Perioperative Anaphylaxis in Japanese Secondary Care Institutions: Incidence, Causes, and the Imperative for Improved Diagnostic Practices.

Background This research investigates the incidence, suspected causes, and diagnostic procedures for perioperative anaphylaxis (POA), a potentially severe complication, in secondary care hospitals across Japan. Methodology We surveyed Saiseikai hospitals and gathered data on surgical procedures, POA occurrences, potential triggers, and diagnostic methods. Results Among 70,523 surgeries, seven were associated with POA, resulting in an approximate incidence rate of 0.01%. Rocuronium was the most commonly suspected trigger, followed by sugammadex, latex, and angiography contrast agents. Despite the importance of skin tests as the most basic and crucial diagnostic method, they were conducted in only three instances. No in vitro tests for drug identification were conducted, and in four cases, the cause was determined merely based on the timing of drug administration, indicating significant diagnostic limitations. Conclusions The study underscores the critical situation in Japan regarding insufficient diagnostic practices and difficulties in identifying triggering drugs rather than the consistent prevalence of POA in secondary care facilities. The findings emphasize the need for improved diagnostic proficiency and more rigorous drug identification practices to ensure prompt and accurate POA diagnosis. It is essential to conduct further research and interventions to increase patient safety during the perioperative period in secondary care settings.

Comparable Psychotropic Prescription Rates After Hospital Discharge Between Patients with COVID-19 and Those With Non-COVID-19-Related Respiratory Infection.

INTRODUCTION: Whether psychiatric symptoms after recovery from coronavirus disease 2019 (COVID-19) are specific to this illness remains unclear. METHODS: In this retrospective study, the Diagnosis Procedure Combination data and outpatient clinic data were used for patients who received inpatient treatment in Saiseikai-affiliated hospitals for COVID-19 or other respiratory tract infections (non-COVID) from 2020 to 2022. The primary outcome was new prescriptions of psychotropic drugs after discharge (i. e., prescriptions of psychotropics to patients who had not received them before or during their hospitalization). Values of interest were compared between groups using the chi-square test or Fisher's exact test. A COX proportional-hazards model was used to examine factors associated with psychotropic prescriptions after discharge in age- and sex-matched COVID-19 and non-COVID patients. RESULTS: Of 31,993 chart records, 19,613 were excluded due to a positive history with psychiatric disorders (n=2,445), prescriptions of psychotropics (n=744), and no follow-ups (n=16,424). Thus, 3,648 COVID-19 and 8,732 non-COVID patients were included (mean [range] duration of follow-up, days: 146.9 [1-727] and 239.2 [1-729], respectively). Two hundred and four (5.6%) of the 3,648 patients with COVID-19 received psychotropic prescriptions after discharge. No statistically significant differences were observed in the prescription rates of any psychotropic category between the COVID-19 and non-COVID groups. An increase in severity during hospitalization was significantly associated with more frequent psychotropic prescriptions (hazard ratio 1.83, p<0.001). DISCUSSION: The development of psychiatric symptoms should be closely observed, especially in patients who experienced increased severity during hospitalization, regardless of whether they suffered from COVID-19.

Association of allergic diseases and epilepsy with risk of glioma, meningioma and acoustic neuroma: results from the INTERPHONE international case-control study.

We investigated the association of allergic diseases and epilepsy with risk of brain tumours, in Interphone, a 13-country case-control study. Data were obtained from 2693 glioma cases, 2396 meningioma cases, and 1102 acoustic neuroma cases and their 6321 controls. Conditional logistic regression models were used to estimate pooled odds ratios (ORs) and their respective 95% confidence intervals (CIs), adjusted for education and time at interview. Reduced ORs were observed for glioma in relation to physician-diagnosed asthma (OR = 0.73; CI 0.58-0.92), hay fever (OR 0.72; CI 0.61-0.86), and eczema (OR 0.78, CI 0.64-0.94), but not for meningioma or acoustic neuroma. Previous diagnosis of epilepsy was associated with an increased OR for glioma (2.94; CI 1.87-4.63) and for meningioma (2.12; CI 1.27-3.56), but not for acoustic neuroma. This large-scale case-control study adds to the growing evidence that people with allergies have a lower risk of developing glioma, but not meningioma or acoustic neuroma. It also supports clinical observations of epilepsy prior to the diagnosis of glioma and meningioma.

