Pulmonary outcome prediction (POP) tools for cystic fibrosis patients

The Elusive Role of Airway Infection in Cystic Fibrosis Exacerbation

Cystic fibrosis (CF) pulmonary exacerbations (PEx) are clinical events that commonly result in increased treatment burden, decreased quality of life, and accelerated lung disease progression. CF PEx have historically been approached as though dealing with acute infections, and antibiotic treatments have been associated with improved outcomes. In this review, we discuss data supporting a causal role of CF airway infection in PEx as well studies that highlight our knowledge gaps in regard to PEx definitions, pathophysiology, and optimal treatment approaches. In the era of highly effective cystic fibrosis transmembrane conductance regulator modulator therapy, and the continually increasing health and longevity of persons with CF, a better understanding of PEx and further optimization of PEx antibiotic treatment approaches are needed.

A screening tool to identify risk for bronchiectasis progression in children with cystic fibrosis

BACKGROUND

The marked heterogeneity in cystic fibrosis (CF) disease complicates the selection of those most likely to benefit from existing or emergent treatments.

OBJECTIVE

We aimed to predict the progression of bronchiectasis in preschool children with CF.

METHODS

Using data collected up to 3 years of age, in the Australian Respiratory Early Surveillance Team for CF cohort study, clinical information, chest computed tomography (CT) scores, and biomarkers from bronchoalveolar lavage were assessed in a multivariable linear regression model as predictors for CT bronchiectasis at age 5-6.

RESULTS

Follow-up at 5-6 years was available in 171 children. Bronchiectasis prevalence at 5-6 was 134/171 (78%) and median bronchiectasis score was 3 (range 0-12). The internally validated multivariate model retained eight independent predictors accounting for 37% (adjusted R² ) of the variance in bronchiectasis score. The strongest predictors of future bronchiectasis were: pancreatic insufficiency, repeated intravenous treatment courses, recurrent lower respiratory infections in the first 3 years of life, and lower airway inflammation. Dichotomizing the resulting prediction score at a bronchiectasis score of above the median resulted in a diagnostic odds ratio of 13 (95% confidence interval [CI], 6.3-27) with positive and negative predictive values of 80% (95% CI, 72%-86%) and 77% (95% CI, 69%-83%), respectively.

CONCLUSION

Early assessment of bronchiectasis risk in children with CF is feasible with reasonable precision at a group level, which can assist in high-risk patient selection for interventional trials. The unexplained variability in disease progression at individual patient levels remains high, limiting the use of this model as a clinical prediction tool.

Unsupervised phenotypic clustering for determining clinical status in children with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a multisystem disease in which the assessment of disease severity based on lung function alone may not be appropriate. The aim of the study was to develop a comprehensive machine-learning algorithm to assess clinical status independent of lung function in children.

METHODS

A comprehensive prospectively collected clinical database (Toronto, Canada) was used to apply unsupervised cluster analysis. The defined clusters were then compared by current and future lung function, risk of future hospitalisation, and risk of future pulmonary exacerbation treated with oral antibiotics. A k-nearest-neighbours (KNN) algorithm was used to prospectively assign clusters. The methods were validated in a paediatric clinical CF dataset from Great Ormond Street Hospital (GOSH).

RESULTS

The optimal cluster model identified four (A-D) phenotypic clusters based on 12 200 encounters from 530 individuals. Two clusters (A and B) consistent with mild disease were identified with high forced expiratory volume in 1 s (FEV₁), and low risk of both hospitalisation and pulmonary exacerbation treated with oral antibiotics. Two clusters (C and D) consistent with severe disease were also identified with low FEV₁. Cluster D had the shortest time to both hospitalisation and pulmonary exacerbation treated with oral antibiotics. The outcomes were consistent in 3124 encounters from 171 children at GOSH. The KNN cluster allocation error rate was low, at 2.5% (Toronto) and 3.5% (GOSH).

CONCLUSION

Machine learning derived phenotypic clusters can predict disease severity independent of lung function and could be used in conjunction with functional measures to predict future disease trajectories in CF patients.

Epidemiologic Study of Cystic Fibrosis: 25 years of observational research

The Epidemiologic Study of Cystic Fibrosis (ESCF) was a prospective observational study of over 32,000 people with cystic fibrosis (CF) from 250 clinical care sites in North America from 1994 to 2005. Begun as a pharmacovigilance study in connection with the approval of dornase alfa in 1993, ESCF was open to all people with CF treated at any participating site in the United States or Canada. In addition to obtaining safety and effectiveness data on dornase alfa, ESCF collected encounter-based data to characterize the natural history and management of CF with a special focus on lung disease. During the study, 32,178 patients reported at least one encounter, contributing 869,136 encounters, 622,592 pulmonary function tests, 432,896 cultures, and 118,563 pulmonary exacerbations treated with intravenous antibiotics. Although ESCF data collection concluded in 2005, through a collaboration with the U.S. Cystic Fibrosis Foundation Patient Registry, additional follow-up data through 2017 was available for two-thirds of patients. This allowed for updating of CF genotype and survival information. Fifty-six peer-reviewed publications (cited over 3600 times) resulted from this study. In this manuscript we summarize the published ESCF manuscripts in thematic groups with key study findings and brief comments, and speculate on how ESCF findings will inform future data registries and patient care practices.

