Abstract Background Evidence on the role of exogenous female sex steroid hormones in asthma development in women remains conflicting. We sought to quantify the potential causal role of hormonal contraceptives and menopausal hormone therapy (MHT) in the development of asthma in women. Methods We conducted a matched case–control study based on the West Sweden Asthma Study, nested in a representative cohort of 15,003 women aged 16–75 years, with 8-year follow-up (2008–2016). Data were analyzed using Frequentist and Bayesian conditional logistic regression models. Results We included 114 cases and 717 controls. In Frequentist analysis, the odds ratio (OR) for new-onset asthma with ever use of hormonal contraceptives was 2.13 (95% confidence interval [CI] 1.03–4.38). Subgroup analyses showed that the OR increased consistently with older baseline age. The OR for new-onset asthma with ever MHT use among menopausal women was 1.17 (95% CI 0.49–2.82). In Bayesian analysis, the ORs for ever use of hormonal contraceptives and MHT were, respectively, 1.11 (95% posterior interval [PI] 0.79–1.55) and 1.18 (95% PI 0.92–1.52). The respective probability of each OR being larger than 1 was 72.3% and 90.6%. Conclusions Although use of hormonal contraceptives was associated with an increased risk of asthma, this may be explained by selection of women by baseline asthma status, given the upward trend in the effect estimate with older age. This indicates that use of hormonal contraceptives may in fact decrease asthma risk in women. Use of MHT may increase asthma risk in menopausal women.

Insomnia and snoring are common sleep disorders. The aim was to investigate the association of having a combination of insomnia symptoms and snoring with comorbidity and daytime sleepiness. The study population comprised 25,901 participants (16–75 years, 54.4

Background Over the last decade, computational sciences have contributed immensely to characterization of phenotypes of airway diseases, but it is difficult to compare derived phenotypes across studies, perhaps as a result of the different decisions that fed into these phenotyping exercises. We aim to perform a systematic review of studies using computational approaches to phenotype obstructive airway diseases in children and adults. Methods and analysis We will search PubMed, Embase, Scopus, Web of Science, and Google Scholar for papers published between 2010 and 2020. Conferences proceedings, reference list of included papers, and experts will form additional sources of literature. We will include observational epidemiological studies that used a computational approach to derive phenotypes of chronic airway diseases, whether in a general population or in a clinical setting. Two reviewers will independently screen the retrieved studies for eligibility, extract relevant data, and perform quality appraisal of included studies. A third reviewer will arbitrate any disagreements in these processes. Quality appraisal of the studies will be undertaken using the Effective Public Health Practice Project quality assessment tool. We will use summary tables to describe the included studies. We will narratively synthesize the generated evidence, providing critical assessment of the populations, variables, and computational approaches used in deriving the phenotypes across studies Conclusion As progress continues to be made in the area of computational phenotyping of chronic obstructive airway diseases, this systematic review, the first on this topic, will provide the state of the art on the field and highlight important perspectives for future works. Ethics and dissemination No ethical approval is needed for this work is based only on the published literature and does not involve collection of any primary or human data. Registration and reporting Systematic review registration PROSPERO CRD42020164898

BACKGROUND:Restrictive lung function may indicate various underlying diseases. The aim of this study was to evaluate the accuracy of different restrictive spirometry patterns (RSPs) to identify restrictive lung function (total lung capacity [TLC] < lower limit of normal [LLN]) according to reference values by the Global Lung Function Initiative (GLI) in a wide age-ranged, general population sample.METHODS:A general population sample (n = 607, age 23-72 years, smokers 18.8%) with proper dynamic spirometry and TLC measurements, was included. Accuracy of two main categories of RSP to identify TLC < LLN were evaluated: traditional RSPs (definition 1: FVC < 80% of predicted and FEV1 /FVC ≥ 0.7 and definition 2: FVC < LLN and FEV1 /FVC ≥ LLN) and RSPs defined by Youden's method (definition 3: FVC < 85.5% of predicted and FEV1 /FVC ≥ LLN and definition 4: FVC Z-score < -1.0 and FEV1 /FVC ≥ LLN).RESULTS:The prevalence of restrictive lung function (TLC < LLN) was 5.3%. The most accurate cut-offs for FVC to identify TLC < LLN were 85.5% for FVC% of predicted, and -1.0 for FVC Z-score. The traditional RSP definitions 1 and 2 had higher specificity (95.0% and 96.9%) but substantially lower sensitivity compared to RSP definitions 3 and 4.CONCLUSION:Based on the GLI reference values, the RSP definition FVC < LLN and FEV1 /FVC ≥ LLN yielded the highest specificity and may appropriately be used to rule out restrictive lung function. The RSP definition with the most favourable trade-off between sensitivity and specificity, FVC < 85.5% of predicted and FEV1 /FVC ≥ LLN, may serve as an alternative with higher sensitivity for screening.

