Individual and neighborhood risk factors of hospital admission and death during the COVID-19 pandemic: a population-based cohort study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) disproportionately affects minority populations in the USA. Sweden - like other Nordic countries - have less income and wealth inequality but lacks data on the socioeconomic impact on the risk of adverse outcomes due to COVID-19. METHODS: This population-wide study from March 2020 to March 2022 included all adults in Stockholm, except those in nursing homes or receiving in-home care. Data sources include hospitals, primary care (individual diagnoses), the Swedish National Tax Agency (death dates), the Total Population Register "RTB" (sex, age, birth country), the Household Register (size of household), the Integrated Database For Labor Market Research "LISA" (educational level, income, and occupation), and SmiNet (COVID data). Individual exposures include education, income, type of work and ability to work from home, living area and living conditions as well as the individual country of origin and co-morbidities. Additionally, we have data on the risks associated with living areas. We used a Cox proportional hazards model and logistic regression to estimate associations. Area-level covariates were used in a principal component analysis to generate a measurement of neighborhood deprivation. As outcomes, we used hospitalization and death due to COVID-19. RESULTS: Among the 1,782,125 persons, male sex, comorbidities, higher age, and not being born in Sweden increase the risk of hospitalization and death. So does lower education and lower income, the lowest incomes doubled the risk of death from COVID-19. Area estimates, where the model includes individual risks, show that high population density and a high percentage of foreign-born inhabitants increased the risk of hospitalization. CONCLUSIONS: Segregation and deprivation are public health issues elucidated by COVID-19. Neighborhood deprivation, prevalent in Stockholm, adds to individual risks and is associated with hospitalization and death. This finding is paramount for governments, agencies, and healthcare institutions interested in targeted interventions.

A population-based cohort study of sex and risk of severe outcomes in covid-19.

There is a male sex disadvantage in morbidity and mortality due to COVID-19. Proposed explanations to this disparity include gender-related health behaviors, differential distribution of comorbidities and biological sex differences. In this study, we investigated the association between sex and risk of severe COVID-19 while adjusting for comorbidities, socioeconomic factors, as well as unmeasured factors shared by cohabitants which are often left unadjusted. We conducted a total-population-based cohort study (n = 1,854,661) based on individual-level register data. Cox models was used to estimate the associations between sex and risk for severe COVID-19. We additionally used a within-household design and conditional Cox models aiming to account for unmeasured factors shared by cohabitants. A secondary aim was to compare the risk of COVID-19 related secondary outcomes between men and women hospitalized due to COVID-19 using logistic regression. Men were at higher risk for hospitalization (HR = 1.63;95%CI = 1.57-1.68), ICU admission (HR = 2.63;95%CI = 2.38-2.91) and death (HR = 1.81;95%CI = 1.68-1.95) due to COVID-19, based on fully adjusted models. However, the effect of sex varied significantly across age groups: Among people in their 50s, men had > four times higher risk of COVID-19 death. The within-household design did not provide any further explanation to the sex disparity. Among patients hospitalized due to COVID-19, men had an increased risk for viral pneumonia, acute respiratory distress syndrome, acute respiratory insufficiency, acute kidney injury, and sepsis which persisted in fully adjusted models. Recognition of the combined effect of sex and age on COVID-19 outcomes has implications for policy strategies to reduce the adverse effects of the disease.

Risk factors for COVID-19-related death, hospitalization and intensive care: a population-wide study of all inhabitants in Stockholm.

Since the beginning of the Covid-19 pandemic, the scientific community has explored determinants of Covid 19 disease severity. However, the majority of studies are based on in-hospital patients with high risk of collider- or selection bias. The present investigation details risk factors associated with overall mortality, hospitalization and intensive care unit (ICU) admission in Covid-19 infections, with complete population coverage and high-resolution data on patient characteristics and comorbid conditions This population-based observational study comprises all residents 18 years and older in Stockholm Region-1.8 million inhabitants-using the real-time Covid-19 monitoring framework. The observation period lasted between March 1 to December 31, 2020. Hazard ratios (HR) for risk factors of Covid-19 disease severity were assessed using Cox proportional hazard models. In total, 3322 deaths, 11,508 hospitalizations and 1423 ICU-admissions related to Covid-19 occurred during the study period. Kidney failure, diabetes and obesity increased risk of mortality and so did heart failure and ischemic heart disease. However, atrial fibrillation and hypertension did not. Risk of hospitalization follow a similar pattern, whereas admission to intensive care differs; triage processes where clearly present as certain co-morbid conditions were associated with lower ICU admission. Observed differences in risk of mortality and hospitalization among patients with Covid 19 raise important questions about potentially protective comedication which will be further addressed using the real-time Covid-19 monitoring framework.

