Browsing by Author "Klaeboe, Lars"
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- ItemImpact of random and systematic recall errors and selection bias in case--control studies on mobile phone use and brain tumors in adolescents (CEFALO study).(2011-05-23) Aydin, Denis; Feychting, Maria; Schüz, Joachim; Andersen, Tina Veje; Poulsen, Aslak Harbo; Prochazka, Michaela; Klaeboe, Lars; Kuehni, Claudia E; Tynes, Tore; Röösli, MartinWhether the use of mobile phones is a risk factor for brain tumors in adolescents is currently being studied Case control studies investigating this possible relationship are prone to recall error and selection bias We assessed the potential impact of random and systematic recall error and selection bias on odds ratios ORs by performing simulations based on real data from an ongoing case control study of mobile phones and brain tumor risk in children and adolescents CEFALO study Simulations were conducted for two mobile phone exposure categories regular and heavy use Our choice of levels of recall error was guided by a validation study that compared objective network operator data with the self reported amount of mobile phone use in CEFALO In our validation study cases overestimated their number of calls by 9 on average and controls by 34 Cases also overestimated their duration of calls by 52 on average and controls by 163 The participation rates in CEFALO were 83 for cases and 71 for controls In a variety of scenarios the combined impact of recall error and selection bias on the estimated ORs was complex These simulations are useful for the interpretation of previous case control studies on brain tumor and mobile phone use in adults as well as for the interpretation of future studies on adolescents
- ItemIncidence trends of adult primary intracerebral tumors in four Nordic countries.(2003-12-03) Lönn, Stefan; Klaeboe, Lars; Hall, Per; Mathiesen, Tiit; Auvinen, Anssi; Christensen, Helle C; Johansen, Christoffer; Salminen, Tiina; Tynes, Tore; Feychting, MariaBrain tumors are some of the most lethal adult cancers and there is a concern that the incidence is increasing It has been suggested that the reported increased incidence can be explained by improvements in diagnostic procedures although this has not been totally resolved The aim of our study was to describe the incidence trends of adult primary intracerebral tumors in four Nordic countries during a period with introduction of new diagnostic procedures and increasing prevalence of mobile phone users Information about benign and malignant primary intracerebral tumor cases 20 79 years of age was obtained from the national cancer registries in Denmark Finland Norway and Sweden for the years 1969 98 and estimates of person years at risk were calculated from the information obtained from national population registries Annual age standardized incidence rates per 100 000 person years were calculated and time trends analyses were carried out using Poisson regression The overall incidence of all intracerebral tumors ranged from 8 4 11 8 for men and 5 8 9 3 for women corresponding to an average annual increase of 0 6 for men 95 confidence interval CI 0 4 0 7 and 0 9 for women 95 CI 0 7 1 0 The increase in the incidence was confined to the late 1970s and early 1980s and coinciding with introduction of improved diagnostic methods This increase was largely confined to the oldest age group After 1983 and during the period with increasing prevalence of mobile phone users the incidence has remained relatively stable for both men and women
- ItemThe INTERPHONE study: design, epidemiological methods, and description of the study population.(2007-09-12) Cardis, Elisabeth; Richardson, Lesley; Deltour, Isabelle; Armstrong, Bruce; Feychting, Maria; Johansen, Christoffer; Kilkenny, Monique; McKinney, Patricia; Modan, Baruch; Sadetzki, Siegal; Schüz, Joachim; Swerdlow, Anthony; Vrijheid, Martine; Auvinen, Anssi; Berg, Gabriele; Blettner, Maria; Bowman, Joseph; Brown, Julianne; Chetrit, Angela; Christensen, Helle Collatz; Cook, Angus; Hepworth, Sarah; Giles, Graham; Hours, Martine; Iavarone, Ivano; Jarus-Hakak, Avital; Klaeboe, Lars; Krewski, Daniel; Lagorio, Susanna; Lönn, Stefan; Mann, Simon; McBride, Mary; Muir, Kenneth; Nadon, Louise; Parent, Marie-Elise; Pearce, Neil; Salminen, Tiina; Schoemaker, Minouk; Schlehofer, Brigitte; Siemiatycki, Jack; Taki, Masao; Takebayashi, Toru; Tynes, Tore; van