Background: Evidence abounds on the independent roles of social class and smoking in relation to obstructive airway diseases, but data are sparse on the impact of their interaction. We evaluated whether and to what extent social class and smoking interact in relation to risk of respiratory diseases in adults. Methods: Data from the population-based studies, West Sweden Asthma Study (WSAS, n = 23,753) and Obstructive Lung Disease in Northern Sweden studies (OLIN, n = 6519), were used, constituting randomly selected adults aged 20-75 years. Bayesian network analysis was used to estimate the probability for the interaction between smoking and socioeconomic status in relation to respiratory outcomes. Results: Occupational and educational SES modified the association between smoking and the probability of allergic and non-allergic asthma. Former smokers who were at intermediate non manual employees and manual workers in service had higher probability of allergic asthma compared to professionals and executives. Furthermore, former smokers with primary education had higher probability of non-allergic asthma than those with secondary and tertiary education. Similarly, former smokers among professionals and executives had higher probability of non-allergic asthma than manual and home workers and primary educated. Likewise, allergic asthma due to former smoking was higher among highly educated compared to low educated. Conclusions: Beyond their independent roles, socioeconomic status and smoking interact in defining the risk of respiratory diseases. Clearer understanding of this interaction can help to identify population subgroups at most need of public health interventions.

BACKGROUND:As the prevalence of dog allergy rises, component resolved diagnosis might improve the diagnosis, understanding of the clinical outcomes and the effectiveness of immunotherapy. Considering the paucity of data in adults, the current study characterized the patterns of sensitization to dog molecular allergens in an adult population.METHODS:Data were derived from the West Sweden Asthma Study, a population-based and representative sample of adults from western Sweden. Of the 2006 subjects clinically examined, 313 participants sensitized to whole dog allergen extract were measured for specific immunoglobulin E (sIgE) levels to Can f 1, Can f 2, Can f 3, Can f 4, Can f 5 and Can f 6 using ImmunoCAP™. Polysensitization was defined as sensitization to ≥3 components. Overlapping sensitization was defined as having concomitant sensitization to at least two dog molecular allergen families (lipocalin, albumin or prostatic kallikrein).RESULTS:Of 313, 218 (70%) subjects tested positive to at least one dog allergen component. Sensitization to Can f 1 (43%) was the most common, followed by Can f 5 (33%) among molecular allergens, while sensitization to lipocalins (56%) was the most common among component families. Polysensitization was found in 22% of all participants and was more common in participants with than in those without asthma. Subjects with asthma were less likely to be monosensitized to Can f 5 than those without asthma. Subjects with asthma had higher IgE levels of Can f 3, Can f 4 and Can f 6 than those without asthma. Overlapping sensitizations also differed between those with asthma and allergic rhinitis and those without.CONCLUSION:Increased knowledge about the sensitization patterns of dog allergen components can aid in defining their role in asthma and rhinitis. In complex clinical cases of dog allergy, a detailed analysis of dog allergen components can provide additional information on the nature of sensitization.

