The measurement properties of tests and tools used in cystic fibrosis studies: a systematic review

Measurement properties of the Polish version of the Cystic Fibrosis Questionnaire Revised 14+ in the adult population

Measuring the quality of life in patients with cystic fibrosis is an important element of the patient care process. Many tools have been created for this measurement among adults. One of them is the Cystic Fibrosis Questionnaire-Revised 14+ (CFQ-R 14+). Its measurement properties have not been comprehensively assessed in the population of Polish adults. The aim of the study is to verify the construct validity, including structural and criterion validity, as well as internal consistency, of the Polish version of the CFQ-R 14+ in the population of adults with cystic fibrosis. We conducted a cross-sectional survey among adults with cystic fibrosis. After preparing the database, we performed a confirmatory factor analysis (CFA) followed by exploratory factor analysis (EFA) using the parallel analysis method principal axis factoring with Oblimin rotation. Intercorrelations of questionnaire factors and the occurrence of relationships among items for the general scale results was checked. We also presented basic descriptive statistics (mean, median, standard deviation, skewness, kurtosis, minimum and maximum values). The analyses included responses from 220 adult patients. CFA results did not show adequate goodness of fit (χ2(1025) = 2112.35, p < 0.001; CFI = 0.831; TLI = 0.814; RMSEA = 0.069; SRMR = 0.074). After EFA, 6 factors were extracted, considering 40 out of 50 questions of the CFQ-R 14+. CFQ-R 14+ may be useful in assessing the quality of life of Polish adult patients with cystic fibrosis. Our analysis demonstrates that the optimal factor structure of the tool in this population includes 6 scales.

Tools used to measure quality of life in adults with cystic fibrosis- a systematic review

BACKGROUND

Measuring the quality of life in patients with cystic fibrosis is important, both in terms of assessing the implementation of new therapies and monitoring their effects, as well as the ongoing evaluation of patients' condition. The objective of this study is to present tools for measuring the quality of life in adult patients with cystic fibrosis, along with their characteristics and measurement properties.

METHODS

The systematic review was performed according to the PRISMA guidelines based on a previously prepared research protocol (PROSPERO: CRD42023491030). Searches were performed in Medline (via PubMed), Embase (via OVID), and Cochrane Library databases. In addition, manual searches of bibliographies from the studies included in the analysis and grey literature were performed. Quality assessment of the included studies was performed according to the guidelines of COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN).

RESULTS

The systematic search identified 3,359 studies, of which 26 met the inclusion criteria for the analysis. Two publications were additionally included as a result of the manual search. A total of 16 tools for measuring the quality of life in adults with cystic fibrosis were identified, the measurement properties of which were presented in the included studies. Among these tools, the Cystic Fibrosis Questionnaire-Revised (CFQ-R) and the Cystic Fibrosis Quality of Life Questionnaire (CFQoL) were most frequently analyzed. There were also other new, promising tools.

CONCLUSION

Most studies reported acceptable measurement properties of tools used to measure quality of life in adult patients with cystic fibrosis. In many cases, however, significant limitations were observed related to the lack of comprehensive analysis of the factor structure and other aspects related to validation and responsiveness. There have also been problems with the reliability of some tool scales (including the CFQ-R 14+). The small number of studies makes it difficult to present clear conclusions regarding the usefulness of existing tools. In turn, new tools that may be used in economic analyses (CFQ-R-8 dimensions) or in individualized assessment of quality of life using a mobile application (Q-Life) seem promising. However, further research on large patient populations is necessary to analyze the measurement properties of all tools.

Thymidine-dependent Staphylococcus aureus and lung function in patients with cystic fibrosis: a 10-year retrospective case-control study

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.

Update on the diagnosis and management of cystic fibrosis pulmonary exacerbations

Pulmonary exacerbations in people with cystic fibrosis are associated with significant morbidity and reduced quality of life. Pulmonary exacerbation treatment guidelines, published by an expert panel assembled by the Cystic Fibrosis Foundation nearly 15 years ago, were primarily consensus-based as there were several gaps in the evidence base. In particular, limited evidence existed regarding optimal pulmonary exacerbation treatment strategies, including duration of antibiotic therapy, treatment location, antibiotic selection, and the role of systemic corticosteroids. Over the last decade, results from observational studies and large multi-center randomized controlled trials have begun to answer important questions related to pulmonary exacerbation treatment. This review focuses on the diagnosis, etiology, and changing epidemiology of pulmonary exacerbations, and also summarizes the most recent and up-to-date studies describing pulmonary exacerbation treatment. Finally, this review provides consideration for future pulmonary exacerbation research priorities, particularly in the current highly effective modulator therapy era.

