International Journal of Family Medicine / 2014 / Article / Tab 3

Research Article

The Danish Symptom Cohort: Questionnaire and Feasibility in the Nationwide Study on Symptom Experience and Healthcare-Seeking among 100 000 Individuals

Table 3

Results from the four waves.

Wave 1Wave 2Wave 3Wave 4Total

Invited for participation 25 000 25 000 25 000 25 000 100 000
Men (%)12 203  (48.8) 12 180  (48.7)12 348  (49.4) 12 179  (48.7)48 910  (48.9)
Women (%)12 797  (51.2)12 820  (51.3)12 652  (50.6) 12 821  (51.3)51 090  (51.1)

Dead (%) 25 (0.1)78 (0.3)85 (0.3)127 (0.5)315 (0.3)
Addresses unknown (%) 247 (1.0)252 (1.0)236 (0.9)226 (0.9)961 (1.0)
Suffering from severe illness (including dementia) (%) 556 (2.2)480 (1.9)468 (1.9)468 (1.9)1 972 (2.0)
Language problems (%) 233 (0.9)228 (0.9)195 (0.8)229 (0.9)885 (0.8)
Moved abroad (%) 53 (0.2)172 (0.7)188 (0.8)201 (0.8)614 (0.6)
Excluded (% of invited) 1 114  (4.5)1 210  (4.8)1 172  (4.7)1 251  (5.0)4 747  (4.7)

Eligible for the study (% of invited) 23 886  (95.5)23 790  (95.2)23 828  (95.3)23 749  (95.0)95 253  (95.3)
Respondents (%) 12 361  (51.7)12 763  (53.6)12 298  (51.6)12 284  (51.7)49 706  (52.2)
Men (%) 5 718 (46.3) 5 911 (46.3) 5 815 (47.3) 5 796 (47.2) 23 240 (46.8)
Women (%)6 643 (53.7)6 852 (53.7)6 483 (52.7)6 488 (52.8) 26 466 (53.3)
Median age (IQR)52 (40–64)52 (40–64)52 (40–64)52 (39–64)52 (40–64)

Completed by telephone interview (% of respondents) 342  (2.8)308  (2.4)286  (2.3)272  (2.2)1 208  (2.4)
Men (%) 129 (37.7)110 (35.7) 93 (32.5)106 (39.0) 438 (36.3)
Women (%)213 (62.3)198 (64.3)193 (67.5)166 (61.0)770 (63.7)
Median age (IQR)74 (67–79)74 (68–96)73 (68–80)74 (68–94)74 (68–96)

Completed after initial letter (% of respondents, cumulative) 6 437  (26.9)7 583  (31.9)7 559  (31.7)7 353  (31.0)28 932  (30.4)
Completed after reminder letter (% of respondents, cumulative) 3 925  (43.4)3 130  (45.0)2 713  (43.1)2 908  (43.2)12 676  (43.7)
Completed after telephone reminder (% of respondents, cumulative) 1 999  (51.7)2 050  (53.6)2 026  (51.6)2 023  (51.7)8 098  (52.2)

Nonrespondents (% of eligible) 11 525  (48.3)11 027  (46.4)11 530  (48.4)11 465  (48.3)45 547  (47.8)
Not wishing to participate (indicated by telephone/email or postal contact) (%)6 880 (28.8)6 287 (26.4)6 407 (26.9)6 116 (25.8)25 690 (27.0)
Indicated “other reasons” for nonparticipation (%)11 (0.04)85 (0.4)99 (0.4)123 (0.5)318 (0.3)
Nonrespondents (no achieved contact in the reminder procedure) (%)4 634 (19.4)4 655 (19.6)5 024 (21.1)5 226 (22.0)19 539 (20.5)