Factors affecting the use of clinical practice guidelines by hospital physicians: the interplay of IT infrastructure and physician attitudes.

BACKGROUND: Compliance with clinical practice guidelines (CPGs) remains insufficient around the world, despite frequent updates and continuing efforts to disseminate and implement these guidelines through a variety of strategies. We describe the current status of young resident physician practices towards CPGs and investigate the multiple factors associated with the active use of CPGs, including the physician's knowledge, attitudes, behaviours, CPG-related education received, and the hospital's IT infrastructures. The aim is to identify a more effective point for intervention to promote CPG implementation. METHODS: We conducted a questionnaire survey among resident physicians working at 111 hospitals across Japan in 2015 and used results with hospital IT score data collected from a prior survey. Multivariable logistic regression analysis was performed to examine the determinants of frequent use of CPGs (defined at least once per week). The independent variables were selected based on physician demographics, clinical speciality and careers, daily knowledge and behaviour items, CPG-related education received, digital preference, and hospital IT score (high/medium/low), with and without interaction terms. RESULTS: Responses from 535 resident physicians, at 61 hospitals, were analysed. The median hospital IT score was 6 out of a possible 10 points. Physicians who had learned about CPGs tended to work at hospitals with medium to high IT scores, had easier access to paywalled medical databases, and had better knowledge of the guideline network 'Minds'. In addition, these physicians tended to use CPGs electronically. A physician's behaviour towards using CPGs for therapeutic decision-making was strongly associated with frequent use of CPGs (odds ratio [95% CI] 6.1 [3.6-10.4]), which indicated that a physician's habit strongly promotes CPG use. Moreover, CPG-related education was associated with active use of CPGs (OR1.7 [1.1-2.5]). The interaction effects between individual digital preferences and higher hospital IT score were also observed for frequent CPG use (OR2.9 [0.9-8.8]). CONCLUSIONS: A physician's habitual behaviours, CPG-related education, and a combination of individual digital preference and superior hospital IT infrastructure are key to bridging the gap between the use and implementation of CPGs.

Clinical presentation of young people (10-24 years old) with brain tumors: results from the international MOBI-Kids study.

INTRODUCTION: We used data from MOBI-Kids, a 14-country international collaborative case-control study of brain tumors (BTs), to study clinical characteristics of the tumors in older children (10 years or older), adolescents and young adults (up to the age of 24). METHODS: Information from clinical records was obtained for 899 BT cases, including signs and symptoms, symptom onset, diagnosis date, tumor type and location. RESULTS: Overall, 64% of all tumors were low-grade, 76% were neuroepithelial tumors and 62% gliomas. There were more males than females among neuroepithelial and embryonal tumor cases, but more females with meningeal tumors. The most frequent locations were cerebellum (22%) and frontal (16%) lobe. The most frequent symptom was headaches (60%), overall, as well as for gliomas, embryonal and 'non-neuroepithelial' tumors; it was convulsions/seizures for neuroepithelial tumors other than glioma, and visual signs and symptoms for meningiomas. A cluster analysis showed that headaches and nausea/vomiting was the only combination of symptoms that exceeded a cutoff of 50%, with a joint occurrence of 67%. Overall, the median time from first symptom to diagnosis was 1.42 months (IQR 0.53-4.80); it exceeded 1 year in 12% of cases, though no particular symptom was associated with exceptionally long or short delays. CONCLUSIONS: This is the largest clinical epidemiology study of BT in young people conducted so far. Many signs and symptoms were identified, dominated by headaches and nausea/vomiting. Diagnosis was generally rapid but in 12% diagnostic delay exceeded 1 year with none of the symptoms been associated with a distinctly long time until diagnosis.

Does hospital information technology infrastructure promote the implementation of clinical practice guidelines? A multicentre observational study of Japanese hospitals.

