1. Quality control and audit visit: process & actions

2. Why quality control? To ensure the correctness, and completeness of the collected information To detect problems in measurements and data management soon after they occur Ideally so that they can be remedied Anyway before erroneous results reported

3. What is quality control? In case of HES includes Training of the field work personnel Setting up the examination site Data collection process Questionnaires Self-administered Interviews Physical measurements Biological samples Transfer of materials

4. Training Lectures and practical training What are standardized procedures How they work What to do in unexpected situations

5. Monitoring of work Both field work and laboratory procedures required monitoring – audit visits Person(s) doing the audit visits should Outsider, not part of team doing the work Well aware of agreed protocols Sometimes internal auditor (trainers during the pilot) may be useful

6. Audit visit to the field How examination room(s) is/are set up How equipment are set up Tidiness of the examination site How daily checking and calibration of the equipment is done Are equipment calibrated correctly Communication Within team With participants How informed consent is obtained How interviews are conducted How measurements are conducted Data security Transfer of materials

7. From each audit visit, a report needs to be prepared Things requiring changes/correcting Positive observations Communicated with the field work team Audit results

8. From collected data In regular bases, the coordinating office should check Frequencies of the variables Means and standard deviation Outliers Possible technical notes, other comments attached to data Jump rules Consistency

9. Quality control is a learning process