Asthma and asthma symptom control in relation to incidence of lung cancer in the HUNT study.

Large prospective studies on asthma, especially asthma symptom control, as a potential risk factor for lung cancer are limited. We followed up 62,791 cancer-free Norwegian adults from 1995-1997 to 2017. Self-reported doctor-diagnosed asthma was categorized into active and non-active asthma. Levels of asthma symptom control were classified into controlled and partially controlled (including partly controlled and uncontrolled) according to the Global Initiative for Asthma guidelines. Incident lung cancer cases were ascertained from the Cancer Registry of Norway. Cox regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for possible associations. Totally, 984 participants developed lung cancer during a median follow-up of 21.1 years. After adjustment for smoking and other potential confounders, an increased incidence of lung cancer was found for adults with partially controlled asthma (HR 1.39, 95% CI 1.00-1.92) compared with those without asthma at baseline. Adults with active asthma had a tendency of increased lung cancer incidence (HR 1.29, 95% CI 0.95-1.75). Sensitivity analyses indicated that the observed associations were less likely resulted from reverse causation or residual confounding by smoking. Our findings suggested that proper control of asthma symptoms might contribute to a reduced incidence of lung cancer.

Mortality prediction in chronic obstructive pulmonary disease comparing the GOLD 2015 and GOLD 2019 staging: a pooled analysis of individual patient data.

In 2019, The Global Initiative for Chronic Obstructive Lung Disease (GOLD) modified the grading system for patients with COPD, creating 16 subgroups (1A-4D). As part of the COPD Cohorts Collaborative International Assessment (3CIA) initiative, we aim to compare the mortality prediction of the 2015 and 2019 COPD GOLD staging systems. We studied 17 139 COPD patients from the 3CIA study, selecting those with complete data. Patients were classified by the 2015 and 2019 GOLD ABCD systems, and we compared the predictive ability for 5-year mortality of both classifications. In total, 17 139 patients with COPD were enrolled in 22 cohorts from 11 countries between 2003 and 2017; 8823 of them had complete data and were analysed. Mean±sd age was 63.9±9.8 years and 62.9% were male. GOLD 2019 classified the patients in milder degrees of COPD. For both classifications, group D had higher mortality. 5-year mortality did not differ between groups B and C in GOLD 2015; in GOLD 2019, mortality was greater for group B than C. Patients classified as group A and B had better sensitivity and positive predictive value with the GOLD 2019 classification than GOLD 2015. GOLD 2015 had better sensitivity for group C and D than GOLD 2019. The area under the curve values for 5-year mortality were only 0.67 (95% CI 0.66-0.68) for GOLD 2015 and 0.65 (95% CI 0.63-0.66) for GOLD 2019. The new GOLD 2019 classification does not predict mortality better than the previous GOLD 2015 system.

Sex differences between women and men with COPD: A new analysis of the 3CIA study.

BACKGROUND: There is partial evidence that COPD is expressed differently in women than in men, namely on symptoms, pulmonary function, exacerbations, comorbidities or prognosis. There is a need to improve the characterization of COPD in females. METHODS: We obtained and pooled data of 17 139 patients from 22 COPD cohorts and analysed the clinical differences by sex, establishing the relationship between these characteristics in women and the prognosis and severity of the disease. Comparisons were established with standard statistics and survival analysis, including crude and multivariate Cox-regression analysis. RESULTS: Overall, 5355 (31.2%) women were compared with men with COPD. Women were younger, had lower pack-years, greater FEV1%, lower BMI and a greater number of exacerbations (all p < 0.05). On symptoms, women reported more dyspnea, equal cough but less expectoration (p < 0.001). There were no differences in the BODE index score in women (2.4) versus men (2.4) (p = 0.5), but the distribution of all BODE components was highly variable by sex within different thresholds of BODE. On prognosis, 5-year survival was higher in COPD females (86.9%) than in males (76.3%), p < 0.001, in all patients and within each of the specific comorbidities that we assessed. The crude and adjusted RR and 95% C.I. for death in males was 1.82 (1.69-1.96) and 1.73 (1.50-2.00), respectively. CONCLUSIONS: COPD in women has some characteristic traits expressed differently than compared to men, mainly with more dyspnea and COPD exacerbations and less phlegm, among others, although long-term survival appears better in female COPD patients.

