Table 4 Quality assurance strategies

● Critical review of protocols

● Fluidity and feasibility of field operations assessed

● Monitoring field activities

● Audit and evaluate validity of findings prior to publication

Coordinating center

● Common manual of operations for three study sites

● Internal peer reviews prior to publication

● Coordination of timelines & activities

Investigators

● Reviewed the design and planning of the study

● Results were audited after completion of the pilot

● Monitoring

● Validity checks

● Results reviewed

● Regular steering committee meetings

Field Personnel

● Extensive training over a period of 7–10 days – theory and practical, field visits and shadowing by the study managers

● Evaluated all field and documenting techniques

● Random checks, re-training

● Easy-to-carry operations guide provided

Survey Questionnaires

● Peer-reviewed

● Established clarity and face validity in small field sample

● Regular checks done to assess completeness

● Compromised or inadequately completed questionnaires identify and discard

● Translated into local languages

● Internal consistency estimates and reliability exercises through review of literature on survey instruments and their published data

Measuring Equipment

● Centrally procured

● Evaluated calibration techniques, acceptability of use in field

● Regular calibration of equipment; faulty equipment replaced as and when required

● Central training

● Calibration guidelines and checks developed

Specimens

● Kits and equipment procured centrally

● Evaluated adherence to protocols, labeling, processing, storage and handling

● Interim analysis conducted to detect outliers

● Random checks done

● Samples stored for future investigation

● External temperature gauge labels to monitor sample temperature

● Compromised samples identify and discard

● Specific protocols for each biochemical assay was developed

● Extensive training (labeling, handling, storage)

Laboratory

● Laboratory selected and reference laboratory identified based on National Accreditation Board for Testing and Calibration Laboratories, Department of Science and Technology, Government of India (NABL) or College of American Pathologists, Northfield, IL, USA(CAP) certification

● Evaluated procedural fluidity

● Internal quality checks and calibration

Assessment of intra- and inter-laboratory coefficients of variation

●Regular external validation – lyophilized samples from reference laboratory

● Evaluated intra- and inter-laboratory variability

● Analysis conducted to detect outliers

● Internal and external quality assessment protocols and schedule of regularity developed

Communication

● Reporting structures were established

● Agility of transfers assessed

● Data transfer planned

Documentation

● Checklists and logbooks were maintained

● Recording legibility assessed

● Audit logbooks for response rates and field activity indicators maintained

Training in appropriate and legible documentation

Data Storage & Confidentiality

● Data back-up and protection policies have been established

● Accessibility, simplicity and flexibility of software assessed

● Locked and password-protected data storage

● Datasets de-identified

● Access to personal identifiers limited

● Active back-up

● Training of all staff

Data Entry

● Protocols, consistent data cleaning methods and verification systems were established

● Variability assessments conducted

● Interim analyses to identify duplicate entries

● Reporting on outliers

● Validity checks

● Decision log to document issues

● Database errors tracked