Table 1

Characteristics of the EPIC-PANACEA Cohort
EPIC-PANACEA centersa Total baseline population n Mean age yrs (SD) Mean follow-up time yrs (SD) Method of contacting for 2nd assessment Not (yet) contacted n (%) Death n (%) (E) migrated n (%) 2nd assessment missingbn (%) Nonresponsec n (%)
Heidelberg (GE) 24,954 51.0 (8.1) 2.1 (0.6) P 0 129 (0.5) na 1,771 (7.1) 1,642 (6.6)
Spain 40,418 49.3 (8.0) 3.3 (0.4) T 0 202 (0.5) na 703 (1.7) 501 (1.2)
France 71,910 52.9 (6.7) 3.4 (0.8) P 0 382 (0.5) na 4,544 (6.3) 4,162 (5.8)
Cambridge (UK) 24,818 59.3 (9.3) 3.7 (0.7) C 0 637 (2.6) 0 10,199 (41.1) 9,562 (39.5)
Utrecht (NL) 16,869 57.7 (6.0) 4.4 (0.8) P 0 225 (1.3) 859 (5.1) 4,723 (28.0) 3,639 (23.1)
Malmo (SW) 27,463 58.1 (7.6) 4.9 (0.5) P 0 776 (2.8) na 5,832 (21.2) 5,056 (18.9)
Doetinchem (NL) 7,139 44.0 (11.8) 5.0 (0.2) C 1,101 (15.5) 68 (1.0) 80 (1.1) 2,584 (36.2) 1332 (22.6)
Denmark 55,753 56.7 (4.4) 5.3 (0.3) P 0 1,610 (2.9) 317 (0.6) 11,594 (20.8) 9,667 (18.0)
Oxford (UK) Health Conscious 47,208 44.5 (14.5) 5.3 (0.5) P 0 827 (1.8) 393 (0.8) 17,188 (36.4) 15,968 (34.7)
Oxford (UK) General Health 7,221 53.1 (7.9) 5.6 (0.6) P 0 138 (1.9) 29 (0.4) 1,945 (26.9) 1,778 (25.2)
Norway 35,829 48.2 (4.3) 6.2 (0.5) P 0 375 (1.0) 157 (0.4) 9,491 (26.5) 8,959 (25.4)
Amsterdam/Maastricht (NL) 14,920 42.3 (10.9) 6.2 (1.1) P 0 163 (1.1) 533 (3.6) 5,483 (36.7) 4,787 (33.7)
Greece 25,997 53.2 (12.6) 7.7 (2.1) T 0 590 (2.3) na 1,832 (5.3) 792 (3.1)
Potsdam (GE) 26,891 50.5 (9.0) 8.5 (0.9) P 4,282 (15.9) 827 (3.1) na 8,528 (31.7) 3,419 (15.7)
Naples (IT) 4,947 50.3 (7.7) 8.7 (1.2) P 4,271 (86.3) 1 (0.0) 0 4356 (88.1) 84 (12.4)
Florence (IT) 13,089 51.6 (7.7) 9.3 (1,1) P 0 230 (1.8) 108 (0.8) 2,883 (22.0) 2,545 (20.0)
Umea (SW) 25,048 46.1 (10.3) 9.9 (0.3) P 0 759 (3.0) 1012 (4.0) 11,501 (45.9) 9,730 (41.8)
Varese (IT) 11,797 51.6 (8.2) 11.1 (1.1) P/T 0 287 (2.4) 209 (1.8) 1,749 (14.8) 1,253 (11.1)
Ragusa (IT)d 5,949 47.3 (7.6) - - 5,949 (100) - - 5,949 (100) -
Turin (IT)d 9,749 50.2 (7.7) - - 9,749 (100) - - 9,749 (100) -
Total 497,969 51.5 (9.9) 5.3 (2.4) 25,355 (5.1) 8,226 (1.7) 3,697 (0.7) 122,154 (24.5) 84,876 (18.4)

Abbreviation: yrs - years, SD ā€“ standard deviation, na - no information available, C - 2nd assessment at study center; P - 2nd assessment by postal survey; T - 2nd assessment by telephone interview.

a Multiple centers within a country were treated as a single study center, when length of follow-up and data collection methods did not differ and when coordination took place out of one center (Spain, France, Denmark). In Norway and Greece only one research center was situated.

b Percentage corresponds to the overall response rates calculated according to the standard definitions used by the American Association for Public Opinion Research (AAPOR) [20].

c For calculation of the proportion non-response, baseline participants who were not (yet) approached, died or emigrated before the second assessment were excluded (nā€‰=ā€‰37,278).

d Ragusa and Turin did not contact any of their participants for a second assessment yet.

May et al.

May et al. BMC Medical Research Methodology 2012 12:148   doi:10.1186/1471-2288-12-148

Open Data