Treatment of Pulmonary Disease of Cystic Fibrosis: A Comprehensive Review

Cystic fibrosis (CF) is a genetic disease that causes absence or dysfunction of a protein named transmembrane conductance regulatory protein (CFTR) that works as an anion channel. As a result, the secretions of the organs where CFTR is expressed are very viscous, so their functionality is altered. The main cause of morbidity is due to the involvement of the respiratory system as a result of recurrent respiratory infections by different pathogens. In recent decades, survival has been increasing, rising by around age 50. This is due to the monitoring of patients in multidisciplinary units, early diagnosis with neonatal screening, and advances in treatments. In this chapter, we will approach the different therapies used in CF for the treatment of symptoms, obstruction, inflammation, and infection. Moreover, we will discuss specific and personalized treatments to correct the defective gene and repair the altered protein CFTR. The obstacle for personalized CF treatment is to predict the drug response of patients due to genetic complexity and heterogeneity of uncommon mutations.

Developing a Decision Aid to Facilitate Informed Decision Making About Invasive Mechanical Ventilation and Lung Transplantation Among Adults With Cystic Fibrosis: Usability Testing

Background

Cystic fibrosis (CF) is a life-limiting genetic disease that causes chronic lung infections. We developed an internet-based decision aid (DA) to help patients with CF make better informed decisions regarding treatments and advance care planning. We built the DA around two major treatment decisions: whether to have a lung transplant and whether to agree to invasive mechanical ventilation (intubation).

Objective

This study aims to conduct usability testing of the InformedChoices CF DA among key stakeholder groups.

Methods

We performed a patient needs assessment using think-aloud usability testing with patients with CF, their surrogates, and CF clinicians. Think-aloud participants provided feedback while navigating the DA, and after viewing, they answered surveys. Transcripts from the think-aloud sessions and survey results were categorized into common, generalizable themes and optimizations for improving content, comprehension, and navigation. We assessed the ease of use of the DA (System Usability Scale) and also assessed the participants’ perceptions regarding the overall tone, with an emphasis on emotional reactions to the DA content, level of detail, and usefulness of the information for making decisions about either intubation or lung transplantation, including how well they understood the information and were able to apply it to their own decision-making process. We also assessed the DA’s ease of navigation, esthetics, and whether participants were able to complete a series of usability tasks (eg, locating specific information in the DA or using the interactive survival estimates calculator) to ensure that the website was easy to navigate during the clinic-based advance care planning discussions.

Results

A total of 12 participants from 3 sites were enrolled from March 9 to August 30, 2018, for the usability testing: 5 CF clinicians (mean age 48.2, SD 12.0 years), 5 adults with CF, and 2 family and surrogate caregivers of people with CF (mean age of CF adults and family and surrogate caregivers 38.8, SD 10.8 years). Among the 12 participants, the average System Usability Scale score for the DA was 88.33 (excellent). Think-aloud analysis identified 3 themes: functionality, visibility and navigation, and content and usefulness. Areas for improvement included reducing repetition, enhancing comprehension, and changing the flow. Several changes to improve the content and usefulness of the DA were recommended, including adding information about alternatives to childbearing, such as adoption and surrogacy. On the basis of survey responses, we found that the navigation of the site was easy for clinicians, patients, and surrogates who participated in usability testing.

Conclusions

Usability testing revealed areas of potential improvement. Testing also yielded positive feedback, suggesting the DA’s future success. Integrating changes before implementation should improve the DA’s comprehension, navigation, and usefulness and lead to greater adoption.

Metabotypes of Pseudomonas aeruginosa Correlate with Antibiotic Resistance, Virulence and Clinical Outcome in Cystic Fibrosis Chronic Infections

Pseudomonas aeruginosa (P.a) is one of the most critical antibiotic resistant bacteria in the world and is the most prevalent pathogen in cystic fibrosis (CF), causing chronic lung infections that are considered one of the major causes of mortality in CF patients. Although several studies have contributed to understanding P.a within-host adaptive evolution at a genomic level, it is still difficult to establish direct relationships between the observed mutations, expression of clinically relevant phenotypes, and clinical outcomes. Here, we performed a comparative untargeted LC/HRMS-based metabolomics analysis of sequential isolates from chronically infected CF patients to obtain a functional view of P.a adaptation. Metabolic profiles were integrated with expression of bacterial phenotypes and clinical measurements following multiscale analysis methods. Our results highlighted significant associations between P.a “metabotypes”, expression of antibiotic resistance and virulence phenotypes, and frequency of clinical exacerbations, thus identifying promising biomarkers and therapeutic targets for difficult-to-treat P.a infections

The Potential of Self-Management mHealth for Pediatric Cystic Fibrosis: Mixed-Methods Study for Health Care and App Assessment

Background

Remote care services and patient empowerment have boosted mobile health (mHealth). A study of user needs related to mHealth for pediatric cystic fibrosis (PCF) identified the set of preferred features mobile apps should support; however, the potential use of PCF apps and their suitability to fit into PCF clinical management remains unexplored.

Objective

We examine whether PCF holds potential for the implementation of mHealth care.

Methods

The study is based on a literature review and qualitative analysis of content and was conducted in two parts: (1) we reviewed scientific and gray literature to explore how European countries manage PCF and conducted a qualitative study of 6 PCF units and (2) we performed a systematic review of apps available in the myhealthapps.net repository searching for cystic fibrosis (CF) management and nutrition apps, which we analyzed for characteristics, business models, number of downloads, and usability.