OBJECTIVES: It remains unclear whether insufficient information technology (IT) infrastructure in hospitals hinders implementation of clinical practice guidelines (CPGs) and affects healthcare quality. The objectives of this study were to describe the present state of IT infrastructure provided in acute care hospitals across Japan and to investigate its association with healthcare quality. METHODS: A questionnaire survey of hospital administrators was conducted in 2015 to gather information on hospital-level policies and elements of IT infrastructure. The number of positive responses by each respondent to the survey items was tallied. Next, a composite quality indicator (QI) score of hospital adherence to CPGs for perioperative antibiotic prophylaxis was calculated using administrative claims data. Based on this QI score, we performed a chi-squared automatic interaction detection (CHAID) analysis to identify correlates of hospital healthcare quality. The independent variables included hospital size and teaching status in addition to hospital policies and elements of IT infrastructure. RESULTS: Wide variations were observed in the availability of various IT infrastructure elements across hospitals, especially in local area network availability and access to paid evidence databases. The CHAID analysis showed that hospitals with a high level of access to paid databases (p<0.05) and internet (p<0.05) were strongly associated with increased care quality in larger or teaching hospitals. CONCLUSIONS: Hospitals with superior IT infrastructure may provide higher-quality care. This allows clinicians to easily access the latest information on evidence-based medicine and facilitate the dissemination of CPGs. The systematic improvement of hospital IT infrastructure may promote CPG use and narrow the evidence-practice gaps.

Simulation of the incidence of malignant brain tumors in birth cohorts that started using mobile phones when they first became popular in Japan.

Over 20 years have passed since the initial spread of mobile phones in Japan. Epidemiological studies of mobile phone use are currently being conducted around the world, but scientific evidence is inconclusive. The present study aimed to simulate the incidence of malignant brain tumors in cohorts that began using mobile phones when they first became popular in Japan. Mobile phone ownership data were collected through an Internet-based questionnaire survey of subjects born between 1960 and 1989. The proportion of mobile phone ownership between 1990 and 2012 was calculated by birth cohort (1960s, 1970s, and 1980s). Subsequently, using the ownership proportion, the incidence of malignant brain tumors was calculated under simulated risk conditions. When the relative risk was set to 1.4 for 1,640 h or more of cumulative mobile phone use and the mean daily call duration was 15 min, the incidence of malignant brain tumors in 2020 was 5.48 per 100,000 population for the 1960s birth cohort, 3.16 for the 1970s birth cohort, and 2.29 for the 1980s birth cohort. Under the modeled scenarios, an increase in the incidence of malignant brain tumors was shown to be observed around 2020. © 2019 Bioelectromagnetics Society.

Exposure to loud noise and risk of vestibular schwannoma: results from the INTERPHONE international case‒control study.

Objective Studies of loud noise exposure and vestibular schwannomas (VS) have shown conflicting results. The population-based INTERPHONE case‒control study was conducted in 13 countries during 2000-2004. In this paper, we report the results of analyses on the association between VS and self-reported loud noise exposure. Methods Self-reported noise exposure was analyzed in 1024 VS cases and 1984 matched controls. Life-long noise exposure was estimated through detailed questions. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using adjusted conditional logistic regression for matched sets. Results The OR for total work and leisure noise exposure was 1.6 (95% CI 1.4-1.9). OR were 1.5 (95% CI 1.3-1.9) for only occupational noise, 1.9 (95% CI 1.4-2.6) for only leisure noise and 1.7 (95% CI 1.2-2.2) for exposure in both contexts. OR increased slightly with increasing lag-time. For occupational exposures, duration, time since exposure start and a metric combining lifetime duration and weekly exposure showed significant trends of increasing risk with increasing exposure. OR did not differ markedly by source or other characteristics of noise. Conclusion The consistent associations seen are likely to reflect either recall bias or a causal association, or potentially indicate a mixture of both.

Nonparticipation Selection Bias in the MOBI-Kids Study.

BACKGROUND: MOBI-Kids is a 14-country case-control study designed to investigate the potential effects of electromagnetic field exposure from mobile telecommunications devices on brain tumor risk in children and young adults conducted from 2010 to 2016. This work describes differences in cellular telephone use and personal characteristics among interviewed participants and refusers responding to a brief nonrespondent questionnaire. It also assesses the potential impact of nonparticipation selection bias on study findings. METHODS: We compared nonrespondent questionnaires completed by 77 cases and 498 control refusers with responses from 683 interviewed cases and 1501 controls (suspected appendicitis patients) in six countries (France, Germany, Israel, Italy, Japan, and Spain). We derived selection bias factors and estimated inverse probability of selection weights for use in analysis of MOBI-Kids data. RESULTS: The prevalence of ever-regular use was somewhat higher among interviewed participants than nonrespondent questionnaire respondents 10-14 years of age (68% vs. 62% controls, 63% vs. 48% cases); in those 20-24 years, the prevalence was ≥97%. Interviewed controls and cases in the 15- to 19- and 20- to 24-year-old age groups were more likely to have a time since start of use of 5+ years. Selection bias factors generally indicated a small underestimation in cellular telephone odds ratios (ORs) ranging from 0.96 to 0.97 for ever-regular use and 0.92 to 0.94 for time since start of use (5+ years), but varied in alternative hypothetical scenarios considered. CONCLUSIONS: Although limited by small numbers of nonrespondent questionnaire respondents, findings generally indicated a small underestimation in cellular telephone ORs due to selective nonparticipation.

