| 41. |
- Backman, Helena, et al.
(författare)
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Decreased prevalence of moderate to severe COPD over 15 years in northern Sweden
- 2016
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 114, s. 103-110
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Tidskriftsartikel (refereegranskat)abstract
- Background: The burden of COPD in terms of mortality, morbidity, costs and prevalence has increased worldwide. Recent results on prevalence in Western Europe are conflicting. In Sweden smoking prevalence has steadily decreased over the past 30 years. Aim: The aim was to study changes in prevalence and risk factor patterns of COPD in the same area and within the same age-span 15 years apart. Material and methods: Two population-based cross-sectional samples in ages 23-72 years participating at examinations in 1994 and 2009, respectively, were compared in terms of COPD prevalence, severity and risk factor patterns. Two different definitions of COPD were used; FEV1/FVC < LLN and FEV1/FVC < 0.7. The severity of COPD was assessed by FEV1, both as % of predicted and in relation to the LLN. Results: The prevalence of COPD decreased significantly from 9.5% to 6.3% (p = 0.030) according to the FEV1/FVC < LLN criterion, while the decrease based on the FEV1/FVC < 0.7 criterion from 10.5% to 8.5% was non-significant. The prevalence of moderate to severe COPD decreased substantially and significantly, and the risk factor pattern was altered in 2009 when, beside age and smoking, also socioeconomic status based on occupation was significantly associated with COPD. Conclusions: Changes in both prevalence and risk factor patterns of COPD were observed between surveys. Following a continuing decrease in smoking habits over several decades, a decrease in the prevalence of moderate to severe COPD was observed from 1994 to 2009 in northern Sweden.
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| 42. |
- Backman, Helena, et al.
(författare)
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Decreased prevalence of moderate to severe COPD over 15 years in northern Sweden
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: The burden of COPD in terms of mortality, morbidity, costs and prevalence has increased worldwide. Recent results on prevalence in Western Europe are conflicting. In Sweden smoking prevalence has steadily decreased over the past 30 years. Aim: The aim was to study changes in prevalence and risk factor patterns of COPD in the same area and within the same age-span 15 years apart.Material and methods: Two population-based cross-sectional samples in ages 23-72 years participating at examinations in 1994 and 2009, respectively, were compared in terms of COPD prevalence, severity and risk factor patterns. Two different definitions of COPD were used; FEV1/FVC1/FVC<0.7. The severity of COPD was assessed by FEV1, both as % of predicted and in relation to the LLN.Results: The prevalence of COPD decreased significantly from 9.5% to 6.3% (p=0.030) according to the FEV1/FVC1/FVC<0.7 criterion from 10.5% to 8.5% was non-significant. The prevalence of moderate to severe COPD decreased substantially and significantly, and the risk factor pattern was altered in 2009 when, beside age and smoking, also socio-economic status based on occupation was significantly associated with COPD. Conclusions: Changes in both prevalence and risk factor patterns of COPD were observed between surveys. Following a continuing decrease in smoking habits over several decades, a decrease in the prevalence of moderate to severe COPD was observed from 1994 to 2009 in northern Sweden.
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| 43. |
- Backman, Helena, et al.
