The interviews with the forest officials had a broader geographical focus compared to the community interviews, but site-specific questions were asked also to the foresters for triangulation of the interview information from the local key informants.
Vaccine histories were collected and verified by using 4 sources: medical record review, patient interview, information from primary care providers, and the NYS Immunization Information System.
A major strength of this study is the obtaining of in-depth interview information from a relatively large number of policymakers.
After each interview, information from previous interviews helped to improve the next one, and step-by-step, the level of redundancy was reached and the data collection was finalized.
In addition, unlike the in-depth interviews, information from focus group discussions could not influence their ongoing trial participation, therefore participants may have felt more comfortable talking about particular information that they had chosen not to report during the trial.
A key informant interview collected information from lady health workers (LHW) in those sites where they worked, including their education and training, visits to the households, any problems they faced, and their relevant knowledge and practice.
Based on interview information, records from other hospitals were collected and more than 99% of all requested records were examined.
In this prospective cohort study we collected detailed interview information directly from the study participants and included information about demographics, lifestyle factors, work exposures, and residential history.
Computer assisted interviewing allows information from the previous month's interview to be available to the interviewer, and respondents are asked whether they worked for the same employer – a direct measure of job-to-job change.
We tried to minimize recall bias (especially for people who were interviewed many years after their departure from Katana) by triangulating the information collected from interviews with information from the document review.
