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Background:The prevalence of prescribed drugs in survivors of colorectal cancer(CRC) was evaluated. Methods:Data from the Cancer Registry of Norway were linked to the Norwegian Prescription Database for a study population of 3.52 million individuals. Prevalenceratios (PRs) with 95% confidence intervals (CIs) of prescribed drugs in CRC-survivorscompared to the cancer-free population, were estimated by log-binomial regression,adjusting for age and education. Results:Almost 27 000 individuals, aged 20 to 84, were diagnosed with CRC during2005 to 2014. The first year after diagnosis, the prevalence of prescribed drugs washigher in CRC-survivors compared with the cancer-free population, especially drugsfor anxiety and tension, and steroid-responsive conditions. PRs for several drugs,especially drugs used for mental and behavioural disorders, decreased with time sincediagnosis. The prevalence of drugs used for anxiety and tension was elevated10 years after diagnosis; PRs the first year after diagnosis were 20 (95% CI: 18-22) inmales and 17 (16-18) in females. Ten years after diagnosis PRs were 5.0 (3.1-7.9) and2.0 (1.0-3.8), respectively. In absolute numbers, the largest increase, compared to thecancer-free population, was in drugs used for gastric acid disorders and pain. Theprevalence of neuromodulatory drugs was higher in CRC-survivors. Conclusions:The prevalence of several drugs was higher in CRC-survivors than inthe cancer-free population 10 years after diagnosis. The largest absolute excess inprevalence was for gastric acid disorder and pain medications, while the relative prevalence of drugs used for anxiety and tension was high in CRC-survivors. Longpersisting neuropathia was indicated. KEYWORDSchronic diseases, colorectal cancer, drugs, medication, pharmacoepidemiology, population-based

Background: The inverse observational association between body mass index (BMI) and lung cancer risk remains unclear. We assessed whether the association is explained by metabolic aberrations, residual confounding, and within-person variability in smoking, and compared against other smoking-related cancers. Methods: We investigated the association between BMI, and its combination with a metabolic score (MS) of mid-blood pressure, glucose, and triglycerides, with lung cancer and other smoking-related cancers in 778,828 individuals. We used Cox regression, adjusted and corrected for within-person variability in smoking (status/pack-years), calculated from 600,201 measurements in 221,958 participants. Results: Over a median follow-up of 20 years, 20,242 smoking-related cancers (6,735 lung cancers) were recorded. Despite adjustment and correction for substantial within-person variability in smoking, BMI remained inversely associated with lung cancer [HR per standard deviation increase, 0.87 (95% confidence interval 0.85–0.89)]. Individuals with BMI less than 25 kg/m2 and high MS had the highest risk [HR 1.52 (1.44–1.60) vs. BMI ≥25 with low MS]. These associations were weaker and nonsignificant among nonsmokers. Similar associations were observed for head and neck cancers and esophageal squamous cell carcinoma, whereas for other smoking-related cancers, we generally observed positive associations with BMI. Conclusions: The increased lung cancer risk with low BMI and high MS is unlikely due to residual confounding and within-person variability in smoking. However, similar results for other cancers strongly related to smoking suggest a remaining, unknown, effect of smoking. Impact: Extensive smoking-adjustments may not capture all the effects of smoking on the relationship between obesity-related factors and risk of smoking-related cancers.

Previous studies of fetal death with maternal influenza have been inconsistent. We explored the effect of maternal influenza-like illness (ILI) in pregnancy on the risk of fetal death, distinguishing between diagnoses during regular influenza seasons and the 2009/2010 pandemic and between trimesters of ILI. We used birth records from the Medical Birth Registry of Norway to identify fetal deaths after the first trimester in singleton pregnancies (2006–2013). The Norwegian Directorate of Health provided dates of clinical influenza diagnoses by primary-health-care providers, whereas dates of laboratory-confirmed influenza A (H1N1) diagnoses were provided by the Norwegian Surveillance System for Communicable Diseases. We obtained dates and types of influenza vaccinations from the Norwegian Immunisation Registry. Cox proportional-hazards regression models were fitted to estimate hazard ratios (HRs) of fetal death, with associated 95% confidence intervals (CIs), comparing women with and without an ILI diagnosis in pregnancy. There were 2510 fetal deaths among 417,406 eligible pregnancies. ILI during regular seasons was not associated with increased risk of fetal death: adjusted HR = 0.90 (95% CI 0.64–1.27). In contrast, ILI during the pandemic was associated with substantially increased risk of fetal death, with an adjusted HR of 1.75 (95% CI 1.21–2.54). The risk was highest following first-trimester ILI (adjusted HR = 2.28 [95% CI 1.45–3.59]). ILI during the pandemic—but not during regular seasons—was associated with increased risk of fetal death in the second and third trimester. The estimated effect was strongest with ILI in first trimester. Electronic supplementary material The online version of this article (10.1007/s10654-020-00600-z) contains supplementary material, which is available to authorized users.

