Table 1.
Demographic characteristics of sample set
| 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2009–2012 | 2013–2014 | Total | |
|---|---|---|---|---|---|---|---|---|---|
| No. of samples (n, %) | 109 (5.6) | 195 (10.0) | 222 (11.3) | 417 (21.3) | 447 (22.8) | 567 (29.0) | 943 (48.2) | 1014 (51.8) | 1957a |
| No. of patients | 109 | 195 | 222 | 417 | 447 | 567 | 943 | 967 | 1909b |
| Gender (n, %) | |||||||||
| Male | 59 (54.1) | 107 (54.9) | 114 (51.4) | 221 (53.0) | 251 (56.2) | 287 (50.6) | 501 (53.1) | 538 (53.2) | 1039 (53.1) |
| Female | 50 (45.9) | 88 (45.1) | 108 (48.6) | 196 (47.0) | 196 (43.8) | 280 (49.4) | 442 (46.9) | 476 (47.8) | 918 (46.9) |
| Agec (years) | 7.0 (3.0, 10.0) | 9.0 (4.0, 11.0) | 10.0 (7.0, 13.0) | 11.0 (8.0, 14.0) | 12.0 (8.0, 14.0) | 11.0 (7.0, 13.0) | 10.0 (6.0, 13.0) | 11.0 (7.0, 14.0) | 11.0 (7.0, 13.0) |
| Age groups (years) (n, %) | |||||||||
| 0–2 | 20 (18.4) | 30 (15.2) | 16 (7.2) | 15 (3.6) | 12 (2.7) | 33 (5.8) | 81 (8.6) | 45 (4.4) | 126 (6.4) |
| 0–12 months | 7 (6.4) | 9 (4.6) | 2 (0.9) | 2 (0.5) | 0 (0.0) | 4 (0.7) | 20 (2.1) | 4 (0.4) | 24 (1.2) |
| > 12–24 months | 13 (12.0) | 21 (10.8) | 14 (6.3) | 13 (3.1) | 12 (2.7) | 29 (5.1) | 61 (6.5) | 41 (4.0) | 102 (5.21) |
| 3–6 | 31 (28.4) | 51 (26.2) | 39 (17.6) | 55 (13.2) | 64 (14.3) | 87 (15.3) | 176 (18.7) | 151 (14.9) | 327 (16.7) |
| 7–10 | 33 (30.3) | 55 (28.2) | 64 (28.8) | 123 (29.5) | 88 (19.7) | 157 (27.7) | 275 (29.2) | 245 (24.2) | 520 (26.6) |
| 11–13 | 15 (13.8) | 35 (18.0) | 66 (29.7) | 101 (24.2) | 150 (33.6) | 161 (28.4) | 217 (23.0) | 311 (30.7) | 528 (27.0) |
| 14–17 | 10 (9.2) | 24 (12.3) | 37 (16.7) | 123 (29.5) | 133 (29.8) | 129 (22.8) | 194 (20.6) | 262 (25.8) | 456 (23.3) |
| Seasond (n, %) | |||||||||
| Spring | 21 (19.2) | 75 (38.4) | 48 (21.6) | 127 (30.5) | 118 (26.4) | 209 (36.9) | 271 (28.7) | 327 (32.2) | 598 (30.6) |
| Summer | 39 (35.8) | 25 (12.8) | 43 (19.4) | 91 (21.8) | 143 (32.0) | 116 (20.5) | 198 (21.0) | 259 (25.6) | 457 (23.4) |
| Fall | 26 (23.9) | 60 (30.8) | 64 (28.8) | 123 (29.5) | 103 (23.0) | 116 (20.5) | 273 (29.0) | 219 (21.6) | 492 (25.0) |
| Winter | 23 (21.1) | 35 (18.0) | 67 (30.2) | 76 (18.2) | 83 (18.6) | 126 (22.1) | 201 (21.3) | 209 (20.6) | 410 (21.0) |
a, bDifference between total number of patients and total number of samples: 24 patients provided a blood sample in 2013 as well as in 2014
cMedian (interquartile range)
dSeasons were classified into spring (March–May), summer (June–August), fall (September–November) and winter (December–February)