Search

Informal caregivers play an important role in chronic disease management but their experience is often neglected. The objective of this study was to explore the content validity of the Zarit Burden Interview (ZBI) in caregivers of individuals with COPD in Canada and Portugal.Cognitive debriefing interviews were conducted with informal caregivers of individuals with moderate to very severe COPD. Participants completed the ZBI and verbalised their thinking process to assess the adequacy of the questionnaire's content and instructions. Content validity was assessed using deductive content analysis of interviews and descriptive statistics of questionnaire responses.Nine caregivers from Canada (age = 67 ± 8 years) and 13 from Portugal (age = 69 ± 7 years) participated. For Canadian caregivers, 3/22 items were not understood, and 8/22 items were not relevant to at least 1/3 of them. For Portuguese caregivers, 1/22 items were not understood, and 20/22 items were not relevant to at least 1/3 of them. The distribution of response choices was approximately symmetrical for 17/22 items in the Canadian sample. The response option "no/never" was selected by at least 75% of Portuguese participants for 18/22 items.The instrument was well understood by caregivers of people with COPD, but its relevance is uncertain.IMPLICATIONS FOR REHABILITATIONInformal caregivers provide essential care for people living with disability and chronic disease, but their experience is often neglected.The Zarit Burden Interview assesses caregiver burden but has not been validated in caregivers of people with chronic obstructive pulmonary disease.In its current form, the Zarit Burden Interview does not adequately represent the experience of COPD caregivers.We recommend selecting tools that assess caregiver burden that have been validated in the caregiver population of interest.

This thesis defined a core outcome set - a minimum set of outcomes that should always be measured and reported – for pulmonary rehabilitation of people with chronic obstructive pulmonary disease (COPD). These core outcomes can increase study comparability and therefore enables drawing robust conclusions regarding the effects of this intervention. Furthermore, together with other indicators, the core outcome set might also enable benchmarking pulmonary rehabilitation and ensure quality of programmes delivered to people with COPD. Other potential benefits of establishing a minimum set of assessments (the work embedded in this thesis), are the increase in transparency of results to patients, pulmonary rehabilitation centres and payers, and the better understanding of patient responses to this therapy. This thesis combined both quantitative and qualitative research methods and had an active involvement of different stakeholders, such as people with COPD, informal caregivers, healthcare professionals, researchers and policy makers.

INTRODUCTION: The 6-minute walking test (6MWT) is a widely used measure to assess functional status of people with chronic obstructive pulmonary disease (COPD). However, it requires a long hallway and might be time-consuming. Other simple measures might be useful as a first screening tool. We explored the predictive ability of the 1-minute sit-to-stand test (1-min STS) in discriminating people with COPD with or without functional impairment.METHODS: A receiver operating characteristics (ROC) curve analysis was performed. We determined a threshold for the 1-min STS to identify functional impairment based on different cut-offs of the 6MWT (300, 350, 400 and 450 m).RESULTS: A total of 135 people with COPD were included. Except for the CONCLUSION: A cut-off of 19.5 repetitions in the 1-min STS discriminates accurately people with COPD with a functional impairment. Future studies may validate our treatable trait candidate in other samples and investigate its utility in predicting other meaningful outcomes.

BACKGROUND: Evidence suggests sex-related differences in chronic obstructive pulmonary disease (COPD). Whether these differences are reflected in the prevalence of treatable traits remains unknown.METHODS: Two samples of patients referred to secondary (n = 530) or tertiary care (n = 2012) were analyzed. Men and women were matched for age, forced expiratory volume in 1 s and body mass index. Sex-related differences were tested using t-tests, Mann-Whitney U, or chi-square tests.RESULTS: Frequent exacerbations (30.5 vs. 19.7%), high cardiovascular risk (88.1 vs. 66.2%) and activity-related severe dyspnea (50.9 vs. 34.8%) were more prevalent in women in secondary care (p < 0.05). Severe hyperinflation (43.0 vs. 25.4%), limited diffusing capacity (79.6 vs. 70.1%), impaired mobility (44.0 vs. 28.7%), frequent exacerbations (66.8 vs. 57.4%), frequent hospitalizations (47.5 vs. 41.6%), severe activity-related dyspnea (89.1 vs. 85.0%), symptoms of anxiety (56.3 vs. 42.0%) and depression (50.3 vs. 44.8%), and poor health status (79.9 vs. 71.0%) were more prevalent in women in tertiary care (p < 0.05). Severe inspiratory muscle weakness (14.6 vs. 8.2%) and impaired exercise capacity (69.1 vs. 59.6%) were more prevalent among men (p < 0.05) in tertiary care.CONCLUSIONS: Sex-related differences were found, with most traits more prevalent and severe among women. Care providers should be aware of these differences to adjust treatment.