Previous studies on metabolic factors and bladder cancer (BC) risk have shown inconsistent results and have commonly not investigated associations separately by sex, smoking, and tumor invasiveness ...

Study question: Among babies born by ART, do singleton survivors of a vanishing twin have lower birth weight than other singletons? Summary answer: Vanishing-twin syndrome was associated with lower birth weight among ART singletons; a sibship analysis indicated that the association was not confounded by maternal characteristics that remain stable between deliveries. What is known already known: Previous studies indicate that ART singletons with vanishing-twin syndrome have increased risk of adverse pregnancy outcomes, compared with other ART singletons. The potential contribution of unmeasured maternal background characteristics has been unclear. Study design, size and duration: This was a Norwegian population-based registry study, including 17,368 mothers with 20,410 ART singleton deliveries between January 1984 and December 2013.Participants/materials, setting, methods: The study population included 17,291 ART singletons without vanishing-twin syndrome, 638 ART singletons with vanishing-twin syndrome, and 2,418 ART singletons with uncertain vanishing-twin status. We estimated differences in birth weight and gestational age comparing ART singletons with vanishing-twin syndrome first to all ART singletons without vanishing-twin syndrome, and subsequently to their ART siblings without vanishing-twin syndrome, using random- and fixed-effects linear regression, respectively. The corresponding comparisons for the associations with preterm birth and small-for-gestational age (SGA) were conducted using random-and fixed-effects logistic regression. The sibling analysis of preterm birth included 587 discordant siblings, while the sibling analysis of SGA included 674 discordant siblings.Main results and the role of chance: ART singletons with vanishing-twin syndrome had lower birth weight when compared to all ART singletons without vanishing-twin syndrome, with an adjusted mean difference (95% CI) of -116 grams (-165, -67). When we compared ART singletons with vanishing-twin syndrome to their ART singletons sibling without vanishing-twin syndrome, the adjusted mean difference was -112 grams (-209, -15). ART singletons with vanishing-twin syndrome also had increased risk of being born SGA, with an adjusted odds ratio (95% CI) of 1.48 (1.07, 2.03) compared to all ART singletons without vanishing twin-syndrome, and 2.79 (1.12, 6.91) in the sibship analyses. ART singletons with vanishing-twin syndrome were also more likely to be born preterm, although this difference did not reach statistical significance.Limitations, reasons for caution: We did not have information on maternal socio-economic status, but this factor is accounted for in the sibship analyses. We have no information on whether fresh or frozen embryos were replaced.Wider implications of the findings: The reduction in birth weight and increased SGA in ART singletons with vanishing-twin syndrome may suggest the presence of harmful intrauterine factors with long-term health impact. While vanishing twins are not routinely observed in naturally conceived pregnancies, loss of a twin is potentially a risk factor for the surviving fetus in any pregnancy. This could be further explored in large samples of naturally conceived pregnancies with the necessary information. Study funding/competing interest(s): The authors of this study are supported in part by the UK Medical Research Council, US National Institute of Environmental Health Sciences, and the Norwegian Research Council. The authors have no conflicts of interest.

Background Obesity is an established risk factor for several cancers. Adult weight gain has been associated with increased cancer risk, but studies on timing and duration of adult weight gain are relatively scarce. We examined the impact of BMI (body mass index) and weight changes over time, as well as the timing and duration of excess weight, on obesity- and non-obesity-related cancers. Methods We pooled health data from six European cohorts and included 221 274 individuals with two or more height and weight measurements during 1972–2014. Several BMI and weight measures were constructed. Cancer cases were identified through linkage with national cancer registries. Hazard ratios (HRs) of cancer with 95% confidence intervals (CIs) were derived from time-dependent Cox-regression models. Results During follow-up, 27 881 cancer cases were diagnosed; 9761 were obesity-related. The HR of all obesity-related cancers increased with increasing BMI at first and last measurement, maximum BMI and longer duration of overweight (men only) and obesity. Participants who were overweight before age 40 years had an HR of obesity-related cancers of 1.16 (95% CI 1.02, 1.32) and 1.15 (95% CI 1.04, 1.27) in men and women, respectively, compared with those who were not overweight. The risk increase was particularly high for endometrial (70%), male renal-cell (58%) and male colon cancer (29%). No positive associations were seen for cancers not regarded as obesity-related. Conclusions Adult weight gain was associated with increased risk of several major cancers. The degree, timing and duration of overweight and obesity also seemed to be important. Preventing weight gain may reduce the cancer risk.