GOLD Classifications, COPD Hospitalization, and All-Cause Mortality in Chronic Obstructive Pulmonary Disease: The HUNT Study.

Purpose: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) has published three classifications of COPD from 2007 to 2017. No studies have investigated the ability of these classifications to predict COPD-related hospitalizations. We aimed to compare the discrimination ability of the GOLD 2007, 2011, and 2017 classifications to predict COPD hospitalization and all-cause mortality. Patients and Methods: We followed 1300 participants with COPD aged ≥40 years who participated in the HUNT Study (1995-1997) through to December 31, 2015. Survival analysis and time-dependent area under receiver operating characteristics curves (AUC) were used to compare the discrimination abilities of the GOLD classifications. Results: Of the 1300 participants, 522 were hospitalized due to COPD and 896 died over 20.4 years of follow-up. In adjusted models, worsening GOLD 2007, GOLD 2011, or GOLD 2017 categories were associated with higher hazards for COPD hospitalization and all-cause mortality, except for the GOLD 2017 classification and all-cause mortality (ptrend=0.114). In crude models, the AUCs (95% CI) for the GOLD 2007, GOLD 2011, and GOLD 2017 for COPD hospitalization were 63.1 (58.7-66.9), 60.9 (56.1-64.4), and 56.1 (54.0-58.1), respectively, at 20-years' follow-up. Corresponding estimates for all-cause mortality were 57.0 (54.8-59.1), 54.1 (52.1-56.0), and 52.6 (51.0-54.3). The differences in AUCs between the GOLD classifications to predict COPD hospitalization and all-cause mortality were constant over the follow-up time. Conclusion: The GOLD 2007 classification was better than the GOLD 2011 and 2017 classifications at predicting COPD hospitalization and all-cause mortality.

Comparison of pre- and post-bronchodilator lung function as predictors of mortality: The HUNT Study.

BACKGROUND AND OBJECTIVE: Post-bronchodilator (BD) lung function is recommended for the diagnosis of chronic obstructive pulmonary disease (COPD). However, often only pre-BD lung function is used in clinical practice or epidemiological studies. We aimed to compare the discrimination ability of pre-BD and post-BD lung function to predict all-cause mortality. METHODS: Participants aged ≥40 years with airflow limitation (n = 2538) and COPD (n = 1262) in the second survey of the Nord-Trøndelag Health Study (HUNT2, 1995-1997) were followed up until 31 December 2015. Survival analysis and time-dependent area under the receiver operating characteristic curves (AUC) were used to compare the discrimination ability of pre-BD and post-BD lung function (percent-predicted forced expiratory volume in the first second (FEV1 ) (ppFEV1 ), FEV1 z-score, FEV1 quotient (FEV1 Q), modified Global Initiative for Chronic Obstructive Lung Disease (GOLD) categories or GOLD grades). RESULTS: Among 2538 participants, 1387 died. The AUC for pre-BD and post-BD ppFEV1 to predict mortality were 60.8 and 61.8 (P = 0.005), respectively, at 20 years' follow-up. The corresponding AUC for FEV1 z-score were 58.5 and 60.4 (P < 0.001), for FEV1 Q were 68.7 and 70.1 (P = 0.002) and for modified GOLD categories were 62.3 and 64.5 (P < 0.001). Among participants with COPD, the AUC for pre-BD and post-BD ppFEV1 were 57.0 and 58.8 (P < 0.001), respectively. The corresponding AUC for FEV1 z-score were 53.1 and 55.8 (P < 0.001), for FEV1 Q were 63.6 and 65.1 (P = 0.037) and for GOLD grades were 56.0 and 57.0 (P = 0.268). CONCLUSION: Mortality was better predicted by post-BD than by pre-BD lung function; however, they differed only by a small margin. The discrimination ability using GOLD grades among COPD participants was similar.

External Validation and Recalculation of the CODEX Index in COPD Patients. A 3CIAplus Cohort Study.