The 6 min walking test (6MWT) has been largely studied. Less is, however, known about responders and non-responders to pulmonary rehabilitation (PR) in other meaningful activities. We explored responders and non-responders and the predictors of response to PR in the 1 min sit-to-stand test (1 min STS) and the 6MWT and compared both measures in classifying responders. An observational study was conducted with 121 people with chronic obstructive pulmonary disease (COPD). The functional status was assessed before and after PR. Baseline differences between responders and non-responders were tested with Mann–Whitney U, chi-square, or Fisher exact tests. Predictors were explored with binary logistic regressions. Agreement between both measures was assessed with chi-square, Cohen’s kappa, and McNemar tests. There were 54.5% and 57.0% of responders in the 1 min STS and the 6MWT, respectively. The proportion of responders was significantly different (p = 0.048), with a small agreement between the measures (kappa = 0.180; p = 0.048). The baseline 6MWT was the only significant predictor of response in the 6MWT (OR = 0.995; pseudo-r2 = 0.117; p < 0.001). No significant predictors were found for the 1 min STS. A large number of non-responders in terms of functional status exist. The 1 min STS and the 6MWT should not be used interchangeably. Future studies should explore the added benefit of personalizing PR to this outcome and investigate other potential predictors.

Submitted by Sara Miranda (sara.souto@ua.pt) on 2020-11-10T16:18:22Z No. of bitstreams: 1 Lettertotheeditor_CrossSectional_revised_v5.pdf: 345440 bytes, checksum: 72abc68f1d355318c6ed6400ed9d9079 (MD5) Approved for entry into archive by Rita Gonçalves (ritaisabel@ua.pt) on 2020-11-12T19:43:01Z (GMT) No. of bitstreams: 1 Lettertotheeditor_CrossSectional_revised_v5.pdf: 345440 bytes, checksum: 72abc68f1d355318c6ed6400ed9d9079 (MD5) Made available in DSpace on 2020-11-12T19:43:01Z (GMT). No. of bitstreams: 1 Lettertotheeditor_CrossSectional_revised_v5.pdf: 345440 bytes, checksum: 72abc68f1d355318c6ed6400ed9d9079 (MD5) Previous issue date: 2020-07-29 published

Functional status is an important and meaningful outcome in people with chronic obstructive pulmonary disease (COPD), although its measurement is not embedded in routine clinical assessments. This study described the functional status of people with COPD using the 1-min sit-to-stand test (1minSTS) over a 6-month period and the examined sociodemographic and clinical characteristics associated with this outcome. Data from a prospective study including people with COPD were analyzed. Functional status was assessed monthly with the 1minSTS over 6 months. Linear-mixed effect models assessed the 1minSTS number of repetitions mean change. One-hundred and eight participants (82.4% men; 66.9 ± 9.5 years) were included. A significantly lower number of repetitions in the 1minSTS over the 6-month period was associated with being female (estimate: −4.69, 95%CI: −8.20; −1.18), being older (estimate: −0.56, 95%CI: −0.77; −0.34), having higher BMI (estimate: −0.55, 95%CI: −0.81; −0.28) and having higher activity-related dyspnea (estimate: −2.04, 95%CI: −3.25; −0.83). Half of the participants showed improvements above three repetitions in the 1minSTS over the 6-month period, independently of their baseline impairment (1minSTS < 70% predicted: 52.5%; ≥70% predicted: 54.4%). To conclude, monthly follow-up assessments were associated with clinically relevant benefits in the functional status of people with COPD. Age, body composition, and activity-related dyspnea were the main predictors of functional status over time. Further research is needed to corroborate our findings and to support the beneficial effects of regular COPD monitoring.