Apart from the consistently observed differential association between obesity and breast cancer risk by menopausal status, the associations between obesity and other metabolic imbalances with risks of cancers have not been systematically investigated across the age‐course. We created two random 50–50% cohorts from six European cohorts comprising 813,927 individuals. In the “discovery cohort”, we used Cox regression with attained age as time‐scale and tested interactions between body mass index (BMI), blood pressure, plasma glucose, triglycerides and cholesterol, and attained age in relation to cancer risk. Results with a p‐value below 0.05 were additionally tested in the “replication cohort” where a replicated result was considered evidence of a linear interaction with attained age. These findings were investigated by flexible parametric survival models for any age‐plateaus in their shape of associations with cancer risk across age. Consistent with other studies, BMI was negatively related to breast cancer risk (n cases = 11,723) among younger (premenopausal) women. However, the association remained negative for several years after menopause and, although gradually weakening over age, the association became positive only at 62 years of age. This linear and positive age‐interaction was also found for triglycerides and breast cancer, and for BMI and triglycerides in relation to liver cancer among men (n cases = 444). These findings are unlikely to be due to chance owing to the replication. The linear age‐interactions in breast cancer may suggest an influence by other age‐related factors than menopause; however, further investigation of age‐related effect modifiers in both breast and liver cancer is needed. acceptedVersion

Patients with multiple sclerosis (MS) are at increased risk of infections and related worsening of neurological function. Influenza infection has been associated with increased risk of various neurological complications. We conducted a population-based registry study to investigate the risk of acute hospitalization of MS patients in relation to influenza infection or pandemic vaccination in Norway. The entire Norwegian population in the years 2008–2014 was defined as our study population (N = 5,219,296). Information on MS diagnosis, influenza infection and vaccination were provided by Norwegian national registries. The self-controlled case series method was used to estimate incidence rate ratios (IRRs) with 95% confidence intervals (95% CI) in defined risk periods. 6755 MS patients were identified during the study period. Average age at first registration of an MS diagnosis was 51.8 years among men and 49.9 years among females (66.9%). The IRR for emergency hospitalization among MS patients the first week after an influenza diagnosis was 3.4 (95% CI 2.4–4.8). The IRR was 5.6 (95% CI 2.7–11.3) after pandemic influenza, and 4.8 (95% CI 3.1–7.4) after seasonal influenza. Pandemic vaccination did not influence risk of hospitalization [IRR within the first week: 0.7 (95% CI 0.5–1.0)]. Among MS patients, influenza infection was associated with increased risk for acute hospitalization while no increased risk was observed after pandemic vaccination. Influenza vaccination could prevent worsening of MS-related symptoms as well as risk of hospitalization. acceptedVersion

In this article, we used Sargassum hystrix algae as biosorbent for removal of Fe (II) from aqueous solutions that was collected along the Persian Gulf coastline, Bushehr, Iran. The concentration level of remaining Fe (II) in the samples was measured by using flame atomic absorption spectrometry (FAAS, Varian AA240, Australia). The isotherms, kinetics and modeling data of Fe (II) biosorption onto Sargassum hystrix were also presented.

Suicide risk in adult cancer patients is found to be elevated, but limited information exists regarding risks of suicide and non-suicidal violent deaths when diagnosed with cancer in young age. We investigate suicide and violent deaths in a national cohort including individuals diagnosed with cancer before age 25. Through the linkage of different national registries (Cancer Registry of Norway, Norwegian Causes of Death Registry, and the National Registry) a cohort of all live births in Norway during 1965-1985 was defined and followed up through 2008. Individuals diagnosed with cancer before age 25 and the cancer-free references were compared using an extended Cox proportional hazard regression model. The cohort comprised 1,218,013 individuals, including 5,440 diagnosed with cancer before age 25. We identified 24 suicides and 14 non-suicidal violent deaths in the cancer group. The hazard ratio (HR) of suicide in the cancer group was 2.5 (95% confidence interval (CI) 1.7-3.8), and was increased both when diagnosed with cancer in childhood (0-14 years of age); HR=2.3 (95% CI 1.2-4.6), and during adolescence/young adulthood (15-24 years); HR=2.6 (95% CI 1.5-4.2). Survivors of bone/soft tissue sarcomas, CNS tumors and testicular cancer were at particular risk. The risk of non-suicidal violent death was not increased in the cancer survivors (HR=1.0; 95% CI 0.6-1.7). Although based on small numbers and the absolute risk of suicide being low, these are novel findings with important implications for establishing adequate follow-up including suicide prevention strategies for young cancer survivors. This article is protected by copyright. All rights reserved.© 2016 UICC. Language: en

