Table A1.
Distribution of the item responses of the RPQ in the general population samples.
| Item | Response Category |
English | Italian | Dutch | Total |
|---|---|---|---|---|---|
| (N = 4646) | (N = 3549) | (N = 3564) | (N = 11,759) | ||
| Headaches | 0 | 2094 (45.1%) | 1399 (39.4%) | 1963 (55.1%) | 5456 (46.4%) |
| 1 | 764 (16.4%) | 625 (17.6%) | 381 (10.7%) | 1770 (15.1%) | |
| 2 | 1137 (24.5%) | 1033 (29.1%) | 736 (20.7%) | 2906 (24.7%) | |
| 3 | 499 (10.7%) | 442 (12.5%) | 360 (10.1%) | 1301 (11.1%) | |
| 4 | 152 (3.3%) | 50 (1.4%) | 124 (3.5%) | 326 (2.8%) | |
| Feeling of Dizziness | 0 | 2661 (57.3%) | 2200 (62.0%) | 2374 (66.6%) | 7235 (61.5%) |
| 1 | 741 (15.9%) | 553 (15.6%) | 445 (12.5%) | 1739 (14.8%) | |
| 2 | 792 (17.0%) | 540 (15.2%) | 487 (13.7%) | 1819 (15.5%) | |
| 3 | 356 (7.7%) | 211 (5.9%) | 203 (5.7%) | 770 (6.5%) | |
| 4 | 96 (2.1%) | 45 (1.3%) | 55 (1.5%) | 196 (1.7%) | |
| Nausea and/or Vomiting | 0 | 3145 (67.7%) | 2174 (61.3%) | 2715 (76.2%) | 8034 (68.3%) |
| 1 | 766 (16.5%) | 746 (21.0%) | 397 (11.1%) | 1909 (16.2%) | |
| 2 | 481 (10.4%) | 470 (13.2%) | 278 (7.8%) | 1229 (10.5%) | |
| 3 | 176 (3.8%) | 137 (3.9%) | 131 (3.7%) | 444 (3.8%) | |
| 4 | 78 (1.7%) | 22 (0.6%) | 43 (1.2%) | 143 (1.2%) | |
| Noise Sensitivity, easily upset by loud noise |
0 | 3012 (64.8%) | 2114 (59.6%) | 2450 (68.7%) | 7576 (64.4%) |
| 1 | 611 (13.2%) | 587 (16.5%) | 387 (10.9%) | 1585 (13.5%) | |
| 2 | 569 (12.2%) | 536 (15.1%) | 398 (11.2%) | 1503 (12.8%) | |
| 3 | 308 (6.6%) | 247 (7.0%) | 243 (6.8%) | 798 (6.8%) | |
| 4 | 146 (3.1%) | 65 (1.8%) | 86 (2.4%) | 297 (2.5%) | |
| Sleep Disturbance | 0 | 1830 (39.4%) | 1582 (44.6%) | 1682 (47.2%) | 5094 (43.3%) |
| 1 | 634 (13.6%) | 585 (16.5%) | 455 (12.8%) | 1674 (14.2%) | |
| 2 | 1050 (22.6%) | 828 (23.3%) | 753 (21.1%) | 2631 (22.4%) | |
| 3 | 686 (14.8%) | 412 (11.6%) | 422 (11.8%) | 1520 (12.9%) | |
| 4 | 446 (9.6%) | 142 (4.0%) | 252 (7.1%) | 840 (7.1%) | |
| Fatigue, tiring more easily | 0 | 1529 (32.9%) | 1176 (33.1%) | 1392 (39.1%) | 4097 (34.8%) |
| 1 | 674 (14.5%) | 665 (18.7%) | 450 (12.6%) | 1789 (15.2%) | |
| 2 | 1132 (24.4%) | 953 (26.9%) | 818 (23.0%) | 2903 (24.7%) | |
| 3 | 792 (17.0%) | 594 (16.7%) | 581 (16.3%) | 1967 (16.7%) | |
| 4 | 519 (11.2%) | 161 (4.5%) | 323 (9.1%) | 1003 (8.5%) | |
| Being Irritable, easily angered | 0 | 1902 (40.9%) | 1222 (34.4%) | 1797 (50.4%) | 4921 (41.8%) |
| 1 | 822 (17.7%) | 764 (21.5%) | 617 (17.3%) | 2203 (18.7%) | |
| 2 | 1004 (21.6%) | 913 (25.7%) | 654 (18.4%) | 2571 (21.9%) | |
| 3 | 593 (12.8%) | 504 (14.2%) | 364 (10.2%) | 1461 (12.4%) | |
| 4 | 325 (7.0%) | 146 (4.1%) | 132 (3.7%) | 603 (5.1%) | |
| Feeling Depressed or Tearful | 0 | 2050 (44.1%) | 1593 (44.9%) | 2161 (60.6%) | 5804 (49.4%) |
| 1 | 703 (15.1%) | 677 (19.1%) | 519 (14.6%) | 1899 (16.1%) | |
| 2 | 846 (18.2%) | 706 (19.9%) | 460 (12.9%) | 2012 (17.1%) | |
| 3 | 620 (13.3%) | 397 (11.2%) | 312 (8.8%) | 1329 (11.3%) | |