INTRODUCTION: Studies suggest that people with chronic obstructive pulmonary disease (COPD) who are worse at baseline respond better to pulmonary rehabilitation (PR). Identifying treatable traits (TTs) may help to distinguish responders from non-responders. We explored the impact of PR on extra-pulmonary traits of people with COPD and whether the presence of TT influences the type of response to PR.METHODS: A comprehensive assessment of 9 TT including symptoms (dyspnoea, fatigue, anxiety and depression), functional capacity, deconditioning, balance, impact of the disease and health-related quality of life was conducted before and after a 12-week community-based PR programme. Pre-post differences between people with or without each TT at baseline were compared with independent samples t-tests or Mann-Whitney U tests. Proportion of responders between groups were explored with chi-square tests and odds ratio.RESULTS: 102 people with COPD were included (70 [65; 75] years old, 78% male, FEV1 47 [36; 60] %predicted). They had a median of 3 (out of 9) TTs per person and each patient responded on average to 5 (out of 9) outcomes of PR. People with TT were more responsive than those without them in all outcomes (p < 0.05) except for the 1-min sit-to-stand test. The presence of TT increased 4 to 20 times the likelihood of being a good responder.CONCLUSIONS: Identification of baseline extra-pulmonary TT in people with COPD showed the potential to inform on PR responsiveness and might therefore be an important strategy for patient prioritization, treatment personalisation (i.e., activation of the most suitable components) and optimisation.

Pulmonary rehabilitation (PR) is an effective intervention for people with chronic respiratory diseases (CRD); however, its effects fade after 6–12 months. Community-based strategies might be valuable to sustain PR benefits, but this has been little explored. People with CRD, informal carers, and healthcare professionals (HCPs) were recruited from pulmonology appointments of two local hospitals, two primary care centres, and one community institutional practice and through snowballing technique. Focus groups were conducted using a semi-structured guide. Data were thematically analysed. Twenty-nine people with CRD (24% female, median 69 years), 5 informal carers (100% female, median 69 years), and 16 HCPs (75% female, median 36 years) were included. Three themes were identified: “Maintaining an independent and active lifestyle” which revealed common strategies adopted by people with “intrinsic motivation and professional and peer support” as key elements to maintain benefits, and that “access to information and partnerships with city councils’ physical activities” were necessary future steps to sustain active lifestyles. This study suggests that motivation, and professional and peer support are key elements to maintaining the benefits of PR in people with CRD, and that different physical activity options (independent or group activities) considering peoples’ preferences, should be available through partnerships with the community, namely city councils.

Pulmonary rehabilitation (PR) is effective in improving symptoms, exercise capacity and quality of life in patientswith interstitial lung disease (ILD). However, little is known about its effects on other meaningful outcomes, suchas functional status. Thus, we aimed to explore whether PR can improve functional status in patients with ILD.Participants enrolled in a 12-week multidisciplinary community-based PR programme, which included exercisetraining, education and psychosocial support. Performance-based functional tests (6-Min Walk Test (6MWT),1-Min Sit-to-Stand Test (1-STS), Chester Step Test (CST), Glittre ADL-Test (TGlittre), Timed Up and Go (TUG),Physical Performance Test (PPT) and Grocery Shelving Task (GST)) were used to assess functional statusbefore and after PR. Based on normality of data distribution, a Paired t-Test or Wilcoxon Signed-Rank Test (w/listwise deletion) were computed in IBM SPSS® 27.0. Data are presented as mean ±SD or median [IQR]. 53patients with ILD (62.3% female; 64.5±1.7years; FVC%pred 80.9±18.2; DLCO%pred 54.8±18.1) participated.6MWT (n=45; 422.8±133.5 vs. 465.6±130.3, p

