Exhibit 1.

Inpatient admissions among patients with cystic fibrosis (CF) who filled a first prescription for ivacaftor, 2012–15

		Before filling prescription				After filling prescription
		With at least 1 admission		Admissions		With at least 1 admission		Admissions		Decrease from before to after
Age (years)	No.	No.	%	No.	Ratea	No.	%	No.	Ratea	% with admission	Ratea
ALL-CAUSE ADMISSIONS
6-64	143	44	31	82	0.57	20	14	37	0.26	55	55
6-17	53	18	34	32	0.60	7	13	13	0.25	61	59
18-64	90	26	29	50	0.56	13	14	24	0.27	50	52
ADMISSIONS RELATED TO CYSTIC FIBROSIS
6-64	143	23	16	42	0.29	5	4	8	0.06	78	81
6-17	53	10	19	17	0.32	2	4	3	0.06	80	82
18-64	90	13	14	25	0.28	3	3	5	0.06	77	80

SOURCE Authors’ analysis of data from the Truven Health Analytics MarketScan Commercial Research database.

NOTES Patients had diagnosis codes indicating cystic fibrosis (see text for details). Patients also had at least one filled ivacaftor prescription during the period February 2012–December 2015 and were continuously enrolled in employer-sponsored health plans for at least twelve months before and twelve months after filling that prescription. Age was the age in years at the time of the first filled prescription. Inpatient admissions during the twelve months before and twelve months after filling the first prescription were calculated for all causes and for those with a cystic fibrosis–related diagnosis code. All changes in proportions were significant (p < 0:01) according to results from McNemar’s one-tailed test of paired sample proportions using exact binomial probability calculations.

^aPer person per year.