Survey Design and Distribution
An online survey (SurveyMonkey,San Mateo, CA) was distributed by email by the US CF Foundation (CFF) (Table 1 in the online supplement) in August of 2021. Survey recipients included CF Care Center directors and members of the CFF Quality Improvement (QI) Consortium, a 75-member group of CF NBS leaders from every state in the USA. Information was also obtained about clustering of states (a practice in which a state sends their dried blood spot specimens to another state and outsourcing to a vendor for analysis). Periodic reminders were sent by the CFF to ensure responses from representatives of every state. In some cases, respondents provide data via email. The survey ended in December 2021.
In order to ensure receipt of responses from across the nation, respondents and other CF leaders from each state were contacted until finalized, confirmed accurate data were received. Following completion of data collection, the responses from within the same state were compared to one another in order to confirm consistency and ensure accuracy. In some cases, multiple representatives from the same state provided discrepant information. When this occurred, CF NBS leaders in those states were informed of the discrepancies and asked to confirm the true values. For some regions, respondents needed to be contacted on multiple occasions before we could ascertain accurate answers regarding either IRT cutoffs or CFTR panels. For three states, state NBS lab leaders were contacted to determine with certainty the algorithm that was being used in 2021.