Table 2.

Multivariate Linear Mixed Model Explaining Lung Function in Adults With CF

Term	Estimate	SE	df	t	P Value
Intercept	32.35	3.90	145.28	8.29	< .01
Quarter of y	0.15	0.27	418.88	0.56	.57
Male sex	–0.48	1.50	101.28	–0.32	.75
BMI	0.00	0.13	167.69	0.03	.98
Patient is taking ETI	4.31	0.84	474.48	5.16	< .01
Age group, y
25-34	–3.56	1.95	100.78	–1.82	.07
35-44	–1.62	2.34	102.22	–0.70	.49
45-54	2.32	2.68	103.68	0.87	.39
55+	2.57	3.25	104.78	0.79	.43
During PY	1.30	2.15	319.33	0.60	.55
FEV1 % predicted
40-69	24.67	2.30	103.63	10.71	< .01
70-89	49.68	2.32	106.84	21.40	< .01
> 90	66.31	2.66	106.87	24.92	< .01
All antibiotic episodes	0.42	0.38	492.93	1.13	.26
Exacerbations	–1.26	0.62	491.14	–2.04	.04
Age during PY, y
25-34	–0.96	1.53	228.47	–0.62	.53
35-44	0.12	1.76	233.08	0.07	.95
45-54	–2.62	2.07	225.44	–1.27	.21
55+	–1.77	2.39	225.30	–0.74	.46
FEV1 % predicted during PY
40-69	0.61	1.77	226.98	0.34	.73
70-89	0.65	1.82	234.66	0.36	.72
> 90	–1.33	2.09	235.90	–0.64	.52

Change in lung function explained by ETI use and controlling for other variables. A multivariate linear mixed model was created with the 110 analyzed patients explaining lung function using ETI use and controlling for the effects of time, sex, BMI, exacerbations, age group, year, lung function cohort, and the interaction between age group and year and between lung function cohort and year. A random slope over time was included for each participant. The effect of ETI on lung function after controlling for the effect of the pandemic and other variables was an increase in FEV₁ % predicted of 4.31% (t₄₇₄ = 5.16; P < .01). Lung function adjusted for ETI use and other variables revealed no significant difference in lung function between the PPY and PY, with a difference in FEV₁ % predicted of 1.30% during the PY (t₃₁₉ = 0.60; P = .55). CF = cystic fibrosis; df = degrees of freedom; ETI = elexacaftor/tezacaftor/ivacaftor; PPY = prepandemic year; PY = pandemic year.