Internet-based data inclusion in a population-based European collaborative follow-up study of inflammatory bowel disease patients: Description of methods used and analysis of factors influencing response rates

Table 1 Cumulative number of IBD (CD+UC) patients per center followed-up or lost to follow-up for ePQ and ePpPFU. Centers indicated in gray had not reached the 60% response rate threshold

Center	Total number of CD+ CU patients	EPQ response (%)	EPQ response without deaths and No IBD %	Reason for non response EPQ					PpPFU response (%)	PpPFU response without No IBD %	Reason for non response PpPFU				EPQ ànd PpPFU (%)
				Not willing	Untrace- able	No IBD	Death	Not started			Not willing	Untrace- able	No IBD	Not started
Beer Sheeva	60	41 (68)	76	5	8	3	3	0	46 (77)	77	3	11	0	0	42 (70)
Copenhagen	147	103 (70)	84	12	7	0	25	0	132 (90)	90	6	9	0	0	120 (82)
Cremona	51	35 (68)	76	4	7	0	5	0	43 (84)	84	1	7	0	0	40 (78)
Heraklion	62	38 (61)	68	2	13	0	5	4	49 (79)	79	3	17	0	0	40 (65)
Ioannina	43	36 (84)	88	2	3	0	2	0	39 (91)	91	0	4	0	0	38 (88)
Oslo	378	226 (60)	69	65	34	6	45	2	332 (88)	89	21	25	1	0	271 (72)
Reggio Emilia	84	61 (73)	79	4	12	0	7	0	69 (82)	82	5	11	0	0	68 (81)
S-Limburg	216	156 (72)	76	28	20	0	11	1	194 (90)	90	0	23	0	0	159 (74)
Vigo	100	73 (73)	77	4	18	0	5	0	81 (81)	81	3	16	0	0	77 (77)
SUBTOTAL	1 141	769 (67	75	126	122	9	108	7	985 (86)	86	42	123	1	0	855 (75)
Almada	21	11 (52)	58	1	7	0	2	0	12 (57)	57	0	9	0	0	11 (52)
Dublin	186	57 (30)	34	10	58	3	17	41	80 (43)	43	1	26	2	78	56 (30)
Firenze	115	48 (42)	42	0	0	0	0	67	39 (34)	34	0	4	0	72	36 (31)
Milano	42	19 (45)	58	1	6	0	9	7	0 (0)	0	0	0	0	42	0 (0)
SUBTOTAL	364	135 (37)	41	12	71	3	28	115	131 (36)	36	1	39	2	192	103 (28)
Total	1 505	904 (60)	67	138	193	12	136	122	1 116 (74)	74	43	162	3	192	958 (64)