Objective: To evaluate the relationship between screen time (ST) and lung function in hospitalized children and adolescents with cystic fibrosis (CF). Methods: This was a cross-sectional study of 45 children with CF in the 0- to 17-year age bracket admitted to a public hospital in southern Brazil. ST during hospitalization was measured by means of a recall diary. Questionnaires were used in order to collect data on screen use and personal data. Data on lung function, nutrition, bacteriology, and the Shwachman-Kulczycki clinical score were obtained from patient medical records. Results: Of the study participants, 51.1% were male, with a median age of 9 years, and 80% were White. The mean FEV1 (Z-score) was -2.9 ± 1.9, and FEV1 (in % of predicted) was 63.7 ± 22.3. The median ST was 315 min, and 95.5% of the study participants exceeded the recommended ST. The most prevalent reasons for using electronic devices during hospitalization were boredom and lack of other activities. In a multivariate analysis, ST (the dependent variable) was significantly associated with age (ß = 26.591; 95% CI, 14.695-38.487), time spent watching television at home (ß = 0.686; 95% CI, 0.304-1.069), and FEV1 Z-score (ß = -60.631; 95% CI, -115.399 to -5.864). Conclusions: Excess ST appears to be associated with worse lung function in hospitalized children with CF, as do older age and longer periods of time spent watching television at home.

Keywords: Screen time; Spirometry; Cystic fibrosis; Child, hospitalized.

Objective: To evaluate the association between nutritional status measurements and pulmonary function in children and adolescents with cystic fibrosis. Methods: We evaluated the nutritional status of 48 children and adolescents (aged 6-18 years) with cystic fibrosis based on body mass index (BMI) and body composition measurements-mid-arm muscle circumference (MAMC) and triceps skinfold thickness (TST)-at a referral center in the city of Rio de Janeiro, Brazil. Pulmonary function was assessed by means of spirometry, using FEV1 to classify the severity of airway obstruction. We used Student's t-tests for comparisons between proportions and linear regression analysis for associations between continuous variables. The level of significance was set at p < 0.05. Results: The evaluation of nutritional status based on BMI identified a smaller number of malnourished patients than did that based on MAMC (14 vs. 25 patients, respectively). Most of the patients presented mild pulmonary disease. Mean FEV1 was 82.5% of predicted. Pulmonary function was found to correlate significantly with BMI, MAMC and TST (p = 0.001, p = 0.001 and p = 0.03, respectively). All subjects with moderate or severe pulmonary involvement were considered malnourished based on BMI and body composition parameters. Of the 25 patients considered malnourished based on body composition (MAMC), 19 were considered well-nourished based on their BMI. Conclusions: In the present study, all nutritional status measurements correlated directly with the pulmonary function of children and adolescents with cystic fibrosis. However, body composition measurements allowed earlier detection of nutritional deficiencies.

Keywords: Cystic fibrosis; Body composition; Spirometry; Nutrition assessment.

Objetivo: Analisar as características funcionais pulmonares, a resposta farmacodinâmica a um broncodilatador e sua prescrição em pacientes com diagnóstico de fibrose cística (FC). Métodos: Estudo de coorte retrospectivo de pacientes (6-18 anos) com diagnóstico de FC acompanhados em um centro de referência, capazes de realizar testes de função pulmonar (TFP) entre 2008 e 2010. Foram analisados CVF, VEF1 e FEF25-75%, em percentual do previsto, antes e após prova broncodilatadora (pré-BD e pós-BD, respectivamente) de 312 TFP. Foram realizadas ANOVA para medidas repetidas e comparações múltiplas. Resultados: Foram incluídos no estudo 56 pacientes. Desses, 37 e 19, respectivamente, tinham resultados de TFP entre 2008 e 2010 e apenas em 2009-2010, formando dois grupos. No grupo com TFP nos três anos estudados, houve redução significativa em VEF1 pós-BD em 2008-2010 (p = 0,028) e 2009-2010 (p = 0,036) e em FEF25-75% pré-BD e pós-BD em todas as comparações múltiplas (2008 vs. 2009; 2008 vs. 2010; e 2009 vs. 2010). No grupo com TFP apenas em 2009-2010, não houve diferenças significativas em nenhuma das comparações das variáveis estudadas. Dos 312 TFP, somente 24 (7,7%) apresentaram resposta significativa ao broncodilatador e pertenciam a pacientes sem prescrição de broncodilatador durante o período estudado. Conclusões: Houve perda funcional, com indicação de doença pulmonar progressiva, nos pacientes com FC estudados. Houve maiores alterações no FEF25-75%, sugerindo o comprometimento inicial de vias aéreas menores.

