Variable | Total cases | p Value | OR (1) (95% CI) | ||||
---|---|---|---|---|---|---|---|
Number | % | ||||||
Head immersion4-150 | |||||||
Non-swimmers | 214 | 6.1 | 1 | ||||
Yes | 1261 | 7.4 | 0.96 (0.51, 1.8) | ||||
No | 328 | 9.1 | 0.38 | 1.44 (0.72, 2.87) | |||
Seabathing | |||||||
No | 214 | 6.1 | 1 | ||||
<15 min | 558 | 7.0 | 1.03 (0.53, 1.99) | ||||
15–30 min | 506 | 6.9 | 1.01 (0.51, 2.00) | ||||
>30 min | 527 | 9.3 | 1.23 (0.62, 2.45) | ||||
Trend in swimmers | 0.16 | (p=0.456) | |||||
Total coliforms (CFU/100 ml)4-151 | |||||||
Non-swimmers | 214 | 6.1 | 1 | ||||
0–499 | 859 | 5.6 | 0.78 (0.41, 1.50) | ||||
500–2499 | 500 | 9.2 | 1.40 (0.71, 2.73) | ||||
2500–9999 | 132 | 15.2 | 2.57 (1.19, 5.57) | ||||
⩾10 000 | 33 | 6.1 | 0.74 (0.15, 3.66) | ||||
Trend in swimmers | 0.00014-160 | (p=0.000144-160) | |||||
Faecal coliforms (CFU/100 ml)4-152 | |||||||
Non-swimmers | 214 | 6.1 | 1 | ||||
0–99 | 649 | 6.3 | 0.88 (0.45, 1.71) | ||||
100–499 | 510 | 7.5 | 1.04 (0.53, 2.06) | ||||
⩾500 | 415 | 10.1 | 1.58 (0.8, 3.12) | ||||
Trend in swimmers | 0.0264-150 | (p=0.0174-150) | |||||
Faecal streptococci (CFU/100 ml)4-154 | |||||||
Non-swimmers | 214 | 6.1 | 1 | ||||
0–39 | 641 | 7.2 | 0.95 (0.49, 1.84) | ||||
40–119 | 382 | 6.3 | 0.94 (0.46, 1.91) | ||||
120–500 | 358 | 9.2 | 1.39 (0.69, 2.79) | ||||
>500 | 177 | 11.3 | 1.72 (0.77, 3.84) | ||||
Trend in swimmers | 0.096 | (p=0.0434-150) | |||||
Staphylococcus aureus (CFU/100 ml) | |||||||
Non-swimmers | 214 | 6.1 | 1 | ||||
0 | 108 | 6.5 | 0.67 (0.25, 1.82) | ||||
1–99 | 402 | 6.7 | 0.87 (0.43, 1.77) | ||||
100–249 | 537 | 10.2 | 1.50 (0.78, 2.87) | ||||
⩾250 | 544 | 6.2 | 0.9 (0.45, 1.77) | ||||
Trend in swimmers | 0.9 | (p=0.49) | |||||
Pseudomonas aeruginosa (CFU/100 ml) | |||||||
Non-swimmers | 214 | 6.1 | 1 | ||||
No | 1100 | 7.3 | 1.00 (0.54, 1.88) | ||||
Yes | 491 | 8.8 | 0.4 | 1.29 (0.65, 2.55 | |||
Floating matter | |||||||
Non-swimmers | 214 | 6.1 | 1 | ||||
No | 1204 | 7.7 | 1.13 (0.61, 2.10) | ||||
Yes | 387 | 7.8 | 0.69 | 0.80 (0.38, 1.71) | |||
Foam | |||||||
Non-swimmers | 214 | 6.1 | 1 | ||||
No | 1276 | 8.1 | 1.12 (0.61, 2.09) | ||||
Yes | 315 | 6.3 | 0.4 | 0.81 (0.38, 1.73) |
(1) Adjusted for sex, age, personal history of allergy, beach, eating on beach, eating on restaurant, sun exposure, sun protector, and use of sunglasses.
↵4-150 Missing data: 2.
↵4-151 Missing data: 67.
↵4-152 Missing data: 17.
↵4-154 Missing organism exposure data in 33 cases. *p values below 0.05.
↵4-160 p values below 0.01.