(författare)
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Eosinophilic inflammation and lung function decline in a long-term follow-up of a large population-based asthma cohort
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 52
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The relationship between lung function decline and airway inflammation among asthmatics has important therapeutic implications, but has rarely been studied in large samples or in population-based asthma cohorts.A population-based adult asthma cohort (n=2055) was recruited during 1986-2001 and clinically examined including spirometry. In 2012-2014, all still eligible subjects (n=1425) were invited to a clinical follow-up including spirometry, blood sampling, and a structured interview, and n=1006 participated (55% women, mean age 59y, 32-92y). Linear regression was performed with age, sex, smoking habits, year of first examination, family history of asthma, socioeconomic status, eosinophils (EOS)>=0.3x109/L, and neutrophils (NEUT)>=5.0x109/L as independent variables and pre-bronchodilator FEV1 decline/year (ml and % of predicted [pp], respectively) as dependent. In secondary models, both ICS use at baseline and ICS use at follow-up were also included.The mean annual FEV1 decline in ml (pp) among asthmatics with EOS<0.3, 0.4>EOS>=0.3 and EOS>=0.4x109/L, respectively, was 26ml (0.03pp), 29ml (0.10pp) and 34ml (0.27pp) (p<0.001). In adjusted analyses, EOS>=0.3 was significantly associated with FEV1 decline, both in terms of ml (4ml excess annual decline vs EOS<0.3) and pp. The association between EOS and FEV1 decline in pp, but not ml, remained when additionally adjusted for ICS use. The association with NEUT>=5.0x109/L was less clear.On group level, adult asthmatics with higher levels of eosinophils in blood have a history of excess FEV1 decline compared to asthmatics with lower levels of eosinophil inflammation, independent of other factors such as ICS use.
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| 44. |
- Backman, Helena, et al.
(författare)
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FEV1 decline in relation to blood eosinophils and neutrophils in a population-based asthma cohort
- 2020
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Ingår i: World Allergy Organization Journal. - : Elsevier. - 1939-4551. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: The relationship between lung function decline and eosinophils and neutrophils has important therapeutic implications among asthmatics, but it has rarely been studied in large cohort studies.Objective: The aim is to study the relationship between blood eosinophils and neutrophils and FEV1 decline in a long-term follow-up of a population-based adult asthma cohort.Methods: In 2012-2014, an adult asthma cohort was invited to a follow-up including spirometry, blood sampling, and structured interviews, and n = 892 participated (55% women, mean age 59 y, 32-92 y). Blood eosinophils, neutrophils and FEV 1 decline were analyzed both as continuous variables and divided into categories with different cut-offs. Regression models adjusted for smoking, exposure to vapors, gas, dust, or fumes (VGDF), use of inhaled and oral corticosteroids, and other possible confounders were utilized to analyze the relationship between eosinophils and neutrophils at follow-up and FEV1 decline.Results: The mean follow-up time was 18 years, and the mean FEV 1 decline was 27 ml/year. The annual FEV1 decline was related to higher levels of both blood eosinophils and neutrophils at follow-up, but only the association with eosinophils remained when adjusted for confounders. Further, the association between FEV1 decline and eosinophils was stronger among those using ICS. With EOS <0.3 × 109/L as reference, a more rapid decline in FEV1 was independently related to EOS ≥0.4 × 109/L in adjusted analyses.Conclusions and clinical relevance: Besides emphasizing the importance of smoking cessation and reduction of other harmful exposures, our real-world results indicate that there is an independent relationship between blood eosinophils and FEV1 decline among adults with asthma.
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| 45. |
- Backman, Helena, 1979-
(författare)
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Lung function and prevalence trends in asthma and COPD
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Asthma and chronic obstructive pulmonary disease (COPD) are common obstructive airway diseases with a substantial burden in terms of morbidity, mortality and costs. Smoking is the single most important risk factor for COPD, and is associated with incident asthma. It is important to know if the prevalence of asthma and COPD is increasing or decreasing in the population in order to effectively allocate health care resources. The definitions of these diseases have varied over time which makes it difficult to measure changes in prevalence. The preferred method is to estimate the prevalence with the same procedures and definitions based on cross-sectional population samples with identical age distributions in the same geographical area at different time points. Measurements of lung function (spirometry) are required to diagnose COPD, and spirometry is used to evaluate disease severity and progress of both asthma and COPD, where observed values are compared to reference values. The most commonly used reference values in Sweden are published during the mid 1980s, and there are few evaluations of how appropriate they are today based on Swedish population samples. The aim of the thesis was to estimate trends in the prevalence of asthma and COPD in relation to smoking habits, and to evaluate and estimate reference values for spirometry.Methods: The project was based on population-based samples of adults from the Obstructive Lung Disease in Northern Sweden (OLIN) studies. Postal questionnaires were sent to large cohorts, recruited in 1992 (n=4851, 20-69 years), 1996 (n=7420, 20-74 years) and 2006 (n=6165, 20-69 years), respectively. The questionnaire included questions on respiratory symptoms and diseases, their comorbidities and several possible risk factors including smoking habits. Structured interviews and spirometry were performed in random samples of the responders to the 1992 and 2006 surveys, of which n=660 (in 1994) and n=623 (in 2009) were within identical age-spans (23-72 years). The trend in asthma prevalence was estimated by comparing the postal questionnaire surveys in 1996 and 2006, and the trend in COPD prevalence was estimated by comparing the samples participating in dynamic spirometry in 1994 and 2009, respectively. The prevalence of COPD was estimated based on two different definitions of COPD. Commonly used reference values for spirometry were evaluated based on randomly sampled healthy non-smokers defined in clinical examinations of participants in the 2006 postal questionnaire (n=501). The main focus of the evaluation was the global lung function initiative (GLI) reference values published in 2012, for which Z-scores and percent of predicted values were analysed. New sex-specific reference values for spirometry were estimated by linear regression, with age and height as predictors. These new OLIN reference values were also evaluated on a sample of healthy non-smokers identified in the population-based West Sweden Asthma Study.Results: Although the prevalence of smoking decreased from 27.4% to 19.1%, p<0.001, between 1996 and 2006, the prevalence of physician-diagnosed asthma increased from 9.4% to 11.6%, p<0.001. The prevalence of symptoms common in asthma such as recurrent wheeze did not change significantly between the surveys or tended to decrease, while bronchitis symptoms such as cough and sputum production decreased significantly. The evaluation of the GLI reference values showed that the predicted values were significantly lower compared to the observed values in Norrbotten, which makes the percent of predicted too high. This was especially true for FVC percent predicted with a mean of 106%. In general, the deviations were more pronounced among women. New OLIN reference values valid for the Norrbotten sample were modelled and showed a high external validity when applied on the sample from western Sweden. The prevalence of moderate to severe COPD decreased substantially over the 15-year period between 1994 and 2009, regardless of definition.Conclusions: In parallel with substantially decreased smoking habits in the population between 1996 and 2006, the prevalence of several airway symptoms decreased while the prevalence of physician-diagnosed asthma increased. These results suggest increased diagnostic activity for asthma, but may also suggest that the asthma prevalence has continued to increase. In contrast to asthma, the prevalence of COPD tended to decrease and moderate to severe COPD decreased substantially. The continuous decrease in smoking in Sweden during several decades prior to the study period is most likely contributing to these results. The evaluation of reference values showed that the GLI reference values were lower than the observed spirometric values in the population, especially for women, why the new up-to date reference values may be of importance for disease evaluation in epidemiology and in the health care as well.
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| 46. |
- Backman, Helena, et al.
(författare)
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Prevalence trends in respiratory symptoms and asthma in relation to smoking : two cross-sectional studies ten years apart among adults in northern Sweden
- 2014
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Ingår i: World Allergy Organization Journal. - : BioMed Central (BMC). - 1939-4551. ; 7:1, s. 1-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Smoking is considered to be the single most important preventable risk factor for respiratory symptoms. Estimating prevalence of respiratory symptoms is important since they most often precede a diagnosis of an obstructive airway disease, which places a major burden on the society. The aim of this study was to estimate prevalence trends of respiratory symptoms and asthma among Swedish adults, in relation to smoking habits. A further aim was to estimate the proportion of respiratory symptom and asthma prevalence attributable to smoking.METHODS: Data from two large-scale cross-sectional surveys among adults performed in northern Sweden in 1996 and 2006 were analysed. Identical methods and the same questionnaire were used in both surveys. The association between smoking, respiratory symptoms and asthma was analysed with multiple logistic regression analyses. Changes in prevalence of respiratory symptoms and asthma from 1996 to 2006 were expressed as odds ratios. Additionally, the population attributable risks of smoking were estimated.RESULTS: The prevalence of most respiratory symptoms decreased significantly from 1996 to 2006. Longstanding cough decreased from 12.4 to 10.1%, sputum production from 19.0 to 15.0%, chronic productive cough from 7.3 to 6.2%, and recurrent wheeze from 13.4 to 12.0%. Any wheeze and asthmatic wheeze remained unchanged. This parallels to a decrease in smoking from 27.4 to 19.1%. In contrast, physician-diagnosed asthma increased from 9.4 to 11.6%. The patterns were similar after correction for confounders. All respiratory symptoms were highly associated with smoking, and the proportion of respiratory symptoms in the population attributed to smoking (PAR) ranged from 9.8 to 25.5%. In 2006, PAR of smoking was highest for recurrent wheeze (20.6%).CONCLUSIONS: In conclusion, we found that respiratory symptoms, in particular symptoms common in bronchitis, decreased among adults in northern Sweden, parallel to a decrease in smoking from 1996 to 2006. In contrast, the prevalence of physician-diagnosed asthma increased during the same time-period. Up to one fourth of the respiratory symptom prevalence in the population was attributable to smoking.
