Christensen HC, Schuz J, Kosteljanetz M, Skovgaard Poulsen H, et al. (2005).
This was part of the INTERPHONE study, an international case-control research project into the association between cell phone use and tumours of the brain and salivary glands.
All cases of glioma and meningioma in Denmark were ascertained as they occurred between September 1, 2000, and August 31, 2002. Of 464 potential cases of glioma, 110 were excluded because they did not meet the inclusion criteria. A further 38 refused to participate, 32 died before interview, and 32 were excluded for medical reasons. This left 252 for face-to-face interview using a computerized personal questionnaire. For meningioma, 291 cases were identified, 238 met the inclusion criteria, and 175 participated in the interviews. Controls were sampled randomly from the Danish Central Population Register. Each case was matched with a control for age and sex, but in fact more controls than cases were interviewed (822).
Details of the tumours were obtained from medical records and medical imaging studies.
Details of the socioeconomic status of patients and controls were obtained anonymously. The information could be used to compare the groups, but could not be used for logistic regression analysis for individual subjects.
An attempt was made to obtain information from cell phone operators about phone use of the cases and controls but details were obtained for only 27 patients and 47 controls.
There were no significant differences in socioeconomic characteristics between cases and controls or between participants and non-participants. There was no increased risk for either glioma or meningioma in relation to no or any regular use of a cell phone, frequency of use, time since first use, or various expressions of cumulative use. All gliomas combined were not associated with regular use of cell phones (OR 0.71; 95% CI 0.50 to 1.01). The equivalent OR for meningioma was 0.83. There was no evidence of an association between use of a cell phone on a particular side of the head and the location of the tumour.