The number of young cancer survivors has increased over the past few decades due to improvement in treatment regimens, and understanding of long-term effects among the survivors has become even more important. Educational achievements and choice of educational fields were explored here. Five-year cancer survivors born in Norway during 1965–1985 (diagnosed

OBJECTIVES: To determine if pandemic influenza vaccination was associated with an increased risk of epilepsy in children. METHODS: Information from Norwegian registries from 2006 through 2014 on all children RESULTS: In Norway, the main period of the influenza A subtype H1N1 pandemic was from October 2009 to December 2009. On October 1, 2009, 1 154 113 children CONCLUSIONS: Pandemic influenza vaccination was not associated with increased risk of epilepsy. Concerns about pandemic vaccination causing epilepsy in children seem to be unwarranted.

Previous studies on metabolic factors and bladder cancer (BC) risk have shown inconsistent results and have commonly not investigated associations separately by sex, smoking, and tumor invasiveness. Among 811,633 participants in six European cohorts, we investigated sex-specific associations between body mass index (BMI), mid-blood pressure (BP, [systolic + diastolic]/2), plasma glucose, triglycerides, total cholesterol and risk of BC overall, non-muscle invasive BC (NMIBC) and muscle invasive BC (MIBC). Among men, we additionally assessed additive interactions between metabolic factors and smoking on BC risk. During follow-up, 2,983 men and 754 women were diagnosed with BC. Among men, triglycerides and BP were positively associated with BC risk overall (hazard ratio [HR] per standard deviation [SD]: 1.17 [95% confidence interval (CI) 1.06-1.27] and 1.09 [1.02-1.17], respectively), and among women, BMI was inversely associated with risk (HR: 0.90 [0.82-0.99]). The associations for BMI and BP differed between men and women (p

Background Influenza is known to be associated with various neurological complications, including encephalitis. We conducted a registry-based study to assess the risk of encephalitis after influenza and A(H1N1)pdm09 vaccine. Methods Data from Norwegian national health registries during 2008–14 were linked using the unique personal identifiers given to all Norwegian residents (N = 5 210 519). Cox proportional-hazard models with time-varying variables were fitted to estimate hazard ratios (HRs) of encephalitis after influenza and A(H1N1)pdm09 vaccine, using the risk windows 0–7, 0–14, 0–30, 0–60, 0–90 and 0–180 days. Results In Norway, 684 172 individuals received an influenza diagnosis and 2793 patients were hospitalized with encephalitis during 2008–14. The risk of encephalitis increased after influenza: HR, 7-day risk window: 47.8 (95% confidence interval (CI): 35.8–63.8), and the HR decreased for longer risk windows; HR, 180-day risk window: 3.8 (95% CI: 3.1–4.7). HR of encephalitis after influenza during the 2009 main pandemic wave using a 7-day risk window was 30.0 (95% CI: 10.8–83.2). We found no differences in the risk of encephalitis after the seasonal influenza compared with influenza during the 2009 main pandemic wave; HR, 7-day risk window: 1.3 (95% CI: 0.4–4.3). A(H1N1)pdm09 vaccine was not associated with the risk of encephalitis: HR, 14-day risk window: 0.6 (95% CI: 0.2–2.1). Conclusions There was an increased risk of encephalitis following influenza but not after A(H1N1)pdm09 vaccine. The risk of encephalitis was highest in the first few weeks after influenza.

Background Associations between influenza infection and sleep disorders are poorly studied. We investigated if pandemic influenza infection or vaccination with Pandemrix in 2009/2010 was associated with narcolepsy or hypersomnia in children and young adults. Methods We followed the Norwegian population under age 30 from January 2008 through December 2012 by linking national health registry data. Narcolepsy diagnoses were validated using hospital records. Risks of narcolepsy or hypersomnia were estimated as adjusted hazard ratios (HRs) in Cox regression models with influenza infection and vaccination as time-dependent exposures. Results Among the 1,638,526 persons under age 30 in Norway in 2009, 3.6% received a physician diagnosis of influenza during the pandemic, while 41.9% were vaccinated against pandemic influenza. Between October 1st 2009 and December 31st 2012, 72 persons had onset of narcolepsy and 305 were diagnosed with hypersomnia. The risk of a sleep disorder was associated with infection during the first six months, adjusted HR 3.31 with 95% confidence interval [CI], 1.01–10.79 for narcolepsy and adjusted HR 3.13 (95% CI, 1.12–8.76) for hypersomnia. The risk of narcolepsy was strongly associated with vaccination during the first six months adjusted HR 17.21 (95% CI, 6.28–47.14), while the adjusted HR for hypersomnia was 1.54 (95% CI, 0.81–2.93). Conclusions The study confirms an increased HR of narcolepsy following pandemic vaccination. Slightly increased HRs of narcolepsy and hypersomnia are also seen after influenza infection. However, the role of infection should be viewed with caution due to underreporting of influenza.

