Review Article

Evaluation of Mobile Phone and Cordless Phone Use and Glioma Risk Using the Bradford Hill Viewpoints from 1965 on Association or Causation

Table 6

Specificity. Estimated elevation in brain tumour risk (α) and 95% confidence interval (CI) in shortest distance group 0–55 mm compared to reference category ≥ 115.01 mm from preferred ear to tumour center. Based on Grell et al. [44].

Covariateα95% CI

Tumour size
≤18 cm31.961.51–3.66
>18 cm34.091.90–12.0
Duration of phone use
<6 years2.021.31–4.28
≥6 years3.271.92–11.3
Cumulative phone use
<200 hours1.571.29–3.36
≥200 hours4.062.03–11.6
Cumulative number of calls
<4,0001.551.25–3.42
≥4,0003.562.05–9.88