Tongeren, Martie; Vecchia, Paolo; Wiart, Joe; Woodward, Alistair; Yamaguchi, NaohitoThe very rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in the possible health effects of exposure to radio frequency RF fields A multinational case control study INTERPHONE was set up to investigate whether mobile phone use increases the risk of cancer and more specifically whether the RF fields emitted by mobile phones are carcinogenic The study focused on tumours arising in the tissues most exposed to RF fields from mobile phones glioma meningioma acoustic neurinoma and parotid gland tumours In addition to a detailed history of mobile phone use information was collected on a number of known and potential risk factors for these tumours The study was conducted in 13 countries Australia Canada Denmark Finland France Germany Israel Italy Japan New Zealand Norway Sweden and the UK using a common core protocol This paper describes the study design and methods and the main characteristics of the study population INTERPHONE is the largest case control study to date investigating risks related to mobile phone use and to other potential risk factors for the tumours of interest and includes 2 765 glioma 2 425 meningioma 1 121 acoustic neurinoma 109 malignant parotid gland tumour cases and 7 658 controls Particular attention was paid to estimating the amount and direction of potential recall and participation biases and their impact on the study results
- ItemLocation of gliomas in relation to mobile telephone use: a case-case and case-specular analysis.(2011-06-22) Larjavaara, Suvi; Schüz, Joachim; Swerdlow, Anthony; Feychting, Maria; Johansen, Christoffer; Lagorio, Susanna; Tynes, Tore; Klaeboe, Lars; Tonjer, Sven Reidar; Blettner, Maria; Berg-Beckhoff, Gabriele; Schlehofer, Brigitte; Schoemaker, Minouk; Britton, Juliet; Mäntylä, Riitta; Lönn, Stefan; Ahlbom, Anders; Flodmark, Olof; Lilja, Anders; Martini, Stefano; Rastelli, Emanuela; Vidiri, Antonello; Kähärä, Veikko; Raitanen, Jani; Heinävaara, Sirpa; Auvinen, AnssiThe energy absorbed from the radio frequency fields of mobile telephones depends strongly on distance from the source The authors objective in this study was to evaluate whether gliomas occur preferentially in the areas of the brain having the highest radio frequency exposure The authors used 2 approaches In a case case analysis tumor locations were compared with varying exposure levels in a case specular analysis a hypothetical reference location was assigned for each glioma and the distances from the actual and specular locations to the handset were compared The study included 888 gliomas from 7 European countries 2000 2004 with tumor midpoints defined on a 3 dimensional grid based on radiologic images The case case analyses were carried out using unconditional logistic regression whereas in the case specular analysis conditional logistic regression was used In the case case analyses tumors were located closest to the source of exposure among never regular and contralateral users but not statistically significantly In the case specular analysis the mean distances between exposure source and location were similar for cases and speculars These results do not suggest that gliomas in mobile phone users are preferentially located in the parts of the brain with the highest radio frequency fields from mobile phones
- ItemMobile phone use and incidence of glioma in the Nordic countries 1979-2008: consistency check.(2012-02-09) Deltour, Isabelle; Auvinen, Anssi; Feychting, Maria; Johansen, Christoffer; Klaeboe, Lars; Sankila, Risto; Schüz, JoachimSome case control studies have reported increased risks of glioma associated with mobile phone use If true this would ultimately affect the time trends for incidence rates IRs Correspondingly lack of change in IRs would exclude certain magnitudes of risk We investigated glioma IR trends in the Nordic countries and compared the observed with expected incidence rates under various risk scenarios
