Validation of Diagnostics to Identify Glucose-6-phosphate Dehydrogenase Activity in the US

Not Applicable

Completed

Conditions: G6PD Deficiency

Interventions: Diagnostic Test: SD Biosensor G6PD Analyzer
Diagnostic Test: Pointe Scientific Test Kit
Diagnostic Test: HemoCue System

Registration Number: NCT04010695

Lead Sponsor: PATH

Brief Summary: The primary objective of this study is to assess the accuracy of the SD Biosensor STANDARD G6PD Analyzer in measuring G6PD activity when used by trained health care workers.

Detailed Description: This is a cross-sectional diagnostic accuracy study with up to 250 participants with a goal of obtaining 20 deficient and 20 intermediate samples. The clinic will recruit and consent study participants. Clinic staff will draw 3 whole blood samples and obtain finger stick capillary blood.

G6PD activity is reported in terms of grams of hemoglobin (Hb), hence the hemoglobin concentration must be measured.

Clinic staff will perform the investigational Standard Diagnostics (SD) Biosensor point-of-care (POC) test for glucose-6-phosphate dehydrogenase (G6PD) deficiency and a HemoCue® hemoglobin test on finger stick capillary blood and on the venous blood samples.

Another venous blood sample will be sent to a clinical laboratory improvement amendments (CLIA)-certified laboratory for reference testing by the gold standard assays:

* G6PD measurement by spectrophotometry using the Pointe Scientific G6PD reference assay

* hemoglobin measurement by a hematology analyzer

Individuals identified as G6PD deficient with the reference test will be notified of their results by the clinic and referred to their physician for follow-up.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 250

Inclusion Criteria

-Willingness to provide consent

Exclusion Criteria

-Blood transfusion in the past 90 days by self-report

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
G6PD Diagnostic Testing	HemoCue System	Participants provided whole blood samples as well as fingerstick capillary blood samples. At the clinic site lab, study staff conducted the SD Biosensor point-of-care G6PD test and the point-of-care HemoCue Hb test on both finger stick blood and whole blood samples. At the reference laboratory, G6PD activity was measured from whole blood samples using the Pointe Scientific G6PD reference assay and hemoglobin was measured using a hematology analyzer.
G6PD Diagnostic Testing	SD Biosensor G6PD Analyzer	Participants provided whole blood samples as well as fingerstick capillary blood samples. At the clinic site lab, study staff conducted the SD Biosensor point-of-care G6PD test and the point-of-care HemoCue Hb test on both finger stick blood and whole blood samples. At the reference laboratory, G6PD activity was measured from whole blood samples using the Pointe Scientific G6PD reference assay and hemoglobin was measured using a hematology analyzer.
G6PD Diagnostic Testing	Pointe Scientific Test Kit	Participants provided whole blood samples as well as fingerstick capillary blood samples. At the clinic site lab, study staff conducted the SD Biosensor point-of-care G6PD test and the point-of-care HemoCue Hb test on both finger stick blood and whole blood samples. At the reference laboratory, G6PD activity was measured from whole blood samples using the Pointe Scientific G6PD reference assay and hemoglobin was measured using a hematology analyzer.

Primary Outcome Measures

Name	Time	Method
Specificity of SD Biosensor POC G6PD Test for Identifying G6PD Deficient Individuals	All samples were collected on study day 1	For the purposes of this study, an individual was considered G6PD deficient if they tested positive by the Pointe Scientific assay. A true negative was defined as \> 30% of normal G6PD activity in circulating venous blood as determined by the Pointe Scientific test. Specificity is the percentage of participants who tested negative for G6PD deficiency on the reference test who were identified as negative using the test assay, calculated as: Number of participants who were both test and true negative / (Number of participants who were test and true negative + Number of participants who were test positive but true negative \[ie false positive\]) \* 100%. Specificity of the SD Biosensor G6PD test was calculated from both venous and capillary blood samples.
Sensitivity of SD Biosensor POC G6PD Test for Identifying G6PD Deficient Individuals	All samples were collected on study day 1	For the purposes of this study, an individual was considered G6PD deficient if they tested positive in the Pointe Scientific assay. A true positive was defined as a participant with ≤ 30% of normal G6PD activity in circulating venous blood determined by the Pointe Scientific test. Diagnostic sensitivity of the SD Biosensor G6PD test is defined as the percentage of participants who tested positive for G6PD deficiency on the reference test who were identified by the test assay as positive, calculated as: Number of participants who were both test and true positive / (Number of participants who were test and true positive + Number of participants who were test negative but true positive \[ie false negative\]) \* 100%. Sensitivity of the SD Biosensor POC G6PD test was calculated from both venous and capillary blood samples.
Sensitivity of SD Biosensor POC G6PD Test for Identifying Women With Intermediate G6PD Activity	All samples were collected on study day 1	To investigate the performance of the SD Biosensor G6PD test to distinguish females with intermediate G6PD activity from females with normal activity, assay sensitivity was determined at a G6PD activity threshold of 70%. A true positive for intermediate G6PD activity in females was defined as G6PD activity between 30 and 70% of normal in circulating venous blood as determined by the Pointe Scientific test. Sensitivity of the SD Biosensor POC G6PD test is the percentage of women who tested positive for intermediate G6PD activity on the reference test who were identified by the test assay as positive, calculated as: Number of women who were both test and true positive / (Number of women who were test and true positive + Number of women who were test negative but true positive \[ie false negative\]) \* 100%. Sensitivity of the SD Biosensor G6PD test for identifying females with intermediate G6PD activity was calculated from both venous and capillary blood samples.
Specificity of SD Biosensor G6PD Test for Identifying Women With Intermediate G6PD Activity	All samples were collected on study day 1	To investigate the performance of the SD Biosensor G6PD test to distinguish females with intermediate G6PD activity from females with normal activity, the specificity was determined at a G6PD activity threshold of 70%. A true negative for intermediate G6PD activity in females was defined as G6PD activity \> 70% of normal in circulating venous blood as determined by the Pointe Scientific test. Specificity is the percentage of participants who tested negative for G6PD deficiency on the reference test who were identified as negative using the test assay, calculated as: Number of participants who were both test and true negative / (Number of participants who were test and true negative + Number of participants who were test positive but true negative \[ie false positive\]) \* 100%. Specificity of the SD Biosensor G6PD test was calculated from both venous and capillary blood samples.

Secondary Outcome Measures

Name	Time	Method
Accuracy Between the SD Biosensor POC G6PD Test Assay and the Pointe Scientific Test Kit	All samples were collected on study day 1	Accuracy between the SD Biosensor POC G6PD test assay and the Pointe Scientific G6PD reference assay was calculated as the percent agreement between both G6PD tests, ie, the percentage of participants with the same diagnosis according to both tests (either deficient, intermediate, or normal G6PD levels). Accuracy of the SD Biosensor G6PD test was calculated from both venous and capillary blood samples.
Accuracy Between the SD Biosensor POC G6PD Test Measure of Hemoglobin and the Reference Hemoglobin Test	All samples were collected on study day 1	Accuracy between the SD Biosensor POC G6PD test measure of hemoglobin and the hemoglobin reference assay was calculated as the percentage agreement between both tests, ie, the percentage of participants with the same diagnosis according to both tests (either non/mild anemia, moderate anemia or severe anemia).
Median G6PD Values Measured by the SD Biosensor G6PD Test for Venous and Capillary Blood Samples	All samples were collected on study day 1