Keywords: Fibrose cística; Testes de função respiratória; Broncodilatadores.

Objective: To determine the prevalence of nocturnal hypoxemia and its association with pulmonary function, nutritional status, sleep macrostructure, and obstructive respiratory events during sleep in a population of clinically stable children and adolescents with cystic fibrosis (CF). Methods: This was a cross-sectional study involving 67 children and adolescents with CF between 2 and 14 years of age. All of the participants underwent polysomnography, and SpO2 was measured by pulse oximetry. We also evaluated the Shwachman-Kulczycki (S-K) scores, spirometry findings, and nutritional status of the patients. Results: The study involved 67 patients. The mean age of the patients was 8 years. The S-K scores differed significantly between the patients with and without nocturnal hypoxemia, which was defined as an SpO2 < 90% for more than 5% of the total sleep time (73.75  6.29 vs. 86.38  8.70; p < 0.01). Nocturnal hypoxemia correlated with the severity of lung disease, FEV1 (rs = −0.42; p = 0.01), FVC (rs = −0.46; p = 0.01), microarousal index (rs = 0.32; p = 0.01), and apnea-hypopnea index (rs = 0.56; p = 0.01). Conclusions: In this sample of patients with CF and mild-to-moderate lung disease, nocturnal oxygenation correlated with the S-K score, spirometry variables, sleep macrostructure variables, and the apnea-hypopnea index.

Keywords: Cystic fibrosis; Sleep; Oximetry.

Objective: To study correlations among pulmonary function, chest radiology and clinical status in cystic fibrosis. Methods: A retrospective cross-sectional study was performed to evaluate chest X-rays and clinical charts of patients treated at the Hospital de Clínicas de Porto Alegre. Spirometry findings, Shwachman-Kulczycki (S-K) scores and Brasfield scores were analyzed. Results: The final sample consisted of 40 patients (mean age 9.72 ± 3.27). The following mean S-K scores were obtained: total, 80.87 ± 10.24; general activity, 24.75 ± 1.1; physical examination, 18.87 ± 4.59; nutrition, 21.87 ± 4.18; radiology, 15.37 ± 5.23. The mean Brasfield score was 18.2 ± 4. The pulmonary function test results, in percentage of predicted, were as follows: forced vital capacity (FVC), 82.99 ± 14.36%; forced expiratory volume in one second (FEV1), 83.62 ± 18.26%; and forced expiratory flow between 25 and 75% of FVC (FEF25-75), 74.63 ± 2.53%. The S-K score correlated moderately with FVC, whereas it correlated strongly with FEV1 and FEF25-75. The Brasfield score correlated strongly with the S-K total and radiology score, whereas it correlated moderately with pulmonary function. Physical examination correlated moderately with FVC, FEV1 and FEF25-75; as did nutrition with FEF25-75; and radiology with FEV1 and FEF25-75. General activity was the domain that had the greatest influence on the total S-K score. Conclusions: These two scoring systems are complementary, correlating with each other, as well as with pulmonary function tests. The radiology domain of the S-K scoring system is a good alternative to the Brasfield score.

Keywords: Cystic fibrosis; Spirometry; Lung/radiography.

