Low Prevalence of Latent Tuberculosis Infection among Contacts of Smear-Positive Adults in Brazil

This follow-up cross-sectional study aimed to analyze the prevalence rate and risk factors related to latent tuberculosis infection (LTBI) and active tuberculosis (TB) in children aged < 15 years in contact with adults with smear-positive pulmonary TB (PTB) in a Brazilian municipality. Data were collected from interviews, clinical evaluations, chest X-rays, tuberculin skin tests, and interferon gamma release assays. The median time elapsed between diagnosis of the index case (IC) and inclusion in the study was 2.5 years (interquartile range [IQR] = 1.5-4.4) and 7.4 years (IQR = 3.8-9.7) when we reassessed the development (or not) of active TB. The median age at the time of exposure to the IC was 6.6 years (IQR = 3.3-9.4) and 14.1 years (IQR = 8.9-17.7) at the last follow-up. Of the 99 children and adolescents in contact with smear-positive PTB, 21.2% (95% CI = 14.0-29.9) were diagnosed with LTBI, and none developed active TB. There was no statistically significant difference between the LTBI and non-LTBI groups regarding demographic, socioeconomic, and epidemiological characteristics. Unlike national and international scenarios, we found a lower frequency of LTBI and no active TB among our studied patients. For better understanding of these findings, further studies might add, among other factors, host and Mycobacterium tuberculosis genetic features.

Childhood asthma in low and middle-income countries: Where are we now?

Pediatric asthma has been increasing in LMICs (Low Middle-Income Countries), leading to an important burden for both children and national health systems. Implementing measures to achieve control are influenced by the degree of organization health systems have, the availability and affordability of essential asthma medications, and the effective implementation of asthma programs and asthma guidelines. In this review authors give an updated view of the current situation of these components of asthma management in LMICs.

Factors associated with asthma expression in adolescents

Objective:

To evaluate risk factors associated with asthma symptoms in adolescents in the 13- to 14-year age bracket.

Methods:

This was a cross-sectional study involving adolescents enrolled in randomly selected public schools in the city of Belo Horizonte, Brazil, and conducted with the use of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and its supplementary module for risk factor assessment. The ISAAC questionnaire was completed by the students themselves, whereas the supplementary questionnaire was completed by their parents or legal guardians. Variables showing p ≤ 0.25 in the univariate analysis were included in the multivariate analysis. Stepwise regression with backward elimination was used for variable selection.

Results:

We evaluated 375 adolescents, 124 (33.1%) of whom had asthma symptoms. The final multivariate analysis model revealed that asthma symptoms were associated with birth weight < 2,500 g (p < 0.001), day care center or nursery attendance (p < 0.002), maternal history of asthma (p < 0.001), contact with animals during the first year of life (p < 0.027), current contact with animals outside the home (dogs, cats, or farm animals; p < 0.005), and more than 20 cigarettes per day smoked by parents or other household members (p < 0.02).

Conclusions:

Exposure to animals in and outside the home is associated with asthma symptoms, as is environmental tobacco smoke exposure. Families, health professionals, and administrators of health care facilities should take that into account in order to prevent asthma and reduce asthma morbidity.

Prophylactic regimens with fluconazole for candidiasis in neonates under 1.500g: A retrospective chart review of two cohorts

BACKGROUND

The incidence rate of invasive candidiasis in newborns with birth weight below 1,500 g ranges from 2% to 8%, and fluconazole prophylaxis in neonatal units is recommended when the incidence of invasive candidiasis is higher than 5%. This study aimed to compare the effectiveness of targeted prophylaxis and universal prophylaxis with fluconazole in the prevention of invasive candidiasis.

METHODS

This was a historical cohort comparing the targeted prophylaxis for newborns weighing less than 1,500 g and the universal prophylaxis for newborns weighing less than 1,000 g.

RESULTS

The overall incidence rate of invasive candidiasis was 5.25% and was reduced from 7.1% to 3.72% with universal prophylaxis (p = 0.04). In a multivariate analysis, the significant factors associated with the development of candidiasis were birth weight less than 1,000 g, prolonged hospitalization, previous surgery, prolonged use of mechanical ventilation, prior exposure to antimicrobial treatments, and use of targeted prophylaxis.