BACKGROUND: There is high heterogeneity of outcomes and measures reported in the literature for pulmonary rehabilitation (PR), which might limit benchmarking and an effective evidence synthesis. A core outcome set (COS) can minimise this problem. It is however unclear which outcomes and measures are most important and suitable for different stakeholders.METHODS: A multicentre qualitative study with one-to-one semi-structured interviews with people with chronic obstructive pulmonary disease (COPD), healthcare professionals (HCPs), researchers and policy makers was conducted. Manifest content analysis was conducted to explore the frequency of outcomes viewed as crucial or not. Thematic analysis was performed to better understand stakeholders' views.RESULTS: 37 participants (17 people with COPD and 20 HCPs/researchers/policy makers) from 14 countries and 4 continents were included. Participants expressed that i) core outcomes need to be meaningful to people with COPD and show PR benefits; ii) there should be comprehensive assessment and similar outcomes across settings; iii) a balance between optimal and practical measures is needed; iv) the COS is needed to benchmark PR and advance knowledge; and v) reluctance to change outcomes/measures used by HCPs and using the COS as a maximum set of outcomes might be the pitfalls. 28 outcomes were identified as crucial, and 12 as not crucial.CONCLUSIONS: This study provided important insights into outcome measurement in PR from the perspectives of different key international stakeholders and a list of outcomes that will inform a future consensus study.

Background The magnitude of response to pulmonary rehabilitation (PR) is influenced by the selection of outcomes and measures. Objectives This systematic review aimed to review all outcomes and measures used in clinical trials of PR for individuals with chronic obstructive pulmonary disease (COPD). Methods The review involved a search of Scopus, Web of Knowledge, Cochrane Library, EBSCO, Science Direct and PubMed databases for studies of stable individuals with COPD undergoing PR. Frequency of reporting for each domain, outcome and measure was synthesized by using Microsoft Excel. Results We included 267 studies (43153 individuals with COPD). A broad range of domains (n = 22), outcomes (n = 163) and measures (n = 217) were reported. Several measures were used for the same outcome. The most reported outcomes were exercise capacity (n = 218) assessed with the 6-min walk test (n = 140), health-related quality of life (n = 204) assessed with the Saint George's respiratory questionnaire (n = 99), and symptoms (n = 158) assessed with the modified Medical Research Council dyspnoea scale (n = 56). The least reported outcomes were comorbidities, adverse events and knowledge. Conclusions This systematic review reinforces the need for a core outcome set for PR in individuals with COPD because of high heterogeneity in reported outcomes and measures. Future studies should assess the importance of each outcome for PR involving different stakeholders. PROSPERO ID CRD42017079935

Introduction: Pulmonary rehabilitation implies a comprehensive assessment. Although several outcomes are commonly measured, those are selected mainly by health professionals and researchers, with the voice of patients and informal caregivers being minimally captured. Qualitative studies are fundamental to enhance our knowledge on perspectives of different stakeholders involved in pulmonary rehabilitation. Objective: This study aimed to explore the views of different stakeholders on outcomes of pulmonary rehabilitation, contributing to one of the stages of a core outcome set for pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD). Methods: Semi-structured interviews were conducted with 12 patients with COPD, 11 informal carers and 10 health professionals. Data were analysed with content analysis, followed by thematic analysis to gain deeper understanding of the different perspectives. Results: A total of 44 outcomes were identified, being the most reported ‘improving functional performance’ (67%) and ‘reducing and taking control over dyspnoea’ (64%). Five relevant themes across stakeholders were generated: having a healthy mind in a healthy body; I can(’t) do it; feeling fulfilled; knowing more, doing better and avoiding doctors and expenses. Although perspectives were mostly consensual, some outcomes were only valued by health professionals (e.g. pulmonary function) or by patients and informal carers (e.g. quality of sleep). Conclusion: Views of the different stakeholders on outcomes of pulmonary rehabilitation were similar although, some specificities existed. Comprehensive assessments are needed to reflect what is valued by the different stakeholders in pulmonary rehabilitation. This study contributed to a future core outcome set in this field.

