Table 2.
Symptom | Symptom categories (N for unadjusted model/N for adjusted model) | Exposure | Exposure categories (N for unadjusted model/N for adjusted model) | Unadjusted OR (95% CI) for each exposure category | Adjusted OR (95% CI) for each exposure category | Confounders in model |
---|---|---|---|---|---|---|
Headache |
No, hardly ever (204/194) |
Cordless calls > 10 mins. made and rec’d weekly |
0 (64/59) |
1 |
1 |
Cold/flu*+ |
1 or 2 weekly (87/84) |
1-2 (104/103) |
1.27 (0.90-1.77) |
1.28 (0.90-1.83) |
Woken by phone+ |
||
3 or 4 weekly (25/24) |
3-9 (84/78) |
1.40 (0.98-1.98) |
1.35 (0.92-1.96) |
Light out time |
||
Most days (16/15) |
10-120 (80/77) |
1.76 (1.23-2.51)* |
1.41 (0.95-2.09) |
|||
Headache |
No, hardly ever (216/216) |
Minutes on cordless phone daily |
0-4 (148/148) |
1 |
1 |
Cold/flu**+ |
1 or 2 weekly (89/89) |
5-15 (104/104) |
0.83 (0.49-1.41) |
0.78 (0.45-1.32) |
|||
3 or more times weekly (43/43) |
16-240 (96/96) |
1.88 (1.14-3.12) |
1.74 (1.05-2.90) |
|||
Headache |
No, hardly ever (218/213) |
Cellphone calls >10 minutes weekly |
0 (277/271) |
1 |
1 |
Cold/flu**+ |
1 or 2 times weekly (91/91) |
1-6 (66/66) |
1.27 (0.95-1.69) |
1.14 (0.84-1.53) |
Woken by phone*+ |
||
3 or 4 times weekly (29/29) |
7-35 (12/12) |
2.37 (1.21-4.62) |
2.40 (1.19-4.83) |
|||
Most days (17/16) | ||||||
Headache |
No, hardly ever (-/215) |
Cellphone headset |
No (320) |
Model invalid |
1 |
Cold/flu**+ |
1 or 2 weekly (-/91) |
Wired (16) |
1.29 (0.71-2.36) |
Woken by phone |
|||
3 or more weekly (-/43) |
Wireless (13) |
2.23 (1.10-4.53) |
Light out time |
|||
Headache |
No, hardly ever (-/93) |
Cordless phone frequency |
Not exposed (-/28) |
Model invalid |
1 |
Cold/flu**+ |
1 or 2 weekly (-/38) |
≤ 900 MHz (-/19) |
1.04 (0.38-2.90) |
Woken by phone |
|||
3 or more weekly (-/14) |
1.8-1.9 GHz (-/27) |
1.42 (0.61-3.34) |
||||
2.4 GHz (-/53) |
0.74 (0.34-1.63) |
|||||
5.8 GHz (-/18) | 1.55 (0.61-3.96) |
Bold font Sig. p < 0.05; *Sig. p ≤ 0.01; **Sig. p ≤ 0.001; + positive association; ‘Model invalid’ means it did not meet the criteria outlined in the methods.