HMG-CoA reductase inhibitors and COVID-19 mortality in Stockholm, Sweden: A registry-based cohort study.

BACKGROUND: The relationship between statin treatment and Coronavirus Disease 2019 (COVID-19) mortality has been discussed due to the pleiotropic effects of statins on coagulation and immune mechanisms. However, available observational studies are hampered by study design flaws, resulting in substantial heterogeneity and ambiguities. Here, we aim to determine the relationship between statin treatment and COVID-19 mortality. METHODS AND FINDINGS: This cohort study included all Stockholm residents aged 45 or older (N = 963,876), followed up from 1 March 2020 until 11 November 2020. The exposure was statin treatment initiated before the COVID-19-pandemic, defined as recorded statin dispensation in the Swedish Prescribed Drug Register between 1 March 2019 and 29 February 2020. COVID-19-specific mortality was ascertained from the Swedish Cause of Death Registry. Hazard ratios (HRs) were calculated using multivariable Cox regression models. We further performed a target trial emulation restricted to initiators of statins. In the cohort (51.6% female), 169,642 individuals (17.6%) were statin users. Statin users were older (71.0 versus 58.0 years), more likely to be male (53.3% versus 46.7%), more often diagnosed with comorbidities (for example, ischemic heart disease 23.3% versus 1.6%), more frequently on anticoagulant and antihypertensive treatments, less likely to have a university-level education (34.5% versus 45.4%), and more likely to have a low disposable income (20.6% versus 25.2%), but less likely to reside in crowded housing (6.1% versus 10.3%). A total of 2,545 individuals died from COVID-19 during follow-up, including 765 (0.5%) of the statin users and 1,780 (0.2%) of the nonusers. Statin treatment was associated with a lowered COVID-19 mortality (adjusted HR, 0.88; 95% CI, 0.79 to 0.97, P = 0.01), and this association did not vary appreciably across age groups, sexes, or COVID-19 risk groups. The confounder adjusted HR for statin treatment initiators was 0.78 (95% CI, 0.59 to 1.05, P = 0.10) in the emulated target trial. Limitations of this study include the observational design, reliance on dispensation data, and the inability to study specific drug regimens. CONCLUSIONS: Statin treatment had a modest negative association with COVID-19 mortality. While this finding needs confirmation from randomized clinical trials, it supports the continued use of statin treatment for medical prevention according to current recommendations also during the COVID-19 pandemic.

Evaluation of the latent tuberculosis screening and treatment strategy for asylum seekers in Stockholm, Sweden 2015-2018: a record linkage study of the care cascade.

INTRODUCTION: About 90% of active tuberculosis (TB) cases in Sweden are foreign born and are mainly due to latent TB infection (LTBI) reactivation. The aim of this study was to assess the current migrant LTBI screening programme with regards to test results and completion of the care cascade. METHOD: A retrospective cohort of all 14173 individuals attending a health examination was established for the Stockholm Region 2015-2018 through record-linkage of data extracted from the Swedish Migration Authority and medical records. Screening results, referrals to specialist care and treatment initiation were ascertained through automated data extraction for the entire cohort. Detailed cascade steps, including treatment completion, were analysed through manual data extraction for a subsample of all persons referred to specialist care in the period 2016-2017. RESULTS: Of 5470 patients screened with an interferon-gamma release assay (IGRA), 1364 (25%) were positive, of whom 358 (26%) initiated LTBI treatment. An increased trend in IGRA-positivity was seen for increased age and TB-incidence in country of origin. Among the IGRA positive patients, 604 (44%) were referred to specialist care. Lower age was the main referral predictor. In the subsample of 443 patients referred to specialist care in 2016-2017, 386 (87%) were invited, of whom 366 (95%) attended. Of 251 patients (69%) recommended for LTBI treatment, 244 (97%) started such treatment and of those 221 (91%) completed it. CONCLUSION: The low attrition in patient-dependent cascade steps shows that the voluntary approach works well. Low LTBI treatment attainment is due to the current conservative local treatment policy, which means the vast majority are IGRA-tested without an intention to treat for LTBI.