Ten-Year Trends of Public-Access Defibrillation in Japanese School-Aged Patients Having Neurologically Favorable Survival After Out-of-Hospital Cardiac Arrest.

The effectiveness of dissemination of public-access automated external defibrillators (AEDs) has been well established for adults, but not for children at the population level. We obtained out-of-hospital cardiac arrest (OHCA) data between January 2005 and December 2014 from a nationwide OHCA registry of Japan. Our study subjects were OHCA cases aged 6 to 17, involving attempted resuscitation by emergency medical service personnel or by bystanders. The primary outcome measure was 1-month survival with favorable neurological outcome after OHCA. We evaluated trends in the proportion of OHCA cases receiving shocks by a public-access AED and outcomes after OHCA over the 10-year study period. Prehospital factors associated with 1-month survival with favorable neurological outcome were also evaluated. During the 10-year study period, a total of 5,899 OHCAs occurred in school-age children, and 1,452 (24.6%) were of cardiac origin. The overall OHCA incidence rate in school-age children was 4.2 per 100,000 people per year. The proportion of patients with OHCA who received shocks by a public-access AED increased significantly during the study period (0.1% in 2005 and 6.4% in 2014, p for-trend <0.001). Accordingly, the 1-month survival with favorable neurological outcome improved significantly (5.3% in 2005 and 9.0% in 2014, p for-trend <0.001). In multivariable analysis, receiving shocks by a public-access AED was significantly associated with improved outcomes (adjusted odds ratio 2.13, 95% confidence interval 1.43 to 4.15; p <0.001). In conclusion, the significant increase in receiving shocks by a public-access AED was followed by a substantial improvement in patient outcomes after OHCA in school-age children in Japan.

Employment sustainability after return to work among Japanese stroke survivors.

PURPOSE: Few studies have investigated the work continuance rate among stroke survivors who return to work (RTW). The objective of this study was to investigate work sustainability after RTW and the causes of recurrent sickness absence (RSA) among Japanese stroke survivors. METHODS: Data on stroke survivors were collected from an occupational health register. The inclusion criteria were as follows: employees who were aged 15-60 years old and returned to work after an episode of sick leave due to a clinically certified stroke that was diagnosed during the period from 1 January 2000 through 31 December 2011. RESULTS: 284 employees returned to work after their first episode of stroke-induced sick leave. The work continuance rate for all subjects was 78.8 and 59.0% at one and 5 years after the subjects' RTW, respectively. After returning to work, the subjects worked for a mean of 7.0 years. Of 284 employees who returned to work, 86 (30.3%) experienced RSA. The RSA were caused by recurrent strokes in 57.0% (49/86) of cases, mental disorders in 20.9% (18/86) of cases, and fractures (often due to accidents involving steps at train stations or the subject's home) in 10.5% (9/86) of cases. 21 employees resigned after returning to work. The resignation rates at 1 and 5 years were 4.9 and 7.6%, respectively. According to the multivariate analysis including all variables, the subjects in the ≥ 50 year group were at greater risk of work discontinuation than the ≤ 49 year (reference) age group (HR: 2.26, 95% CI 1.39-3.68). CONCLUSIONS: Occupational health professionals need to provide better RTW support to stroke survivors and should pay particularly close attention to preventing recurrent strokes, mental disorders, and fractures.

[Use of Clinical Practice Guidelines in Daily Practice].

Clinical practice guidelines aim to improve patients' outcomes by providing recommendations for key clinical issues with alternative care options. Improvement in healthcare quality can be expected by applying clinical practice guidelines to daily practice for appropriate decision-making by patients and practitioners. Integration of clinical practice guidelines with the original articles, textbooks, and experiences, together with the patient's personal situation, is essential for the appropriate use of clinical practice guidelines.

Epidemiology of Pediatric Out-of-Hospital Cardiac Arrest at School　- An Investigation of a Nationwide Registry in Japan.