Results

European CF routine care guidelines are acknowledged in most European countries, and treatments are fully covered in almost all countries. The majority of teams in CF units are interdisciplinary. With respect to the systematic review of apps, we reviewed 12 apps for CF management and 9 for general nutrition management in the myhealthapps.net directory. All analyzed apps provided functionalities for recording aspects related to the disease and nutrition such as medication, meals, measurements, reminders, and educational material. None of the apps reviewed in this study supported pancreatic enzyme replacement therapy. CF apps proved to be less appealing and usable than nutrition apps (2.66 [SD 1.15] vs 4.01 [SD 0.90]; P<.001, z-value: –2.6). User needs detected in previous research are partially matched by current apps for CF management.

Conclusions

The health care context for PCF is a unique opportunity for the adoption of mHealth. Well-established clinical guidelines, heterogeneous clinical teams, and coverage by national health care systems provide a suitable scenario for the use of mHealth solutions. However, available apps for CF self-management do not cover essential aspects such as nutrition and education. To increase the adoption of mHealth for CF self-management, new apps should include these features.

International Registered Report Identifier (IRRID)

RR2-10.1136/bmjopen-2016-014931

Quantitative chest computerized tomography and FEV1 equally identify pulmonary exacerbation risk in children with cystic fibrosis

BACKGROUND

Chest computerized tomography (CT) scores are associated with the frequency of future pulmonary exacerbations in people with cystic fibrosis (CF). However, cut-off values to identify children with mild lung disease with different risks for frequent future pulmonary exacerbations have not been identified.

METHODS

Chest CT scans were assessed using the Brody score for participants of the Pulmozyme Early Intervention Trial (PEIT) and Wisconsin Randomized Clinical Trial of CF Newborn Screening (WI RCT). We determined the area under the receiver operating characteristic (ROC) curve for Brody scores and forced expiratory volume in 1 s (FEV₁ ) to compare with the frequency of pulmonary exacerbations up to 10 years later.

RESULTS

There were 60 participants in the PEIT with mean (SD) age 10.6 (1.7) years at the time of the CT and 81 participants in the WI RCT with mean age 11.5 (3.0) years. The Brody score cut-off that best identified children at-risk for ≥0.3 annual pulmonary exacerbations was 3.6 in the PEIT and 2.1 in the WI RCT. There were no statistical differences between ROC curves for the Brody CT score and FEV₁ % predicted in either study (P ≥ 0.4).

CONCLUSIONS

CT score cut-off values that identify children with CF with mild lung disease at different risks for frequent pulmonary exacerbations over an extended follow up period are similar in separate cohorts. Brody scores and FEV₁ % predicted have similar abilities to identify these children, suggesting that FEV₁ % predicted alone may be adequate for predicting future frequency of pulmonary exacerbations.

Predicting disease progression in cystic fibrosis

INTRODUCTION

Progressive lung disease is the major cause of morbidity and mortality in patients with cystic fibrosis (CF). Methods of correctly predicting the future progression of lung disease in patients with CF are essential for directing aggressive treatment to prevent loss of lung function and end stage respiratory failure. Areas covered: This review addresses predictors of respiratory disease progression in patients with CF. We searched Web of Science and Medline, with no restriction on publication date, with the search terms 'cystic fibrosis' and 'disease progression', 'lung function decline', 'prognosis', 'prediction/predictive', 'prediction/prognostic scores', 'risk factors', 'outcome measures/endpoints/disease surrogate', 'longitudinal/long term', 'statistical model', and 'survival'. Expert commentary: Forced expiratory volume in 1 sec (FEV₁) and rate of FEV₁ decline, remain the most significant predictors of mortality in patients with CF while CT scores and airway secretion biomarkers are the main predictors of early CF lung disease. Comprehensive scores incorporating clinical, lung function, imaging and laboratory data will become essential in the future for predicting disease progression and for use in clinical trials. Early interventions may delay the progression of structural lung disease.

Hypoglycemia is common in children with cystic fibrosis and seen predominantly in females

OBJECTIVE

To determine the prevalence of hypoglycemia in children and adolescents with cystic fibrosis (CF) in 2-hour oral glucose tolerance test (OGTT) and continuous glucose monitoring (CGM) under free-living conditions.

RESEARCH DESIGN AND METHODS

Height, weight, body mass index (BMI), hemoglobin A1c (HbA1c), and Forced expiratory volume (FEV1%) were measured in children with CF (aged 5-18 years). Following OGTT, CGM was installed for 3 days. The total hypoglycemic and hyperglycemic time (%) during 3 days was measured. Subjects were categorized according to hypoglycemic time <3% (hypo -) and ≥3% (hypo +). Each category was further divided according to hyperglycemic time <3% (hyper -) or ≥3% (hyper +).

RESULTS

OGTT and CGM were sequentially performed in 45 CF patients. The frequency of hypoglycemia in OGTT and hypoglycemic time ≧3% of CGM were 13.3% and 27.5%, respectively. After 5 cystic fibrosis-related diabetes (CFRD) subjects were excluded, the number of subjects in each subgroup was 17 (hypo-/hyper-), 12 (hypo-/hyper+), 6 (hypo+/hyper-), and 5 (hypo+/hyper+). Significantly higher insulin at 120 minutes was observed in OGTT in (hypo+/hyper-), as compared with subgroup (hypo-/hyper-) (P = .018). Total insulin levels were also significantly higher in (hypo+/hyper-), than (hypo-/hyper-), but were similar to those in the healthy control group (P = .049 and P = .076, respectively). There was a female predominance in hypoglycemic subjects both in OGTT and subgroup (hypo+/hyper-) in the CGM group (P = .033 and P = .033, respectively). FEV1 was significantly lower in hypo + group as a whole, and (hypo+/hyper+) subgroup than in (hypo-/hyper-), (P = .044 and P = .042, respectively); the difference was independent of body mass index-standard deviation score (BMI-SDS) (P = .15 and P = .12, respectively).

