Test-retest reliability, agreement and construct validity of the International Physical Activity Questionnaire short-form (IPAQ-sf) in people with COPD.

INTRODUCTION: This study assessed the test-retest reliability/agreement and construct validity of the International Physical Activity Questionnaire short-form (IPAQ-sf) in patients with chronic obstructive pulmonary disease (COPD). It also explored differences in its validity according to age, sex and GOLD airflow obstruction levels. METHODS: 62 participants (68 ± 8 years, 53 males, FEV1 51 ± 23%pred) completed the Portuguese IPAQ-sf, wore an accelerometer for 7 days and completed a second IPAQ-sf. Test-retest reliability/agreement was assessed with Intraclass Correlation Coefficient (ICC2,1), 95% Limits of Agreement (LoA), standard error of measurement (SEM) and minimal detectable change (MDC95) for continuous variables, and percentage of agreement (%agreement) for categories ("active"/"inactive"). Validity was assessed with 95% LoA and Spearman's correlations (ρ) between IPAQ-sf 2 (METs-min/week, time in vigorous [VPA], moderate PA [MPA] and walking) and accelerometry (time in MVPA, VPA, MPA and step counts) for continuous variables; %agreement, Cohen's kappa, and sensitivity specificity and±predictive values for categories. Correlations were also performed for age, sex and GOLD airflow obstruction grades. RESULTS: Reliability was good (ICC2,1 = 0.707) with wide LoA (-6446-6409 METs-min/week). SEM and MDC95 were 1840 and 4971 METs-min/week, respectively. %agreement between the two IPAQ-sf was 84% (kappa = 0.660). Positive, moderate and significant correlations were found between IPAQ-sf and accelerometry (0.396 ≤ ρ ≤ 0.527, p < 0.001), except for VPA (p > 0.05). The strongest correlations were found in age (<65 years) and male (0.466 ≤ ρ ≤ 0.653, p < 0.05). %agreement between tools was 65% (kappa = 0.313), with high sensitivity (0.830) but low specificity (0.500). CONCLUSIONS: The IPAQ-sf seems valid to be used in COPD but caution on its widespread use is recommended as its accuracy may be limited.

Construct validity and reliability of the Informal Caregiver Burden Assessment Questionnaire (QASCI) in caregivers of patients with COPD.

INTRODUCTION: COPD often leads to loss of independence in daily activities which may increase the dependency on the informal caregiver, resulting in caregiving burden. Several instruments have been used to assess caregiving burden in COPD; however, their measurement properties have been poorly investigated in this population. This study assessed the construct validity and reliability of the Informal Caregiver Burden Assessment Questionnaire (QASCI) in informal caregivers of patients with COPD. METHODS: Participants completed the QASCI (higher scores indicate higher burden) and the following questionnaires to assess construct validity: Zarit Burden Interview (ZBI), Hospital Anxiety and Depression Scale (HADS) and World Health Organization Quality of Life Instrument - Short Form (WHOQOL-Bref). QASCI was completed again one week later to assess test-retest reliability. Statistical analyses included: Pearson's (r) or Spearman's (ρ) correlations (construct validity); Cronbach's α (internal consistency); Intraclass Correlation Coefficient (ICC2,1, test-retest reliability) and Standard Error of Measurement (SEM), Minimal Detectable Change (MDC95) and Bland and Altman 95% Limits of Agreement (LoA). RESULTS: Fifty caregivers (62.7 ± 9.8 years, 88% female; patients' FEV1 = 45.2 ± 21.3%predicted) participated. QASCI mean score was 28.5 ± 19.8 (moderate burden). QASCI was positively correlated with ZBI (r = 0.908; p < 0.01), HADS anxiety (r = 0.613; p < 0.01) and depression (ρ = 0.634; <0.01) and negatively correlated with WHOQOL-Bref (-0.476 to -0.739) (all p < 0.01). Cronbach's α was 0.793 for the QASCI total score (subscales: 0.747-0.932). The ICC2,1 was 0.924, SEM 2.8 and MDC95 7.8, and the LoA were -18.3 to 11.1. CONCLUSIONS: The QASCI seems to be a promising measure to assess burden levels associated with informal caregiving in COPD.

What Motivates Patients with COPD to Be Physically Active? A Cross-Sectional Study.