| 4 | 427 (9.2%) | 176 (5.0%) | 112 (3.1%) | 715 (6.1%) | |
| Feeling Frustrated or Impatient | 0 | 1825 (39.3%) | 1483 (41.8%) | 1838 (51.6%) | 5146 (43.8%) |
| 1 | 817 (17.6%) | 721 (20.3%) | 587 (16.5%) | 2125 (18.1%) | |
| 2 | 1018 (21.9%) | 791 (22.3%) | 640 (18.0%) | 2449 (20.8%) | |
| 3 | 606 (13.0%) | 423 (11.9%) | 375 (10.5%) | 1404 (11.9%) | |
| 4 | 380 (8.2%) | 131 (3.7%) | 124 (3.5%) | 635 (5.4%) | |
| Forgetfulness, poor memory | 0 | 2302 (49.5%) | 1810 (51.0%) | 2074 (58.2%) | 6186 (52.6%) |
| 1 | 893 (19.2%) | 742 (20.9%) | 518 (14.5%) | 2153 (18.3%) | |
| 2 | 813 (17.5%) | 688 (19.4%) | 636 (17.8%) | 2137 (18.2%) | |
| 3 | 432 (9.3%) | 249 (7.0%) | 245 (6.9%) | 926 (7.9%) | |
| 4 | 206 (4.4%) | 60 (1.7%) | 91 (2.6%) | 357 (3.0%) | |
| Poor Concentration | 0 | 2248 (48.4%) | 1656 (46.7%) | 2004 (56.2%) | 5908 (50.2%) |
| 1 | 888 (19.1%) | 823 (23.2%) | 561 (15.7%) | 2272 (19.3%) | |
| 2 | 866 (18.6%) | 761 (21.4%) | 605 (17.0%) | 2232 (19.0%) | |
| 3 | 425 (9.1%) | 248 (7.0%) | 286 (8.0%) | 959 (8.2%) | |
| 4 | 219 (4.7%) | 61 (1.7%) | 108 (3.0%) | 388 (3.3%) | |
| Taking Longer to Think | 0 | 2348 (50.5%) | 2042 (57.5%) | 2040 (57.2%) | 6430 (54.7%) |
| 1 | 864 (18.6%) | 711 (20.0%) | 537 (15.1%) | 2112 (18.0%) | |
| 2 | 831 (17.9%) | 571 (16.1%) | 607 (17.0%) | 2009 (17.1%) | |
| 3 | 414 (8.9%) | 177 (5.0%) | 293 (8.2%) | 884 (7.5%) | |
| 4 | 189 (4.1%) | 48 (1.4%) | 87 (2.4%) | 324 (2.8%) | |
| Blurred Vision | 0 | 2948 (63.5%) | 2149 (60.6%) | 2444 (68.6%) | 7541 (64.1%) |
| 1 | 759 (16.3%) | 670 (18.9%) | 466 (13.1%) | 1895 (16.1%) | |
| 2 | 587 (12.6%) | 518 (14.6%) | 418 (11.7%) | 1523 (13.0%) | |
| 3 | 249 (5.4%) | 175 (4.9%) | 166 (4.7%) | 590 (5.0%) | |
| 4 | 103 (2.2%) | 37 (1.0%) | 70 (2.0%) | 210 (1.8%) | |
| Light Sensitivity, easily upset by bright light | 0 | 3110 (66.9%) | 2088 (58.8%) | 2484 (69.7%) | 7682 (65.3%) |
| 1 | 664 (14.3%) | 632 (17.8%) | 476 (13.4%) | 1772 (15.1%) | |
| 2 | 525 (11.3%) | 556 (15.7%) | 356 (10.0%) | 1437 (12.2%) | |
| 3 | 227 (4.9%) | 215 (6.1%) | 176 (4.9%) | 618 (5.3%) | |
| 4 | 120 (2.6%) | 58 (1.6%) | 72 (2.0%) | 250 (2.1%) | |
| Double Vision | 0 | 3559 (76.6%) | 2688 (75.7%) | 2806 (78.7%) | 9053 (77.0%) |
| 1 | 592 (12.7%) | 472 (13.3%) | 394 (11.1%) | 1458 (12.4%) | |
| 2 | 310 (6.7%) | 268 (7.6%) | 218 (6.1%) | 796 (6.8%) | |
| 3 | 121 (2.6%) | 96 (2.7%) | 88 (2.5%) | 305 (2.6%) | |
| 4 | 64 (1.4%) | 25 (0.7%) | 58 (1.6%) | 147 (1.3%) | |
| Restlessness | 0 | 2337 (50.3%) | 1782 (50.2%) | 2077 (58.3%) | 6196 (52.7%) |
| 1 | 714 (15.4%) | 739 (20.8%) | 493 (13.8%) | 1946 (16.5%) | |
| 2 | 917 (19.7%) | 743 (20.9%) | 628 (17.6%) | 2288 (19.5%) | |
| 3 | 439 (9.4%) | 223 (6.3%) | 263 (7.4%) | 925 (7.9%) | |
| 4 | 239 (5.1%) | 62 (1.7%) | 103 (2.9%) | 404 (3.4%) |
Note: N: absolute frequencies, %: relative frequencies, 0: not experienced at all, 1: no more of a problem (than before), 2: a mild problem, 3: a moderate problem, 4: a severe problem.