CONCLUSION

The frequency of hypoglycemia in children with CF was higher in CGM than that in OGTT. Insulin secretion was delayed and total insulin levels increased in the hypoglycemic patients. Glucose instability/hypoglycemia is associated with poorer lung function in patients with CF, independent of nutritional status.

Standardized Treatment of Pulmonary Exacerbations (STOP) study: Observations at the initiation of intravenous antibiotics for cystic fibrosis pulmonary exacerbations

BACKGROUND

The Standardized Treatment of Pulmonary Exacerbations (STOP) program has the intent of defining best practices in the treatment of pulmonary exacerbations (PEx) in patients with cystic fibrosis (CF). The objective of this analysis was to describe the clinical presentations of patients admitted for intravenous (IV) antibiotics and enrolled in a prospective observational PEx study as well as to understand physician treatment goals at the start of the intervention.

METHODS

We enrolled adolescents and adults admitted to the hospital for a PEx treated with IV antibiotics. We recorded patient and PEx characteristics at the time of enrollment. We surveyed treating physicians on treatment goals as well as their willingness to enroll patients in various study designs. Additional demographic and clinical data were obtained from the CF Foundation Patient Registry.

RESULTS

Of 220 patients enrolled, 56% were female, 19% were adolescents, and 71% were infected with P. aeruginosa. The mean (SD) FEV₁ at enrollment was 51.1 (21.6)% predicted. Most patients (85%) experienced symptoms for ≥7days before admission, 43% had received IV antibiotics within the previous 6months, and 48% received oral and/or inhaled antibiotics prior to IV antibiotic initiation. Forty percent had ≥10% FEV₁ decrease from their best value recorded in the previous 6months, but for 20% of patients, their enrollment FEV₁ was their best FEV₁ recorded within the previous 6months. Physicians reported that their primary treatment objectives were lung function recovery (53%) and improvement of symptoms (47%) of PEx. Most physicians stated they would enroll patients in studies involving 10-day (72%) or 14-day (87%), but not 7-day (29%), treatment regimens.

CONCLUSIONS

Based on the results of this study, prospective studies are feasible and physician willingness for interventional studies of PEx exists. Results of this observational study will help design future PEx trials.

Socioeconomic Status, Smoke Exposure, and Health Outcomes in Young Children With Cystic Fibrosis

BACKGROUND

Lower socioeconomic status (SES) and environmental tobacco smoke (ETS) exposure are both associated with poorer disease outcomes in cystic fibrosis (CF), and children with low SES are disproportionately exposed to ETS. We analyzed a large cohort of young children with CF to distinguish the impact of SES and ETS on clinical outcomes.

METHODS

The Early Pseudomonas Infection Control Observational study enrolled Pseudomonas-negative young children with CF <13 years of age. An enrollment survey assessed SES and ETS exposures. Forced expiratory volume in 1 second (FEV₁), crackles and wheezes, and weight-for-age percentile were assessed at each clinical encounter over at least 4 years. Repeated measures analyses estimated the association of SES and ETS exposures with longitudinal clinical outcomes, adjusting for confounders.

RESULTS

Of 1797 participants, 1375 were eligible for analysis. Maternal education was high school or less in 28.1%, 26.8% had household income <$40 000, and 43.8% had Medicaid or no insurance. Maternal smoking after birth was present in 24.8%, more prevalent in household with low SES. In separate models, lower SES and ETS exposure were significantly associated with lower FEV₁% predicted, presence of crackles or wheezes, and lower weight percentile. In combined models, effect estimates for SES changed minimally after adjustment for ETS exposures, whereas estimates for ETS exposures were attenuated after adjusting for SES.

CONCLUSIONS

ETS exposure was disproportionately high in low SES families in this cohort of children with CF. Lower SES and ETS exposure had independent adverse effects on pulmonary and nutritional outcomes. Estimated effect of SES on FEV₁ decreased minimally after ETS adjustment, suggesting health disparity risks independent of ETS exposure.

Effects of Autogenic Drainage on Sputum Recovery and Pulmonary Function in People with Cystic Fibrosis: A Systematic Review

PURPOSE

To determine the effects of short- and long-term use of autogenic drainage (AD) on pulmonary function and sputum recovery in people with cystic fibrosis (CF).

METHODS

The authors conducted a systematic review of randomized and quasi-randomized clinical trials in which participants were people with CF who use AD as their sole airway clearance technique.

RESULTS

Searches in 4 databases and secondary sources using 5 key terms yielded 735 articles, of which 58 contained the terms autogenic drainage and cystic fibrosis. Ultimately, 4 studies, 2 of which were long term, were included. All measured forced expiratory volume in 1 second (FEV1) and found no change. The long-term studies were underpowered to detect change in FEV1; however, the short-term studies found a clinically significant sputum yield (≥4 g).

CONCLUSION

AD has been shown to produce clinically significant sputum yields in a limited number of investigations. The effect of AD on the function of the pulmonary system remains uncertain, and questions have emerged regarding the appropriateness of FEV1 as a valid measure of airway clearance from peripheral lung regions. Further consideration should be given to the use of FEV1 as a primary measure of the effect of AD.