The CODEX index was developed and validated in patients hospitalized for COPD exacerbation to predict the risk of death and readmission within one year after discharge. Our study aimed to validate the CODEX index in a large external population of COPD patients with variable durations of follow-up. Additionally, we aimed to recalculate the thresholds of the CODEX index using the cutoffs of variables previously suggested in the 3CIA study (mCODEX). Individual data on 2,755 patients included in the COPD Cohorts Collaborative International Assessment Plus (3CIA+) were explored. A further two cohorts (ESMI AND EGARPOC-2) were added. To validate the CODEX index, the relationship between mortality and the CODEX index was assessed using cumulative/dynamic ROC curves at different follow-up periods, ranging from 3 months up to 10 years. Calibration was performed using univariate and multivariate Cox proportional hazard models and Hosmer-Lemeshow test. A total of 3,321 (87.8% males) patients were included with a mean ± SD age of 66.9 ± 10.5 years, and a median follow-up of 1,064 days (IQR 25-75% 426-1643), totaling 11,190 person-years. The CODEX index was statistically associated with mortality in the short- (≤3 months), medium- (≤1 year) and long-term (10 years), with an area under the curve of 0.72, 0.70 and 0.76, respectively. The mCODEX index performed better in the medium-term (<1 year) than the original CODEX, and similarly in the long-term. In conclusion, CODEX and mCODEX index are good predictors of mortality in patients with COPD, regardless of disease severity or duration of follow-up.

Regional variation in hospitalizations and outpatient appointments for diverticular disease in Norway: a nationwide cross-sectional study.

OBJECTIVE: To investigate the use of specialized health care services for diverticular disease in different hospital referral regions in Norway. MATERIALS AND METHODS: Nationwide cross-sectional study with data from the Norwegian Patient Registry and Statistics Norway. All Norwegian inhabitants aged 40 years and older in the years 2012-16 (2,517,938) were included. We obtained the rates (n/100,000 population) for hospitalizations, outpatient appointments, and surgery for diverticular disease for the population in each hospital referral region. We also quantified the use of lower gastrointestinal (LGI) endoscopy in hospitalizations and outpatient appointments for diverticular disease and the use of LGI endoscopy performed on any indication. RESULTS: There were 131 hospitalizations and 381 outpatient appointments for diverticular disease per 100,000 population annually. Hospitalization rates varied 1.9-fold across regions from 94 to 175. Outpatient appointment rates varied 2.5-fold across regions from 258 to 655. Outpatient appointments were strongly correlated to hospitalizations (rs=0.75, p < .001) and outpatient LGI endoscopy for any indication (rs=0.67, p < .001). Hospitalization and surgery rates remained stable over the study period, while outpatient appointment rates increased by 37%. Concurrently, rates of outpatient LGI endoscopy performed on any indication increased by 35%. CONCLUSION: There was considerable regional variation in both hospitalizations and outpatient appointments for diverticular disease. The extent of variation and the correlation with diagnostic intensity of LGI endoscopy indicate that the regional variation in health care utilization for diverticular disease to a large extent can be explained by regional differences in clinical practice rather than disease burden.

Prevalence and trend of COPD from 1995-1997 to 2006-2008: The HUNT study, Norway.

BACKGROUND: COPD is a major cause of morbidity and mortality across the world and new estimates of prevalence and trend are of great importance. We aimed to estimate the prevalence and trend of COPD from 1995-1997 to 2006-2008 in Norwegian adults ≥40 years from the Nord-Trøndelag Health Study. MATERIAL AND METHODS: COPD was assessed using a fixed-ratio and lower limit of normal (LLN) criteria. Pre-bronchodilator spirometry was performed during 1995-1997 (n = 7158) and 2006-2008 (n = 8788). The prevalence of COPD was weighted using the inverse probability of selection and predicted probability of response. RESULTS: The prevalence of pre-bronchodilator COPD was 16.7% in 1995-1997 and 14.8% in 2006-2008 using fixed-ratio criteria, and 10.4% in 1995-1997 and 7.3% in 2006-2008 using LLN criteria. The prevalence of LLN COPD was higher among men (13.0% in 1995-1997, 7.7% in 2006-2008) than women (8.0% in 1995-1997, 6.9% in 2006-2008). From 1995-1997 to 2006-2008, the prevalence decreased among men but remained relatively stable among women. Over the 11-year period, the cumulative incidence of pre-bronchodilator COPD using LLN criteria was 3.3% and 2.7% among men and women respectively. The prevalence of self-reported asthma and respiratory symptoms increased. CONCLUSIONS: The prevalence declined in men but not in women from 1995-1997 to 2006-2008, and was consistently higher among men than women.