Background Nonsteroidal anti-inflammatory drugs (NSAIDs) may exacerbate respiratory symptoms. A recent European Academy of Allergy and Clinical Immunology position paper recommended the use of an acronym, N-ERD (NSAID-exacerbated respiratory disease), for this hypersensitivity associated with asthma or chronic rhinosinusitis with or without nasal polyposis. Our aim was to estimate the prevalence of N-ERD and identify factors associated with N-ERD. Methods In 2016, a cross-sectional questionnaire survey of a random adult population of 16 000 subjects aged 20–69 years was performed in Helsinki and Western Finland. The response rate was 51.5%. Results The prevalence was 1.4% for N-ERD, and 0.7% for aspirin-exacerbated respiratory disease (AERD). The prevalence of N-ERD was 6.9% among subjects with asthma and 2.7% among subjects with rhinitis. The risk factors for N-ERD were older age, family history of asthma or allergic rhinitis, long-term smoking and exposure to environmental pollutants. Asthmatic subjects with N-ERD had a higher risk of respiratory symptoms, severe hypersensitivity reactions and hospitalisations than asthmatic subjects without N-ERD. The subphenotype of N-ERD with asthma was most symptomatic. Subjects with rhinitis associated with N-ERD, which would not be included in AERD, had the fewest symptoms. Conclusion We conclude that the prevalence of N-ERD was 1.4% in a representative Finnish adult population sample. Older age, family history of asthma or allergic rhinitis, cumulative exposure to tobacco smoke, secondhand smoke, and occupational exposures increased odds of N-ERD. N-ERD was associated with significant morbidity.

BACKGROUND:Allergic sensitization increases the risk of asthma and allergic rhinitis, but the impact of age at onset of sensitization is less studied. OBJECTIVE:To examine the cumulative incidence of asthma and rhinitis up to age 19 years in relation to age at onset of sensitization to airborne allergens. METHOD:All children in grade 1 and 2 (median age, 8 years) in 2 municipalities in Northern Sweden were invited to undergo skin prick tests and answer a questionnaire about allergic diseases, and 88% participated. At ages 12 and 19 years, the protocol was repeated, and 1510 individuals participated in all 3 examinations. Specific IgE data were collected in a random sample at age 19 years (n = 770). Onset of sensitization was defined: 8 years or less, 8 to 12 years, 12 to 19 years, and never sensitized. Adjusted Poisson regression was used to calculate risk ratios (RRs). RESULTS:At 19 years, those sensitized at 8 years of age or earlier had the highest risk of asthma (RR, 4.68; 95% CI, 3.15-6.97) and rhinitis (RR, 22.3; 95% CI, 13.3-37.6), and 84% had developed either asthma or rhinitis. The combination of sensitization at age 8 years or earlier and family history of allergic diseases rendered high risks for asthma (RR, 10.6; 95% CI, 6.71-16.7) and rhinitis (RR, 36.3; 95% CI, 18.9-69.7). Individuals sensitized at age 8 years or earlier showed significantly highest level of sensitization, as judged by number of positive skin test results and titers of specific IgE. CONCLUSIONS:Most individuals with sensitization at age 8 years or earlier developed asthma or rhinitis before young adulthood. The high level of sensitization in those sensitized early contributes to the high incidence of allergic airway conditions.