Motivation can be broadly defined as what moves people to act. Low motivation is a frequently reported factor for the reduced physical activity (PA) levels observed in patients with chronic obstructive pulmonary disease (COPD). This study assessed patients' motives to be physically active, according to three pulmonary rehabilitation (PR) participation groups (Never PR, Previous PR and Current PR) and explored whether these motives were related to the PA levels and clinical characteristics. The motives to be physically active were assessed with the Exercise Motivation Inventory-2 (EMI-2, 14 motivational factors, five dimensions) and PA with accelerometry (PA groups: <5000 steps/day vs. ≥5000 steps/day). The clinical variables included symptoms, impact of the disease, exercise capacity and comorbidities. Ninety-two patients (67.4 ± 8.1 years, 82.6% male, forced expiratory volume in 1s (FEV1) 48.3 ± 18.9% predicted; 30.4% Never PR, 51% Previous PR and 18.5% Current PR) participated. The motivational dimensions related to health/fitness presented the highest scores (3.8 ± 1.1; 3.4 ± 1.3). The motives to be active were not significantly different between PA groups (p > 0.05) but having less symptoms and ≥two comorbidities were associated with higher scores in psychological/health and body-related motives, respectively (p < 0.05). The findings may encourage health professionals to actively explore with patients their motives to be physically active to individualise PA promotion.

Risk Factors for Low Humoral Response to BNT-162b2 In Hemodialysis Patients

IntroductionMaintenance Hemodialysis (HD) patients are at higher risk of both infection and mortality associated with the new coronavirus 2. Immunization through large-scale vaccination is the cornerstone of infection prevention in this population. This study aims to identify risk factors for low response to the BNT-162b2 (Pfizer BioNTech) vaccine in a HD cohort. Materials and MethodsObservational prospective study of a HD group followed in a Portuguese Public Founded Hemodialysis Center who received BNT-162b2 vaccination. Specific anti-Spike IgG was evaluated as arbitrary units per milliliter (AU/mL) on two separate occasions: 3 weeks after the first dose and 3 weeks after the second. IgG titers, Non-Responders (NR), and Weak-Responders (WR) after each dose were evaluated against risk factors that included demographic, clinical and analytical variables. ResultsHumoral response evaluated by IgG anti-Spike levels showed a strong correlation with Charlson comorbidity index (CCI) and intact parathormone (iPTH) after each inoculation (1st dose: {rho}=-0.64/0.54; 2nd dose: {rho}=-0.66/0.63, respectively; p<0.01 throughout). After completing both doses: 1) NR were associated with female sex (p<0.01), lower albumin and iPTH (p=0.01); 2) WR showed higher CCI, older age, lower iPTH and lower albumin (p=<0.01, p=0.03, p<0.01, p=0.05, respectively) and, consistently, associated with CCI over 8, age over 75, iPTH under 150 ng/L, female sex, dialysis vintage under 24 months and central venous catheter (CVC) over arteriovenous fistula (p=0.01, p=0.03, p<0.01, p=0.01, p=0.01, p<0.01, respectively). A binary regression model using CCI, sex (male) and CVC was statistically significant in prediction of WR after the 2nd dose with OR (95% CI): 1.81 (1.06-3.08); 0.05 (0.01-0.65); 13.55 (1.06-174.18), respectively (p=0.01). ConclusionOlder age, higher CCI, lower iPTH and albumin, CVC as vascular access and recent hemodialysis initiation (less than 2 years) associate with lower response to vaccination in our study. A higher comorbidity burden is suggested as a more significant surrogate marker for low immunogenicity rather than age alone. Identifying HD patients as a population at high-risk for low response to vaccination is essential for proper policy-making, facilitating the implementation of adequate and individualized contingency protocols. What is already known about this subjectO_LIMaintenance hemodialysis patients have lower humoral response to BNT-162b2 COVID-19 vaccine when compared to the general population. C_LIO_LIMaintenance dialysis patients are at high risk of exposure to coronavirus 2 in addition to a more severe disease course. C_LI What this study addsO_LIWe suggest Charlson commorbidity index, older age, intact parathormone, central venous catheter as vascular access and lower dialysis vintage as possible surrogate markers of immunogenicity in HD patients. C_LIO_LIThere is a low humoral response after a single dose of the vaccine (50%) that can be increased after the second (86%). C_LI What impact this may have on practice or policyO_LIStrict Protocols for follow-up measures in HD patients, including closer humoral titers assessment, risk stratification, adequate isolation, and surveillance of symptoms might be necessary in order to improve this population survival/life expectancy. C_LIO_LIScreening HD patients, seroconversion rates may be improved by giving extra inoculations for patients at risk for low response. C_LI