Large-scale external validation and comparison of prognostic models: an application to chronic obstructive pulmonary disease.

BACKGROUND: External validations and comparisons of prognostic models or scores are a prerequisite for their use in routine clinical care but are lacking in most medical fields including chronic obstructive pulmonary disease (COPD). Our aim was to externally validate and concurrently compare prognostic scores for 3-year all-cause mortality in mostly multimorbid patients with COPD. METHODS: We relied on 24 cohort studies of the COPD Cohorts Collaborative International Assessment consortium, corresponding to primary, secondary, and tertiary care in Europe, the Americas, and Japan. These studies include globally 15,762 patients with COPD (1871 deaths and 42,203 person years of follow-up). We used network meta-analysis adapted to multiple score comparison (MSC), following a frequentist two-stage approach; thus, we were able to compare all scores in a single analytical framework accounting for correlations among scores within cohorts. We assessed transitivity, heterogeneity, and inconsistency and provided a performance ranking of the prognostic scores. RESULTS: Depending on data availability, between two and nine prognostic scores could be calculated for each cohort. The BODE score (body mass index, airflow obstruction, dyspnea, and exercise capacity) had a median area under the curve (AUC) of 0.679 [1st quartile-3rd quartile = 0.655-0.733] across cohorts. The ADO score (age, dyspnea, and airflow obstruction) showed the best performance for predicting mortality (difference AUCADO - AUCBODE = 0.015 [95% confidence interval (CI) = -0.002 to 0.032]; p = 0.08) followed by the updated BODE (AUCBODE updated - AUCBODE = 0.008 [95% CI = -0.005 to +0.022]; p = 0.23). The assumption of transitivity was not violated. Heterogeneity across direct comparisons was small, and we did not identify any local or global inconsistency. CONCLUSIONS: Our analyses showed best discriminatory performance for the ADO and updated BODE scores in patients with COPD. A limitation to be addressed in future studies is the extension of MSC network meta-analysis to measures of calibration. MSC network meta-analysis can be applied to prognostic scores in any medical field to identify the best scores, possibly paving the way for stratified medicine, public health, and research.

A simple algorithm for the identification of clinical COPD phenotypes.

This study aimed to identify simple rules for allocating chronic obstructive pulmonary disease (COPD) patients to clinical phenotypes identified by cluster analyses.Data from 2409 COPD patients of French/Belgian COPD cohorts were analysed using cluster analysis resulting in the identification of subgroups, for which clinical relevance was determined by comparing 3-year all-cause mortality. Classification and regression trees (CARTs) were used to develop an algorithm for allocating patients to these subgroups. This algorithm was tested in 3651 patients from the COPD Cohorts Collaborative International Assessment (3CIA) initiative.Cluster analysis identified five subgroups of COPD patients with different clinical characteristics (especially regarding severity of respiratory disease and the presence of cardiovascular comorbidities and diabetes). The CART-based algorithm indicated that the variables relevant for patient grouping differed markedly between patients with isolated respiratory disease (FEV1, dyspnoea grade) and those with multi-morbidity (dyspnoea grade, age, FEV1 and body mass index). Application of this algorithm to the 3CIA cohorts confirmed that it identified subgroups of patients with different clinical characteristics, mortality rates (median, from 4% to 27%) and age at death (median, from 68 to 76 years).A simple algorithm, integrating respiratory characteristics and comorbidities, allowed the identification of clinically relevant COPD phenotypes.

