Table 4

Frequency (percentage) and binary logistic regression estimates of crude and multivariable O.R. and associated 95% confidence intervals (95%CI).


Exposure
Symptoms





Cyanobacterial cell surface area1
None
Present
Crude models2
Multivariable3


n (%)
n (%)
O.R. (95%CI)
O.R. (95%CI)
Any symptom

Low
569 (70)
241 (30)
1
1

Intermediate
134 (74)
46 (26)
0.8 (0.6–1.2)
0.8 (0.6–1.3)

High
99 (67)
48 (33)
1.6 (1.0–2.7)
1.7 (1.0–2.9)
Ear symptoms

Low
895 (96)
33 (4)
1
1

Intermediate
199 (98)
4 (2)
0.6 (0.2–1.5)
0.5 (0.2–1.5)

High
159 (96)
7 (4)
1.9 (0.6–6.5)
2.0 (0.6–7.1)
Eye symptoms

Low
872 (94)
59 (6)
1
1

Intermediate
196 (95)
10 (5)
0.8 (0.4–1.8)
0.8 (0.4–1.9)

High
154 (95)
9 (6)
0.6 (0.2–1.6)
0.6 (0.3–1.7)
G-I symptoms

Low
871 (94)
57 (6)
1
1

Intermediate
199 (95)
10 (5)
0.9 (0.4–1.7)
0.9 (0.4–1.8)

High
158 (95)
8 (5)
0.9 (0.3–2.2)
0.9 (0.4–2.2)
Respiratory symptoms

Low
691 (86)
116 (14)
1
1

Intermediate
169 (88)
24 (12)
1.0 (0.6–1.6)
0.9 (0.6–1.6)

High
122 (82)
27 (18)
2.0 (1.1–3.7)
2.1 (1.1–4.0)
Cutaneous symptoms

Low
875 (95)
43 (5)
1
1

Intermediate
197 (96)
8 (4)
0.7 (0.3–1.7)
0.7 (0.3–1.8)

High
159 (96)
7 (4)
1.9 (0.9–4.3)
1.9 (0.9–4.4)
Fever

Low
938 (99)
10 (1)
1
1

Intermediate
208 (99)
3 (1)
1.5 (0.4–5.6)
1.8 (0.5–6.7)

High
165 (99)
2 (1)
2.0 (0.5–8.7)
1.8 (0.4–8.1)
Any symptom – after exclusion of subjects with recent (5 days prior to recruitment) exposure

Low
436 (67)
200 (31)
1
1

Intermediate
74 (69)
33 (31)
0.9 (0.6–1.5)
0.9 (0.6–1.5)

High
71 (69)
32 (31)
1.5 (0.8–2.9)
1.6 (0.8–3.2)

1: Low = <2.4 mm2/mL; intermediate = 2.4 - 12.0 mm2/mL; high = >12.0 mm2/mL

2: Adjusted for geographic region (QLD, NSW, Florida) as a design variable and clustered by household

3: Adjusted for geographic region (QLD, NSW, Florida), age-group, sex, smoking and reported prior history of asthma, hay fever or eczema, and clustered by household

Stewart et al. BMC Public Health 2006 6:93   doi:10.1186/1471-2458-6-93