Mid-season real-time estimates of seasonal influenza vaccine effectiveness in persons 65 years and older in register-based surveillance, Stockholm County, Sweden, and Finland, January 2017.

Systems for register-based monitoring of vaccine effectiveness (VE) against laboratory-confirmed influenza (LCI) in real time were set up in Stockholm County, Sweden, and Finland, before start of the 2016/17 influenza season, using population-based cohort studies. Both in Stockholm and Finland, an early epidemic of influenza A(H3N2) peaked in week 52, 2016. Already during weeks 48 to 50, analyses of influenza VE in persons 65 years and above showed moderately good estimates of around 50%, then rapidly declined by week 2, 2017 to 28% and 32% in Stockholm and Finland, respectively. The sensitivity analyses, where time since vaccination was taken into account, could not demonstrate a clear decline, neither by calendar week nor by time since vaccination. Most (68%) of the samples collected from vaccinated patients belonged to the 3C.2a1 subclade with the additional amino acid substitution T135K in haemagglutinin (64%) or to subclade 3C.2a with the additional haemagglutinin substitutions T131K and R142K (36%). The proportion of samples containing these alterations increased during the studied period. These substitutions may be responsible for viral antigenic change and part of the observed VE drop. Another possible cause is poor vaccine immunogenicity in older persons. Improved influenza vaccines are needed, especially for the elderly.

Investigation of a food-borne outbreak of gastroenteritis in a school canteen revealed a variant of sapovirus genogroup V not detected by standard PCR, Sollentuna, Sweden, 2016.

A food-borne outbreak of gastroenteritis with more than 650 suspected cases occurred in April 2016 in Sollentuna, Sweden. It originated in a school kitchen serving a total of 2,700 meals daily. Initial microbiological testing (for Campylobacter, Salmonella, Shigella, Yersinia, Giardia, Cryptosporidium, Entamoeba histolytica, adeno-, astro-, noro-, rota- and sapovirus) of stool samples from 15 symptomatic cases was negative, despite a clinical presentation suggestive of calicivirus. Analyses of the findings from both the Sollentuna municipality environmental team and a web-based questionnaire suggested that the source of the outbreak was the salad buffet served on 20 April, although no specific food item could be identified. Subsequent electron microscopic examination of stool samples followed by whole genome sequencing revealed a variant of sapovirus genogroup V. The virus was not detected using standard PCR screening. This paper describes the epidemiological outbreak investigation and findings leading to the discovery.

Prevalence of gastro-esophageal reflux disease and its risk factors in a community-based population in southern India.

BACKGROUND: The prevalence of gastro-esophageal reflux disease (GERD) varies widely around the world. This study aimed to investigate the prevalence and risk factors of GERD in a general population of southern India. METHODS: An interview-based observational study was carried out in southern India during 2010 and early 2011 using a GERD questionnaire (GerdQ). In total 1072 participants were enrolled using a multi-stage cluster sampling method. Presence of GERD was defined as a score of ≥ 8. Logistic regression models were used to derive odds ratios (ORs) with 95 % confidence intervals (CIs). RESULTS: The prevalence of GERD was 22.2 % (238/1072) in southern India, and was more common among older subjects and men. Overweight and obese subjects had a dose-dependent increased risk of GERD, compared to those with body mass index less than 25 (multivariate-adjusted OR = 1.4, 95 % CI 1.0-2.0; OR = 2.3, 95 % CI 1.3-4.1, respectively). People residing in urban community were more vulnerable to GERD than those in rural community (multivariate-adjusted OR = 1.8, 95 % CI 1.3-2.5). Similarly, those with a lower educational level appeared to have an increased risk of GERD. Further, those with a habit of pan masala chewing were more likely to develop GERD compared with those abstained from the habit (multivariate-adjusted OR = 2.0, 95 % CI 1.2-3.2). CONCLUSIONS: GERD is highly prevalent in southern India. Increasing age and BMI, an urban environment, lower educational level, and pan masala chewing appear to be risk factors of GERD symptoms for the studied population.