Summary Background Epilepsy affects around 70 million people worldwide. Psychiatric comorbidity may add to the burden of the disease. We studied substance use disorders and psychotic disorders among people with epilepsy from a population-based perspective. Methods Norwegian specialist health services (hospitals and outpatient clinics) report diagnoses for individual patients to the Norwegian Patient Register. We used information on subjects born in 1930–1994 who were registered with a diagnosis of epilepsy at least once during the five-year period of 2008–2012. We compared the proportion of people with epilepsy registered with substance use disorders (alcohol use disorders or non-alcohol drug use disorders) and psychotic disorders (schizophrenia spectrum disorders or bipolar disorder) with similar figures in the population without epilepsy. We applied chi-square tests and log-binomial regression for analysis. Results Overall, 0.90% of the Norwegian adult population was registered with epilepsy in somatic hospitals during 2008–2012. The total proportion registered with alcohol use disorder was 5.74% among people with epilepsy and 1.29% in the population without epilepsy (age- and sex-adjusted relative risk [RR]: 4.42, 95% confidence interval [CI]: 4.22–4.62). The corresponding figures were 4.32% and 1.22% (RR 3.86 [95% CI: 3.67–4.06] for drug use disorder, 1.72% and 0.60% (RR 2.94 [95% CI: 2.71–3.19]) for schizophrenia spectrum disorders, and 1.50% and 0.68% (RR 2.29 [95% CI: 2.10–2.49]) for bipolar disorder. Conclusion People with epilepsy were more often registered with substance use disorders and psychotic disorders than people without epilepsy. Psychiatric comorbidity requires particular attention in both diagnostic work-up and management of epilepsy, and creates complex medical challenges that require close cooperation between neurologists and psychiatrists. These findings may have implications for the organization and further development of comprehensive epilepsy care.

Background: As the number of cancer survivors increases, their health and welfare have come into focus. Thus, long-term medical consequences of cancer at a young age (

Suicide risk in adult cancer patients is found to be elevated, but limited information exists regarding risks of suicide and non-suicidal violent deaths when diagnosed with cancer in young age. We investigate suicide and violent deaths in a national cohort including individuals diagnosed with cancer before age 25. Through the linkage of different national registries (Cancer Registry of Norway, Norwegian Causes of Death Registry and the National Registry) a cohort of all live births in Norway during 1965-1985 was defined and followed up through 2008. Individuals diagnosed with cancer before age 25 and the cancer-free references were compared using an extended Cox proportional hazard regression model. The cohort comprised 1,218,013 individuals, including 5,440 diagnosed with cancer before age 25. We identified 24 suicides and 14 non-suicidal violent deaths in the cancer group. The hazard ratio (HR) of suicide in the cancer group was 2.5 (95% confidence interval (CI) 1.7-3.8), and was increased both when diagnosed with cancer in childhood (0-14 years of age); HR = 2.3 (95% CI: 1.2-4.6), and during adolescence/young adulthood (15-24 years); HR = 2.6 (95% CI: 1.5-4.2). Survivors of bone/soft tissue sarcomas, CNS tumors and testicular cancer were at particular risk. The risk of non-suicidal violent death was not increased in the cancer survivors (HR = 1.0; 95% CI: 0.6-1.7). Although based on small numbers and the absolute risk of suicide being low, these are novel findings with important implications for establishing adequate follow-up including suicide prevention strategies for young cancer survivors.

Cancer is one of the most common causes of death among young individuals. The purpose of this study was to explore the risk of early death (the first five years after diagnosis) among children (0–14 years), adolescents (15–19 years), and young adults (20–24 years) with cancer in Norway, born during 1965–1985. The overall and cancer-specific early deaths were explored by linking population-based national registers (including the Cancer Registry of Norway and the Cause of Death Registry) that include the entire population of Norway (approximately 1.3 million individuals). Hazard and sub-hazard ratios were estimated using Cox regression analyses and competing risk models. A total of 5,828 individuals were diagnosed with cancer (56.3 % males). During follow-up, 1,415 individuals died from cancer (60.2 % males) within five years after diagnosis. The hazard ratio (HR) of overall death of the cancer patients relative to the general population decreased from 1965 (from HR, 385.8 (95 % confidence interval (CI): 335.3, 443.4) in 1965-74 to HR, 19.7 (CI: 9.3, 41.5) in 2005-09). Over all, there were fewer cancer-related deaths among female compared with male patients (sub-hazard ratio (SHR), 0.83 (CI: 0.74, 0.92)). Except for all hematopoietic malignancies, adolescents and young adult patients had lower risk of cancer death than children. The difference in risk of cancer and overall deaths between the cancer patients and the general population has been substantially reduced since 1965.