On-site pulmonary rehabilitation (PR) programmes are currently scarce due to the COVID-19 pandemic. Existingprogrammes faced major routine changes to ensure safety and continuity of care with unknown impacts onpatients. Thus, we explored the impact of such changes in people with chronic respiratory diseases goingthrough PR during the pandemic. A qualitative study was conducted. Semi-structured interviews were audio-recorded and transcribed perverbatim. A preliminary deductive thematic analysis was performed. 17 patients (7 ILD, 8 COPD and, 2 asthma; 9 males; 63±10 years) were interviewed and 5 themes wereidentified. Implemented infection prevention and control measures and a closer healthcare professional (HCP)-patient interaction were identified as important factors that contributed to patients’ perception of a safeenvironment. Reduced social interaction with peers and increased HCP workload and stress were recognised ashaving a negative impact. PR was perceived as essential, to break social isolation and relieve stress induced bythe pandemic, and for patients to feel fitter, more capable, and confident (Fig.1). On-site PR is valued by patients and was perceived safe and beneficial during the pandemic. Careful reflectionabout maintaining PR programmes closed is recommended. Future studies should also explore the impact of these changes on PR effectiveness and seek perspectives of other stakeholders, such as HCPs. published

The magnitude of response to pulmonary rehabilitation (PR) is influenced by the selection of outcomes and measures. Outcome and measure selection depends on various factors which can lead to high heterogeneity of reported outcomes/measures in the literature, hindering bench marking between and within PR centers and an effective evidence synthesis. We aimed to review all outcomes and measures used in clinical trials of PR for patients with COPD. A systematic review was conducted (CRD42017079935) with searches on Scopus, Web of Knowledge, Cochrane Library, EBSCO, Science Direct and PubMed. Studies reporting on PR of stable patients with COPD and from 2000 onwards were included. Data were extracted into a standardized table. Frequency of reporting for each domain, outcome and measure was synthesized using Microsoft Excel®. 267 studies were included with 43153 patients with COPD. 22 domains, 163 outcomes and 217 measures were found. Several measures were used to assess the same outcome. Exercise capacity (n=218) assessed with the six-minute walk test (n=140), health-related quality of life (n=204) assessed with the Saint George’s respiratory questionnaire (n=99), and symptoms (n=158) assessed with the modified medical research council dyspnoea scale (n=56) were mostly reported. The least reported outcomes were comorbidities, adverse events and knowledge. This systematic review reinforced the need of a core outcome set in this field, as high heterogeneity in reported outcomes and measures was found. Future studies should assess the importance of each outcome for PR according to different stakeholders. published

Chronic obstructive pulmonary disease (COPD) is influenced by environmental factors, such as indoor/outdoor contaminants. However, patients’ views on environmental exposure are little-known and this is an often-neglected topic in psychoeducational sessions in pulmonary rehabilitation (PR). We explored the views of patients with COPD about indoor/outdoor environment and its influence on their health and the impact of an environmental educational session within PR, on their daily living. Focus groups were conducted before and after community-based PR. An educational session was designed and included in PR after the first focus group. Data were analysed with thematic analysis. Four focus groups were conducted with 31 patients with COPD (71±8y; 74%male; FEV1 48±17pp; 45% GOLD2; 58% GOLDB). Prior to PR, 3 themes emerged: 1) “just seeing the tip of the iceberg” since some awareness existed but a feeling of probably not knowing the real impact was shared; 2) “feeling resigned” where patients acknowledged having poor strategies to avoid contaminants and felt there was little they could do; and 3) “willingness to learn” as they reported the need for an educational session to improve their knowledge on environmental exposures. After PR, 2 themes were found: 1) “gratefulness” where patients shared that the session was helpful for themselves and significant others; and 2) “personal change”, where patients expressed how their behaviour changed towards more health-enhancing strategies to deal with contaminants. Environmental education within PR is valued by patients and leads to specific behaviour changes to deal with contaminants’ exposure. Further attention to this topic is warranted. published

Chronic obstructive pulmonary disease (COPD) is impacted by exposure to environmental contaminants. Improving health literacy on this topic might help to optimize health outcomes. We aimed to design and deliver a health-education session about the impact of environmental contaminants on respiratory symptoms and explore participants&rsquo, perceptions on such session. Patients with COPD were recruited from a pulmonary rehabilitation (PR) program. Two focus groups were first conducted to explore knowledge amongst the group. Then, the session was designed and delivered, and three focus groups were conducted to obtain feedback from participants. Data were analyzed thematically by two independent researchers. Thirty-one patients (71 &plusmn, 8 years old, FEV1 = 47.6 &plusmn, 16.8% predicted, 74.2% male) were included. Prior to the session, participants recognized the importance of this topic and described avoidance strategies to deal with symptom triggering due to air pollution. After the session, participants had their knowledge validated, kept some avoidance strategies, but also adapted some &ldquo, unavoidable&rdquo, activities of daily living. Patients with COPD value education on this topic, and PR offers a friendly environment to discuss prevention and management strategies. Contents of the session are provided to help deliver these sessions. Future studies could investigate the effectiveness of this intervention on self-management and exacerbations of COPD.

