Clinical performance validation of the STANDARD G6PD test: A multi-country pooled analysis

INTRODUCTION

Screening for G6PD deficiency can inform disease management including malaria. Treatment with the antimalarial drugs primaquine and tafenoquine can be guided by point-of-care testing for G6PD deficiency.

METHODS AND FINDINGS

Data from similar clinical studies evaluating the performance of the STANDARD G6PD Test (SD Biosensor, South Korea) conducted in Bangladesh, Brazil, Ethiopia, India, Thailand, the United Kingdom, and the United States were pooled. Test performance was assessed in a retrospective analysis on capillary and venous specimens. All study sites used spectrophotometry for reference G6PD testing, and either the HemoCue or complete blood count for reference hemoglobin measurement. The sensitivity of the STANDARD G6PD Test using the manufacturer thresholds for G6PD deficient and intermediate cases in capillary specimens from 4212 study participants was 100% (95% Confidence Interval (CI): 97.5%-100%) for G6PD deficient cases with <30% activity and 77% (95% CI 66.8%-85.4%) for females with intermediate activity between 30%-70%. Specificity was 98.1% (95% CI 97.6%-98.5%) and 92.8% (95% CI 91.6%-93.9%) for G6PD deficient individuals and intermediate females, respectively. Out of 20 G6PD intermediate females with false normal results, 12 had activity levels >60% on the reference assay. The negative predictive value for females with G6PD activity >60% was 99.6% (95% CI 99.1%-99.8%) on capillary specimens. Sensitivity among 396 P. vivax malaria cases was 100% (69.2%-100.0%) for both deficient and intermediate cases. Across the full dataset, 37% of those classified as G6PD deficient or intermediate resulted from true normal cases. Despite this, over 95% of cases would receive correct treatment with primaquine, over 87% of cases would receive correct treatment with tafenoquine, and no true G6PD deficient cases would be treated inappropriately based on the result of the STANDARD G6PD Test.

CONCLUSIONS

The STANDARD G6PD Test enables safe access to drugs which are contraindicated for individuals with G6PD deficiency. Operational considerations will inform test uptake in specific settings.

The general profile of children and adolescents with major depression referred to the Free State Psychiatric complex

<div style="left: 155.087px; top: 577.926px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.856878);" data-canvas-width="318.63"><strong>Background:</strong> Depression can have far-reaching effects on the</div><div style="left: 80.9418px; top: 601.256px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.92316);" data-canvas-width="392.82000000000005">functioning and adjustment of young people. Among both</div><div style="left: 80.9418px; top: 624.585px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.910571);" data-canvas-width="392.775">children and adolescents depression confers an increased risk</div><div style="left: 80.9418px; top: 647.915px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.898096);" data-canvas-width="325.38">for illness, interpersonal and psychosocial difficulties.</div><div style="left: 80.9418px; top: 647.915px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.898096);" data-canvas-width="325.38"> </div><div style="left: 141.257px; top: 685.427px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.906132);" data-canvas-width="332.50499999999994"><strong>Objective:</strong>The aim of this study was to determine the profile of</div><div style="left: 80.9418px; top: 708.757px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.914105);" data-canvas-width="392.7450000000001">children (birth - 12 years) and adolescents (13 - 18 years) with</div><div style="left: 80.9418px; top: 732.086px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.896099);" data-canvas-width="392.76000000000005">major depression referred to the Child Mental Health Unit at the</div><div style="left: 80.9418px; top: 755.416px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.893043);" data-canvas-width="392.77500000000015">Free State Psychiatric Complex (FSPC) from 1 January 2004 to</div><div style="left: 80.9418px; top: 778.745px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.976556);" data-canvas-width="132.6">31 December 2004.</div><div style="left: 80.9418px; top: 778.745px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.976556);" data-canvas-width="132.6"> </div><div style="left: 129.137px; top: 816.258px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.917412);" data-canvas-width="344.5799999999999"><strong>Method:</strong> A total of 904 children and adolescents were referred</div><div style="left: 80.9418px; top: 839.587px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.919419);" data-canvas-width="392.745">to the Unit during 2004. From these referrals 100 children and</div><div style="left: 80.9418px; top: 862.917px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.933475);" data-canvas-width="392.775">adolescents (11.06%) were diagnosed with major depression</div><div style="left: 80.9418px; top: 886.246px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.910612);" data-canvas-width="193.06499999999997">and were included in the study.</div><div style="left: 80.9418px; top: 886.246px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.910612);" data-canvas-width="193.06499999999997"> </div><div style="left: 180.887px; top: 923.759px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.870766);" data-canvas-width="312.75000000000006"><strong>Data analysis:</strong> The data were summarised using frequencies</div><div style="left: 80.9418px; top: 947.088px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.925438);" data-canvas-width="392.91000000000014">and percentages (categorical variables) and means of</div><div style="left: 80.9418px; top: 970.418px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.885185);" data-canvas-width="200.76000000000002">percentiles (numerical variables).</div><div style="left: 80.9418px; top: 970.418px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.885185);" data-canvas-width="200.76000000000002"> </div><div style="left: 120.362px; top: 1007.93px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.905652);" data-canvas-width="353.31000000000006"><strong>Results:</strong> The majority (74%) of the cases were in the adolescent</div><div style="left: 80.9418px; top: 1031.26px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.904977);" data-canvas-width="392.74499999999995">age group and 61% were girls. The main complaints presented</div><div style="left: 80.9418px; top: 1054.59px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.882313);" data-canvas-width="392.8350000000001">by the parents or in the referral letter by the general practitioners</div><div style="left: 80.9418px; top: 1077.92px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.903519);" data-canvas-width="392.83500000000004">were behavioural problems (37%) such as stealing, aggression</div><div style="left: 80.9418px; top: 1101.25px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.936476);" data-canvas-width="392.80500000000006">and attention-seeking behaviour, followed by decrease in</div><div style="left: 80.9418px; top: 1124.58px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.898045);" data-canvas-width="392.7899999999999">school performance (25%), suspected depression (21%),</div><div style="left: 80.9418px; top: 1147.91px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.8945);" data-canvas-width="392.74499999999983">suicidal tendencies (17%), and school refusal (8%). Twelve per</div><div style="left: 80.9418px; top: 1171.24px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.880596);" data-canvas-width="392.775">cent of the group had lost a family member. The main presenting</div><div style="left: 80.9418px; top: 1194.57px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.912615);" data-canvas-width="392.81999999999994">clinical symptoms of major depression in the study group were</div><div style="left: 80.9418px; top: 1217.9px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.870739);" data-canvas-width="392.805">sleep disturbance (59%), dysphoric (depressed) mood (57%),</div><div style="left: 80.9418px; top: 1241.23px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.92694);" data-canvas-width="392.7599999999999">disturbance in appetite (49%), constant fatigue/loss of energy</div><div style="left: 80.9418px; top: 1264.56px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.908711);" data-canvas-width="392.76">(43%), inability to enjoy activities that would normally give</div><div style="left: 80.9418px; top: 1287.88px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.892772);" data-canvas-width="392.80500000000006">pleasure (37%), and impaired concentration (36%). Somatic</div><div style="left: 80.9418px; top: 1311.21px; font-size: 15.45px; font-family: sans-serif; transform: scaleX(0.909585);" data-canvas-width="325.965">complaints occurred in 42% of the study population.</div>