Published field study results were found for three of the six POC CD4 tests, 24 of which used Pima. For Pima, test failure rates varied from 2 to 23 % across study settings. Pooled sensitivity and specificity were 0.92 (95 % CI = 0.88-0.95) and 0.87 (95 % CI = 0.85-0.88) respectively. Diagnostic performance by blood sample type (venous vs. capillary) revealed non-significant differences in sensitivity (0.94 vs 0.89) and specificity (0.86 vs 0.87), respectively in the extended model (Wald χ2(2) = 4.77, p = 0.09).
  
  
  CONCLUSIONS
  POC CD4 testing can provides reliable results for making treatment decision under field conditions in low-resource settings. The Pima test shows a good diagnostic performance at CD4 cut-off of 350 cells/μl. More data are required to evaluate performance of POC CD4 testing using venous versus capillary blood in LMICs which might otherwise influence clinical practice.
authors: Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia. minh.pham@burnet.edu.au.|Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia. minh.pham@burnet.edu.au.
authors: Minh D
authors: MD
authors: Pham
authors: Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.
authors: Paul A
authors: PA
authors: Agius
authors: The Alfred Hospital, The Ian Potter Library, Melbourne, VIC, Australia.
authors: Lorena
authors: L
authors: Romero
authors: Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia.
authors: Peter
authors: P
authors: McGlynn
authors: Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.|Department of Immunology, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia.
authors: David
authors: D
authors: Anderson
authors: Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.|Department of Infectious Diseases, The Alfred Hospital and Monash University, Melbourne, Australia.
authors: Suzanne M
authors: SM
authors: Crowe
authors: Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.|Department of Epidemiology and Preventive Medicine, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Australia.|Department of Obstetrics and Gynecology, International Centre for Reproductive Health, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
authors: Stanley
authors: S
authors: Luchters
mesh_terms: D018791:CD4 Lymphocyte Count / Q000379:methods*; D003906:Developing Countries; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy; D006295:Health Resources; D006801:Humans; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity
keywords: CD4; Diagnostic accuracy; Meta-analysis; Point of care testing; Systematic review