Objective: To analyze the effects of Pilates mat exercises in patients with cystic fibrosis (CF). Methods: This was a clinical trial involving 19 CF patients recruited from either the CF Outpatient Clinic of the State University at Campinas Hospital de Clínicas or the Children's Institute of the University of São Paulo School of Medicine Hospital das Clínicas. All of the patients performed Pilates mat exercises for four months (one 60-min session per week). The variables studied (before and after the intervention) were respiratory muscle strength, MIP, MEP, FVC, and FEV1. Results: After the intervention, MIP was significantly higher in the male patients (p = 0.017), as were MIP and MEP in the female patients (p = 0.005 and p = 0.007, respectively). There were no significant differences between the pre- and post-intervention values of FVC or FEV1, neither in the sample as a whole nor among the patients of either gender. Conclusions: Our results show that Pilates mat exercises have beneficial effects on respiratory muscle strength in CF patients. (Brazilian Registry of Clinical Trials - ReBEC; identification number RBR-86vp8x [http://www.ensaiosclinicos.gov.br])

Keywords: Cystic fibrosis; Muscle strength; Exercise movement techniques; Respiratory function tests.

Objective: Depression and anxiety have been documented in people with cystic fibrosis (CF), jeopardizing treatment adherence. To date, no studies have assessed the prevalence of psychosocial issues in adolescents with CF in Brazil. We sought to assess the prevalence of depression and anxiety in adolescents with CF in Brazil, as well as the impact of depression and anxiety on treatment adherence. Methods: This was a multicenter, prospective, observational, longitudinal study conducted between 2017 and 2019 at 14 CF referral centers in Brazil. We used standardized tools such as the nine-item Patient Health Questionnaire (for depression), the seven-item Generalized Anxiety Disorder scale (for anxiety), and the eight-item Morisky Medication Adherence Scale (for treatment adherence) in order to collect data on 218 CF patients at two different time points. Results: The prevalence of depression was 19.1% at time point 1 and 15.4% at time point 2. The prevalence of anxiety was 19.1% at time point 1 and 18.0% at time point 2. Depression and anxiety were significantly higher in female patients and lower in those who underwent home physiotherapy or had psychological support. Significant correlations were found between depression and anxiety at both time points, the associations being strongest at time point 1 (r = 0.68; p < 0.001). Most (66.7%) of the study participants reported low adherence to treatment, and the remainder reported either average adherence (in 28%) or high adherence (in 5.3%). Depression and anxiety showed inverse correlations with treatment adherence. Conclusions: The prevalence of depression and anxiety in adolescents with CF in Brazil appears to be similar to that reported in other countries, being higher in females and lower in those undergoing home physiotherapy or receiving psychological care. Depression and anxiety appear to correlate with lower treatment adherence. Treating psychosocial issues may effectively improve rates of treatment adherence in adolescents with CF.

Keywords: Cystic fibrosis; Anxiety; Depression; Treatment adherence and compliance; Adolescent.

Objective: To describe the pulmonary function in children and adolescents with postinfectious bronchiolitis oblite­rans (PIBO), as well as to evaluate potential risk factors for severe impairment of pulmonary function. Methods: The pulmonary function of 77 participants, aged 8-18 years, was assessed by spirometry and plethysmography. The following parameters were analyzed: FVC; FEV1; FEF25-75%; FEV1/FVC; RV; TLC; RV/TLC; intrathoracic gas volume; and specific airway resistance (sRaw). We used Poisson regression to investigate the following potential risk factors for severe impairment of pulmonary function: gender; age at first wheeze; age at diagnosis; family history of asthma; tobacco smoke exposure; length of hospital stay; and duration of mechanical ventilation. Results: The mean age was 13.5 years. There were pronounced decreases in FEV1 and FEF25-75%, as well as increases in RV and sRaw. These alterations are characteristic of obstructive airway disease. For the parameters that were the most affected, the mean values (percentage of predicted) were as follows: FEV1 = 45.9%; FEF25-75% = 21.5%; RV = 281.1%; RV/TLC = 236.2%; and sRaw = 665.3%. None of the potential risk factors studied showed a significant association with severely impaired pulmonary function. Conclusions: The patients with PIBO had a common pattern of severe pulmonary function impairment, characterized by marked airway obstruction and pronounced increases in RV and sRaw. The combination of spirometric and plethysmographic measurements can be more useful for assessing functional damage, as well as in the follow-up of these patients, than are either of these techniques used in isolation. Known risk factors for respiratory diseases do not seem to be associated with severely impaired pulmonary function in PIBO.

