Table 2 Risk factor analysis of multiple episodes of malaria in western Thailand
Characteristics | Total | Not infected | Single episode | Multiple episodes | Odds ratioa (95% CI) |
|---|---|---|---|---|---|
N | n (%) | n (%) | n (%) | ||
Sex | |||||
 Female | 3908 | 3739 (95.7) | 145 (3.7) | 24 (0.6) | 1 |
 Male | 3904 | 3663 (93.8) | 198 (5.1) | 43 (1.1) | 1.46 (1.19–1.78) |
Age groups | |||||
 < 5 | 1755 | 1657 (94.4) | 82 (4.7) | 16 (0.9) | 1 |
 6–10 | 1051 | 953 (90.7) | 80 (7.6) | 18 (1.7) | 1.74 (1.30–2.33) |
 11–20 | 1705 | 1610 (94.4) | 79 (4.7) | 16 (0.9) | 1.00 (0.75–1.33) |
 21–60 | 2963 | 2849 (96.1) | 97 (3.3) | 17 (0.6) | 0.68 (0.51–0.89) |
 > 60 | 328 | 323 (98.5) | 5 (1.5) | 0 (0.0) | 0.26 (0.11–0.65) |
Ethnic groups | |||||
 Thai | 1083 | 1034 (95.5) | 47 (4.3) | 2 (0.2) | 1 |
 Karen | 5703 | 5355 (93.9) | 284 (5.0) | 64 (1.1) | 1.38 (1.02–1.88) |
 Other | 51 | 50 (98.0) | 1 (2.0) | 0 (0.0) | 0.42 (0.06–3.13) |
Education attainment | |||||
 Illiterate | 4280 | 4035 (94.3) | 205 (4.8) | 40 (0.9) | 1 |
 Primary | 1700 | 1580 (92.9) | 98 (5.8) | 22 (1.3) | 1.25 (0.99–1.57) |
 Secondary | 824 | 793 (96.2) | 28 (3.4) | 3 (0.4) | 0.64 (0.44–0.94) |
 College | 19 | 18 (94.7) | 0 (0.0) | 1 (5.3) | 0.96 (0.13–7.23) |
Occupational risk | |||||
 Low risk work | 742 | 728 (98.1) | 13 (1.8) | 1 (0.1) | 1 |
 Child/student | 3632 | 3376 (92.9) | 210 (5.8) | 46 (1.3) | 3.95 (2.30–6.81) |
 Factory laborers | 393 | 367 (93.4) | 21 (5.3) | 5 (1.3) | 3.70 (1.91–7.16) |
 Plantation workers | 1187 | 1143 (96.3) | 38 (3.2) | 6 (0.5) | 2.00 (1.09–3.68) |
 High risk work | 55 | 53 (96.4) | 2 (3.6) | 0 (0.0) | 1.95 (0.43–8.82) |
 Unspecified | 820 | 765 (93.2) | 47 (5.8) | 8 (1.0) | 3.74 (2.06–6.78) |
Having other infected person in the same HHb | |||||
 No | 333 | – | 290 (87.1) | 43 (12.9) | 1 |
 Yes | 77 | – | 53 (66.8) | 24 (31.2) | 3.05 (1.71–5.45) |