- OBJECTIVES: The goal of this study was to examine the ability of the current Canadian CF center network to conduct sweat testing, with a particular focus on testing in infants less than 3 months old. METHODS: Surveys were sent to the 37 CF centers in Canada supported by the Canadian CF Foundation, and results were interpreted with respect to their ability to obtain adequate sweat volumes in children less than 3 months and potential factors influencing these results. RESULTS: Ten centers that care for adult patients referred patients to their local pediatric CF center for sweat testing; the remaining 27 centers conducted sweat tests and 26 responded. Insufficient sweat volume results in children <3 months occurred in a median of 18.3% of tests. The corresponding proportion for the remaining population was 4.5% (P < 0.001). 15 of 19 centers had an incidence of >5% of insufficient tests in children <3 months of age, and 9 of 19 had an incidence of <20% in this age group. Six of 19 had an incidence of >5% of insufficient sweat volumes in older children and adults. CONCLUSIONS: Standardization of testing procedures is required to reduce the rates of insufficient sweat volumes in both infants less than 3 months old and children >3 months old. This will decrease the need for repeat testing and delay in diagnosis.