Comprehensive understanding of COPD phenotypes, incorporating simple, widely used and meaningful outcomes (e.g., functional status), might contribute to personalise patients’ assessment and management. We described COPD phenotypes and developed a classification tree for its prediction. A cross-sectional study was conducted with patients with COPD. Data collection included airway obstruction (FEV1pp); comorbidities (Charlson comorbidity index); functional status (one-minute sit-to-stand test [1-minSTS]) and impact of the disease (COPD assessment test [CAT]). Clustering analysis using k-medoids was used to explore existent phenotypes. A classification tree was generated with 70% of the sample. The remaining 30% was used for its validation, i.e., to determine its prediction ability to identify the correct phenotype. Accuracy/agreement (Cohen’s Kappa) were determined. 364 patients with COPD (67yrs; 76%male; FEV1 57±21pp) participated. Four phenotypes (C1, C2, C3, C4) were found (Fig. 1): two presenting severe (C1, C4) and two mild-to-moderate (C2, C3) airflow obstruction; two low (C1, C2) and two high (C3, C4) impact of the disease; two low (C3, C4) and two high (C1, C2) functional status. The classification tree established cut-offs for these variables and correctly classified 85% of new individuals in their phenotype (Cohen’s Kappa=0.8). Meaningful and easily available assessments were able to differentiate COPD phenotypes and may guide patient-centred interventions.

Due to similarities in extrapulmonary features, patients with chronic obstructive pulmonary disease (COPD) and interstitial lung diseases (ILD) are commonly treated with a one size fits all approach in pulmonary rehabilitation (PR). Though this approach is inadequate, differences between populations in meaningful outcomes, such as activities of daily living (ADL), have been scarcely explored. This study explored the functional performance of patients with COPD and ILD in upper and lower-limb ADL. Patients with COPD and ILD entering a 12-week community-based PR programme were comprehensively assessed. Functional performance was assessed with Glittre, 1-min sit to stand (STS), grocery shelving task (GST), physical performance (PPT), Chester step and 6-minute walk tests. Data were analysed with Mann-Whitney U tests. Patients with COPD (n=68, 72%male, 66±10y; FEV1 56±20pp), showed worse functional performance than patients with ILD (n=78; 46%male, 65±14years, FVC 77±19 DLCO 57±52%predicted) in the number of laps in Glittre (COPD 3.9±1.5; ILD 4.6±0.9; p=0.014), time of the GST (COPD 49.8±14.1; ILD 45.4±14.6; p=0.018) and score of the PPT (COPD 28.1±5.6; ILD 30.6±4.0; p=0.008). No other significant differences were found. Significant differences exist in functional performance of ADL that involve the upper limbs between patients with COPD and ILD. Future research is needed to confirm these findings and move PR to a personalised approach. published

Fatigue is a prevalent, multi-dimensional and burdensome symptom in chronic obstructive pulmonary disease (COPD), yet it is still underdiagnosed, undertreated and little understood. This study explored associations between fatigue and key outcomes in COPD and which of them could explain fatigue. A cross-sectional study with people with COPD was conducted. Assessments included the modified functional assessment of chronic illness therapy-fatigue subscale (mod-FACIT-FS; lower scores mean worst fatigue), modified Medical Research Council dyspnea scale (mMRC), six-minute walk test (6MWT), COPD assessment test (CAT) and St. George’s Respiratory Questionnaire (SGRQ). Correlations were explored with the Pearson’s (r)/Spearman’s (rs) coefficients. Multiple linear regressions were performed with the stepwise model and the variance inflation factor (VIF) was confirmed. 89 people with COPD (68±9years; 76%male; 50±18FEV1pp) were enrolled. Significant moderate correlations were found between the mod-FACIT-FS and all outcomes (mMRC:rs=-0.53; 6MWT:r=0.50; CAT:r=-0.56; SGRQ:r=-0.63; p