BACKGROUND: A better understanding of the epidemiology of pediatric out-of-hospital cardiac arrest (OHCA) occurring in school settings is important to establish an evidence-based strategy for prevention and better prognosis.Methods and Results:The Stop and Prevent cardIac aRrest, Injury, and Trauma in Schools (SPIRITS) is a nationwide prospective observational study linking databases from 2 nationally representative registries, the Injury and the Accident Mutual Aid Benefit System of The Japan Sport Council and the All-Japan Utstein Registry of the Fire and Disaster Management Agency. Using these databases, we described the detailed characteristics and outcomes of pediatric OHCAs that occurred in school settings in Japan between 2009 and 2014. During the 6-year study period, 295 OHCA cases were confirmed. Overall incidence rate was 0.4 per 100,000 students per year. The majority of OHCA cases had a cardiac origin (71%), occurred during exercise (65%), were witnessed by bystanders (70%), and received bystander-initiated cardiopulmonary resuscitation (73%). In approximately one-third of cases the student was defibrillated by public-access automated external defibrillator (38%). The proportion of patients with 1-month survival and a favorable neurological outcome was 34% among all OHCAs and 43% among OHCAs of cardiac origin. CONCLUSIONS: In Japan, approximately 50 pediatric cases of OHCA consistently occur yearly in school settings. The majority of students received basic life support from bystanders, and patients with OHCA of cardiac origin had a relatively good prognosis.

Long-term recall accuracy for mobile phone calls in young Japanese people: A follow-up validation study using software-modified phones.

This study examined changes in recall accuracy for mobile phone calls over a long period. Japanese students' actual call statuses were monitored for 1 month using software-modified phones (SMPs). Three face-to-face interviews were conducted to obtain information regarding self-reported call status during the monitoring period: first interview: immediately after the monitoring period; second interview: after 10-12 months; third interview: after 48-55 months. Using the SMP records as the "gold standard", phone call recall accuracy was assessed for each interview. Data for 94 participants were analyzed. The number of calls made was underestimated considerably and the duration of calls was overestimated slightly in all interviews. Agreement between self-report and SMP records regarding the number of calls, duration of calls and laterality (i.e., use of the dominant ear while making calls) gradually deteriorated with the increase in the interval following the monitoring period (number of calls: first interview: Pearson's r=0.641, third interview: 0.396; duration of calls: first interview: Pearson's r=0.763, third interview: 0.356; laterality: first interview: weighted-κ=0.677, third interview: 0.448). Thus, recall accuracy for mobile phone calls would be consistently imperfect over a long period, and the results of related epidemiological studies should be interpreted carefully.

Analysis of ear side of mobile phone use in the general population of Japan.

This study aimed to clarify the distribution of the ear side of mobile phone use in the general population of Japan and clarify what factors are associated with the ear side of mobile phone use. Children at elementary and junior high schools (n = 2,518) and adults aged ≥20 years (n = 1,529) completed an Internet-based survey. Data were subjected to a logistic regression analysis. In children, due to the tendency to use the dominant hand, we analyzed the factors associated with the use of right ear in right-handed people. Statistically significant differences were observed only in talk time per call (odds ratio (OR) = 2.17; 95% confidence interval (CI): 1.22-3.99). In adults, due to the tendency to use the left ear, we analyzed factors associated with the use of left ear in right-handed people. Significant differences were observed in those aged 30-39 years (OR = 2.55; 95% CI: 1.79-3.68), those aged 40-49 years (OR = 3.08; 95% CI: 2.15-4.43), those aged >50 years (OR = 1.85; 95% CI: 1.20-2.85), and in those with a percentage of total talk time when using mobile phones at work of 51-100% (OR = 1.75; 95% CI: 1.21-2.55). We believe that future epidemiological studies on mobile phone use can be improved by considering the trends in mobile phone use identified in this study. Bioelectromagnetics. 39:53-59, 2018. © 2017 Wiley Periodicals, Inc.

Work Sustainability Among Male Cancer Survivors After Returning to Work.