CONCLUSIONS

Universal prophylaxis had lower incidence of invasive candidiasis, and preventive measures considering the risk factors are mandatory to reduce the incidence of invasive candidiasis.

Treatment adherence and level of control in moderate persistent asthma in children and adolescents treated with fluticasone and salmeterol

OBJECTIVE

There is a scarcity of studies that assessed the association between adherence to combination therapy and asthma control in pediatric patients. The authors investigated the association between adherence to fluticasone propionate/salmeterol xinafoate combination-metered aerosol and the level of asthma control in children.

METHODS

This was a prospective observational study of 84 patients aged 5-16 years with moderate persistent asthma, who remained uncontrolled despite the use of 1000μg/day of inhaled nonextrafine-hydrofluoric alkane-beclomethasone dipropionate in the three months prior to study enrollment. Participants were prescribed two daily doses of FP (125μg)/salmeterol xinafoate (25μg) combination by metered aerosol/spacer for six months. Adherence rates were assessed using the device's dose counter after the 2nd, 4th, and 6th months of follow up. Asthma control was assessed using a simplified Global Initiative for Asthma 2014 Report classification.

RESULTS

Mean adherence rates after the second, fourth, and sixth months were 87.8%, 74.9%, and 62.1% respectively, for controlled asthma, and 71.7%, 56.0%, and 47.6% respectively, for uncontrolled asthma (all p-values≤0.03). The proportion of children achieving asthma control increased to 42.9%, 67.9% and 89.3% after the 2nd, 4th and 6th months of follow-up, respectively (p≤0.001).

CONCLUSION

Adherence rates between 87.8% in the 2nd month and 62.1% in the 6th month were strong determinants of asthma control.

Electronic Clinical Decision Support System for allergic rhinitis management: MASK e-CDSS

BACKGROUND

Allergic rhinitis (AR) management has changed in recent years following the switch from the concept of disease severity to the concept of disease control, publication of the AR clinical decision support system (CDSS) and development of mobile health (m-health) tools for patients (eg Allergy Diary). The Allergy Diary Companion app for healthcare providers is currently being developed and will be launched in 2018. It incorporates the AR CDSS to provide evidence-based treatment recommendations, linking all key stakeholders in AR management.

OBJECTIVE

To produce an electronic version of the AR CDSS (e-CDSS) for incorporation into the Allergy Diary Companion, to describe the app interfaces used to collect information necessary to inform the e-CDSS and to summarize some key features of the Allergy Diary Companion.

METHODS

The steps involved in producing the e-CDSS and incorporating it into the Allergy Diary Companion were (a) generation of treatment management scenarios; (b) expert consensus on treatment recommendations; (c) generation of electronic decisional algorithms to describe all AR CDSS scenarios; (d) digitization of these algorithms to form the e-CDSS; and (e) embedding the e-CDSS into the app to permit easy user e-CDSS interfacing.

RESULTS

Key experts in the AR field agreed on the AR CDSS approach to AR management and on specific treatment recommendations provided by Allergy Diary Companion. Based on this consensus, decision processes were developed and programmed into the Allergy Diary Companion using Titanium Appcelerator (JavaScript) for IOS tablets. To our knowledge, this is the first time the development of any m-health tool has been described in this transparent and detailed way, providing confidence, not only in the app, but also in the provided management recommendations.

CONCLUSION

The Allergy Diary Companion for providers provides guideline and expert-endorsed AR management recommendations. [MASK paper No 32].

On-demand intermittent beclomethasone is effective for mild asthma in Brazil

BACKGROUND

Daily inhaled corticosteroids are widely recommended for mild persistent asthma. This study aimed to assess the efficacy of the intermittent use of beclomethasone as an alternative treatment for mild persistent asthma.

METHODS

In this 16-week trial, children aged 6-18 years were evaluated. Subjects in the continuous treatment arm of the study received 500 μg/day of beclomethasone, whereas the intermittent ones were given 1000 μg/day (250 μg every 6 h) in combination with albuterol for 7 days upon exacerbations or worsening of symptoms. Primary outcome (i.e., treatment failure) was the occurrence of any asthma exacerbation requiring prednisone, and co-secondary outcomes were the mean/median differences for both, (1) the pre-bronchodilator FEV1 (% predicted) and (2) asthma control test (ACT/cACT) scores, from randomization to the last follow-up visit, and beclomethasone and albuterol consumption.