Keywords: Respiratory function tests; Airway obstruction; Bronchiolitis obliterans

Objective: Asthma is the most common chronic pulmonary disease, characterized by bronchial inflammation. Some children with asthma have persistent pulmonary function impairment. The prevalence and etiology of this abnormality in children with asthma in developing countries remain unknown. The objective of this study was to estimate the proportion of patients with impaired pulmonary function who were unresponsive to treatment in a group of children and adolescents with asthma, and to describe the phenotypic characteristics of the sample. Methods: Using a standardized questionnaire, we selected outpatients (5-17 years of age) diagnosed with persistent asthma. These patients underwent spirometry and skin prick tests for sensitivity to common aeroallergens. Persistent pulmonary function impairment was defined as an FEV1/FVC ratio < 0.80, even after 10 days of treatment with bronchodilators and oral corticosteroids. We used the atopic index to differentiate between patients with little or no response to the skin prick test and those with a strong response (cut-off point: 4 allergens). Results: We included 96 patients with a mean age of 10.6 years. Of those, 52 (54.1%) were male, and 89 (92.7%) were atopic. Of the 96 patients, 8 (8.3%) had impaired pulmonary function even after the treatment. Among those patients, 8 (100%) were atopic, 7 (87.5%) had moderate or severe asthma, and 7 (87.5%) had a history of hospitalization for acute bronchiolitis. Conclusions: Children and adolescents with moderate or severe asthma can present with impaired pulmonary function and be unresponsive to treatment. This clinical situation has been little studied in developing countries, and its risk factors and etiology will be better understood only through birth cohort studies.

Keywords: Asthma; Respiratory function tests; Allergy and immunology.

Objective: To determine the cut-off point for the six-minute walk distance (6MWD) that indicates lower survival time in patients with idiopathic pulmonary fibrosis (IPF) in Brazil. Methods: This was retrospective study carried out in two referral centers for IPF. The 6MWT was performed twice, considering the highest value of the 6MWD. Various cut-off points were estimated, in absolute values and in percentage of predicted values, using ROC curves, the Kaplan-Meier method, and data from other studies. Results: The sample comprised 70 patients with IPF. The mean age was 71.9 ± 6.4 years, and 50 patients (71.4%) were male. The mean FVC was 76.6 ± 18.2% of predicted value. The mean SpO2 at rest before and after 6MWT were 93.8 ± 2.5% and 85.3 ± 6.5%, respectively. The median survival time was 44 months (95% CI: 37-51 months). The mean 6MWD was 381 ± 115 m (79.2 ± 24.0% of predicted). After the analyses, the best cut-off points for estimating survival were 6MWD < 330 m and < 70% of predicted. The median survival time of patients with a 6MWD < 330 m was 24 months (95% CI: 3-45 months), whereas that of those with a 6MWD ≥ 330 m was 59 months (95% CI: 41-77 months; p = 0.009). Similarly, the median survival times of those with a 6MWD < 70% and ≥ 70% of predicted, respectively, were 24 months (95% CI: 13-35 months) and 59 months (95% CI: 38-80 months; p = 0.013). Cox multivariate regression models including age, sex, smoking status, SpO2 at the end of the 6MWT, and FVC% showed that 6MWD remained significantly associated with survival (p = 0.003). Conclusions: Values of 6MWD < 330 m and < 70% of predicted value were associated with lower survival time in IPF patients in Brazil.

Keywords: Lung diseases, interstitial; Pulmonary fibrosis; Exercise tolerance.