Real-time real-world analysis of seasonal influenza vaccine effectiveness: method development and assessment of a population-based cohort in Stockholm County, Sweden, seasons 2011/12 to 2014/15.

Real-world estimates of seasonal influenza vaccine effectiveness (VE) are important for early detection of vaccine failure. We developed a method for evaluating real-time in-season vaccine effectiveness (IVE) and overall seasonal VE. In a retrospective, register-based, cohort study including all two million individuals in Stockholm County, Sweden, during the influenza seasons from 2011/12 to 2014/15, vaccination status was obtained from Stockholm's vaccine register. Main outcomes were hospitalisation or primary care visits for influenza (International Classification of Disease (ICD)-10 codes J09-J11). VE was assessed using Cox multivariate stratified and non-stratified analyses adjusting for age, sex, socioeconomic status, comorbidities and previous influenza vaccinations. Stratified analyses showed moderate VE in prevention of influenza hospitalisations among chronically ill adults ≥ 65 years in two of four seasons, and lower but still significant VE in one season; 53% (95% confidence interval (CI): 33-67) in 2012/13, 55% (95% CI: 25-73) in 2013/14 and 18% (95% CI: 3-31) in 2014/15. In conclusion, seasonal influenza vaccination was associated with substantial reductions in influenza-specific hospitalisation, particularly in adults ≥ 65 years with underlying chronic conditions. With the use of population-based patient register data on influenza-specific outcomes it will be possible to obtain real-time estimates of seasonal influenza VE.

Use of Scandinavian moist smokeless tobacco (snus) and the risk of atrial fibrillation.

BACKGROUND: Snus is a smokeless tobacco product, widely used among Swedish men and increasingly so elsewhere. There is debate as to whether snus is an acceptable "harm-reduction" tobacco product. Since snus use delivers a dose of nicotine equivalent to cigarettes, and has been implicated in cardiac arrhythmia because of associations with sudden cardiovascular death, a relation with atrial fibrillation is plausible and important to investigate. METHODS: To assess the relation between use of snus and risk of atrial fibrillation, we carried out a pooled analysis of 7 prospective Swedish cohort studies. In total, 274,882 men, recruited between 1978 and 2004, were followed via the National Patient Register for atrial fibrillation. Primary analyses were restricted to 127,907 never-smokers. Relative risks were estimated using Cox proportional hazard regression. RESULTS: The prevalence of snus use was 25% among never-smokers. During follow-up, 3,069 cases of atrial fibrillation were identified. The pooled relative risk of atrial fibrillation was 1.07 (95% confidence interval = 0.97-1.19) in current snus users, compared with nonusers. CONCLUSION: Findings from this large national pooling project indicate that snus use is unlikely to confer any important increase in risk of atrial fibrillation.

Use of snus and acute myocardial infarction: pooled analysis of eight prospective observational studies.

The use of snus (also referred to as Scandinavian or Swedish moist smokeless tobacco), which is common in Sweden and increasing elsewhere, is receiving increasing attention since considered a tobacco smoke "potential reduction exposure product". Snus delivers a high dose of nicotine with possible hemodynamic effects, but its impact on cardiovascular morbidity and mortality is uncertain. The aim of this study was to investigate whether snus use is associated with risk of and survival after acute myocardial infarction (AMI). Data from eight prospective cohort studies set in Sweden was pooled and reanalysed. The relative risk of first time AMI and 28-day case-fatality was calculated for 130,361 men who never smoked. During 2,262,333 person-years of follow-up, 3,390 incident events of AMI were identified. Current snus use was not associated with risk of AMI (pooled multivariable hazard ratio 1.04, 95 % confidence interval 0.93 to 1.17). The short-term case fatality rate appeared increased in snus users (odds ratio 1.28, 95 % confidence interval 0.99 to 1.68). This study does not support any association between use of snus and development of AMI. Hence, toxic components other than nicotine appear implicated in the pathophysiology of smoking related ischemic heart disease. Case fatality after AMI is seemingly increased among snus users, but this relationship may be due to confounding by socioeconomic or life style factors.

The early impact of vaccination against SARS-CoV-2 in Region Stockholm, Sweden.