Early Childhood Risk Factors for Decreased FEV1 at Age Six to Seven Years in Young Children with Cystic Fibrosis

RATIONALE

There are limited objective measures of the severity of lung disease before children are able to routinely perform spirometry, generally at age 6 years. Identifying risk factors for reduced lung function at age 6 provides opportunities to intervene and slow the progression of cystic fibrosis (CF) lung disease.

OBJECTIVES

To evaluate early childhood predictors of lung function at age 6-7 in a large U.S. CF cohort in the current era of widespread early eradication therapy for Pseudomonas aeruginosa (P. aeruginosa).

METHODS

Participants were children with CF enrolled before age 4 in the Early Pseudomonas Infection Control (EPIC) Observational Study, a multicenter, longitudinal study that enrolled P. aeruginosa-negative children not exceeding 12 years of age. Linear regression was used to estimate the association between potential early childhood risk factors and the best FEV1% predicted at age 6-7 years.

MEASUREMENTS AND MAIN RESULTS

Four hundred and eighty-four children (of 1,797 enrolled in the EPIC Observational Study) met the eligibility criteria for this analysis. Mean (SD) age at enrollment was 2.0 (1.3) years. In a multivariable model adjusted for age at enrollment, the following risk factors were significantly associated with lower mean (95% confidence interval) FEV1% predicted at age 6-7: weight percentile less than 10% during the year of enrollment (-5.3 [-9.1, -1.5]), P. aeruginosa positive during the year of enrollment (-2.8 [-5.7, 0.0]), crackles or wheeze during the year of enrollment (-5.7 [-9.4, -1.9]), mother's education of high school or less (-4.2 [-7.3, -1.2]), and mother smoked during pregnancy (-4.4 [-8.8, 0.1]).

CONCLUSIONS

In this large U.S. cohort, we identified several early childhood risk factors for lower FEV1 at age 6-7 years, most of which are modifiable. Clinical trial registered with www.clinicaltrials.gov (NCT00097773).

Probability of IV antibiotic retreatment within thirty days is associated with duration and location of IV antibiotic treatment for pulmonary exacerbation in cystic fibrosis

BACKGROUND

There are few objective data to guide management of cystic fibrosis (CF) pulmonary exacerbations. We studied intravenous (IV) antibiotic treatment failure as defined by a need to retreat patients with IV antibiotics within 30days of completion of a prior IV antibiotic treatment for pulmonary exacerbation.

METHODS

The first IV-treated exacerbation on or after Jan. 1, 2010 among US CF Foundation Patient Registry patients was studied, combining treatments separated by <7days into single treatments. IV treatment duration categories were: 1-4, 5-8, 9-12, 13-16, 17-22, and ≥23days (inclusive). Logistic regressions for IV retreatment in ≤30days were adjusted with 12 categorical covariates, including age, sex, lung function, prior-year exacerbations, CF complications, CF Care Program, and ever/never treated in hospital.

RESULTS

777 of 13,579 patients (5.7%) were retreated within 30days, with incidence varying by treatment duration: 1-4days, 8.7%; 5-8days; 6.6%; 9-12days, 3.2%; 13-16days, 4.5%; 17-22days, 6.2%; ≥23days, 10.3% and hospitalization: ever, 5.0%; never 8.5%. Adjusted odds ratios (OR) for retreatment (compared to 13-16days treatment) were: 1-4days, 1.94 [95%CI 1.49, 2.54] P<.001; 5-8days, 1.55 [1.18, 2.04] P=.002; 9-12days, 0.78 [0.58, 1.04] P=.09; 17-22days, 1.12 [0.88, 1.42] P=.37; ≥23days, 1.46 [1.12, 1.91] P=.005. Adjusted retreatment OR for never/ever hospitalized was 1.57 [1.29, 1.90] P<.001. Prior-year exacerbation number, oxygen therapy, non-invasive ventilation, and female sex were significantly associated with retreatment. Modeling hazard rate time-dependence showed that treatment duration and location-associated hazard rates attenuated within a few months after treatment.

CONCLUSION

After adjustment for covariates known to be associated with increased risk of IV treatment for exacerbation, IV antibiotic treatments of <9 and ≥23days and those without hospitalization were significant risk factors for IV retreatment within 30days of completion of an exacerbation treatment.

Early Life Growth Trajectories in Cystic Fibrosis are Associated with Pulmonary Function at Age 6 Years

OBJECTIVE

To determine whether severity of lung disease at age 6 years is associated with changes in nutritional status before age 6 within individual children with cystic fibrosis (CF).

STUDY DESIGN

Children with CF born between 1994 and 2005 and followed in the CF Foundation Patient Registry from age ≤2 through 7 years were assessed according to changes in annualized weight-for-length (WFL) percentiles between ages 0 and 2 years and body mass index (BMI) percentiles between ages 2 and 6 years. The association between growth trajectories before age 6 and forced expiratory volume in 1 second (FEV1)% predicted at age 6-7 years was evaluated using multivariable linear regression.

RESULTS

A total of 6805 subjects met inclusion criteria. Children with annualized WFL-BMI always >50th percentile (N = 1323 [19%]) had the highest adjusted mean (95% CI) FEV1 at 6-7 years (101.8 [100.1, 103.5]). FEV1 at 6-7 years for children whose WFL-BMI increased >10 percentile points by age 6 years was 98.3 (96.6, 100.0). This was statistically significantly higher than FEV1 for children whose WFL-BMI was stable (94.4 [92.6, 96.2]) or decreased >10 percentile points (92.9 [91.1, 94.8]). Among children whose WFL-BMI increased >10 percentile points, achieving and maintaining WFL-BMI >50th percentile at younger ages was associated with significantly higher FEV1 at 6-7 years.