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| 47. |
- Backman, Helena, et al.
(författare)
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Restrictive spirometric pattern in the general adult population: Methods of defining the condition and consequences on prevalence
- 2016
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 120, s. 116-123
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Tidskriftsartikel (refereegranskat)abstract
- Background Attempts have been made to use dynamic spirometry to define restrictive lung function, but the definition of a restrictive spirometric pattern (RSP) varies between studies such as BOLD and NHANES. The aim of this study was to estimate the prevalence and risk factors of RSP among adults in northern Sweden based on different definitions. Methods In 2008–2009 a general population sample aged 21–86y within the obstructive lung disease in northern Sweden (OLIN) studies was examined by structured interview and spirometry, and 726 subjects participated (71% of invited). The prevalence of RSP was calculated according to three different definitions based on pre-as well as post-bronchodilator spirometry: 1) FVC < 80% & FEV1/FVC > 0.7 2) FVC < 80% & FEV1/FVC > LLN 3) FVC < LLN & FEV1/FVC > LLN Results The three definitions yielded RSP prevalence estimates of 10.5%, 11.2% and 9.4% respectively, when based on pre-bronchodilator values. The prevalence was lower when based on post-bronchodilator values, i.e. 7.3%, 7.9% and 6.6%. According to definition 1 and 2, the RSP prevalence increased by age, but not according to definition 3. The overlap between the definitions was substantial. When corrected for confounding factors, manual work in industry and diabetes with obesity were independently associated with an increased risk for RSP regardless of definition. Conclusions The prevalence of RSP was 7–11%. The prevalence estimates differed more depending on the choice of pre- compared to post-bronchodilator values than on the choice of RSP definition. RSP was, regardless of definition, independently associated with manual work in industry and diabetes with obesity. © 2016 The Authors
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| 48. |
- Backman, Helena, et al.
(författare)
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Risk factors for severe asthma among adults with asthma
- 2020
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 56:Suppl 64
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Severe asthma is a considerable challenge for patients, health care professionals and society, but there are few long-term studies on risk factors for severe asthma.Aim: To identify baseline risk factors of severe asthma in a longitudinal adult asthma cohort study.Methods: An adult asthma cohort was identified in 1986-2001 by clinical examinations of population samples within the OLIN studies in northern Sweden. The examinations included structured interviews, spirometry with reversibility testing, skin prick testing and metacholine challenge. The cohort was followed up in 2012-2014 when n=1006 participated (mean age 59y). Adjusted Risk Ratios (RR) for baseline factors as risk factors for GINA defined severe asthma (SA) at follow-up (n=51) were estimated by Poisson regression.Results: Older age, impaired lung function, increased reversibility and hyperreactivity, asthmatic wheeze, persistent wheeze, nighttime awakenings due to respiratory symptoms, and dyspnea were significant baseline risk factors for SA. Allergic sensitization, smoking, occupational groups or BMI did not predict SA. When adjusted for age, sex and smoking, post-bronchodilator FEV1/FVC<0.7, both present at baseline (RR 4.2, 95%CI 1.8-9.9) and developed during follow-up (2.9, 1.6-5.3), increased the risk. Also FEV1<80% at baseline associated with SA (2.9, 1.6-5.2). Triggers for respiratory symptoms at baseline such as tobacco smoke (2.1, 1.2-3.7) and physical activity (3.5, 1.5-81) associated with SA at follow-up, while pollen and furry animals did not.Conclusion: Among adults with asthma, impaired lung function, wheeze, dyspnea and nighttime awakenings due to respiratory symptoms are important long-term risk factors for severe asthma.