RESULTS

Ninety-four subjects from each treatment arm were included. They were comparable regarding all baseline characteristics; prednisone was used by 10 (10.6%) and 7 (7.4%) patients, respectively (95% CI - 6.1 to 12.6%, for the difference; p = 0.47). Statistical analysis showed no statistically significant differences with respect to both FEV1 (p = 0.39) and ACT/cACT scores (p = 0.38). As assessed through canister weighting, children used from 0.5 to 0.7 and from 1.6 to 1.8 puffs per day of beclomethasone in the intermittent and continuous regimens, respectively. Regarding albuterol, received 0.3-0.4 (intermittent) and 0.1-0.2 (continuous) inhalations per day. There were no relevant clinical or functional differences between the two treatment regimens.

CONCLUSION

Clinicians might consider intermittent inhaled steroid therapy as a therapeutic regimen for mild persistent asthma.Trial registration The Portuguese and English versions of the study protocol were submitted, approved, and registered in the Brazilian Network Platform for Clinical Trials (http://www.ensaiosclinicos.gov.br) under the primary identifier number "RBR-3gbyhk". This platform is part of the Primary Registries in the World Health Organization Registry Network, where the trial is registered under the following Universal Trial Number: 1111-1149-4774.

Cause-specific mortality for 249 causes in Brazil and states during 1990-2015: a systematic analysis for the global burden of disease study 2015

Background

Reliable data on cause of death (COD) are fundamental for planning and resource allocation priorities. We used GBD 2015 estimates to examine levels and trends for the leading causes of death in Brazil from 1990 to 2015.

Methods

We describe the main analytical approaches focused on both overall and specific causes of death for Brazil and Brazilian states.

Results

There was an overall improvement in life expectancy at birth from 1990 to 2015, but with important heterogeneity among states. Reduced mortality due to diarrhea, lower respiratory infections, and other infectious diseases contributed the most for increasing life expectancy in most states from the North and Northeast regions. Reduced mortality due to cardiovascular diseases was the highest contributor in the South, Southeast, and Center West regions. However, among men, intentional injuries reduced life expectancy in 17 out of 27 states. Although age-standardized rates due to ischemic heart disease (IHD) and cerebrovascular disease declined over time, these remained the leading CODs in the country and states. In contrast, leading causes of premature mortality changed substantially - e.g., diarrheal diseases moved from 1st to 13th and then the 36th position in 1990, 2005, and 2015, respectively, while violence moved from 7th to 1st and to 2nd. Overall, the total age-standardized years of life lost (YLL) rate was reduced from 1990 to 2015, bringing the burden of premature deaths closer to expected rates given the country’s Socio-demographic Index (SDI). In 1990, IHD, stroke, diarrhea, neonatal preterm birth complications, road injury, and violence had ratios higher than the expected, while in 2015 only violence was higher, overall and in all states, according to the SDI.

Conclusions

A widespread reduction of mortality levels occurred in Brazil from 1990 to 2015, particularly among children under 5 years old. Major shifts in mortality rates took place among communicable, maternal, neonatal, and nutritional disorders. The mortality profile has shifted to older ages with increases in non-communicable diseases as well as premature deaths due to violence. Policymakers should address health interventions accordingly.

Electronic supplementary material

The online version of this article (10.1186/s12963-017-0156-y) contains supplementary material, which is available to authorized users.

CHRODIS criteria applied to the MASK (MACVIA-ARIA Sentinel NetworK) Good Practice in allergic rhinitis: a SUNFRAIL report

A Good Practice is a practice that works well, produces good results, and is recommended as a model. MACVIA-ARIA Sentinel Network (MASK), the new Allergic Rhinitis and its Impact on Asthma (ARIA) initiative, is an example of a Good Practice focusing on the implementation of multi-sectoral care pathways using emerging technologies with real life data in rhinitis and asthma multi-morbidity. The European Union Joint Action on Chronic Diseases and Promoting Healthy Ageing across the Life Cycle (JA-CHRODIS) has developed a checklist of 28 items for the evaluation of Good Practices. SUNFRAIL (Reference Sites Network for Prevention and Care of Frailty and Chronic Conditions in community dwelling persons of EU Countries), a European Union project, assessed whether MASK is in line with the 28 items of JA-CHRODIS. A short summary was proposed for each item and 18 experts, all members of ARIA and SUNFRAIL from 12 countries, assessed the 28 items using a Survey Monkey-based questionnaire. A visual analogue scale (VAS) from 0 (strongly disagree) to 100 (strongly agree) was used. Agreement equal or over 75% was observed for 14 items (50%). MASK is following the JA-CHRODIS recommendations for the evaluation of Good Practices.