Vaccination against SARS-CoV-2 started in Region Stockholm, Sweden in December 2020 with those in long-term care facilities or receiving home care vaccinated first followed by those aged over 80 years. In this population-based, retrospective cohort study, we performed a Poisson regression to model the expected incidence of infections and deaths which we compared to the observed incidence and compared this to an unvaccinated control group of those aged 18-79 years. The aim of this study was to measure the early impact of the vaccination programme in Region Stockholm. Infections and deaths reduced substantially amongst the first two groups targeted for SARS-CoV-2 vaccination with an estimated total 3112 infections prevented, and 854 deaths prevented in these two groups from 4 weeks after the introduction of vaccination through to 2nd May 2021.

Smoking, use of moist snuff, and risk of chronic inflammatory diseases.

RATIONALE: Cigarette smoking is emerging as a strong risk factor in the otherwise unknown etiology of chronic inflammatory diseases. Whether the same applies also to smokeless tobacco remains unknown. Nicotine is a powerful modifier of the inflammatory response. By comparing risks associated with tobacco smoking and with smokeless tobacco, the role of nicotine in the development of chronic inflammation may be evaluated. OBJECTIVES: To assess and compare the risks of rheumatoid arthritis (RA), ulcerative colitis (UC), Crohn's disease (CD), sarcoidosis, and multiple sclerosis (MS) associated with cigarette smoking and with the use of Swedish moist snuff. METHODS: We performed a cohort study of 277,777 males within a cohort of Swedish construction workers who had provided information about tobacco use in 1978-1993. Cross-linkage to the nationwide Swedish Hospital Discharge Register provided information about the occurrence of RA, UC, CD, sarcoidosis, and MS through 2004. MEASUREMENTS AND MAIN RESULTS: Age-adjusted relative risks (RRs) associated with smoking and moist snuff, respectively, were estimated by Cox regression. Ever-smoking was associated with an increased risk for RA (RR, 2.1; 95% confidence interval [CI], 1.7-2.5), CD (RR, 1.5; 95% CI, 1.2-1.8), MS (RR, 1.9; 95% CI, 1.4-2.6), and UC (RR, 1.3; 95% CI, 1.1-1.5, confined to ex-smokers), and a decreased risk of sarcoidosis (RR, 0.5; 95% CI, 0.4-0.5). By contrast, ever-use of moist snuff, adjusted for smoking, was not associated with RA (RR, 1.0; 95% CI, 0.9-1.2), UC (RR, 1.1; 95% CI, 0.9-1.2), CD (RR, 0.9; 95% CI, 0.8-1.1), sarcoidosis (RR, 1.1; 95% CI, 0.8-1.5), or MS (RR, 1.0; 95% CI, 0.8-1.4). CONCLUSIONS: Smokeless tobacco does not increase the risk of chronic inflammatory diseases, suggesting that inhaled nonnicotinic components of cigarette smoke are more important than nicotine itself in the etiology of these diseases.

Weight gain and incident obesity among male snus users.

BACKGROUND: Snus is a moist smokeless tobacco product which has recently reached beyond its original market of Scandinavia. Snus is now being increasingly used in both the United States and South Africa. The effect of snus use on weight is unknown. This study has therefore investigated the relationship between the use of snus, weight gain (≥5%) and the incidence of obesity (body mass index ≥30 kg/m(2)). METHODS: The study participants (n = 9,954 males living in Stockholm County, Sweden) were recruited in 2002 and reassessed in 2007. Tobacco use was categorized according to information obtained in both the baseline and follow-up surveys. Outcomes were assessed by comparing self-reported weight and body mass index between the baseline and follow-up surveys. RESULTS: Stable current snus use (according to both surveys), compared to never having used any kind of tobacco, seemed to be associated with both weight gain (odds ratio = 1.31, 95% confidence interval: 1.04-1.65) and incident obesity (odds ratio = 1.93, 95% confidence interval: 1.13-3.30) after adjustment for age, baseline weight, alcohol consumption, physical activity, education, consumption of fruit and berries, and the frequency of having breakfast. No associations with incident obesity or weight gain were seen for stable former users of snus (according to both surveys) or among men who quit or began using snus during follow-up. CONCLUSIONS: These data suggest that the use of snus is moderately associated with weight gain and incident obesity among men.