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| 49. |
- Backman, Helena, et al.
(författare)
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Severe asthma : A population study perspective
- 2019
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Ingår i: Clinical and Experimental Allergy. - : John Wiley & Sons. - 0954-7894 .- 1365-2222. ; 49:6, s. 819-828
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundSevere asthma is a considerable challenge for patients, health care professionals and society. Few studies have estimated the prevalence of severe asthma according to modern definitions of which none based on a population study.ObjectiveTo describe characteristics and estimate the prevalence of severe asthma in a large adult population‐based asthma cohort followed for 10‐28 years.MethodsN=1006 subjects with asthma participated in a follow‐up during 2012‐14, when 830 (mean age 59y, 56% women) still had current asthma. Severe asthma was defined according to three internationally well‐known criteria: the ATS workshop definition from 2000 used in the US Severe Asthma Research Program (SARP), the 2014 ATS/ERS Task force definition and the GINA 2017. All subjects with severe asthma according to any of these criteria were undergoing respiratory specialist care, and were also contacted by telephone to verify treatment adherence.ResultsThe prevalence of severe asthma according to the three definitions was 3.6% (US SARP), 4.8% (ERS/ATS Taskforce), and 6.1% (GINA) among subjects with current asthma. Although all were using high ICS doses and other maintenance treatment, >40% had uncontrolled asthma according to the asthma control test. Severe asthma was related to age >50 years, nasal polyposis, impaired lung function, sensitization to aspergillus, and tended to be more common in women. Further, neutrophils in blood significantly discriminated severe asthma from other asthma.Conclusions and clinical relevanceSevere asthma differed significantly from other asthma in terms of demographic, clinical and inflammatory characteristics, results suggesting possibilities for improved treatment regimens of severe asthma. The prevalence of severe asthma in this asthma cohort was 4‐6%, corresponding to approximately 0.5% of the general population.
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| 50. |
- Backman, Helena, et al.
(författare)
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Severe asthma among adults : Prevalence and clinical characteristics
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 52
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Severe asthma is a considerable challenge for patients, health care professionals and society. Few studies have estimated the prevalence of severe asthma according to modern definitions of which none based on a population study.Methods: We estimated the prevalence and studied characteristics of severe asthma in a large adult population-based asthma cohort followed for 10-28 years in northern Sweden: 1006 subjects participated in a follow-up during 2012-14, when 830 (82.5%) still had current asthma (mean age 59y, 32-92y, 56% women). Severe asthma was defined according to three internationally well-known criteria: the US SARP, ATS/ERS and GINA. All subjects with severe asthma were undergoing respiratory specialist care, and were also contacted by telephone to verify adherence to treatment.Results: The prevalence of severe asthma according to the three definitions was 3.6% (US SARP), 4.8% (ERS/ATS), and 6.1% (GINA) among subjects with current asthma. Although all were using high ICS doses and other maintenance treatment, >40% had uncontrolled asthma and <10% had controlled asthma according to the ACT. Severe asthma was related to age >50 years, nasal polyposis, decreased FEV1, not fully reversible airway obstruction, sensitization to aspergillus, elevated neutrophils and partly to eosinophils, and tended to be more common in women.Conclusion: The prevalence of severe asthma in this asthma cohort was 4-6%, corresponding to approximately 0.5% of the population in northern Sweden. A substantial proportion of those with severe asthma had uncontrolled disease, and severe asthma differed significantly from other asthma in terms of both clinical and inflammatory characteristics.
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