Table 1 General Characteristics of Participants in Study I and Study II (matched 1:4).
Characteristics | Study I (n = 11,630) | Study II (n = 11,400) | ||
|---|---|---|---|---|
Tonsillectomy group (n, %) | Control I group (n, %) | Tonsillectomy group (n, %) | Control II group (n, %) | |
Age (years old) | ||||
0–4 | 283 (12.2) | 1,132 (12.2) | 278 (12.2) | 1,112 (12.2) |
5–9 | 1,553 (66.8) | 6,212 (66.8) | 1,518 (66.6) | 6,072 (66.6) |
10–14 | 490 (21.1) | 1,960 (21.1) | 484 (21.2) | 1,936 (21.2) |
Sex | ||||
Male | 1,452 (62.4) | 5,808 (62.4) | 1,424 (62.5) | 5,696 (62.5) |
Female | 874 (37.6) | 3,496 (37.6) | 856 (37.5) | 3,424 (37.5) |
Income | ||||
1 (lowest) | 7 (0.3) | 28 (0.3) | 7 (0.3) | 28 (0.3) |
2 | 83 (3.6) | 332 (3.6) | 81 (3.6) | 324 (3.6) |
3 | 93 (4.0) | 372 (4.0) | 87 (3.8) | 348 (3.8) |
4 | 104 (4.5) | 416 (4.5) | 99 (4.3) | 396 (4.3) |
5 | 130 (5.6) | 520 (5.6) | 126 (5.5) | 504 (5.5) |
6 | 179 (7.7) | 716 (7.7) | 177 (7.8) | 708 (7.8) |
7 | 246 (10.6) | 984 (10.6) | 241 (10.6) | 964 (10.6) |
8 | 313 (13.5) | 1,252 (13.5) | 306 (13.4) | 1,224 (13.4) |
9 | 427 (18.4) | 1,708 (18.4) | 420 (18.4) | 1,680 (18.4) |
10 | 402 (17.3) | 1,608 (17.3) | 399 (17.5) | 1,596 (17.5) |
11 (highest) | 342 (14.7) | 1,368 (14.7) | 337 (14.8) | 1,348 (14.8) |
Region | ||||
Urban | 992 (42.6) | 3,968 (42.6) | 965 (42.3) | 3,860 (42.3) |
Rural | 1,334 (57.4) | 5,336 (57.4) | 1,315 (57.7) | 5,260 (57.7) |