Extent, regional variation and impact of gynecologist payment models in routine pelvic examinations: a nationwide cross-sectional study.

BACKGROUND: Based on moderate quality evidence, routine pelvic examination is strongly recommended against in asymptomatic women. The aims of this study was to quantify the extent of routine pelvic examinations within specialized health care in Norway, to assess if the use of these services differs across hospital referral regions and to assess if the use of colposcopy and ultrasound differs with gynecologists' payment models. METHODS: Nationwide cross-sectional study including all women aged 18 years and older in Norway in the years 2014-16 (2,038,747). Data was extracted from the Norwegian Patient Registry and Statistics Norway. The main outcome measures were 1. The number of appointments per 1000 women with a primary diagnosis of "Encounter for gynecological examination without complaint, suspected or reported diagnosis." 2. The age-standardized number of these appointments per 1000 women in the 21 different hospital referral regions of Norway. 3. The use of colposcopy and ultrasound in routine pelvic examinations, provided by gynecologists with fixed salaries and gynecologists paid by a fee-for-service model. RESULTS: Annually 22.2 out of every 1000 women in Norway had a routine pelvic examination, with variation across regions from 6.6 to 43.9 per 1000. Gynecologists with fixed salaries performed colposcopy in 1.6% and ultrasound in 74.5% of appointments. Corresponding numbers for fee-for-service gynecologists were 49.2% and 96.2%, respectively. CONCLUSIONS: Routine pelvic examinations are widely performed in Norway. The variation across regions is extensive. Our results strongly indicate that fee-for-service payments for gynecologists skyrocket the use of colposcopy and increase the use of ultrasound in pelvic examinations of asymptomatic women.

Mortality prediction in chronic obstructive pulmonary disease comparing the GOLD 2007 and 2011 staging systems: a pooled analysis of individual patient data.

BACKGROUND: There is no universal consensus on the best staging system for chronic obstructive pulmonary disease (COPD). Although documents (eg, the Global Initiative for Chronic Obstructive Lung Disease [GOLD] 2007) have traditionally used forced expiratory volume in 1 s (FEV1) for staging, clinical parameters have been added to some guidelines (eg, GOLD 2011) to improve patient management. As part of the COPD Cohorts Collaborative International Assessment (3CIA) initiative, we aimed to investigate how individual patients were categorised by GOLD 2007 and 2011, and compare the prognostic accuracy of the staging documents for mortality. METHODS: We searched reports published from Jan 1, 2008, to Dec 31, 2014. Using data from cohorts that agreed to participate and had a minimum amount of information needed for GOLD 2007 and 2011, we did a patient-based pooled analysis of existing data. With use of raw data, we recalculated all participant assignments to GOLD 2007 I-IV classes, and GOLD 2011 A-D stages. We used survival analysis, C statistics, and non-parametric regression to model time-to-death data and compare GOLD 2007 and GOLD 2011 staging systems to predict mortality. FINDINGS: We collected individual data for 15 632 patients from 22 COPD cohorts from seven countries, totalling 70 184 person-years. Mean age of the patients was 63·9 years (SD 10·1); 10 751 (69%) were men. Based on FEV1 alone (GOLD 2007), 2424 (16%) patients had mild (I), 7142 (46%) moderate (II), 4346 (28%) severe (III), and 1670 (11%) very severe (IV) disease. We compared staging with the GOLD 2007 document with that of the new GOLD 2011 system in 14 660 patients: 5548 (38%) were grade A, 2733 (19%) were grade B, 1835 (13%) were grade C, and 4544 (31%) were grade D. GOLD 2011 shifted the overall COPD severity distribution to more severe categories. There were nearly three times more COPD patients in stage D than in former stage IV (p<0·05). The predictive capacity for survival up to 10 years was significant for both systems (p<0·01) but area under the curves were only 0·623 (GOLD 2007) and 0·634 (GOLD 2011), and GOLD 2007 and 2011 did not differ significantly. We identified the percent predicted FEV1 thresholds of 85%, 55% and 35% as better to stage COPD severity for mortality, which are similar to the ones used previously. INTERPRETATION: Neither GOLD COPD classification schemes have sufficient discriminatory power to be used clinically for risk classification at the individual level to predict total mortality for 3 years of follow-up and onwards. Increasing intensity of treatment of patients with COPD due to their GOLD 2011 reclassification is not known to improve health outcomes. Evidence-based thresholds should be searched when exploring the prognostic ability of current and new COPD multicomponent indices. FUNDING: None.