BACKGROUND: Few studies have investigated the work continuance rate among cancer survivors after return to work (RTW). The objective of this study was to clarify work sustainability after RTW among Japanese male cancer survivors. METHODS: We collected data on male cancer survivors from an occupational health register. Inclusion criteria were as follows: employees who returned to work after an episode of sick leave due to clinically certified cancer diagnosed between January 1, 2000 and December 31, 2011. RESULTS: Of 1,033 male employees who were diagnosed with cancer, 786 employees (76.1%) returned to work after their first episode of sick leave due to cancer. Work continuance rates among all subjects were 80.1% 1 year after RTW and 48.5% 5 years after RTW. The mean duration of work after RTW was 4.5 years. The work continuance rates varied significantly by cancer type. The "Lung" and "Hepatic, Pancreatic" cancer groups had the shortest duration of work (0.9 year after RTW). CONCLUSIONS: Of workers who returned to work after their first episode of leave after cancer, 50% continued to work after 5 years in large-scale companies. There was a steep decrease in work continuance rates during the first year after RTW, with considerable differences according to cancer site.

Association between climatic elements and acute appendicitis in Japan.

BACKGROUND: In Japan, it has been reported that an increase in atmospheric pressure is associated with a higher incidence of acute appendicitis. The aim of this epidemiologic study was to investigate the association between climatic elements and the incidence of acute appendicitis. MATERIALS AND METHODS: A case-crossover design was used in the present study. Two wk before diagnosis was used for the target period. The same 2-wk period, but 1, 2, and 3 y before diagnosis, was used for the control period. The study participants were patients with acute appendicitis (10-29 y) from 14 facilities in the Greater Tokyo Area. Mean of the observed values for atmospheric pressure, temperature, relative humidity, and hours of sunshine calculated for each target and control period were used as climatic elements to investigate trends 1 and 2 wk before diagnosis. RESULTS: The year of diagnosis, a statistically significant moderate upward trend in atmospheric pressure was observed during the 2-wk period before diagnosis of acute appendicitis (tau = 0.47; P = 0.0213), whereas a weak nonsignificant downward trend was observed 1 y before diagnosis (tau = -0.29; P = 0.1596), and weak nonsignificant upward trends were observed 2 (tau = 0.24; P = 0.2505) and 3 y (tau = 0.28; P = 0.1634) before diagnosis. CONCLUSIONS: An association was found between atmospheric pressure and the incidence of acute appendicitis. However, no significant differences were found in relation to sex or age. These findings suggest that changes in atmospheric pressure are associated with the likelihood of patients visiting the hospital.

Analysis of mobile phone use among young patients with brain tumors in Japan.

The purpose of this study was to clarify ownership and usage of mobile phones among young patients with brain tumors in Japan. The subjects of this study were patients with brain tumors diagnosed between 2006 and 2010 who were between the ages of 6 and 18 years. The target population for the analysis was 82 patients. Patients were divided into two groups: 16 patients who were mobile phone owners 1 year before diagnosis, and 66 patients who did not own mobile phones (non-owners). Using data on the mobile phone ownership rate obtained from three general-population surveys, we calculated the expected number of mobile phone owners. The three age-adjusted standardized ownership ratios were 0.83 (95% confidence interval [CI]: 0.56-1.22), 0.51 (95% CI: 0.24-1.04), and 0.75 (95% CI: 0.42-1.32). The mobile phone ownership prevalence among the young Japanese patients with brain tumors in the current study does not differ from available estimates for the general population of corresponding age. However, since the use of mobile phones among children is increasing annually, investigations into the health effects of mobile phone use among children should continue. Bioelectromagnetics. 38:349-355, 2017. © 2017 Wiley Periodicals, Inc.

The Intracranial Distribution of Gliomas in Relation to Exposure From Mobile Phones: Analyses From the INTERPHONE Study.

When investigating the association between brain tumors and use of mobile telephones, accurate data on tumor position are essential, due to the highly localized absorption of energy in the human brain from the radio-frequency fields emitted. We used a point process model to investigate this association using information that included tumor localization data from the INTERPHONE Study (Australia, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Norway, Sweden, and the United Kingdom). Our main analysis included 792 regular mobile phone users diagnosed with a glioma between 2000 and 2004. Similar to earlier results, we found a statistically significant association between the intracranial distribution of gliomas and the self-reported location of the phone. When we accounted for the preferred side of the head not being exclusively used for all mobile phone calls, the results were similar. The association was independent of the cumulative call time and cumulative number of calls. However, our model used reported side of mobile phone use, which is potentially influenced by recall bias. The point process method provides an alternative to previously used epidemiologic research designs when one is including localization in the investigation of brain tumors and mobile phone use.