Demographic and travel characteristics according to route of vaccine administration
| Variable | Route; no. of travellers (% of category)* | Standardized difference (95% CI) | |
|---|---|---|---|
| Intradermal n = 941 | Intramuscular n = 780 | ||
| Age, mean ± SD; yr | 34.60 ± 15.15 | 37.18 ± 15.02 | −0.171 (−0.266 to −0.076) |
| Age, yr | −0.121 (−0.216 to −0.026) | ||
| < 18 | 60 (63.8) | 34 (36.2) | |
| 18–40 | 581 (55.6) | 463 (44.3) | |
| 41–60 | 246 (52.3) | 224 (47.6) | |
| > 60 | 54 (47.8) | 59 (52.2) | |
| Sex | −0.097 (−0.191 to −0.002) | ||
| Female | 535 (56.8) | 406 (43.1) | |
| Male | 406 (52.0) | 374 (47.9) | |
| Travel duration, mean ± SD; wk | 16.85 ± 19.70 | 16.44 ± 26.20 | 0.018 (−0.082 to 0.117) |
| Travel duration, wk | 0.153 (0.053 to 0.253) | ||
| ≤ 4 | 302 (50.2) | 300 (49.8) | |
| 5–12 | 208 (54.0) | 177 (46.0) | |
| 13–24 | 169 (66.8) | 84 (33.2) | |
| 25–52 | 156 (62.9) | 92 (37.1) | |
| > 52 | 32 (44.4) | 40 (55.6) | |
| Missing | 74 (7.9) | 87 (11.2) | |
| Continent | 0.274 (0.174 to 0.373) | ||
| Africa | 129 (47.1) | 145 (52.9) | |
| Americas | 145 (44.2) | 183 (55.8) | |
| Asia | 610 (62.2) | 371 (37.8) | |
| Europe | 6 (42.8) | 8 (57.1) | |
| Missing | 51 (5.4) | 73 (9.4) | |
| Reason for travel | −0.361 (−0.460 to −0.262) | ||
| Tourism | 696 (63.1) | 407 (36.9) | |
| Work/business | 40 (21.8) | 143 (78.1) | |
| Education/research | 38 (67.8) | 18 (32.1) | |
| Volunteer/aid work | 101 (39.6) | 154 (60.4) | |
| Visiting friends and relatives | 0 (0.0) | 2 (100.0) | |
| Missing | 66 (7.0) | 56 (7.2) | |
| No. of travellers in group | −0.166 (−0.264 to −0.067) | ||
| 1 | 212 (51.4) | 200 (48.5) | |
| 2 | 388 (61.0) | 248 (39.0) | |
| ≥ 3 | 285 (51.6) | 267 (48.4) | |
| Missing | 56 (6.0) | 65 (8.3) | |
Note: CI = confidence interval, SD = standard deviation.
↵* Except where noted otherwise.