Background There remains uncertainty about the impact of menopausal hormone therapy (MHT) on women’s health. A systematic, comprehensive assessment of the effects on multiple outcomes is lacking. We conducted an umbrella review to comprehensively summarize evidence on the benefits and harms of MHT across diverse health outcomes. Methods and findings We searched MEDLINE, EMBASE, and 10 other databases from inception to November 26, 2017, updated on December 17, 2020, to identify systematic reviews or meta-analyses of randomized controlled trials (RCTs) and observational studies investigating effects of MHT, including estrogen-alone therapy (ET) and estrogen plus progestin therapy (EPT), in perimenopausal or postmenopausal women in all countries and settings. All health outcomes in previous systematic reviews were included, including menopausal symptoms, surrogate endpoints, biomarkers, various morbidity outcomes, and mortality. Two investigators independently extracted data and assessed methodological quality of systematic reviews using the updated 16-item AMSTAR 2 instrument. Random-effects robust variance estimation was used to combine effect estimates, and 95% prediction intervals (PIs) were calculated whenever possible. We used the term MHT to encompass ET and EPT, and results are presented for MHT for each outcome, unless otherwise indicated. Sixty systematic reviews were included, involving 102 meta-analyses of RCTs and 38 of observational studies, with 102 unique outcomes. The overall quality of included systematic reviews was moderate to poor. In meta-analyses of RCTs, MHT was beneficial for vasomotor symptoms (frequency: 9 trials, 1,104 women, risk ratio [RR] 0.43, 95% CI 0.33 to 0.57, p < 0.001; severity: 7 trials, 503 women, RR 0.29, 95% CI 0.17 to 0.50, p = 0.002) and all fracture (30 trials, 43,188 women, RR 0.72, 95% CI 0.62 to 0.84, p = 0.002, 95% PI 0.58 to 0.87), as well as vaginal atrophy (intravaginal ET), sexual function, vertebral and nonvertebral fracture, diabetes mellitus, cardiovascular mortality (ET), and colorectal cancer (EPT), but harmful for stroke (17 trials, 37,272 women, RR 1.17, 95% CI 1.05 to 1.29, p = 0.027) and venous thromboembolism (23 trials, 42,292 women, RR 1.60, 95% CI 0.99 to 2.58, p = 0.052, 95% PI 1.03 to 2.99), as well as cardiovascular disease incidence and recurrence, cerebrovascular disease, nonfatal stroke, deep vein thrombosis, gallbladder disease requiring surgery, and lung cancer mortality (EPT). In meta-analyses of observational studies, MHT was associated with decreased risks of cataract, glioma, and esophageal, gastric, and colorectal cancer, but increased risks of pulmonary embolism, cholelithiasis, asthma, meningioma, and thyroid, breast, and ovarian cancer. ET and EPT had opposite effects for endometrial cancer, endometrial hyperplasia, and Alzheimer disease. The major limitations include the inability to address the varying effects of MHT by type, dose, formulation, duration of use, route of administration, and age of initiation and to take into account the quality of individual studies included in the systematic reviews. The study protocol is publicly available on PROSPERO (CRD42017083412). Conclusions MHT has a complex balance of benefits and harms on multiple health outcomes. Some effects differ qualitatively between ET and EPT. The quality of available evidence is only moderate to poor.

Background: Obesity is an important risk factor for adult-onset asthma, but the association between obesity and markers of inflammation has rarely been studied in this patient group. Aim: To study the associations between obesity and inflammatory markers in adult-onset asthma. Methods: Population-based samples have been recruited since 1985 within the OLIN studies in northern Sweden. In 2019-2020, previous participants were invited to follow-ups including structured interviews, spirometry, measurements of FeNO, skin prick testing and blood sampling, in which n=251 with asthma onset after 15 years of age participated. BMI was categorized as: underweight (<18.5), normal weight (18.5-24.9.0), overweight (25.0-29.9), obesity (30.0-34.9) and severe obesity (≥35). Results: In total, 66.1% were women, mean age: 62.7 years, mean BMI: 29.1, and 0.0% had underweight, 22.2% normal weight, 41.1% overweight, 26.2% obesity, and 10.5% severe obesity. Allergic sensitization, FeNO and blood eosinophils did not differ significantly between BMI categories. The mean blood neutrophils (*109/L) differed accordingly: 3.7 in normal weight, 3.5 in overweight, 3.6 in obesity, and 5.3 in severe obesity (p<0.001). When dichotomizing blood neutrophils by different thresholds, the highest proportions were consistently seen in severe obesity, among which e.g. 83.3% had blood neutrophils≥4.0*109/L compared to 31.5% in normal weight (p<0.001). This difference was significant also when adjusted for age, sex, and smoking by regression analysis (OR 13.8, 95%CI 3.8-49.4). The lowest mean FEV1 (82.5%) and FVC (82.4%) percent of predicted were observed in severe obesity. Conclusion: Severe obesity is strongly associated with blood neutrophils in adult-onset asthma.