Objective: To evaluate whether anthropometric and dietary intake indicators are predictors of pulmonary function in cystic fibrosis (CF) patients. Methods: This was a cross-sectional study involving 69 patients (age range, 5.4-16.5 years) diagnosed with CF under follow-up at the Hospital de Clínicas de Porto Alegre, located in the city of Porto Alegre, Brazil. Anthropometric assessment was based on body mass index (BMI), mid-arm muscle circumference (MAMC), and triceps skinfold thickness (TST). Dietary intake was assessed by using recall data, which were compared with the recommended dietary allowances. Pulmonary function was assessed by ventilatory capacity, expressed as FEV1. Prevalence ratios for the outcome studied (FEV1 < 80% of predicted) were calculated by indicator. Results: In patients with MAMC and TST below the 25th percentile, the prevalence of FEV1 < 80% of predicted was significantly higher than in those with higher MAMC and TST (p < 0.001 and p = 0.011, respectively). In comparison with other patients, those with a BMI below the 50th percentile showed a 4.43 times higher prevalence of FEV1 < 80% of predicted (95% CI: 1.58-12.41), and that prevalence was 2.54 times higher in those colonized with methicillin-resistant Staphylococcus aureus (MRSA) than in those not so colonized (95% CI: 1.43-4.53). The association between dietary intake and the prevalence of FEV1 < 80% of predicted was of only borderline significance (95% CI: 0.95-3.45). Conclusions: Not being colonized with MRSA and having a BMI above the 50th percentile appear to preserve pulmonary function in CF patients.

Keywords: Cystic fibrosis; Respiratory function tests; Nutrition assessment; Energy intake.

Objectives: To characterize the main identified mutations on cystic fibrosis transmembrane conductance regulator (CFTR) in a group of children and adolescents at a cystic fibrosis center and its association with the clinical and laboratorial characteristics. Method: Descriptive cross-sectional study including patients with cystic fibrosis who had two alleles identified with CFTR mutation. Clinical, anthropometrical, laboratorial and pulmonary function (spirometry) data were collected from patients' records in charts and described with the results of the sample genotyping. Results: 42 patients with cystic fibrosis were included in the study. The most frequent mutation was F508del, covering 60 alleles (71.4%). The second most common mutation was G542X (six alleles, 7.1%), followed by N1303K and R1162X mutations (both with four alleles each). Three patients (7.14%) presented type III and IV mutations, and 22 patients (52.38%) presented homozygous mutation for F508del. Thirty three patients (78.6%) suffered of pancreatic insufficiency, 26.2% presented meconium ileus, and 16.7%, nutritional deficit. Of the patients in the study, 59.52% would be potential candidates for the use of CFTR-modulating drugs. Conclusions: The mutations of CFTR identified more frequently were F508del and G542X. These are type II and I mutations, respectively. Along with type III, they present a more severe cystic fibrosis phenotype. More than half of the sample (52.38%) presented homozygous mutation for F508del, that is, patients who could be treated with Lumacaftor/Ivacaftor. Approximately 7% of the patients (7.14%) presented type III and IV mutations, therefore becoming candidates for the treatment with Ivacaftor.

Keywords: Cystic fibrosis; Mutations; Genetics; Phenotype; Child

Objective: To analyze the shuttle walk test, and its respective retest, comparing children with cystic fibrosis (CF) to normal children. Methods: The children were divided into two groups: the CF group, composed of children in whom the diagnosis had been confirmed through sweat testing; and the control group, composed of normal children with no history of pulmonary diseases and no alterations in respiratory function. The children were submitted to at least two consecutive tests, 30 min apart. We evaluated distance walked, cardiac overload, peripheral oxygen saturation (SpO2) and subjective perception of exertion (dyspnea at rest scale and Borg dyspnea scale). Results: A total of 28 children were evaluated. Ages ranged from 7 to 15 years (11.57 ± 2.50 and 11.28 ± 1.85 years for the CF and control groups, respectively). The Borg scale scores were significantly higher in the controls (p = 0.007). No differences were found regarding cardiac overload and SpO2. In relation to the intergroup retest, the controls presented significant improvements on the second test, both in the distance walked and in dyspnea at rest (p = 0.014 and p = 0.036, respectively). The CF group presented a significant improvement only in the dyspnea at rest score (p = 0.168 and p = 0.042, respectively). Conclusion: The cardiac overload imposed by the test did not differ between the groups. The greater fatigue at the beginning of the second test suggests that the 30 min rest between the tests was insufficient.

