Developing a Screening Tool for Primary Immunodeficiency Disease (PID) in Pakistan

Study Overview
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Brief Summary
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Case-control diagnostic accuracy study with 130 potential pediatric PID+ (primary immunodeficiency) patients, and 100 age-matched, healthy controls (PID-). The potential PID+ participants will be recruited prospectively through 9 hospitals in Sindh and Punjab states or contacted via the PID surveillance registry developed by AKU Hospital's Polio Excretion in PID study to identify children with primary antibody deficiency (PAD+: a type of PID+); healthy, age-matched PID-participants will be recruited by snowball sampling. At the point of care, health care workers (HCWs) will collect capillary blood samples (0.1mL) to run the PID rapid screening test and reader on potential PID+ participants (identified by exhibiting >2 of the Jeffrey Modell warning signs) and healthy, age-matched controls. All pediatric study participants will be sent to the hospital lab to have a confirmatory immunology panel (see 4.4.1 Diagnosing PID for the battery of tests) run on a serum/plasma sample to confirm their PID diagnosis (PID+/PAD-, PID+/PAD+, PID-); a 1.5uL aliquot of serum/plasma will simultaneously be used to run a PID rapid screening test by a laboratory technician (LT). HCWs and LTs will be blinded to true PID status. Blood and serum PID rapid screening test results will be compared to the confirmatory immunology panel to determine diagnostic accuracy. All clinical management of study participants will follow the standard of care for PID in Pakistan and will be based upon the immunology panel result. The HCWs and LTs administering the tests will be trained prior to the diagnostic accuracy test (see Objectives below) and will provide feedback on the tool post-training and post-use to assess usability, acceptability, and feasibility of integrating the test and digital reader into tertiary hospitals for the purpose of improved national PID surveillance, improved PID patient care, and polio eradication in Pakistan.

Official Title
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Developing a Screening Tool for Primary Immunodeficiency Disease (PID) in Pakistan

Conditions
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Primary Immunodeficiency Diseases

Intervention / Treatment
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* Device: Primary Immunodeficiency (PID) Rapid Diagnostic Test (RDT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 3 months to 15 years Presents for care at 1 of 9tertiary hospitals participating in the study Potential PID+ (Case): Child is identified by HCW to have >2 Jeffrey Model warning signs of PID. [Note: Upon immunology panel testing, this group will be separated into three categories: PID-, PID+, and PID+/PAD+ meaning they have 1 of 5 relevant primary antibody deficiencies (PAD+)]. PID-(Control): Child is identified (by snowball sampling) as being in good health, and having the same age (within 12 months) as another child who produced a PID+ result. Caregiver consents to participate in the study and provides informed consent. If their children are 10 years of age or older, that child must also give assent. Exclusion Criteria: Aged less than 3 months or greater than 15 years of age Caregiver does not consent to participate, or child >10years does not give assent to participate. Having received IVIG in the past 90 days

Ages Eligible for Study
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Minimum Age: 3 Months
Maximum Age: 15 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pediatric PID patients (prospective)<br>Prospective, age-matched, healthy patients | Device: Primary Immunodeficiency (PID) Rapid Diagnostic Test (RDT)<br>* We are evaluating the accuracy of a new rapid diagnostic screening test. There is no medical intervention with the participants in this study.<br>|
| Pediatric PID patients (recontacted from registry)<br> | Device: Primary Immunodeficiency (PID) Rapid Diagnostic Test (RDT)<br>* We are evaluating the accuracy of a new rapid diagnostic screening test. There is no medical intervention with the participants in this study.<br>|
| Prospective, age-matched, healthy patients<br> | Device: Primary Immunodeficiency (PID) Rapid Diagnostic Test (RDT)<br>* We are evaluating the accuracy of a new rapid diagnostic screening test. There is no medical intervention with the participants in this study.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic accuracy | Estimates of diagnostic accuracy characteristics with 95% confidence intervals (sensitivity, specificity, PPV, NPV) of the PID screening test for relevant PIDs in a Pakistani population of both PID+ children and PID- age-matched healthy controls | 8 month | 
| Determine usability, acceptability, feasibility of integrating PID test and digital reader into tertiary hospitals for improved patient care | Estimates of user effectiveness, efficacy, satisfaction, learnability, and feasibility among trained health care workers (HCWs) and laboratory technicians (LTs) will be evaluated using observation checklists and surveys. The observation checklist will evaluate the ability to administer the test, read the test results accurately after the appropriate amount of waiting time, record the result in the digital reader app, operate the digital app to read a photograph of the test result, and their ease of performing these tasks. This methodology adheres to ISO 9241-210 on human-centered design principles in usability testing. | 8 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effectiveness - agreement between the PID screening test readouts (#1, #2) with each other, the digital reading, a PATH expert panel, and the local PID standard of care immunology tests. | Percent (%) agreement between each of the PID screening test results, digital app result, expert panel, and immunology panel. | 8 months | 
| Effectiveness | Percent (%) agreement in PID screening test results between capillary whole blood samples and serum samples. | 8 months | 
| Understandability of diagnostic instruction | Percent of trained end users who can accurately comprehend the material presented in the training course curriculum and the IFU. | 8 months | 
| Usability of screening test result outputs | Percent of trained end users who can accurately interpret the investigational device result output. | 8 months | 
| Usability for facilitators | List of barriers to use, and facilitators of use in the Pakistani context among HCWs, LTs, and MOH key stakeholders. | 8 months |