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 14

Analogy. Odds ratio (OR) and 95% confidence interval (CI) for glioblastoma multiforme for occupational exposure to ELF-EMF in time windows; 1–14 years and 15+ years before diagnosis. Unconditional logistic regression, adjusted for age at diagnosis, gender, socioeconomic index (SEI), and year of diagnosis. Exposure the year before diagnosis was excluded (“1-year lag”). Numbers of exposed cases (Ca) and controls (Co) are given [66].

Cumulative exposure (µT-years)Glioblastoma multiforme ()
Ca/CoOR95% CI

1–14 years’ time window
 <0.91106/7701.00
 0.91–<1.42138/8721.280.96–1.70
 1.42–<1.82187/7781.791.36–2.35
 1.82–<2.75129/5371.811.35–2.43
 2.75+89/3291.881.35–2.62
p, linear trend<0.001
15+ years’ time window
 <1.44119/7821.00
 1.44–<2.55154/7771.050.80–1.39
 2.55–<4.17173/7870.990.74–1.32
 4.17–<6.59126/4710.930.66–1.30
 6.59+88/3130.910.62–1.32
p, linear trend0.44