Humoral Response to BNT162b2 mRNA Covid19 Vaccine in Peritoneal and Hemodialysis Patients: a Comparative Study

IntroductionGeneralized immunization against COVID19 has become the cornerstone in prevention of severe acute respiratory syndrome associated with this pandemic. Maintenance dialysis patients (MDP) are at higher risk of both exposure and mortality from the disease. Efficacy and security of BNT162b2 vaccine is well documented for the general population, but not in MDP, particularly in peritoneal dialysis (PD) patients. This study aims to compare humoral response between hemodialysis (HD) and PD patients. Materials and MethodsObservational prospective study including MDP on HD or PD program from a Portuguese middle-sized Nephrology Center, who received BNT162b2 vaccine. Specific anti-Spike IgG was measured as arbitrary units per milliliter (AU/mL) on two separate occasions: 3 weeks after the first dose and 3 weeks after the second. The two modality groups were compared both for absolute value and number of non-responders (NR) after both inoculations. Demographic data was also compared. ResultsOf 73 patients enrolled, 67 were eligible for the final study: 42 HD and 25 PD patients. PD group developed significantly higher antibody titers in both inoculations: first dose with Med 5.44 vs 0.99 (p<0.01) and second dose with Med 170.43 vs 65.81 (p<0.01). HD status was associated with NR after the first dose (Phi=0.383; p<0.01), but not after the second (p=0.08). Age, Charlson comorbidity index and dialysis vintage were lower in the PD group (p<0.01; p=0.02; p<0.01, respectively). ConclusionThis study demonstrated a better humoral response to immunization with BNT162b2 in PD patients, when compared to HD patients, after each of the two recommended inoculations. Both groups showed substantial humoral response after just one dose of the vaccine. Older age and higher comorbidity burden may explain the relative immunogenicity deficit, probably in a superior degree comparing with age matched healthy population. What is already known about this subjectO_LIMaintenance hemodialysis patients have lower humoral response to BNT162b2 mRNA COVID19 vaccine when compared to the general population; C_LIO_LIMaintenance dialysis patients are at high risk of exposure to COVID19 in addition to a more severe course of the disease; C_LI What this study addsO_LIMaintenance peritoneal dialysis patients have better humoral response with BNT162b2 when compared to those on hemodialysis; C_LIO_LIThere is a substantial humoral response after a single dose of the vaccine for both hemodialysis (50%) and peritoneal dialysis (88%) patients. C_LI What impact this may have on clinical practice or policyO_LIProtocols for follow-up measures, including extra inoculations, might have to be considered for hemodialysis patients; C_LIO_LIPeritoneal dialysis patients should be promptly immunized in all centers, rejecting constraints regarding lower effectiveness or yield. C_LI

Construct validity of the brief physical activity assessment tool for clinical use in COPD.

INTRODUCTION: Low physical activity (PA) levels are associated with poor health-related outcomes in Chronic Obstructive Pulmonary Disease (COPD). Thus, PA should be routinely assessed in clinical practice. OBJECTIVES: This study assessed the construct validity of the Brief Physical Activity Assessment Tool (BPAAT) for clinical use in COPD and explored differences in age, sex and COPD grades. METHODS: After linguistic adaptation of the tool to Portuguese, 110 patients (66.4 ± 9.6yrs, 72.7% male, FEV1  = 59.3 ± 25.5%predicted) completed the BPAAT and received an accelerometer. The BPAAT includes two questions assessing the weekly frequency and duration of vigorous- and moderate-intensity PA/walking, classifying individuals as insufficiently or sufficiently active. The BPAAT was correlated with accelerometry (moderate PA, MPA = 1952-5724 counts-per-min [CPM]); vigorous PA, VPA = 5725-∞CPM; moderate-to-vigorous PA, MVPA = 1952-∞CPM; daily steps), through: Spearman's correlations (ρ) for continuous data; %agreement, Kappa, sensitivity and specificity, positive and negative predictive values (PPV, NPV) for categorical data. RESULTS: The BPAAT identified 73.6% patients as "insufficiently active" and 26.4% as "sufficiently active". The BPAAT was weakly to moderately correlated with accelerometry (0.394 ≤ ρ ≤ 0.435, P < 0.05), except for VPA (P = 0.440). This was also observed in age (<65/≥65yrs), COPD grades (GOLD 1-2/3-4) and in male patients (0.363 ≤ ρ ≤ 0.518, P < 0.05 except for VPA). No significant correlations were found in female patients (P > 0.05). Agreement was fair to moderate (0.36 ≤ κ ≤ 0.43; 73.6% ≤ %agreement ≤ 74.5%; 0.50 ≤ sensitivity ≤ 0.52; 0.84 ≤ specificity ≤ 0.91, 0.55 ≤ PPV ≤ 0.79, 0.72 ≤ NPV ≤ 0.82). CONCLUSION: The BPAAT may be useful to screen patients' PA, independently of age and COPD grade, and identify male patients who are insufficiently active. Care should be taken when using this tool to assess vigorous PA or female patients.