Keywords: Cystic fibrosis; Exercise test; Heart rate.

Objective: To determine whether air trapping (expressed as the percentage of air trapping relative to total lung volume [AT%]) correlates with clinical and functional parameters in children with obliterative bronchiolitis (OB). Methods: CT scans of 19 children with OB were post-processed for AT% quantification with the use of a fixed threshold of −950 HU (AT%950) and of thresholds selected with the aid of density masks (AT%DM). Patients were divided into three groups by AT% severity. We examined AT% correlations with oxygen saturation (SO2) at rest, six-minute walk distance (6MWD), minimum SO2 during the six-minute walk test (6MWT_SO2), FVC, FEV1, FEV1/FVC, and clinical parameters. Results: The 6MWD was longer in the patients with larger normal lung volumes (r = 0.53). We found that AT%950 showed significant correlations (before and after the exclusion of outliers, respectively) with the clinical score (r = 0.72; 0.80), FVC (r = 0.24; 0.59), FEV1 (r = −0.58; −0.67), and FEV1/FVC (r = −0.53; r = −0.62), as did AT%DM with the clinical score (r = 0.58; r = 0.63), SO2 at rest (r = −0.40; r = −0.61), 6MWT_SO2 (r = −0.24; r = −0.55), FVC (r = −0.44; r = −0.80), FEV1 (r = −0.65; r = −0.71), and FEV1/FVC (r = −0.41; r = −0.52). Conclusions: Our results show that AT% correlates significantly with clinical scores and pulmonary function test results in children with OB.

Keywords: Multidetector computed tomography; Respiratory function tests; Bronchiolitis obliterans.

Objective: Thymidine-dependent small-colony variants (TD-SCVs) of Staphylococcus aureus are being isolated with increasing frequency from patients with cystic fibrosis (CF). The aim of this study was to evaluate the relationship between TD-SCV isolation and pulmonary function in patients with CF, as well as to determine whether the emergence of TD-SCVs was associated with trimethoprim-sulfamethoxazole (TMP-SMX) use and with coinfection with other microorganisms. Methods: This was a retrospective case-control study including patients with CF who visited the Clinical Hospital Complex of the Federal University of Paraná, in Curitiba, Brazil, between 2013 and 2022. Demographic, clinical, and spirometric data, as well as information on TD-SCVs and other isolated microorganisms, were collected from the medical records of patients with CF and TD-SCVs (TD-SCV group; n = 32) and compared with those of a matched group of patients with CF without TD-SCVs (control group; n = 64). Results: Isolation of TD-SCVs was positively associated with TMP-SMX use (p = 0.009), hospitalization (p < 0.001), and impaired pulmonary function (p = 0.04). Conclusions: The use of TMP-SMX seems to contribute to the emergence of TD-SCVs, the isolation of which was directly associated with worse pulmonary function in our sample.

Keywords: Staphylococcus aureus/drug effects; Thymidine/metabolism; Trimethoprim, sulfamethoxazole drug combination/adverse effects; Lung/physiopathology; Cystic fibrosis/complications.

Objectives: To examine the relationship between chronic bacterial infection and pulmonary hypertension, using Doppler echocardiography, in patients with cystic fibrosis (CF). Methods: A prospective cross-sectional study involving CF patients (≥ 16 years of age) admitted to a program for adults with the disease. The study included 40 patients with a mean age of 23.7 ± 6.3 years. Patients were submitted to clinical evaluation, Doppler echocardiography, pulmonary function tests, chest X-rays and sputum cultures of Pseudomonas aeruginosa and Burkholderia cepacia. Results: In terms of the following variables, no significant differences were found between P. aeruginosapositive patients and P. aeruginosa-negative patients: clinical score (p = 0.472); forced expiratory volume in one second (FEV1; p = 0.693); radiological score (p = 0.760); tricuspid regurgitant jet velocity (TRV, p = 0.330); diameter of the right ventricle (DRV, p = 0.191); and right ventricular/pulmonary artery (RV/PA) systolic acceleration time (SAT, p = 0.330). B. cepacia-positive patients presented significantly lower FEV1 than did B. cepacia-negative patients (p = 0.011). No significant differences were found between B. cepacia-positive patients and B. cepacia-negative patients regarding the following variables: clinical score (p = 0.080); radiological score (p = 0.760); TRV (p = 0.613); DRV (p = 0.429); and RV/PA SAT (p = 0.149). Conclusions: Chronic infection with P. aeruginosa or B. cepacia presented no association with pulmonary hypertension in adult CF patients. Pulmonary function was worse in B. cepacia-positive patients than in P. aeruginosa-positive patients.