Cost-effectiveness of the latent tuberculosis screening program for migrants in Stockholm Region.

INTRODUCTION: The majority of tuberculosis (TB) cases in Sweden occur among migrants from endemic countries through activation of latent tuberculosis infection (LTBI). Sweden has LTBI-screening policies for migrants that have not been previously evaluated. This study aimed to assess the cost-effectiveness of the current screening strategy in Stockholm. METHODS: A Markov model was developed to predict the costs and effects of the current LTBI-screening program compared to a scenario of no LTBI screening over a 50-year time horizon. Epidemiological and cost data were obtained from local sources when available. The primary outcomes were incremental cost-effectiveness ratio (ICER) in terms of societal cost per quality-adjusted life year (QALY). RESULTS: Screening migrants in the age group 13-19 years had the lowest ICER, 300,082 Swedish Kronor (SEK)/QALY, which is considered cost-effective in Sweden. In the age group 20-34, ICER was 714,527 SEK/QALY (moderately cost-effectives) and in all age groups above 34 ICERs were above 1,000,000 SEK/QALY (not cost-effective). ICER decreased with increasing TB incidence in country of origin. CONCLUSION: Screening is cost-effective for young cohorts, mainly between 13 and 19, while cost-effectiveness in age group 20-34 years could be enhanced by focusing on migrants from highest incidence countries and/or by increasing the LTBI treatment initiation rate. Screening is not cost-effective in older cohorts regardless of the country of origin.

Blood pressure, body size and prostate cancer risk in the Swedish Construction Workers cohort.

Data from prospective studies on blood pressure and prostate cancer risk are limited, and results are inconclusive. Baseline measurements of height, weight and blood pressure were available in 336,159 men in the Swedish Construction Workers cohort. During an average of 22.2 years of follow-up, 10,002 incident cases and 2,601 fatal cases of prostate cancer were identified in National registers. For 5,219 cases, tumor characteristics were available; 2,817 tumors were classified as nonaggressive and 2,402 as aggressive. Relative risks of disease were estimated from Cox regression models, using attained age as time-scale, and adjusting for birth year, smoking status and body mass index (BMI). Top compared to bottom quintile level of systolic or diastolic blood pressure was associated with a significant 15-20% decreased risk of incident prostate cancer (p for trend: systolic < 0.0001, diastolic = 0.3), but blood pressure was not significantly associated with risk of fatal prostate cancer. BMI was not associated with prostate cancer incidence, but was positively associated with fatal prostate cancer; men in the top quintile had a 30% increased risk (p for trend = 0.0004). The associations between blood pressure and BMI and nonaggressive tumors were similar to those of incident prostate cancer, and associations with aggressive tumors were similar to those of fatal prostate cancer. Data from our study suggest that hypertension is associated with a decreased risk of incident prostate cancer, but the explanation for this finding is unclear. Our study support a positive association between overweight and risk of fatal prostate cancer.

Building a European database to gather multi-country evidence on active and latent TB screening for migrants.

BACKGROUND AND AIM: Screening for active and latent TB among migrants in low TB incidence countries may constitute an important contribution to TB elimination. E-DETECT TB, a European multi-county collaboration, aims to address the present lack of evidence on effectiveness of migrant TB screening by collating data in an international database and perform cross-country pooled and comparative analyses of screening coverage, results and linkage to care. METHOD: A database was established using migrant TB screening data from participating countries' national screening programs, national screening pilots and local research projects. All partner countries contributed to a common agreed protocol with standardized variables, pooling available numerator and denominator screening data from participating countries and sites. RESULTS: All collaborating members drafted and agreed upon a data sharing accord as well as a protocol that clearly defined responsibilities and data governance principles. The database has been created and data transfer is ongoing. CONCLUSION: By persistence and focus the project has overcome considerable administrative, practical and legal challenges. This international collaboration provides greater power of analysis of harmonized data and thereby a unique opportunity to contribute migrant TB screening evidence. E-DETECT TB has started to invite other countries to contribute data to the database.

Smokeless tobacco and the risk of stroke.