First Clinical Consensus and National Recommendations on Tracheostomized Children of the Brazilian Academy of Pediatric Otorhinolaryngology (ABOPe) and Brazilian Society of Pediatrics (SBP)

Introduction

Tracheostomy is a procedure that can be performed in any age group, including children under 1 year of age. Unfortunately health professionals in Brazil have great difficulty dealing with this condition due to the lack of standard care orientation.

Objective

This clinical consensus by Academia Brasileira de Otorrinolaringologia Pediátrica (ABOPe) and Sociedade Brasileira de Pediatria (SBP) aims to generate national recommendations on the care concerning tracheostomized children.

Methods

A group of experts experienced in pediatric tracheostomy (otorhinolaryngologists, intensive care pediatricians, endoscopists, and pediatric pulmonologists) were selected, taking into account the different regions of Brazil and following inclusion and exclusion criteria.

Results

The results generated from this document were based on the agreement of the majority of participants regarding the indications, type of cannula, surgical techniques, care, and general guidelines and decannulation.

Conclusion

These guidelines can be used as directives for a wide range of health professionals across the country that deal with tracheostomized children.

Transfer of innovation on allergic rhinitis and asthma multimorbidity in the elderly (MACVIA-ARIA) - EIP on AHA Twinning Reference Site (GARD research demonstration project)

The overarching goals of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) are to enable European citizens to lead healthy, active and independent lives whilst ageing. The EIP on AHA includes 74 Reference Sites. The aim of this study was to transfer innovation from an app developed by the MACVIA-France EIP on AHA reference site (Allergy Diary) to other reference sites. The phenotypic characteristics of rhinitis and asthma multimorbidity in adults and the elderly will be compared using validated information and communication technology (ICT) tools (i.e. the Allergy Diary and CARAT: Control of Allergic Rhinitis and Asthma Test) in 22 Reference Sites or regions across Europe. This will improve the understanding, assessment of burden, diagnosis and management of rhinitis in the elderly by comparison with an adult population. Specific objectives will be: (i) to assess the percentage of adults and elderly who are able to use the Allergy Diary, (ii) to study the phenotypic characteristics and treatment over a 1-year period of rhinitis and asthma multimorbidity at baseline (cross-sectional study) and (iii) to follow-up using visual analogue scale (VAS). This part of the study may provide some insight into the differences between the elderly and adults in terms of response to treatment and practice. Finally (iv) work productivity will be examined in adults.

Control measures to trace ≤ 15-year-old contacts of index cases of active pulmonary tuberculosis

This was descriptive study carried out in a medium-sized Brazilian city. In ≤ 15-year-old contacts of index cases of active pulmonary tuberculosis, we assessed compliance with the Brazilian national guidelines for tuberculosis control. We interviewed 43 contacts and their legal guardians. Approximately 80% of the contacts were not assessed by the municipal public health care system, and only 21% underwent tuberculin skin testing. The results obtained with the Chi-square Automatic Interaction Detector method suggest that health care teams have a biased attitude toward assessing such contacts and underscore the need for training health professionals regarding tuberculosis control programs.

A workshop on asthma management programs and centers in Brazil: reviewing and explaining concepts

Objective:

To report the results of a workshop regarding asthma management programs and centers (AMPCs) in Brazil, so that they can be used as a tool for the improvement and advancement of current and future AMPCs.

Methods:

The workshop consisted of five presentations and the corresponding group discussions. The working groups discussed the following themes: implementation of asthma management strategies; human resources needed for AMPCs; financial resources needed for AMPCs; and operational maintenance of AMPCs.