CONCLUSIONS

Within-patient changes in nutritional status in the first 6 years of life are significantly associated with FEV1 at age 6-7 years. The establishment of a clear relationship between early childhood growth measurements and later lung function suggests that early nutritional interventions may impact on eventual lung health.

IV-treated pulmonary exacerbations in the prior year: An important independent risk factor for future pulmonary exacerbation in cystic fibrosis

BACKGROUND

Single-center analyses have suggested that the number of CF pulmonary exacerbations (PEx) treated with intravenous antibiotics an individual has experienced in the prior year is significantly associated with their future PEx hazard.

METHODS

We studied Prior-year PEx association with future PEx hazard by Cox proportional hazards regression among CF Foundation Patient Registry patients who experienced PEx after Jan 1, 2010.

RESULTS

Among 13,579 patients, those with 1, 2, 3, or ≥4 Prior-year PEx treated with intravenous antibiotics were at 1.8, 2.9, 4.8, and 8.7 higher PEx hazard vs those without (P<.0001). Adjustment with significant demographic and clinical covariates (univariate P≤.0001) reduced Prior-year PEx hazard ratios to 1.6, 2.4, 3.6, and 6.0 (P<.0001). No other covariates had adjusted hazard ratios of >1.7.

CONCLUSIONS

Prior-year PEx strongly associate with future PEx hazard and should be accounted for in prospective trials where treatment-associated change in PEx hazard is an efficacy outcome.

Clinical applications of pulmonary delivery of antibiotics

The treatment of infection typically involves administration of antibiotics by a systemic route, such as intravenous or oral. However, pulmonary infections can also be approached by inhalation of antibiotics as the infection is more directly accessible via the airways, making inhalation delivery essentially topical administration. This approach offers deposition of high antimicrobial concentrations directly at the site of infection but with a potentially reduced systemic exposure. This review covers the evidence for aerosolized antibiotics for the treatment of a number of conditions such as cystic fibrosis (CF), where it has become the standard of care for chronic infection, as well as non-CF bronchiectasis, non-tuberculous mycobacteria, and ventilator-associated infection where such therapy does not have an approved indication but has been used with increasing frequency.

Treatment and demographic factors affecting time to next pulmonary exacerbation in cystic fibrosis

BACKGROUND

Pulmonary exacerbations (PEx) are important CF clinical events.

METHODS

We studied time to next PEx following intravenous (IV) antibiotic PEx treatment among Cleveland Ohio CF center patients occurring between January 2010 and September 2014. Patient demographics, clinical presentations, and treatments were modeled by Cox proportional hazards regression to identify covariates associated with time to next PEx.

RESULTS

193 patients were treated for PEx; 155 had a subsequent IV-treated PEx. Six covariates were associated with future PEx hazard: number of PEx in the prior year (hazard ratio 25.1 for ≥3 and 4.4 for 1-2 prior-year PEx versus none; P<.0001), IV treatment duration in weeks (1.2; P=.0004), percent hospital treatment (1.1; P=.0018), and chronic inhaled aminoglycosides (2.5; P<.0001), leukotriene modifiers (1.8; P=.0031), and high dose ibuprofen (0.52; P=.0006).

CONCLUSIONS

Time to next PEx was profoundly associated with prior-year PEx, suggestive of high-risk PEx phenotypes that warrant recognition and further study.

A pulmonary exacerbation risk score among cystic fibrosis patients not receiving recommended care

BACKGROUND

Pulmonary exacerbations (PEx) lead to substantial morbidity in cystic fibrosis (CF), and guidelines recommend chronic medication including dornase alfa and inhaled tobramycin. However PEx risk and medication use vary across patients.

OBJECTIVE

To develop a PEx risk score among CF patients not receiving guideline-recommended chronic respiratory medications.

METHODS

A cohort of patients with FEV1%-predicted between 25% and 75% without evidence of dornase alfa or inhaled tobramycin use in an index year, despite meeting guideline recommended criteria, was identified from the CF Foundation Patient Registry (2002-2008). This sample was randomly split into 2/3 for a development sample and 1/3 for a validation sample. A multivariable risk score was developed to predict PEx requiring hospitalization or home IV treatment using available patient characteristics. Its predictive performance was assessed in the validation sample.

RESULTS

Among 3,069 patient-years, 1,275 (42%) had PEx in the subsequent year. The risk score included, in order of decreasing impact on PEx risk, prior PEx, Pseudomonas aeruginosa, allergic bronchopulmonary aspergillosis, depression, methicillin-resistant Staphylococcus aureus, CF-related diabetes, Burkholderia cepacia, prior use of dornase alfa, bronchodilator use, prior use of inhaled tobramycin and lower FEV1%-predicted. Stratifying patients by risk score in the validation sample identified actual risks ranging from 14% in the lowest decile to 90% in the highest. The c-statistic was 0.8.

CONCLUSIONS

A PEx risk score for CF patients not receiving guideline-recommended chronic therapies was developed and validated, and identified patients with a wide range of risk. This score could identify high-risk patients in whom chronic therapies should be initiated or continued.

