Table 2.

Response rates for the surveys.

Cystic fibrosis center	Clinical trial participants			Survey 1			Survey 2			Survey 3
	Number of recruited participants	Number of dropouts	Number of participants who completed the survey, n (%)		Number of answers	Users, %		Number of answers	Estimated usersa, %		Number of answers	Users, %
Rotterdam	17	2	15 (88.2)		53b	93.0b		46b	80.7-90.2b		37b	72.5b
Leuven	40	4	36 (90.0)		—b	—b		—b	—b		—b	—b
Valencia	25	0	25 (100.0)		46c	80.7c		36c	63.2-65.5c		20c	36.4c
Madrid	32	2	30 (93.8)		—c	—c		—c	—c		—c	—c
Milan	26	6	20 (76.9)		19	73.1		17	65.4-85.0		12	60.0
Lisbon	31	3	28 (90.3)		24	77.4		21	67.7-75.0		15	53.6
Total	171	17	154 (90)		142	83.0		120	70.2-77.9		84	54.5

^aSome dropouts answered survey 2. The rate pertains to recruited users and users who completed the survey.

^bData from Rotterdam and Leuven are merged (language: Dutch).

^cData from Valencia and Madrid are merged (language: Spanish).