Results:

The workshop involved 39 participants, from all regions of the country, representing associations of asthma patients (n = 3), universities (n = 7), and AMPCs (n = 29). We found a direct relationship between a lack of planning and the failure of AMPCs. Based on the experiences reported during the workshop, the common assumptions about AMPCs in Brazil were the importance of raising awareness of managers; greater community participation; interdependence between primary care and specialized care; awareness of regionalization; and use of medications available in the public health system.

Conclusions:

Brazil already has a core of experience in the area of asthma management programs. The implementation of strategies for the management of chronic respiratory disease and their incorporation into health care system protocols would seem to be a natural progression. However, there is minimal experience in this area. Joint efforts by individuals with expertise in AMPCs could promote the implementation of asthma management strategies, thus speeding the creation of treatment networks, which might have a multiplier effect, precluding the need for isolated centers to start from zero.

The role of latex agglutination test for the etiological diagnosis of pleural effusion in children and adolescents

INTRODUCTION

The etiological diagnosis of pleural effusion is a difficult task because the diagnostic tools can only establish a definitive etiological diagnosis in at most 76% of cases.

OBJECTIVES

To verify the diagnostic accuracy of the latex agglutination test (LAT) for the etiological diagnosis of pleural effusions caused by Streptococcus pneumoniae and Haemophilus influenzae type b.

METHODS

After thoracocentesis, paired fresh samples of pleural fluid from 418 children and adolescents were included in this investigation. They were tested blindly and simultaneously through counterimmunoelectrophoresis (CIE) and LAT for both bacteria. Sensitivity, specificity, predictive values and likelihood ratios (LR) were calculated taking CIE as a reference standard.

RESULTS

The sensitivity and specificity of LAT was 100% (95% confidence interval, 94.4%-100%) and 83.3% (95% confidence interval, 79.0%-87.0%), respectively, whereas the positive (calculated from Bayes' theorem) and negative predictive values were, respectively, lower than 1% and 100% (95% confidence interval, 98.8%-100%). Positive and negative LR were 6.0 (95% confidence interval, 4.7-7.6) and zero, respectively.

CONCLUSIONS

Our results suggest that LAT is a useful tool for the etiological diagnosis of pleural effusion. It is a reliable, rapid, simple to perform and shows an excellent yield in our studied population, helping to prescribe appropriate antibiotics for this clinical condition.

From lip to lab: salty tasting skin is the main clue that raises clinical suspicion of cystic fibrosis in young infants

AIM

This study developed a clinical decision rule (CDR) to rule in or rule out cystic fibrosis (CF) in the first weeks of life.

METHODS

We combined a two-step nonconcurrent birth cohort and a cross-sectional controlled study in which observers and mothers were blinded to confirmatory sweat test results. Neonates from uncomplicated pregnancies and deliveries, with two subsequent tests for immunoreactive trypsinogen (IRT) higher than 70 ng/mL, were eligible to take part.

RESULTS

We included 49 CF-affected and 177 CF-unaffected infants with an average age of 34 days. CF-affected infants demonstrated statistically significant differences in weight gain, stool frequency and salty tasting skin from birth. Multivariate analysis showed that the main predictors of CF were salty tasting skin (odds ratio 17.2) and weight gain of <10.5 g per day (odds ratio 4.6). Depending on the CDR score, we obtained the following results: sensitivity (42.9-61.2%), specificity (89.6-96.5%), positive (62.5-77.8%) and negative (85.6-89.1%) predictive value and positive (5.8-12.3) and negative (0.4-0.6) likelihood ratio.

CONCLUSION

The CDR could provide a reliable index of clinical suspicion and timely referral for sweat testing in settings without newborn screening programmes and may also be applied to false-negative individuals where such programmes already exist.

Exposure to environmental factors and relationship to allergic rhinitis and/or asthma

INTRODUCTION AND OBJECTIVES

Studies analyzing risk factors, multiple indoor and outdoor factors related to asthma and/or allergic rhinitis (AR) in childhood, are very rare. The presented study was carried out to simultaneously assess host-related, indoor and particulate matter exposure with current allergic rhinitis (AR) and/or asthma in children (6-7 years) and adolescents (13-14 years).

MATERIAL AND METHODS

The method was a cross-sectional population-based study in which participants were diagnosed by means of the International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire.

