Table 2.
Estimated regression coefficients (robust standard error) derived from generalised estimating equation models used to assess effects of group, exposure, duration of exposure, and baseline score on symptom severity
| Symptom | Baseline severity | Duration (linear function) | Duration (quadratic function) | Sensitivev control | Shamv GSM | CWv GSM | Group x (shamv GSM) | Group x (CWv GSM) |
|---|---|---|---|---|---|---|---|---|
| Headache | 0.04 (0.008) | 0.04 (0.004) | −0.0004 (0.0004) | 0.7 (0.2) | 0.07 (0.1) | −0.02 (0.1) | −0.08 (0.2) | 0.2 (0.2) |
| Nausea | 0.02 (0.05) | 0.006 (0.001) | −0.0002 (0.00004) | 0.2 (0.3) | 0.06 (0.1) | −0.2 (0.1) | 0.1 (0.4) | 0.3 (0.3) |
| Fatigue | 0.04 (0.005) | 0.01 (0.002) | −0.0003 (0.00005) | 0.2 (0.2) | −0.08 (0.1) | −0.2 (0.1) | −0.09 (0.2) | 0.2 (0.2) |
| Dizziness | 0.05 (0.02) | 0.007 (0.001) | −0.0003 (0.00005) | 0.3 (0.2) | −0.2 (0.1) | −0.09 (0.1) | 0.2 (0.3) | −0.01 (0.3) |
| Skin | 0.05 (0.01) | 0.004 (0.001) | −0.0003 (0.00005) | 0.5 (0.2) | −0.09 (0.1) | −0.1 (0.1) | 0.1 (0.2) | 0.3 (0.2) |
| Burning | 0.03 (0.00005) | 0.007 (0.001) | −0.0007 (0.0004) | 0.4 (0.2) | −0.05 (0.1) | −0.09 (0.09) | 0.2 (0.2) | 0.4 (0.2) |
| Eye pain | 0.05 (0.008) | 0.007 (0.001) | −0.0003 (0.00004) | 0.6 (0.2) | −0.04 (0.1) | 0.2 (0.1) | −0.3 (0.2) | −0.08 (0.2) |
CW=continuous wave; GSM=global system for mobile communication.
In each model, the dependent variable used was log(symptom severity +1).