Differences in the pattern of structural abnormalities on CT scan in patients with cystic fibrosis and pancreatic sufficiency or insufficiency

BACKGROUND

Cystic fibrosis (CF) genotypes characterized by pancreatic sufficiency (PS) are generally associated with milder disease vs genotypes characterized by pancreatic insufficiency (PI); however, the correlation between pancreatic status and type and severity of structural lung changes has not been studied. We aimed to evaluate differences in the severity and distribution of pulmonary manifestations of CF in patients with PS vs PI.

METHODS

We retrospectively evaluated changes in individual lobes and the whole lung on chest CT scan with the modified Brody score. The study population included 84 (39 female, 45 male) patients with CF aged 4 to 68 years (mean, 20.5) treated from 2000 to 2010. Our institutional review board waived the requirement for informed consent. The severity of lung changes and distribution of pulmonary disease were compared by Student t test, nonparametric Pearson χ2 test, or mixed-design analysis of variance for 28 patients with CF-PS and 56 with CF-PI. Correlations were evaluated with the Pearson (continuous variables) or Spearman ρ (nonparametric variables) tests. A linear regression model was used for multivariate analyses.

RESULTS

Compared with patients with CF-PS, those with CF-PI had more-severe lung disease (P=.001) with predominant upper lobe involvement (P=.002) and significant differences in Brody scores for bronchiectasis and bronchial wall thickening. Lung manifestations in patients with CF-PS did not show predominant involvement of any one area (P=.133).

CONCLUSIONS

In patients with CF-PI, structural lung changes are more severe with upper lobe predominance, prominent bronchiectasis, and bronchial wall thickening vs lower severity and more general distribution of changes in those with CF-PS.

The CF-ABLE score: a novel clinical prediction rule for prognosis in patients with cystic fibrosis

BACKGROUND

Determining prognosis and predicting outcomes in cystic fibrosis (CF) is a complex issue, and there have been very few clinically applicable models for this. The aim was to create a simple, practical outcome prediction tool for CF.

METHODS

Forty-nine consecutive patients with CF from a single center were studied over an 84-month period (2004-2010). All baseline clinical parameters were gathered, and FEV₁ measurements were analyzed over the study period. Using patterns of FEV₁ decline, a tipping point of 52.8% predicted was identified. Other clinical variables were analyzed and correlated with outcome. Poor outcome was defined as death or transplantation. Using age, BMI, lung function (ie, FEV₁), and number of exacerbations in the past 3 months, the CF-ABLE score was created. The score was validated for data from 370 patients from the national Cystic Fibrosis Registry of Ireland.

RESULTS

The ABLE score uses clinical parameters that are measured at every clinic visit and scored on a scale from 0 to 7. If FEV₁ is < 52%, then 3.5 points are added; if the number of exacerbations in the past 3 months is > 1, then 1.5 points are added; if BMI is < 20.1 kg/m² or age < 24 years, each receive 1 point.

CONCLUSIONS

Patients with a low score have a very low risk of death or lung transplantation within 4 years; however, as the score increases, the risk significantly increases. Patients who score > 5 points have a 26% risk of poor outcome within 4 years. This score is simple and applicable and better predicts outcome than FEV₁ alone.

Oral, inhaled, and intravenous antibiotic choice for treating pulmonary exacerbations in cystic fibrosis

RATIONALE

Patients with cystic fibrosis (CF) experience frequent pulmonary exacerbations (PExs). Clinicians manage these episodes of worsening signs and symptoms in a variety of ways.

OBJECTIVES

To characterize the antibiotic management and associated change in lung function following PExs.

METHODS

We used 2003-2005 data from the Epidemiologic Study of Cystic Fibrosis to examine antibiotic treatment and the immediate and long-term lung function change associated with clinician reported PExs.

RESULTS

A total of 45,374 PExs were reported in 13,194 unique patients. Most PExs (73%) were treated with oral antibiotics, while 39% were treated IV and 24% were treated with inhaled antibiotics. The likelihood of non-IV versus IV antibiotic treatment was associated with the patient's age, stage of lung disease, and magnitude of lung function drop prior to the PEx. Following treatment, the average improvement in the FEV1 was 3.4 ± 12.2% predicted with a greater (5.1 ± 12.7% predicted) improvement following IV antibiotic treatment than with non-IV treatment (2.0 ± 11.6% predicted). When the best FEV1 from the year before was compared with 180 days following the PEx there was an average fall of 3.8 ± 10.5% predicted with little difference observed between antibiotic treatment routes. Patients with only one exacerbation during the 3-year study had a similar loss of lung function to patients with no reported exacerbations.

CONCLUSION

Clinicians treat the majority of PExs with oral antibiotics, particularly in younger, healthier patients. Pulmonary function improves with antibiotic therapy, however, PExs are associated with lung function deterioration over time.

State of progress in treating cystic fibrosis respiratory disease

Since the discovery of the gene associated with cystic fibrosis (CF), there has been tremendous progress in the care of patients with this disease. New therapies have entered the market and are part of the standard treatment of patients with CF, and have been associated with marked improvement in survival. Now there are even more promising therapies directed at different components of the pathophysiology of this disease. In this review, our current knowledge of the pathophysiology of lung disease in patients with CF is described, along with the current treatment of CF lung disease, and the therapies in development that offer great promise to our patients.