In this paper, homotopy perturbation method is applied to solve moving boundary and isoperimetric problems. This method does not depend upon a small parameter in the equation. homotopy is constructed with an imbedding parameter p, which is considered as a “small parameter”. Finally, we use combined homotopy perturbation method and Green’s function method for solving second order problems. Some examples are given to illustrate the effectiveness of methods. The results show that these methods provides a powerful mathematical tools for solving problems.

In this paper, He’s variational iterative method has been applied to give exact solution of the Euler Lagrange equation which arises from the variational problems with moving boundaries and isoperimetric problems. In this method, general Lagrange multipliers are introduced to construct correction functional for the variational problems. The initial approximations can be freely chosen with possible unknown constant, which can be determined by imposing the boundary conditions. Illustrative examples have been presented to demonstrate the efficiency and applicability of the variational iterative method.

In this paper, Homotopy perturbation method is used to find the approximate solution of the optimal control of linear systems. In this method the initial approximations are freely chosen, and a Homotopy is constructed with an embedding parameter , which is considered as a “small parameter”. Some examples are given in order to find the approximate solution and verify the efficiency of the proposed method.

Introduction Influenza infection has been associated with various neurological complications. The cause of Multiple Sclerosis (MS) is not fully understood, but is thought to be immune-mediated. In MS patients, influenza infection may trigger the immune-response and possibly cause a relapse. The role of influenza infection is understudied, and safety of vaccination among MS patients is debated. We conducted a population-based study to determine the risk of a relapse among MS patients after an influenza infection and after pandemic vaccination. Methods The entire Norwegian population during 2008–2014 was defined as our study population (n = 5219,904). Data on exposures and outcomes from the Norwegian Patient Registry (NPR), the Norwegian Directorate of Health, the Norwegian Surveillance System for Communicable Diseases, the Norwegian Immunisation Registry and the Norwegian Prescription Database (NorPD) were linked using the unique 11-digit personal identification number. MS patients were defined, as either having at least one registry of MS in NPR and at least one MS medication dispensed or in cases with lack of information on medication from NorPD, at least two registries of MS from NPR was required. Relapse was defined as new contact with the health services and a new registration of International Classification of Diseases, Version 10 (ICD-10) code G35. Risk of relapse among MS patients was studied after an influenza infection (seasonal and pandemic influenza combined), pandemic influenza infection (influenza A [H1N1]), and vaccination with Pandemrix®. Incidence rate ratios (IRRs) with 95% confidence interval (95% CI) in pre-defined risk periods compared with the background period were estimated in self-controlled case series. Results The IRR for relapse among MS patients within one week after an influenza infection (seasonal and pandemic influenza combined) was 8.14 (95% CI: 6.33–10.44). Considering pandemic influenza infection alone, similarly, risk of relapse among MS patients increased significantly within one week after an infection (IRR: 5.69 [95% CI: 3.02–10.71]). The IRR for other risk periods was not significant. Relapse among MS patients was not associated with the Pandemrix® vaccination for any risk periods. Conclusions A significantly increased risk for relapse among MS patients was observed within the first week after an influenza infection (seasonal and pandemic influenza combined). The results indicated a similar trend also after pandemic influenza infection. Pandemrix® vaccination was not associated with increased risk of relapse.