RESULTS

Exposure to indoor risk factors were verified in 1,302 individuals, in which the prevalence of AR, asthma and AR-asthma comorbidity were 37.3%, 28.4%, and 16%, for children and 31.5%, 16.2%, and 10.5% for adolescents, respectively. Smoking during pregnancy was associated with current asthma (OR=1.5), second-hand smoking with AR-asthma comorbidity (OR=1.4) and visible mold on the walls with current AR, asthma, and AR-asthma comorbidity (OR=1.6). In a subgroup of 590 children, in addition to the indoor risk factors, exposure to PM10 was assessed. In this joint analysis, there was association with the same previously mentioned risk factors (p values ≤ 0.5) and a negative association to PM10 (p ≤ 0.002).

CONCLUSION

The results suggest that avoidance of smoking during pregnancy, second-hand smoking and exposure to mould at home can contribute to reducing current AR and/or current asthma. Exposure to PM10 was not associated with the prevalence rate of these diseases.

Risk factors associated with hypoxemia during foreign body removal from airways in childhood

OBJECTIVE

The aim of this study was to analyze the association between variables associated with hypoxemia in children who underwent rigid bronchoscopy for foreign body removal.

METHODS

From April 1993 to April 2011, four hundred and one children who inhaled foreign bodies were included. Apart from descriptive statistics, univariate and multivariate analyses were performed to identify risk factors related to hypoxemia.

RESULTS

Among the patients aged up to one year, the risk of hypoxemia was five and a half times higher than for patients aged 1 or older (OR=5.6), whereas the risk of patients who underwent foreign body removal using seed type tweezers having hypoxemia was approximately 4 times higher than that of patients who underwent this procedure with other types of tweezers (OR=3.7). Furthermore, for each additional minute in the duration of the procedure, the risk of hypoxemia reached 4% (OR=1.04).

CONCLUSION

Our results suggest that children younger than 1 year who require RB seem to be vulnerable to a higher risk of hypoxemia, especially in longer procedures in which seed tweezers are used.

Does BCG revaccination protect against the development of asthma?

Single BCG vaccination has been considered as a protective factor against asthma. However the effect of a second dose of BCG on the prevalence rate of asthma and asthma-allergic rhinitis-eczema comorbidity has not been studied exclusively among adolescents. In this ISAAC protocol-based cross sectional study we assessed the association between one single versus two doses of BCG among 2213 individuals aged 13-14 years old. We found no association between BCG revaccination and asthma, associated (OR = 0.68, 95% CI, 0.37-1.25) or not to allergic rhinitis and/or atopic eczema (OR = 1.07, 95% CI, 0.84-1.36).

Oral magnesium supplementation in children with cystic fibrosis improves clinical and functional variables: a double-blind, randomized, placebo-controlled crossover trial

BACKGROUND

Magnesium is one of the most important minerals in the body. Although some studies reported that patients with cystic fibrosis (CF) lack magnesium, no international study has assessed the importance of oral magnesium supplementation in CF patients.

OBJECTIVE

We prospectively investigated the long-term effect of oral magnesium supplementation on respiratory muscle strength by using manuvacuometry and the Shwachman-Kulczycki (SK) score among children and adolescents with CF.

DESIGN

This double-blind, randomized, placebo-controlled crossover study included 44 CF patients (aged 7-19 y; 20 males) who were randomly assigned to receive magnesium (n = 22; 300 mg/d) or placebo (n = 22) for 8 wk with a 4-wk washout period between trials. All patients were undergoing conventional treatment of CF. The experimental protocol included clinical evaluation, assessment of urinary concentration of magnesium, and manuvacuometric measurements [maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP)]. MIP was the primary outcome.

RESULTS

Urinary magnesium increased after the administration of magnesium (change: 36.38 mg/d after magnesium compared with 0.72 mg/d after placebo; P < 0.001). Moreover, MIP and MEP significantly improved only after magnesium administration (change in MIP: 11% predicted after magnesium compared with 0.5% predicted after placebo; change in MEP: 11.9% predicted after magnesium compared with 0.8% predicted after placebo; P < 0.001 for both). Magnesium administration had a beneficial effect on clinical variables assessed by the SK score (change: 4.48 points after magnesium compared with -1.30 points after placebo; P < 0.001).

CONCLUSION

Oral magnesium supplementation helped improve both the SK score and respiratory muscle strength in pediatric patients with CF.