- ItemMobile phone use and risk of glioma in 5 North European countries.(2007-03-13) Lahkola, Anna; Auvinen, Anssi; Raitanen, Jani; Schoemaker, Minouk J; Christensen, Helle C; Feychting, Maria; Johansen, Christoffer; Klaeboe, Lars; Lönn, Stefan; Swerdlow, Anthony J; Tynes, Tore; Salminen, TiinaPublic concern has been expressed about the possible adverse health effects of mobile telephones mainly related to intracranial tumors We conducted a population based case control study to investigate the relationship between mobile phone use and risk of glioma among 1 522 glioma patients and 3 301 controls We found no evidence of increased risk of glioma related to regular mobile phone use odds ratio OR 0 78 95 confidence interval CI 0 68 0 91 No significant association was found across categories with duration of use years since first use cumulative number of calls or cumulative hours of use When the linear trend was examined the OR for cumulative hours of mobile phone use was 1 006 1 002 1 010 per 100 hr but no such relationship was found for the years of use or the number of calls We found no increased risks when analogue and digital phones were analyzed separately For more than 10 years of mobile phone use reported on the side of the head where the tumor was located an increased OR of borderline statistical significance OR 1 39 95 CI 1 01 1 92 p trend 0 04 was found whereas similar use on the opposite side of the head resulted in an OR of 0 98 95 CI 0 71 1 37 Although our results overall do not indicate an increased risk of glioma in relation to mobile phone use the possible risk in the most heavily exposed part of the brain with long term use needs to be explored further before firm conclusions can be drawn
- ItemTime trends in brain tumor incidence rates in Denmark, Finland, Norway, and Sweden, 1974-2003.(2009-12-16) Deltour, Isabelle; Johansen, Christoffer; Auvinen, Anssi; Feychting, Maria; Klaeboe, Lars; Schüz, JoachimIn Denmark Finland Norway and Sweden the use of mobile phones increased sharply in the mid 1990s thus time trends in brain tumor incidence after 1998 may provide information about possible tumor risks associated with mobile phone use We investigated time trends in the incidence of glioma and meningioma in Denmark Finland Norway and Sweden from 1974 to 2003 using data from national cancer registries We used joinpoint regression models to analyze the annual incidence rates of glioma and meningioma During this period 59 984 men and women aged 20 79 years were diagnosed with brain tumors in a population of 16 million adults All statistical tests were two sided From 1974 to 2003 the incidence rate of glioma increased by 0 5 per year 95 confidence interval CI 0 2 to 0 8 among men and by 0 2 per year 95 CI 0 1 to 0 5 among women and that of meningioma increased by 0 8 per year 95 CI 0 4 to 1 3 among men and after the early 1990s by 3 8 per year 95 CI 3 2 to 4 4 among women No change in incidence trends were observed from 1998 to 2003 the time when possible associations between mobile phone use and cancer risk would be informative about an induction period of 5 10 years
- ItemUse of mobile phones in Norway and risk of intracranial tumours.(2007-02-13) Klaeboe, Lars; Blaasaas, Karl Gerhard; Tynes, ToreTo test the hypothesis that exposure to radio frequency electromagnetic fields from mobile phones increases the incidence of gliomas meningiomas and acoustic neuromas in adults The incident cases were of patients aged 19 69 years who were diagnosed during 2001 2002 in Southern Norway Population controls were selected and frequency matched for age sex and residential area Detailed information about mobile phone use was collected from 289 glioma response rate 77 207 meningioma patients 71 and 45 acoustic neuroma patients 68 and from 358 69 controls For regular mobile phone use defined as use on average at least once a week or more for at least 6 months the odds ratio was 0 6 95 confidence interval 0 4 0 9 for gliomas 0 8 95 confidence interval 0 5 1 1 for meningiomas and 0 5 95 confidence interval 0 2 1 0 for acoustic neuromas Similar results were found with mobile phone use for 6 years or more for gliomas and acoustic neuromas An exception was meningiomas where the odds ratio was 1 2 95 confidence interval 0 6 2 2 Furthermore no increasing trend was observed for gliomas or acoustic neuromas by increasing duration of regular use the time since first regular use or cumulative use of mobile phones The results from the present study indicate that use of mobile phones is not associated with an increased risk of gliomas meningiomas or acoustic neuromas