Longterm follow-up in European respiratory health studies – patterns and implications

BMC Pulmonary Medicine

Table 1 Response rates by study centres at baseline and follow-up stages ^a

Study center	Baseline	10-yrs follow-up	20-yrs follow-up
RHINE
Aarhus	3614 (85%)	2 589 (72%)	1959 (54%)
Bergen	3449 (82%)	2 506 (73%)	1833 (53%)
Gothenburg	2861 (83%)	2 175 (76%)	1496 (52%)
Reykjavik	2899 (84%)	1 967 (68%)	1572 (54%)
Tartu	2449 (85%)	1 705 (70%)	1066 (44%)
Umea	3273 (92%)	2 621 (80%)	1745 (53%)
Uppsala	3114 (89%)	2 543 (82%)	1770 (57%)
TOTAL	21 659 (86%)	16 106 (75%)	11 441 (53%)
Italian ECRHS
Verona	2711 (92%)	1737 (64%)	1338 (49%)
Pavia	816 (86%)	701 (86%)	-
Turin	2502 (84%)	1443 (58%)	-
TOTAL	6 029 (88%)	3 881 (64%)	1338 (49%)^b
ISAYA
Verona	2158 (74%)	1421 (66%)	-
Sassari	2053 (70%)	810 (39%)	-
TOTAL	4 211 (72%)	2 231 (53%)	-

^aSubjects who have answered one or more of the following questions at each of the relevant study stages: asthma, hay fever, wheeze. Baseline: 1989–92 in RHINE, 1991–93 in Italian ECRHS, 1998–2000 in ISAYA. 10-yrs follow-up: 1999–2000 in RHINE, 1998-2000 in Italian ECRHS, 2008–09 in ISAYA. 20-yrs follow-up: 2010–12 in RHINE, 2008–09 in Italian ECRHS.
Response rates are calculated based on those invited to baseline for baseline populations, and based on those participating in baseline for follow-up populations.
^bResponse rate for 20-yrs follow-up in Italian ECRHS is calculated based on original response rate in Verona.

ISSN: 1471-2466