ID Number		2340
Study Type		Epidemiology
Model		Case-control study of acoustic neuroma in Sweden.
Details		AUTHORS' ABSTRACT: Pettersson, Feychting et al. 2014 (IEEE #5406): BACKGROUND: There is concern about potential effects of radiofrequency fields generated by mobile phones on cancer risk. Most previous studies have found no association between mobile phone use and acoustic neuroma, although information about long-term use is limited. METHODS: We conducted a population-based, nation-wide, case-control study of acoustic neuroma in Sweden. Eligible cases were persons aged 20 to 69 years, who were diagnosed between 2002 and 2007. Controls were randomly selected from the population registry, matched on age, sex, and residential area. Postal questionnaires were completed by 451 cases (83%) and 710 controls (65%). RESULTS: Ever having used mobile phones regularly (defined as weekly use for at least 6 months) was associated with an odds ratio (OR) of 1.18 (95% confidence interval = 0.88 to 1.59). The association was weaker for the longest induction time (e10 years) (1.11 [0.76 to 1.61]) and for regular use on the tumor side (0.98 [0.68 to 1.43]). The OR for the highest quartile of cumulative calling time (e680 hours) was 1.46 (0.98 to 2.17). Restricting analyses to histologically confirmed cases reduced all ORs; the OR for e680 hours was 1.14 (0.63 to 2.07). A similar pattern was seen for cordless land-line phones, although with slightly higher ORs. Analyses of the complete history of laterality of mobile phone revealed considerable bias in laterality analyses. CONCLUSIONS: The findings do not support the hypothesis that long-term mobile phone use increases the risk of acoustic neuroma. The study suggests that phone use might increase the likelihood that an acoustic neuroma case is detected and that there could be bias in the laterality analyses performed in previous studies. AUTHORS' ABSTRACT: Pettersson, Feychting et al. 2015 (IEEE #5851): The possible effect of radiofrequency exposure from mobile phones on tumor risk has been studied since the late 1990s. Yet, empirical information about recall of the start of mobile phone use among adult cases and controls has never been reported. Limited knowledge about recall errors hampers interpretations of the epidemiological evidence. We used network operator data to validate the self-reported start year of mobile phone use in a casecontrol study of mobile phone use and acoustic neuroma risk. The answers of 96 (29%) cases and 111 (22%) controls could be included in the validation. The larger proportion of cases reflects a more complete and detailed reporting of subscription history. Misclassification was substantial, with large random errors, small systematic errors, and no significant differences between cases and controls. The average difference between self-reported and operator start year was  0.62 (95% confidence interval:  1.42, 0.17) years for cases and  0.71 (1.50, 0.07) years for controls, standard deviations were 3.92 and 4.17 years, respectively. Agreement between self-reported and operator-recorded data categorized into short, intermediate and long-term use was moderate (kappa statistic: 0.42). Should an association exist, dilution of risk estimates and distortion of exposureresponse patterns for time since first mobile phone use could result from the large random errors in self-reported start year. Retrospective collection of operator data likely leads to a selection of good reporters, with a higher proportion of cases. Thus, differential recall cannot be entirely excluded.
Findings		No Effects
Status		Completed With Publication
Principal Investigator		Karolinska Institutet, Stockholm, Sweden
Funding Agency		?????
Country		SWEDEN
References		Pettersson, D et al. Epidemiology., (2014) 25:233-241 Pettersson , D et al. Journal of Exposure Science and Environmental Epidemiology., (2015) 25:72-79
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