An overview of international literature from cystic fibrosis registries. Part 4: update 2011

A total of 53 national cystic fibrosis (CF) patient registry studies published between July 2008 and November 2011 have been reviewed, focusing on the following topics: CF epidemiology, nutrition, microbiology, clinical complications, factors influencing diagnosis and lung disease, effects of socioeconomic status, therapeutic strategy evaluation, clinical trial methodology. The studies describe the clinical characteristics of CF patients, the incidence and prevalence of disease and role of gender gap, as well as the influence of socioeconomic status and environmental factors on clinical outcomes, covering a variety of countries and ethnic groups. Original observations describe patients as they get older, with special reference to the adult presentation of CF and long-term survival. Methodological aspects are discussed, covering the design of clinical trials, survival analysis, auxometry, measures of quality of life, follow up of lung disease, predictability of disease progression and life expectancy. Microbiology studies have investigated the role of selected pathogens, such as Burkholderia species and MRSA. Pulmonary exacerbations are discussed both as a factor influencing morbidity and an endpoint in clinical trials. Finally, some studies give insights on complications, such as CF-related diabetes and hemoptysis, and emerging problems, such as chronic nephropathy.

Understanding the natural progression in %FEV1 decline in patients with cystic fibrosis: a longitudinal study

BACKGROUND

Forced expiratory volume in 1 s as a percentage of predicted (%FEV1) is a key outcome in cystic fibrosis (CF) and other lung diseases. As people with CF survive for longer periods, new methods are required to understand the way %FEV1 changes over time. An up to date approach for longitudinal modelling of %FEV1 is presented and applied to a unique CF dataset to demonstrate its utility at the clinical and population level.

METHODS AND FINDINGS

The Danish CF register contains 70,448 %FEV1 measures on 479 patients seen monthly between 1969 and 2010. The variability in the data is partitioned into three components (between patient, within patient and measurement error) using the empirical variogram. Then a linear mixed effects model is developed to explore factors influencing %FEV1 in this population. Lung function measures are correlated for over 15 years. A baseline %FEV1 value explains 63% of the variability in %FEV1 at 1 year, 40% at 3 years, and about 30% at 5 years. The model output smooths out the short-term variability in %FEV1 (SD 6.3%), aiding clinical interpretation of changes in %FEV1. At the population level significant effects of birth cohort, pancreatic status and Pseudomonas aeruginosa infection status on %FEV1 are shown over time.

CONCLUSIONS

This approach provides a more realistic estimate of the %FEV1 trajectory of people with chronic lung disease by acknowledging the imprecision in individual measurements and the correlation structure of repeated measurements on the same individual over time. This method has applications for clinicians in assessing prognosis and the need for treatment intensification, and for use in clinical trials.

Chest computed tomography scores of severity are associated with future lung disease progression in children with cystic fibrosis

RATIONALE

Most children with cystic fibrosis (CF) experience a slow decline in spirometry, although some children continue to be at risk for more significant lung disease progression. Chest computed tomography (CT) scans have been shown to be more sensitive to changes in lung disease than spirometry and may provide a means for predicting future lung disease progression.

OBJECTIVES

We hypothesized that Brody chest CT scan scores obtained in 2000 in a prospectively monitored cohort of children with CF would be associated with the most recent measures of lung disease severity.

METHODS

Brody chest CT scan scores were calculated for 81 children enrolled in the Wisconsin CF Neonatal Screening Project. Multivariable linear regression was used to determine associations between Brody scores and the most recent (age 21 yr or June 30, 2010, whichever was later) measures of CF lung disease.

MEASUREMENTS AND MAIN RESULTS

The mean observation time after the chest CT scan was 7.5 years. Brody chest CT scan scores were significantly associated with the most recent measures of spirometry (P < 0.001) and Wisconsin and Brasfield chest radiograph scores (P < 0.001). The strength of this association was much stronger than spirometry obtained near the time of the chest CT scan (P < 0.01) but not chest radiograph scores.

CONCLUSIONS

Chest CT scan scores are associated with future lung disease severity, and quantitative chest imaging(chest CT scan and chest radiograph scores) is more strongly associated with future lung disease severity than measures of spirometry. These findings may help clinicians identify patients at risk of future lung disease progression.

Chest computed tomography scores of severity are associated with future lung disease progression in children with cystic fibrosis

RATIONALE

Most children with cystic fibrosis (CF) experience a slow decline in spirometry, although some children continue to be at risk for more significant lung disease progression. Chest computed tomography (CT) scans have been shown to be more sensitive to changes in lung disease than spirometry and may provide a means for predicting future lung disease progression.

OBJECTIVES

We hypothesized that Brody chest CT scan scores obtained in 2000 in a prospectively monitored cohort of children with CF would be associated with the most recent measures of lung disease severity.

METHODS

Brody chest CT scan scores were calculated for 81 children enrolled in the Wisconsin CF Neonatal Screening Project. Multivariable linear regression was used to determine associations between Brody scores and the most recent (age 21 yr or June 30, 2010, whichever was later) measures of CF lung disease.

MEASUREMENTS AND MAIN RESULTS

The mean observation time after the chest CT scan was 7.5 years. Brody chest CT scan scores were significantly associated with the most recent measures of spirometry (P < 0.001) and Wisconsin and Brasfield chest radiograph scores (P < 0.001). The strength of this association was much stronger than spirometry obtained near the time of the chest CT scan (P < 0.01) but not chest radiograph scores.

CONCLUSIONS

Chest CT scan scores are associated with future lung disease severity, and quantitative chest imaging(chest CT scan and chest radiograph scores) is more strongly associated with future lung disease severity than measures of spirometry. These findings may help clinicians identify patients at risk of future lung disease progression.