Introduction Cancer patient's survival has improved steadily in Europe during the past decades, mainly due to major changes in diagnostic work-up, treatment and follow-up of patients. Hence, the population of cancer survivors has increased. Increasing use of multimodal curative therapies and novel treatment options for advanced cancers may cause adverse health effects. Prescribed medications provide a comprehensive assessment of long-term health-related issues among cancer survivors. We conducted a registry-based study to explore long-term adverse health effects, using prescribed medications as a proxy of disease, in adult cancer patients surviving at least five years after diagnosis. Methods The entire Norwegian population, born in 1990 or earlier, alive per January 1, 2005, approximately 3.8 million individuals were defined as our study cohort. The individuals were followed-up by linking compulsory national registers; the National Registry, the Cancer Registry of Norway (1953–2014), and the Norwegian Prescription Database (since 2004). Five-year cancer survivors were identified and the proportions of medication use in cancer survivors and cancer-free populations was calculated. The proportions were standardized for age per January 1, 2005; categorized as 0–19, 20–39, 49–59, 60–79, and over 80 years of age. Incidence rates of prescribed medication will be estimated using Cox proportional hazard models. Preliminary results A total of 299,326 cancer survivors, born during 1896-1990, were identified (47% males). The largest group of cancer survivors among males were those with cancer of the prostate (35%), skin (13%), bladder (8%), colon (7%), testis (5%) and rectum (5%). Among females, the largest group of survivors were those with cancer of the breast (32%), skin (14%), colon (8%), corpus uteri (7%), cervix uteri (5%), and rectum (3%). The study identified differences between cancer survivors and the cancer-free population in the use of medications (proportions presented as percentages) for the digestive tract and metabolism (22% versus 16%, respectively), blood and blood-forming organs (24% versus 17%), cardiovascular system (39% versus 28%), genito-urinary system and sex hormones (10% versus 16%), nervous system (39% versus 32%), systemic hormones other than sex hormones and insulin (12% versus 9%), musculo-skeletal system (23% versus 27%), and anti-neoplastic and immune-modulating agents (7% versus 2%). In contrast, similar medication use were found for antiparasitic products, insecticides and repellents (3% in each group), anti-infectives (for systemic use) (∼ 26%), dermatological (∼ 13%), sensory organs (∼ 13%), and for respiratory system (∼ 22%). Conclusions Our preliminary findings indicate a higher use of various prescribed medications among cancer survivors compared with the cancer-free population. This could suggest increased health challenges among the cancer survivors. Optimized follow-up of cancer survivors as well as primary and secondary prevention strategies of major comorbidities are recommended. More specific analyses, both regarding type of cancer and medications, will be performed.

Background: Increased survival after cancer in young age has made long-term follow-up studies of high external validity important. In this national cohort study, we explored the impact of cancer in young age on reproduction and marital status in male survivors. Methods: Hazard ratios (HRs) and relative risks (RRs) of reproductive and marital outcomes were studied for male survivors of cancer in young age (

Background During the 2009 influenza A (H1N1) pandemic, a monovalent pandemic strain vaccine containing the oil-in-water adjuvant AS03 (Pandemrix®) was offered to the Norwegian population. The coverage among children reached 54 %. Our aim was to estimate the risk of febrile seizure in children after exposure to pandemic influenza vaccination or infection. Methods The study population comprised 226,889 children born 2006–2009 resident in Norway per October 1st, 2009. Febrile seizure episodes were defined by emergency hospital admissions / emergency outpatient hospital care with International Classification of Diseases, Version 10, codes R56.0 or R56.8. The self-controlled case series method was applied to estimate incidence rate ratios (IRRs) in pre-defined risk periods compared to the background period. The total observation window was ± 180 days from exposure day. Among 113,068 vaccinated children, 656 (0.6 %) had at least one febrile seizure episode. Results The IRR of febrile seizures 1–3 days after vaccination was 2.00 (95 % confidence interval [CI]: 1.15–3.51). In the period 4–7 days after vaccination, no increased risk was observed. Among the 8172 children diagnosed with pandemic influenza, 84 (1.0 %) had at least one febrile seizure episode. The IRR of febrile seizures on the same day as a diagnosis of influenza was 116.70 (95 % CI: 62.81–216.90). In the period 1–3 days after a diagnosis of influenza, a tenfold increased risk was observed (IRR 10.12, 95 % CI: 3.82 – 26.82). Conclusions In this large population-based study with precise timing of exposures and outcomes, we found a twofold increased risk of febrile seizures 1–3 days after pandemic influenza vaccination. However, we found that pandemic influenza infection was associated with a much stronger increase in risk of febrile seizures.

Background Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is associated to infections and it has been suggested that vaccination can trigger the disease. However, little is known about the specific association between clinically manifest influenza/influenza vaccine and CFS/ME. As part of a registry surveillance of adverse effects after mass vaccination in Norway during the 2009 influenza A (H1N1) pandemic, we had the opportunity to estimate and contrast the risk of CFS/ME after infection and vaccination. Methods Using the unique personal identification number assigned to everybody who is registered as resident in Norway, we followed the complete Norwegian population as of October 1, 2009, through national registries of vaccination, communicable diseases, primary health, and specialist health care until December 31, 2012. Hazard ratios (HRs) of CFS/ME, as diagnosed in the specialist health care services (diagnostic code G93.3 in the International Classification of Diseases, Version 10), after influenza infection and/or vaccination were estimated using Cox proportional-hazards regression. Results The incidence rate of CFS/ME was 2.08 per 100,000 person-months at risk. The adjusted HR of CFS/ME after pandemic vaccination was 0.97 (95% confidence interval [CI]: 0.91–1.04), while it was 2.04 (95% CI: 1.78–2.33) after being diagnosed with influenza infection during the peak pandemic period. Conclusions Pandemic influenza A (H1N1) infection was associated with a more than two-fold increased risk of CFS/ME. We found no indication of increased risk of CFS/ME after vaccination. Our findings are consistent with a model whereby symptomatic infection, rather than antigenic stimulation may trigger CFS/ME.