Objective Education in itself and as a proxy for socioeconomic status, may influence asthma control, but remains poorly studied in adult-onset asthma. Our aim was to study the association between the level of education and asthma control in adult-onset asthma. Methods Subjects with current asthma with onset >15 years were examined within the Obstructive Lung Disease in Northern Sweden study (OLIN, n = 593), Seinajoki Adult Asthma Study (SAAS, n = 200), and West Sweden Asthma Study (WSAS, n = 301) in 2009-2014 in a cross-sectional setting. Educational level was classified as primary, secondary and tertiary. Uncontrolled asthma was defined as Asthma Control Test (ACT) score <= 19. Altogether, 896 subjects with complete data on ACT and education were included (OLIN n = 511, SAAS n = 200 and WSAS n = 185). Results In each cohort and in pooled data of all cohorts, median ACT score was lower among those with primary education than in those with secondary and tertiary education. Uncontrolled asthma was most common among those with primary education, especially among daily ICS users (42.6% primary, 28.6% secondary and 24.2% tertiary; p = 0.001). In adjusted analysis, primary education was associated with uncontrolled asthma in daily ICS users (OR 1.92, 95% CI 1.15-3.20). When stratified by atopy, the association between primary education and uncontrolled asthma was seen in non-atopic (OR 3.42, 95% CI 1.30-8.96) but not in atopic subjects. Conclusions In high-income Nordic countries, lower educational level was a risk factor for uncontrolled asthma in subjects with adult-onset asthma. Educational level should be considered in the management of adult-onset asthma.

Objective Habitual snoring is associated with fatigue, headaches and low work performance. This cross-sectional study aimed to investigate if snoring is affected by environmental factors such as home dampness and exposure to air pollution. Setting General population sample from four Swedish cities. Participants 25 848 participants from the Swedish part of the epidemiological Global Asthma and Allergy and European network of excellence study carried out in 2008. The participants completed a postal questionnaire on snoring and, indoor and outdoor environmental exposure as well as potential confounders including smoking, weight, height and educational level. Results Of the participants, 4211 (16.3%) were habitual snorers. Habitual snorers reported water damage (8.3% vs 7.0% p<0.0001), floor dampness (4.6% vs 3.8% % p<0.0001) and visible mould (5.2% vs 3.8% p<0.0001) in their homes more often than non-snorers. Habitual snorers stated being annoyed by air pollution more often than non-snorers with habitual snorers reporting being irritated with the air in their residential area to a higher extent (sometimes 16.2% vs 13.9%, and daily 4.6% vs 3.1%) as well as annoyance from traffic fumes (somewhat 19% vs 18.5% and very 5% vs 3.6%) (p<0.0001). These results remained significant after adjustment for age, body mass index, smoking history and educational level. Conclusion Snoring is more prevalent in subjects reporting home dampness and air pollution. These association should be confirmed in further research using objective measurements and a longitudinal approach.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Background: Obesity-related asthma is associated with increased severity and female dominance. Increased aeroallergen sensitization is common in asthma. There remains uncertainty as to what extent aeroallergen sensitization is related to obesity and modified by gender in asthma patients. We examined the frequency of sensitization to aeroallergens by obesity and gender amongst asthmatics. Methods: Within the West Sweden Asthma Study, of 2006 subjects that underwent extensive clinical examinations, 878 were with active asthma. Sensitization to aeroallergens, animal pollen and mite, was defined as a positive IgE level ≥ 0,35 kUA/L. Results: Most of the 878 asthmatics were women (60%). Most were either normal (BMI< 25)or overweight ( BMI 25-29.9), 32% and 41%, respectively. Every fourth patient (27%) was obese (BMI ≥30). Women dominated in each group (66 /55/60,75 % respectively). In the asthmatics with normal BMI, no differences in sensitization to any aeroallergen between men and women (66 % vs. 58 %, p= 0,178 ) were found, while in overweight (72 % vs 44%, p< 0,001) and obese (58 vs 35%, p=0,001) men were significantly more often sensitized than women. The same pattern was observed in poly-sensitization status (sensitization to ≥ 2aeroallergens). Obese women had a lower odds ratio for atopic asthma (0.59 95% CI 0.38-0.91) compared to men. Conclusions: The prevalence of sensitization to aeroallergens is similar between men and women when patients are lean. Among overweight and obese patients, sensitization prevalence is lower among women while remaining higher within men.

