Data management in the field

Electronic data

The Team leader is responsible for managing data collected in the field. Electronic data should be backed up to protect records from accidental loss. Data entry should be set up so that interviewer data are backed up on the device on which they were entered, and uploaded onto the Team leader’s device at the end of each day. Where possible, data should also be uploaded to the server. USB sticks with adapters to fit the device, as needed, can also be used to back up data. This may be an important option in areas where it is not possible to upload data to the server for several days.

All teams should have a global positioning system (GPS) to assist them in finding selected clusters and households. Most mobile phones and tablets come with these systems installed, and they should be used whenever possible to verify the location of data collection and allow for cross-checks with the team number and number of data files received.

Paper-based data collection forms and other records

The most important paper-based forms collected in the field (for example, cluster control forms, specimen tracking forms and questionnaires) should be tracked as they move from the household to the cluster to the region and then to the central data entry point. Where electronic devices are being used for the main questionnaire, any paper-based forms should be photographed and the image uploaded along with the completed questionnaires from the cluster. All forms should be stored securely, using methods to protect confidentiality during fieldwork, while in transit, and at the final data entry point.

Where paper-based data collection is used, there should be a central data entry system to track the data on all types of forms. Typically, information from the cluster control form, which includes the total number and types of specimens collected, is entered by the same personnel who enter the questionnaire data.

Detailed specimen tracking data are typically entered by the central laboratory. Where barcode labels are used, a hand-held barcode reader should be used at the laboratory to record incoming specimens onto a spreadsheet and compare specimens received with the specimen tracking form. The Survey coordinator should be made aware of any inconsistencies. This spreadsheet should be shared with the relevant laboratories for later entry of analysis results.

Labeling

The unique ID should accompany participants throughout the data collection process. For paper-based data collection, a label should be placed on the household and individual questionnaire forms at the time of interview. For electronic data collection, a code is scanned or entered by hand into an electronic collection device. At the time of any sample or specimen collection, a corresponding label should be placed on the food sample or biological specimen and on the specimen control forms, and this number should be checked against the label on the household or individual form. These label codes can be scanned into an electronic device to ensure that they match the ID of the household or survey participant. If there is a discrepancy between a scanned ID (for example it does not match to any household or individual) then the data collection system will generate a warning and block further data entry until the ID does match a household or individual. It is imperative for the quality and reliability of survey results that each team member responsible for handling the labels reads them very carefully so that they are not mixed up or used interchangeably.

Procedures should be in place to ensure that barcode data and linkages are checked and corrected where necessary before leaving any cluster. The unique ID can be scanned by the electronic device used in the field (note that this may require downloading an easy-to-use scanner onto all devices, which is then linked to open at the appropriate point in the data collection modules). For paper-based data collection, the label barcode for questionnaire data (double) entry and for recording sample analysis results at the laboratory can be entered manually. However, barcode scanners that plug into a computer and can insert a scanned code into, for example, a selected database entry field or cell on an electronic spreadsheet are not costly, and these are the recommended option.