Lung function and respiratory symptoms in association with mortality: The HUNT Study.

Whether respiratory symptoms are associated with mortality independent of lung function is unclear. The authors explored the association of the exposures i) lung function, ii) respiratory symptoms, and iii) lung function and respiratory symptoms combined, with the outcomes all-cause and cardiovascular mortality. The study included 10,491 adults who participated in the Nord-Trøndelag Health Study (HUNT) Lung Study in 1995-1997 and were followed through 2009. Cox regression was used to calculate adjusted hazard ratios (HRs) with 95% confidence intervals for all-cause and cardiovascular mortality associated with pre-bronchodilator% predicted forced expiratory volume in 1 second (ppFEV1), chronic obstructive pulmonary disease (COPD) grades, and respiratory symptoms (chronic bronchitis, wheeze, and levels of dyspnoea). Lung function was inversely associated with all-cause mortality. Compared to ppFEV1 ≥100, ppFEV1 <50 increased the HR to 6.85 (4.46-10.52) in women and 3.88 (2.60-5.79) in men. Correspondingly, compared to normal airflow, COPD grade 3 or 4 increased the HR to 6.50 (4.33-9.75) in women and 3.57 (2.60-4.91) in men. Of the respiratory symptoms, only dyspnoea when walking remained associated with all-cause mortality after controlling for lung function (HR 1.73 [1.04-2.89] in women and 1.57 [1.04-2.36] in men). Analyses of lung function and dyspnoea when walking as a combined exposure further supported this finding. Overall, associations between lung function and cardiovascular mortality were weaker, and respiratory symptoms were not associated with cardiovascular mortality. In conclusion, lung function was inversely associated with all-cause and cardiovascular mortality, and dyspnoea when walking was associated with all-cause mortality independent of lung function.

The joint association of anxiety, depression and obesity with incident asthma in adults: the HUNT study.

BACKGROUND: Anxiety or depression symptoms may increase the risk of developing asthma, and their interaction with obesity is not known. We aimed to assess the association of anxiety or depression symptoms and the joint association of these symptoms and obesity with incident asthma. METHODS: We conducted a prospective cohort study of 23 599 adults who were 19-55 years old and free from asthma at baseline in the Norwegian Nord-Trøndelag Health Study. The Hospital Anxiety and Depression Scale was used to measure anxiety or depression symptoms. Obesity was defined as a body mass index≥30.0 kg/m2. Incident asthma was self-reported new cases of asthma during the 11-year follow-up. RESULTS: Having anxiety or depression symptoms was associated with incident asthma [odds ratio (OR) 1.39, 95% confidence interval (CI) 1.09-1.78). Obese participants with anxiety or depression symptoms had a substantially higher risk of incident asthma (OR 2.93, 95% CI 2.20-3.91) than any other group (non-obese participants without anxiety or depression symptoms [reference], non-obese participants with anxiety or depression symptoms (OR 1.20, 95% CI 1.00-1.45) and obese participants without anxiety or depression symptoms (OR 1.47, 95% CI 1.19-1.82)]. The relative excess risk for incident asthma due to interaction between anxiety or depression symptoms and obesity was 1.26 (95% CI 0.39-2.12). CONCLUSIONS: This study suggests that having anxiety or depression symptoms contributes to the development of asthma in adults. The risk of asthma may be further increased by the interaction between anxiety or depression symptoms and obesity.

Natural course of acute neck and low back pain in the general population: the HUNT study.