Objective: To study occupational groups and occupational exposure in association with chronic obstructive respiratory diseases. Methods: In early 2000s, structured interviews on chronic respiratory diseases and measurements of lung function as well as fractional expiratory nitric oxide (F-ENO) were performed in adult random population samples of Finland, Sweden and Estonia. Occupations were categorized according to three classification systems. Occupational exposure to vapours, gases, dusts and fumes (VGDF) was assessed by a Job-Exposure Matrix (JEM). The data from the countries were combined. Results: COPD, smoking and occupational exposure were most common in Estonia, while asthma and occupations requiring higher educational levels in Sweden and Finland. In an adjusted regression model, non-manual workers had a three-fold risk for physician-diagnosed asthma (OR 3.18, 95%CI 1.07-9.47) compared to professionals and executives, and the risk was two-fold for healthcare & social workers (OR 2.28, 95%CI 1.14-4.59) compared to administration and sales. An increased risk for physician-diagnosed COPD was seen in manual workers, regardless of classification system, but in contrast to asthma, the risk was mostly explained by smoking and less by occupational exposure to VGDF. For F-ENO, no associations with occupation were observed. Conclusions: In this multicenter study from Finland, Sweden and Estonia, COPD was consistently associated with manual occupations with high smoking prevalence, highlighting the need to control for tobacco smoking in studies on occupational associations. In contrast, asthma tended to associate with non-manual occupations requiring higher educational levels. The occupational associations with asthma were not driven by eosinophilic inflammation presented by increased F-ENO.

Citation for published version: Zhang, G-Q, Chen, J-L, Luo, Y, Mathur, MB, Anagnostis, P, Nurmatov, U, Talibov, M, Zhang, J, Hawrylowicz, CM, Lumsden, MA, Critchley, H, Sheikh, A, Lundbäck, B, Lässer, C, Kankaanranta, H, Lee, SH & Nwaru, BI 2021, 'Menopausal hormone therapy and women's health: An umbrella review', PLoS Medicine, vol. 18, no. 8, pp. e1003731. https://doi.org/10.1371/journal.pmed.1003731

Background Smoking and occupational airborne exposures are known to increase asthma symptoms, but less is known about their influence by the age of asthma diagnosis. Objective To evaluate the effect of exposures to VGDF (vapors, gases, dusts and fumes), tobacco smoke and their combination for asthma symptoms comparing subjects with asthma diagnosed in childhood and adulthood. Methods A random sample of 16 000 adults aged 20–69 years were invited to a postal survey on obstructive pulmonary diseases in Finland in 2016. Those reporting physician-diagnosed asthma and age at diagnosis were included in the analysis and their reported VGDF-exposure and smoking habits were analyzed. Age 18 years was chosen to delineate child- and adult-diagnosed asthma. Results 8199 (51.5%) responded. Of the responders, 831 reported physician-diagnosed asthma. 41% of asthmatics reported child-diagnosed and 59% adult-diagnosed asthma. Current smoking was reported by 25.2% and 20.2% and VGDF exposure by 31.3% and 44.7% in child -diagnosed and adult-diagnosed asthma, respectively. Combined VGDF-exposure and current smoking was reported by 9.7% and 10.6%, respectively. Compared to the unexposed, those with asthma diagnosed in childhood and with combined current smoking and VGDF exposure, had higher prevalence of wheeze (69.7% vs 39.5%, p=0.009), sputum production (39.4% vs 11.4%, p=0.001) and morning dyspnea (42.4% vs 21.9%, p=0.002). Corresponding pattern was seen in those with asthma diagnosed in adulthood; for wheeze (78.8% vs 53.6%, p=0.007), sputum production (40.4% vs 25.0%, p=0.014) and morning dyspnea (65.4% vs 42.0%, p=0.008). Child-diagnosed asthmatics both without exposure history (46.5% vs 69.6%, p=0.001) and with combined exposure to smoking and VGDF (66.7% vs 94.2%, p=0.003) reported less often ≥3 symptoms compared to adult-diagnosed asthmatics, even though they reported less frequently use of asthma medication (60.7% vs 82.0%, p>0.001). Smoking asthmatics with adult-diagnosis and exposure to VGDF had the highest prevalence estimates of having multiple symptoms (94.2%) in our study. Conclusion Although asthmatics diagnosed in child- and adulthood reported symptoms related to exposure to smoking and VGDF, symptoms were reported more often by those with adult diagnosis. The results indicate the importance of targeted asthma treatment and follow-up by patient's exposure history and asthma diagnosis age.