Phenotyping Adopters of Mobile Applications Among Patients With COPD: A Cross-Sectional Study.

Effectiveness of technology-based interventions to improve physical activity (PA) in people with COPD is controversial. Mixed results may be due to participants' characteristics influencing their use of and engagement with mobile health apps. This study compared demographic, clinical, physical and PA characteristics of patients with COPD using and not using mobile apps in daily life. Patients with COPD who used smartphones were asked about their sociodemographic and clinic characteristics, PA habits and use of mobile apps (general and PA-related). Participants performed a six-minute walk test (6MWT), gait speed test and wore an accelerometer for 7 days. Data were compared between participants using (App Users) and not using (Non-App Users) mobile apps. A sub-analysis was conducted comparing characteristics of PA-App Users and Non-Users. 59 participants were enrolled (73% Male; 66.3 ± 8.3 yrs; FEV1 48.7 ± 18.4% predicted): 59% were App Users and 25% were PA-App Users. Significant differences between App Users and Non-App Users were found for age (64.2 ± 8.9 vs. 69.2 ± 6.3yrs), 6MWT (462.9 ± 91.7 vs. 414.9 ± 82.3 m), Gait Speed (Median 1.5 [Q1-Q3: 1.4-1.8] vs. 2.0 [1.0-1.5]m/s), Time in Vigorous PA (0.6 [0.2-2.8] vs. 0.14 [0.1-0.7]min) and Self-Reported PA (4.0 [1.0-4.0] vs. 1.0 [0.0-4.0] Points). Differences between PA-App Users and Non-Users were found in time in sedentary behavior (764.1 [641.8-819.8] vs. 672.2 [581.2-749.4] min) and self-reported PA (4.0 [2.0-6.0] vs. 2.0 [0.0-4.0] points). People with COPD using mobile apps were younger and had higher physical capacity than their peers not using mobile apps. PA-App Users spent more time in sedentary behaviors than Non-Users although self-reporting more time in PA.

Relationship between Distress Related to Caregiver Burden and Physical Activity in Informal Caregivers of Patients with COPD.

Chronic obstructive pulmonary disease (COPD) can lead to increased dependence on the informal caregiver and, consequently, to distress associated with caregiving burden. In the general population, higher levels of physical activity (PA) are related to lower distress levels; however, this relationship has been scarcely studied in COPD. This study aimed to explore the relationship between distress and PA in informal caregivers of patients with COPD, and the influence of caregivers' (age, sex) and patients' (age, sex, lung function) characteristics and caregiving duration on this relationship.A cross-sectional study was conducted with 50 caregivers (62.7 ± 9.8 years, 88% female; 78% caring for a spouse/partner; 38% caring >40 h/week; patients' FEV1=45.2 ± 21.3% predicted). Data collection comprised questions related to the caregiving context, distress related to caregiving burden assessed with the Informal Caregiver Burden Assessment Questionnaire (QASCI; total score, 7 subscales), and self-reported PA with the Habitual Physical Activity Questionnaire (HPAQ). Spearman's correlation coefficient and linear regressions were used.Significant, negative and moderate correlations were found between the QASCI (28.5 ± 19.8) and the HPAQ (5.2 ± 1.3) (ρ=-0.46; p = 0.01); and between the HPAQ and some QASCI subscales (emotional burden ρ=-0.47; implications for personal life ρ=-0.52; financial burden ρ=-0.44; perception of efficacy and control mechanisms ρ=-0.42; p < 0.01). Two linear regression models were tested to predict QASCI total score including as predictors: 1) HPAQ alone (p = 0.001; r2=0.23); 2) HPAQ and caregiving h/week (p < 0.001; r2=0.34).Higher self-reported PA levels are related to decreased levels of distress associated with caregiver burden in COPD caregivers. Duration of caregiving may negatively influence this relationship.