Rationale: Cystic Fibrosis (CF) Centers transitioned to telemedicine during the Spring 2020 peak of the COVID-19 pandemic.Objectives: We hypothesized that people with CF (pwCF) with more severe disease would be more likely to be seen in-person.
Methods:We used paired t-tests to compare within-subject changes in BMI and percent predicted forced expiratory volume in one second (FEV 1 ), and calculated relative risk (RR) to compare pulmonary exacerbations (PEx) between pwCF enrolled in the CF Foundation Patient Registry with at least one in-person clinic visit after March 15 in both 2019 and 2020.Results: Overall, the proportion of clinical encounters that were in-person clinic visits decreased from 91% in 2019 to a low of 9% in April, 2020. Among pwCF seen after March 15 in both 2019 and 2020, the mean (95% CI) FEV 1 % predicted was 1.3 (0.1, 2.4)% predicted higher in 2020 for children 6-<12 years of age, and 7.5 (7.1, 7.9)% predicted higher in 2020 among pwCF 12 years of age eligible for the highly effective CFTR modulator, elexacaftor-tezacaftor-ivacaftor (ETI).There was no difference in FEV 1 % predicted for pwCF 12 years of age who were not eligible for ETI. Similarly, the mean (95% CI) BMI percentile was 2.4 (2.0, 2.8) higher in 2020 for children 6-<12 years of age, and 5.2 (4.8, 5.7) higher in 2020 among children 12-<18 years of age eligible for ETI. Mean (95% CI) BMI (kg/m 2 ) was 1.2 (1.2, 1.3) higher for pwCF 18 years of age eligible for ETI, and 0.2 (0.1, 0.3) higher for pwCF 18 years of age not eligible for ETI. The proportion of in-person clinic visits where any PEx was present was lower in 2020 compared with 2019, 25% as compared to 38%, RR 0.82 (0.79, 0.86).