BACKGROUND: : In Sweden, use of smokeless tobacco (oral moist snuff) is common among adult men. Research on cerebrovascular effects associated with long-term use of snuff is limited and inconclusive. We aimed to study whether long-term use of snuff affects the risk of stroke. METHODS: : Information on tobacco use was collected by questionnaire among Swedish construction workers attending health check-ups between 1978 and 1993. In total, 118,465 never-smoking men without a history of stroke were followed through 2003. We used the Inpatient Register and Causes of Death Register to identify subsequent morbidity and mortality from stroke and its subtypes (ischemic, hemorrhagic, and unspecified stroke). Relative risk estimates were derived from Cox proportional hazards regression model. RESULTS: : Almost 30% of the nonsmoking men had ever used snuff. Overall, 3248 cases of stroke were identified during follow-up. Compared with nonusers of tobacco, the multivariable-adjusted relative risks for ever-users of snuff were 1.02 (95% confidence interval; 0.92-1.13) for all cases and 1.27 (0.92-1.76) for fatal cases. Further analyses on subtypes of stroke revealed an increased risk of fatal ischemic stroke associated with current snuff use (1.72; 1.06-2.78), whereas no increased risk was noted for hemorrhagic stroke. CONCLUSION: : Snuff use may elevate the risk of fatal stroke, and particularly of fatal ischemic stroke.

Impact of repeated influenza vaccinations in persons over 65 years of age: A large population-based cohort study of severe influenza over six consecutive seasons, 2011/12-2016/17.

BACKGROUND: A forty-year debate on the potential negative effects of repeated seasonal influenza vaccination has been inconclusive, with multiple observational studies of various design providing heterogeneous results too inadequate to inform vaccination policy. METHODS: A large population-based cohort study including over one-million observations in individuals over age 65 from six consecutive seasons (2011/12-2016/17) in Stockholm County, Sweden. Current season vaccine effectiveness (VE) against severe, mostly hospital-attended, influenza was assessed using Cox multivariate regression analyses adjusting for demographic variables, comorbidities and previous seasonal influenza vaccination status. RESULTS: In none of the six seasons was VE significantly different in persons vaccinated in the current season only, compared to those who had been vaccinated in both the current and the previous season. Neither were there any differences in VE during the seasons 2014/15-2016/17 when comparing persons vaccinated during the current season only vs. those vaccinated during one-three or four-five previous influenza seasons. In contrast, persons only vaccinated during one or more previous years had no protection during the current season. CONCLUSIONS: Persons above 65 years are the largest group at risk for severe or complicated influenza and policy should support their yearly seasonal influenza vaccination, which is to-date the best preventive measure available for all risk groups. No negative effects of repeated seasonal vaccination were seen in this large population-based cohort of older persons with severe influenza, which strengthens the recommendation that persons belonging to this age group should be vaccinated yearly.

Estimating costs and health outcomes of publicly funded tick-born encephalitis vaccination: A cost-effectiveness analysis.

BACKGROUND: The number of notified cases of Tick-Borne Encephalitis (TBE) in Sweden has been increasing the past years despite the increased use of TBE-vaccine not subsidized by the healthcare system. Stockholm County is a high endemic area and an earlier study has shown that low-income households have lower vaccination coverage even when they are at high risk. This paper aims to determine the cost-effectiveness of a publicly funded TBE vaccination program in Stockholm. METHODS: In three different cohorts with individuals aged 3, 40 or 50 years, long-term costs and health outcomes of an out-of-pocket strategy (53% of the cohort is vaccinated on their own expenses) and a structured vaccination program (full cohort is vaccinated covered by the publicly funded health care system), were estimated using a Markov model. The Markov model predicts the costs and effects in term of Quality-adjusted Life Years (QALYs) over a lifetime horizon using a third-party healthcare payer perspective. The primary results are presented as an incremental cost effectiveness ratio (ICER) indicating the additional cost required to achieve one additional QALY with the structured vaccination program. RESULTS: The results show that the structured vaccination program is associated with a gain in QALYs and increased costs compared with an out-of-pocket strategy. The calculated ICERs were 27 761, 99 527 and 160 827 SEK/QALY in cohorts of age 3, 40 and 50, respectively. The sensitivity analyses showed that the results are robust when varying different parameters. CONCLUSION: Given the setting of Stockholm county, this analysis shows a cost per QALY of a free vaccinations program, especially for children of 3 years old, below generally acceptable cost-effectiveness thresholds in Sweden.