In this prospective cohort study we aimed to describe the natural course of acute neck and low back pain in a general population of Norway. We screened 9056 subjects aged 20-67 years who participated in a general health survey for a new episode of neck or low back pain the previous month. The screening identified 219 subjects who formed the cohort for this study. Pain intensity was reported on a numeric rating scale (0-10) at 1, 2, 3, 6, and 12 months after start of the new pain episode. The course of pain was described for neck and low back pain, different baseline pain levels, age groups, and number of pain sites at baseline. Use of medication and health care was described and associations between pain intensity and seeking health care were estimated. Pain declined rapidly within 1 month after a new pain episode, with a reduction of 0.91 (95% confidence interval [CI] 0.50-1.32) for neck pain and 1.40 (95% CI 0.82-1.99) for low back pain with little change thereafter. However, pain remained unchanged over the follow-up year for those with equal pain in the neck and low back areas at baseline and for those reporting 4 or more pain sites at baseline. Only 1 in 5 sought health care for their complaints. Still, the course of pain was comparable to effect sizes reported in interventional studies. This study thus contributes natural course reference data for comparisons of pain outcome in clinical trials and practice.

GOLD classifications and mortality in chronic obstructive pulmonary disease: the HUNT Study, Norway.

BACKGROUND: How different Global Initiative for Chronic Obstructive Lung Disease (GOLD) classifications of chronic obstructive pulmonary disease (COPD) predict mortality is unclear. OBJECTIVE: To examine the association of spirometric GOLD grades and the new ABCD groups with mortality, and to compare their informativeness in relation to mortality. METHODS: We studied 1540 people with post-bronchodilator COPD who participated in the Norwegian Nord-Trøndelag Health Study 1995-1997 and were followed up on all-cause mortality until May 2012. The associations of spirometric GOLD grades and ABCD groups with mortality were estimated by sex specific adjusted HRs from Cox regression and standardised mortality ratios. To assess the informativeness of spirometric GOLD grades and ABCD groups at predicting mortality we used the difference in twice the log-likelihood of a Cox regression model with and without each COPD classification. RESULTS: The distribution of participants was 28% in GOLD 1, 57% in GOLD 2, 13% in GOLD 3 and 2% in GOLD 4, in contrast to 61% in group A, 18% in group B, 12% in group C and 10% in group D. During a median of 14.6 years of follow-up, 837 people (54%) died. Mortality increased gradually from GOLD 1 to 4, while it was generally similar in groups A and B, and in groups C and D. Spirometric GOLD grades were substantially more informative than ABCD groups at predicting mortality. CONCLUSIONS: Spirometric GOLD grades predicted mortality better than the new ABCD groups among people with COPD from a Norwegian general population.

Lung function and anxiety in association with dyspnoea: the HUNT study.

BACKGROUND: Few studies from the general population have investigated the role of anxiety in reporting dyspnoea. We examined the independent and combined association of lung function and anxiety symptoms with the prevalence of dyspnoea in different situations. METHODS: The study included 5627 women and 5066 men who participated in the Lung study of the Nord-Trøndelag Health Study second survey in 1995-97. In a cross-sectional design we used logistic regression to calculate adjusted odds ratios (ORs) for reporting dyspnoea associated with levels of percent predicted FEV(1) (ppFEV(1)) and anxiety (Hospital Anxiety and Depression Scale). RESULTS: Overall, there was a linear inverse association between ppFEV(1) and dyspnoea (all P(trend) < 0.001), and a positive association between anxiety symptoms and dyspnoea (all P(trend) < 0.001). In combined analysis, using people with ppFEV(1) ≥100 without anxiety as reference, the OR (95% confidence interval) for reporting dyspnoea when walking on flat ground was 6.23 (3.45-11.28) in women with ppFEV(1) <80 without anxiety and 15.14 (7.13-32.12) in women with ppFEV(1) <80 with anxiety. The corresponding ORs among men were 5.75 (2.23-14.18) and 15.19 (4.74-48.64), respectively. Similar patterns were seen for dyspnoea when sitting still and woken at night by dyspnoea. CONCLUSION: Impaired lung function and anxiety symptoms were independently associated with reporting dyspnoea. Within lung function levels, reporting dyspnoea was more common among people with anxiety symptoms than among people without. This suggests that, in addition to its relation to reduced lung function, the subjective experience of breathing discomfort may also influence or be influenced by anxiety.