Vaccinations and infections are possible triggers of Guillain-Barré syndrome (GBS). However, studies on GBS after vaccinations during the influenza A(H1N1)pmd09 pandemic in 2009, show inconsistent results. Only few studies have addressed the role of influenza infection. We used information from national health data-bases with information on the total Norwegian population (N = 4,832,211). Cox regression analyses with time-varying covariates and self-controlled case series was applied. The risk of being hospitalized with GBS during the pandemic period, within 42 days after an influenza diagnosis or pandemic vaccination was estimated. There were 490 GBS cases during 2009-2012 of which 410 cases occurred after October 1, 2009 of which 46 new cases occurred during the peak period of the influenza pandemic. An influenza diagnosis was registered for 2.47% of the population and the vaccination coverage was 39.25%. The incidence rate ratio of GBS during the pandemic peak relative to other periods was 1.46 [95% confidence interval (CI) 1.08-1.98]. The adjusted hazard ratio (HR) of GBS within 42 days after a diagnosis of pandemic influenza was 4.89 (95% CI 1.17-20.36). After pandemic vaccination the adjusted HR was 1.11 (95% CI 0.51-2.43). Our results indicated that there was a significantly increased risk of GBS during the pandemic season and after pandemic influenza infection. However, vaccination did not increase the risk of GBS. The small number of GBS cases in this study warrants caution in the interpretation of the findings.

BACKGROUND According to Norwegian guidelines, infections caused by Chlamydia trachomatis should be treated rapidly with antibiotics and a control test should be offered after 5-6 weeks. The purpose of the present registry study was to investigate Chlamydia treatment and the use of control tests among men and women tested for Chlamydia in South Trondelag county in the period 2004-2006. MATERIAL AND METHODS Data on all Chlamydia tests from men and women 15-59 years of age resident in South Trondelag County were retrieved from the Department of Medical Microbiology at St. Olavs Hospital. Information about Norwegian pharmacies' handling of prescriptions for antibiotics were obtained from the Norwegian Prescription Database (NorPD). RESULTS 8.5% (3,127/36 590) of those tested for Chlamydia in the study period were positive. Among those who were positive 87% (1,681/1 920) of women and 74% (909/1,207) of men bought antibiotics from a pharmacy within 4 weeks after the test was analyzed. The average time from available test result to treatment was 13.1 days (95% CI 12.7-13.5). Among those who received antibiotics, 41% (689/1,681) of women and 27% (247/909) of men were registered with a control test 4-16 weeks after the prescription was handled. INTERPRETATION Compliance to guidelines for treatment and follow-up of people with a positive Chlamydia test is poor, especially among men.

Background: Chlamydia trachomatis is a highly prevalent sexually transmitted disease. Testing rates among young Norwegian women are high. Young women diagnosed with C. trachomatis are often worried about future complications. Methods: Our cohort consisted of 24,947 women born 1970–1984 who were tested for C. trachomatis infection during 1990–2005. We linked C. trachomatis laboratory data to data on hospitalizations for pelvic inflammatory disease during 1990–2005. Cox regression analysis with time-dependent covariates adjusted for age at first test was used to assess the association between C. trachomatis history and pelvic inflammatory disease. Results: Follow-up until the end of 2005 included 201,387 woman-years. The incidence rate of hospitalization for pelvic inflammatory disease was higher among women with prior C. trachomatis infection than among women with negative tests only (48 events during 32,057 person-years and 143 events during 169,192 person-years, corresponding to 0.15 and 0.08 per 100 person-years, respectively). The corresponding hazard ratio adjusted for age at first test was 1.69 (95% CI, 1.21– 2.36). Conclusion: Our data show a link between a diagnosis of C. trachomatis infection and subsequent pelvic inflammatory disease. However, pelvic inflammatory disease was a rare event irrespective of C. trachomatis status. These, together with other recent findings, can be used to reassure women worried about their future reproductive health following a diagnosis of C. trachomatis. © 2009 Bakken and Ghaderi; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.