Background: Some 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. Methods: We analyzed annual age-standardized incidence rates in men and women aged 20 to 79 years during 1979–2008 using joinpoint regression (35,250 glioma cases). Probabilities of detecting various levels of relative risk were computed using simulations. Results: For the period 1979 through 2008, the annual percent change in incidence rates was 0.4% (95% confidence interval = 0.1% to 0.6%) among men and 0.3% (0.1% to 0.5%) among women. Incidence rates have decreased in young men (20–39 years) since 1987, remained stable in middle-aged men (40–59 years) throughout the 30-year study period, and increased slightly in older men (60–79 years). In simulations, assumed relative risks for all users of 2.0 for an induction time of up to 15 years, 1.5 for up to 10 years, and 1.2 for up to 5 years were incompatible with observed incidence time trends. For heavy users of mobile phones, risks of 2.0 for up to 5 years' induction were also incompatible. Conclusion: No clear trend change in glioma incidence rates was observed. Several of the risk increases seen in case-control studies appear to be incompatible with the observed lack of incidence rate increase in middle-aged men. This suggests longer induction periods than currently investigated, lower risks than reported from some case-control studies, or the absence of any association.
2 February 2015 in Acta Obstetricia et Gynecologica Scandinavica
Objective: Adequate follow‐up of women who have undergone conization for high‐grade cervical lesions is crucial in cervical cancer screening programs. We evaluated the performance of testing for high‐risk human papillomavirus (HPV) types, cytology alone, and combined testing in predicting cervical intraepithelial neoplasia grade 2 or worse (CIN2+) after conization.Design: Prospective cohort study.Setting: Denmark.Population: 667 women attending for conization.Methods: Cervical specimens were collected during 2002–2006 at first visit after conization for cytological examination and Hybrid Capture 2 detection of high‐risk HPV. The women were passively followed until 2 years after first follow‐up visit by linkage to the nationwide Pathology Data Bank.Results: At first visit after conization (median time, 3.4 months), 20.4% were HPV‐positive and 17.2% had atypical squamous intraepithelial lesions or more severe cytology (ASCUS+). The 2‐year incidence of CIN2+ after conization was 3.6%. Sensitivity for detection of CIN2+ after conization was 81.0% [95% confidence interval (CI) 58.1–94.6] for positive cytology (ASCUS+ threshold) and 95.2% (95% CI 76.2–99.9) for HPV testing and for combined testing. Specificity of ASCUS+ cytology (85.2%; 95% CI 82.0–88.0) was higher than that of HPV testing (82.4%; 95% CI 79.0–85.4) and markedly higher than that of combined testing (73.2%; 95% CI 69.3–76.8). The margin status had no significant added value.Conclusions: Testing for high‐risk HPV three to four months after conization is more sensitive than ASCUS+ cytology for identifying women at risk for relapse of CIN2+ within 2 years. Further studies are needed to evaluate whether HPV testing could be a stand‐alone test in follow up after conization.
In the Nordic countries, the use of mobile phones increased sharply in the mid-1990s especially among middle-aged men. We investigated time trends in glioma incidence rates (IR) with the perspective to inform about the plausibility of brain tumour risks from mobile phone use reported in some case-control studies. We analysed IR of glioma in Denmark, Finland, Norway, and Sweden among men aged 40–69 years, using data from national cancer registries and population statistics during 1979–2016, using log-linear joinpoint analysis. Information on regular mobile phone use and amount of call-time was obtained from major studies of mobile phones in these countries. We compared annual observed incidence with that expected under various risk scenarios to assess which of the reported effect sizes are compatible with the observed IR. The expected numbers of cases were computed accounting for an impact of other factors besides mobile phone use, such as improved cancer registration. Based on 18,232 glioma cases, IR increased slightly but steadily with a change of 0.1% (95 %CI 0.0%; 0.3%) per year during 1979–2016 among 40–59-year-old men and for ages 60–69, by 0.6 % (95 %CI 0.4; 0.9) annually. The observed IR trends among men aged 40–59 years were incompatible with risk ratios (RR) 1.08 or higher with a 10-year lag, RR ≥ 1.2 with 15-year lag and RR ≥ 1.5 with 20-year lag. For the age group 60–69 years, corresponding effect sizes RR ≥ 1.4, ≥2 and ≥ 2.5 could be rejected for lag times 10, 15 and 20 years. This study confirms and reinforces the conclusions that no changes in glioma incidence in the Nordic countries have occurred that are consistent with a substantial risk attributable to mobile phone use. This particularly applies to virtually all reported risk increases reported by previous case-control studies with positive findings.
The city of Ozyorsk (Southern Urals) was created as a secret city in 1945 and is a closed city until today. It housed workers of the earliest and one of the country’s largest nuclear facilities. Workers of the nuclear reactors, radiochemical or reprocessing plants were exposed to high levels of ionising radiation in the early years of operation and possibly further exposed from inhalation of plutonium aerosols. The cause-of-death registry of Ozyorsk received paper copies of original death certificates of all deaths of residents of the city. Data were analysed for recent mortality rates (1998–2010) and time trends in age-standardised mortality rates between 1953 and 2010 of main groups of causes of deaths, in particular cancer. Comparing workers of the three main plant types with the remainder of the Ozyorsk residents, and with national figures, all-cause mortality rates were lowest among workers, with ratios compared to national figures of 0.65 (men) and 0.56 (women), and compared to the other residents of 0.77 (men) and of 0.74 (women). For cancer overall, the differences were smaller in men (ratio between workers and national figures of 0.86) and there were no differences in women (ratio of 1.00), but ratios differed by cancer type. Most cancer deaths were however least common in the workers, including leukaemia. Over the last 60 years, all-cause mortality has gradually increased among men in all three groups but was stable among women, whereas cancer death rates have slightly declined in both sexes. Healthy worker effect, relatively better living conditions in Ozyorsk and healthier lifestyles may explain the lower mortality rates in Ozyorsk. Overall mortality time trends in Ozyorsk were similar to the entire country. No apparent radiation-related effects were seen in this population-level analysis, but the radiation-related risks can be better addressed in individual-level studies.
3 February 2022 in European Journal of Epidemiology
The Cohort Study of Mobile Phone Use and Health (COSMOS) has repeatedly collected self-reported and operator-recorded data on mobile phone use. Assessing health effects using self-reported information is prone to measurement error, but operator data were available prospectively for only part of the study population and did not cover past mobile phone use. To optimize the available data and reduce bias, we evaluated different statistical approaches for constructing mobile phone exposure histories within COSMOS. We evaluated and compared the performance of 4 regression calibration (RC) methods (simple, direct, inverse, and generalized additive model for location, shape, and scale), complete-case analysis, and multiple imputation in a simulation study with a binary health outcome. We used self-reported and operator-recorded mobile phone call data collected at baseline (2007-2012) from participants in Denmark, Finland, the Netherlands, Sweden, and the United Kingdom. Parameter estimates obtained using simple, direct, and inverse RC methods were associated with less bias and lower mean squared error than those obtained with complete-case analysis or multiple imputation. We showed that RC methods resulted in more accurate estimation of the relationship between mobile phone use and health outcomes by combining self-reported data with objective operator-recorded data available for a subset of participants.