Background: In 2019, WHO estimated COPD to be the third leading cause of death in the world. However, COPD is probably underestimated as cause of death due to the well-known under-diagnosis. Aim: To evaluate the proportion of and factors associated with COPD recorded as cause of death in a long-term follow-up of a population-based COPD cohort. Methods: The study population includes all individuals (n = 551) with COPD defined as chronic airway obstruction (post-bronchodilator FEV1/FVC<0.70) + respiratory symptoms identified after re-examinations of four population-based cohorts. Mortality and underlying or contributing cause of death following ICD-10 classification were collected from the Swedish National Board of Health and Welfares register from date of examination in 2002-04 until 2016. Results: The study sample consisted of 32.3% GOLD 1, 55.9% GOLD 2, and 11.8% GOLD 3-4. The mean follow-up time was 10.3 (SD3.77) years and the cumulative mortality 45.0%. COPD (ICD-10 J43-J44) was recorded on 28.2% (n = 70) of the death certificates (11.1%, 25.7% and 57.1% by GOLD stage), whereof n = 35 had COPD recorded as underlying and n = 35 as contributing cause of death. To have COPD recorded as cause of death was independently associated with ex- and current smoking and a self-reported physician diagnosis of COPD, while male sex, overweight/obesity and higher FEV1% of predicted associated with the absence. Conclusions: COPD was largely underreported cause of death. Even among those with severe/very severe disease, COPD was only mentioned on 57.1% of the death certificates.