Keywords: Cystic fibrosis; Bacterial infections; Hypertension, pulmonary; Echocardiography, Doppler.

Objective: To determine whether the variation in lung function over one year is associated with worse clinical outcomes, as well as with a decline in lung function in the following years, in patients with cystic fibrosis (CF). Methods: This was a retrospective study involving CF patients (4-19 years of age), evaluated over a three-year period. We evaluated demographic characteristics, chronic Pseudomonas aeruginosa infection, antibiotic use, hospitalization, six-minute walk distance (6MWD), and lung function. The inclusion criterion was having undergone pulmonary function testing at least three times in the first year and at least once in each of the next two years. Results: We evaluated 35 CF patients. The variation in FEV1 in the first year (ΔFEV1) was greater among those who, in the third year, showed reduced FEV1, had a below-average 6MWD, or were hospitalized than among those with normal FEV1, normal 6MWD, or no hospital admissions, in that same year (p < 0.05), although no such difference was found for antibiotic use in the third year. Subjects showing a ΔFEV1 ≥ 10% also showed a greater decline in FEV1 over the two subsequent years (p = 0.04). The ΔFEV1 also showed an inverse correlation with absolute FEV1 in the third year (r = −0.340, p = 0.04) and with the rate of FEV1 decline (r = −0.52, p = 0.001). Linear regression identified ΔFEV1 as a predictor of FEV1 decline (coefficient of determination, 0.27). Conclusions: Significant variation in lung function over one year seems to be associated with a higher subsequent rate of FEV1 decline and worse clinical outcomes in CF patients. Short-term ΔFEV1 might prove useful as a predictor of CF progression in clinical practice.

Keywords: Cystic fibrosis; Respiratory function tests; Disease progression; Hospitalization; Forced expiratory volume.

Objective: To evaluate the level of self-reported adherence to physical therapy recommendations in pediatric patients (6-17 years) with cystic fibrosis (CF) and to ascertain whether the different levels of adherence correlate with pulmonary function, clinical aspects, and quality of life. Methods: This was a cross-sectional study. The patients and their legal guardians completed a questionnaire regarding adherence to physical therapy recommendations and a CF quality of life questionnaire. We collected demographic, spirometric, and bacteriological data, as well as recording the frequency of hospitalizations and Shwachman-Kulczycki (S-K) clinical scores. Results: We included 66 patients in the study. Mean age, FEV1 (% of predicted), and BMI were 12.2 ± 3.2 years, 90 ± 24%, and 18.3 ± 2.5 kg/m2, respectively. The patients were divided into two groups: high-adherence (n = 39) and moderate/poor-adherence (n = 27). No statistically significant differences were found between the groups regarding age, gender, family income, and total S-K clinical scores. There were statistically significant differences between the high-adherence group and the moderate/poor-adherence group, the latter showing lower scores for the "radiological findings" domain of the S-K clinical score (p = 0.030), a greater number of hospitalizations (p = 0.004), and more days of hospitalization in the last year (p = 0.012), as well as lower scores for the quality of life questionnaire domains emotion (p = 0.002), physical (p = 0.019), treatment burden (p < 0.001), health perceptions (p = 0.036), social (p = 0.039), and respiratory (p = 0.048). Conclusions: Low self-reported adherence to physical therapy recommendations was associated with worse radiological findings, a greater number of hospitalizations, and decreased quality of life in pediatric CF patients.

Keywords: Cystic fibrosis; Patient compliance; Physical therapy modalities; Quality of life.