Background: Functional impairment is a critical consequence of COPD. The 1-minute sit-to-stand (1STS) is a valid and reliable test to measure this health domain in patients with COPD, with established reference values. We aimed to quantify the prevalence of functional impairment in patients with COPD and identify the distribution of this impairment across disease stages. Methods: A cross-sectional study with patients with COPD and healthy age-/gender-matched controls was conducted. Spirometry, the modified British Medical Research Council questionnaire (mMRC) and the 1STS were collected. Patients were grouped by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classifications. Differences between groups were explored with Kruskal-Wallis and Bonferroni-adjusted pairwise comparisons. Results: 366 patients with COPD (76% male, 67±10y, FEV1 56±21pp) and 345 controls (70% male, 67±9y, FEV1104±21pp) participated. 50% of the patients presented functional impairment (i.e., performed below 80%predicted). Patients with COPD presented lower functional ability than controls, independently of the GOLD grade/group (Fig. 1). The most symptomatic patients (i.e., GOLD B and D) had the lowest functional levels. Conclusion: Functional ability is reduced in patients with COPD in all GOLD grades/groups, especially in the most symptomatic. Future studies should explore therapeutic interventions to address this problem.

Background Maximum inspiratory (Pimax) and expiratory (Pemax) mouth pressures are commonly used to detect respiratory muscle weakness resorting to predictive equations established for healthy people. There are several predictive equations, but they are widespread in the literature. This study aimed to review the existent predictive equations of maximum inspiratory (Pimax) and expiratory (Pemax) mouth pressures for adults. Additionally, we aimed to identify which ones were generated based on international standards. Methods A systematic review of predictive equations of Pimax and Pemax for healthy adults was conducted. A comprehensive search was performed of Cochrane Library, EBSCO, PubMed, Scopus and Web of Science to identify studies that presented at least one equation for Pimax or Pemax developed for healthy adults. The quality of studies was assessed by two reviewers with the Quality Assessment of Diagnostic Accuracy Studies (Quadas-2). Results Risk of bias was high in 8 of the 20 studies included. Forty-two Pimax and 34 Pemax equations were found, mostly using the variables age (n = 39), weight (n = 20) and height (n = 8). These equations explained 3 to 96% of the Pimax/Pemax variance. They were developed with individuals from 11 countries (Portugal not included). Twelve Pimax and eight Pemax equations complied with international standards. Conclusions This review gathered the predictive equations that have been developed for both Pimax and Pemax, however most were generated from unstandardized procedures. Future studies should explore the suitability of these equations for populations for which specific ones are not available, such as the Portuguese population, and develop new equations if necessary.

Respiratory muscle weakness is frequent in chronic respiratory diseases. Several equations exist to predict maximum respiratory pressures but there are no recommendations of which should be used and none was developed for Portugal. This study revised predictive equations of maximum inspiratory (MIP) and expiratory (MEP) pressure for healthy adults and explored their suitability for the Portuguese population. A systematic review was conducted. Studies were eligible if they presented at least 1 equation for MIP or MEP developed for healthy adults. For equation testing, MIP/MEP were collected from healthy adults. Predicted values were computed from the equations and compared with actual values using Wilcoxon tests and Bland-Altman plots. 19 studies were included. 36 MIP and 30 MEP equations were found but only 32 and 25 were possible to test in 229 subjects (62%♂, 101.8±20.5FEV1pp, 66.7±9.7yrs). 4 MIP equations showed no significant differences between actual and predicted values (p>0.05, rs=0.32-0.47, R2=9-47%). From these, 3 overestimated (bias=0.19-4.06 cmH2O, men) and 1 underestimated (bias=0.99 cmH2O, women) the actual values (Fig. 1). All MEP equations showed significant differences between actual and predicted values. Only 4 MIP equations seem to be useful for the Portuguese population. Future studies should aim to develop an equation for the Portuguese population with higher coefficients of determination. published