In Sweden, physicians have faced major changes in their working conditions over the past three to four decades. Sweden is now ranked second or third among the 27 EU countries with the lowest number of hospital beds in relation to the population size. Regarding respiratory medicine, departments are now fewer in number and smaller than previously, and in most hospitals they are small sections within departments of internal medicine. Above that, for some decades, the ruling system of public health care has followed the ideas of ‘new public management’, which has resulted in an increased bureaucracy parallel to working conditions somewhat resembling industrial assembly lines. Parallel to these changes, the healthcare system in Sweden has faced an increased privatization both of primary and specialist care. Related or unrelated to this, it is noted that the relative proportion of original scientific articles from Sweden in international peer-reviewed journals has decreased, which is also true for respiratory medicine. The decrease in Swedish impact on research of respiratory diseases, and of the Scandinavian countries as well, is reflected by the history of the European scientific journals within the field of respiratory medicine. The Scandinavian Journal of Respiratory Diseases was highly reputable 40 years ago. It merged with the Belgian journal Acta Tuberculosea et Pneumologica Belgica in 1985 to form the European Journal of Respiratory Diseases (the precursor of the modern European Respiratory Journal), with its first editors being Erik Berglund from Sweden and Jean-Claude Yernault from Belgium. The development of the journals is not bad in itself, but it reflects changes in the impact of Sweden and Scandinavia in Europe. Scandinavia and Sweden have a strong focus on epidemiology. Two recent large-scale population studies on respiratory health, the West Sweden Asthma Study (WSAS) in the south-west and Obstructive Lung Disease in Northern Sweden (OLIN), indicate the prevalence of asthma is still increasing in Sweden, although the increase seems to be levelling off.1, 2 The prevalence of adult asthma is today about 10%, slightly higher than found in 2008 in the Swedish part of the GA(2)LEN collaboration in four centres in different parts of the country. With the introduction of biologics, severe asthma has become a greater focus, with a prevalence estimated at 0.5–1% of the general adult population in Sweden.3 Collaboration of research and management of severe asthma is in progress with researchers and physicians in the Nordic countries, as well as within the European Respiratory Society and the European Academy of Allergy and Clinical Immunology. Specialist units for management of severe asthma, and for guidance of other units, are under development in Sweden. Another major field of respiratory medicine, as in most countries, is chronic obstructive pulmonary disease (COPD). Primary care units are the main bodies for COPD patient care. This is in collaboration with lung departments at hospitals in case of exacerbations that need hospitalization or more complex care. There are only a few specialized units for COPD management in Sweden, with the leading one in the second largest city of Gothenburg. As in all European countries, there is considerable under-diagnosis of COPD. Reasons are the same as in most other countries, that is, lack of use of spirometry in primary care in combination with the slow progress of disease in the majority of cases. However, nation-wide standard-of-care programmes are being developed for multiple common non-communicable diseases including COPD, which might importantly improve the rate of a correct (!) diagnosis. Interestingly, it was recently shown that after decades of decreases in smoking, the prevalence of COPD has finally started after the millennium shift to go down. COPD prevalence was recently estimated at 8.6% in people aged ≥40 years in population-based studies using the fixed-ratio definition, and slightly lower when the lower limit of normal criteria of obstruction is applied.4 The decrease in prevalence is most pronounced for moderate to severe COPD. However, COPD mortality is still increasing among women, in contrast to men. Sweden is a country of registers coupled to the unique personal identifier number of each individual. There is a national patient register, a national cause of death register, a socio-economic register and also multiple registries related to chronic diseases such as diabetes and heart failure. In 2013, the Swedish National Airway Registry started; nowadays, more than 1000 clinics are participating from both primary and secondary care with registered data on 205,833 patients with asthma and 80,372 with COPD. The aim of the registry is to improve the care for people with airway disease by providing the key indicators for follow-up, direct feedback to registering units and creating new possibilities for research questions.5 Several researchers are involved in international co-operative projects. For example, both the GA(2)LEN and European Respiratory Health Survey (ECRHS) collaborations cover the Nordic and Baltic countries with Professor Christer Janson from the University of Uppsala as PI for the Nordic-Baltic parts. The collaborations have resulted in several publications on asthma and allergic diseases in high impact journals, including sleep medicine.6 Finally, a few words about coronavirus disease 2019 (COVID-19). Sweden had an unusual coronavirus control strategy, relative to other countries. The focus was an initial aim for herd immunity through viral infection, an aim also communicated during the spring of 2020 by Swedish infection control physicians. Compared to the other Nordic countries, the strategy resulted in a more rapid increase in cases and deaths (Table 1). While incremental interventions are being introduced to control the spread of the virus in Sweden, in our view, there is still not sufficient recognition in the national strategy of potentially effective measures such as more strict quarantine and mandatary use of masks. The vaccination campaign has started and many of the most vulnerable have already been vaccinated. However, a third wave of COVID-19 is pending. Discussions on what works and what does not continue throughout the world, but particularly in Sweden. The authors declare that they have no conflicts of interest.

Multimorbidity is an emerging public health priority. This study aims to assess the role of lifestyle and socioeconomic status in the prevalence of multimorbidity and chronic diseases by using two language groups that are part of the same genetic subgroup but differ by daily habits. We conducted a cross-sectional survey in 2016 with randomly selected population sample with 4173 responders (52.3%) aged 20-69 years in Western Finland. We included 3864 Finnish participants with Swedish (28.1%) or Finnish (71.9%) as a native language. We used a questionnaire to assess participants' chronic diseases and lifestyle. We determined multimorbidity as a disease count ≥ 2. Finnish speakers were more likely to have a diagnosis of COPD, heart failure, diabetes, reflux disease, chronic kidney failure, and painful conditions than Swedish speakers. The prevalence of multimorbidity was higher for Finnish speakers in the age group of 60-69 years (41.0% vs. 32.0%, p = 0.018) than Swedish speakers. A higher proportion of Finnish speakers smoked, were obese, inactive, and had lower socioeconomic status compared to Swedish speakers. All these factors, in addition to age and female sex, were significant risk factors for multimorbidity. Prevalence of multimorbidity was different in two language groups living in the same area and was associated with differences in lifestyle factors such as smoking, physical inactivity and obesity.