Factors associated with quality of life for cystic fibrosis family caregivers

Cystic Fibrosis (CF) is a genetic and chronic disease affecting 32,100 people in the United States as of 2021, with a life expectancy of 56 years for people with CF (PwCF) born between 2018 and 2022. While there is extensive literature about cystic fibrosis, there are few studies examining the complexity and challenges experienced by family caregivers for PwCF. The aim of this study was to examine the Caregiver Quality of Life Cystic Fibrosis (CQOLCF) scale using data (N = 217) from two separate studies that used the scale to determine if its items represent multiple factors relevant to CF family caregiver QoL. Factor analysis was conducted on the Seven distinct factors were found with analysis of the CQOLCF. Factors were Existential Dread (12%), Burden (11%), Strain (7%), Support (7%), Positivity (6%), Finance (5%) and Guilt (3%). Study findings indicated it is important for healthcare providers and researchers who use the CQOLCF to be knowledgeable and aware of the multiple factors associated with quality of life in this population in addition to an overall quality of life score.

Guidance and standard operating procedures for functional exercise testing in cystic fibrosis

Regular exercise testing is recommended for all people with cystic fibrosis (PwCF). A range of validated tests, which integrate both strength and aerobic function, are available and increasingly being used. Together, these tests offer the ability for comprehensive exercise evaluation. Extensive research and expert consensus over recent years has enabled the adaptation and standardisation of a range of exercise tests to aid the understanding of the pathophysiology related to exercise limitation in PwCF and has led to the development of novel exercise tests which may be applied to PwCF. This article provides expert, opinion-based clinical practice guidance, along with test instructions, for a selection of commonly used valid tests which have documented clinimetric properties for PwCF. Importantly, this document also highlights previously used tests that are no longer suggested for PwCF and areas where research is mandated. This collaboration, on behalf of the European Cystic Fibrosis Society Exercise Working Group, represents expert consensus by a multidisciplinary panel of physiotherapists, exercise scientists and clinicians and aims to improve global standardisation of functional exercise testing of PwCF. In short, the standardised use of a small selection of tests performed to a high standard is advocated.

Saline at lower tonicity in cystic fibrosis (SALTI-CF) trial comparing 0.9% versus 3% versus 6% nebulised saline

BACKGROUND

In people with cystic fibrosis (CF), regular nebulisation of 6% or 7% saline improves lung function; however, these concentrations are not always tolerable. Clinically, some CF patients report using lower concentrations of saline to improve tolerability, yet the effects of lower concentrations are unknown. This study therefore aimed to evaluate the relative effectiveness and tolerability of 0.9% versus 3% versus 6% saline nebulised twice daily with an eFlow rapid nebuliser.

METHODS

This was a randomised, blinded, placebo-controlled, parallel-group, multicentre study where subjects inhaled 4 mL of 0.9%, 3% or 6% saline twice daily for 16 weeks. The primary outcome was forced expiratory volume in 1 s. The secondary outcomes were: forced vital capacity (FVC) and forced expiratory flow at 25-75% of FVC; quality of life; exercise capacity; acquisition or loss of bacterial organisms in expectorated sputum; tolerability of nebulised saline; pulmonary exacerbations; and adverse events.

RESULTS

140 participants were randomised to 0.9% (n=47), 3% (n=48) or 6% (n=45) saline. 134 participants (96%) contributed to the intention-to-treat analysis. 3% saline significantly improved lung function and increased the time to first pulmonary exacerbation compared with 0.9% saline but did not improve quality of life. 6% saline had similar benefits to 3% saline but also significantly improved quality of life compared with 3% saline. Only 6% saline delayed the time to intravenous antibiotics for pulmonary exacerbation. Tolerability and adherence were similar.

CONCLUSIONS

Dilution of 6% saline to 3% maintains the benefits for lung function and exacerbation prevention; however, the positive impacts of 6% saline on quality of life and time to i.v. antibiotics for pulmonary exacerbations are lost.

A systematic review to explore how exercise-based physiotherapy via telemedicine can promote health related benefits for people with cystic fibrosis

To conduct a systematic review to evaluate the effects of physiotherapy exercises delivered via telemedicine on lung function and quality-of-life in people with Cystic Fibrosis (CF). The databases AMED, CINAHL and MEDLINE were searched from December 2001 until December 2021. Reference lists of included studies were hand-searched. The PRISMA 2020 statement was used to report the review. Studies of any design reported in the English language, included participants with CF, and within outpatient settings were included. Meta-analysis was not deemed appropriate due to the diversity of interventions and heterogeneity of the included studies. Following screening, eight studies with 180 total participants met the inclusion criteria. Sample sizes ranged from 9 to 41 participants. Research designs included five single cohort intervention studies, two randomised control trials and one feasibility study. Telemedicine-based interventions included Tai-Chi, aerobic, and resistance exercise delivered over a study period of six to twelve weeks. All included studies which measured percentage predicted forced expiratory volume in one second found no significant difference. Five studies measuring the Cystic Fibrosis Questionnaire-Revised (CFQ-R) respiratory domain found improvements, however, did not meet statistical significance. For the CFQ-R physical domain, measured by five studies, two studies found an improvement, although not statistically significant. No adverse events were reported across all studies. The included studies indicate that telemedicine-based exercise over 6-12 weeks does not significantly change lung function or quality-of-life in people with CF. Whilst the role of telemedicine in the care of pwCF is acceptable and promising; further research with standardised outcome measures, larger sample sizes and longer follow-up are required before clinical practice recommendations can be developed.

Telerehabilitation and telemonitoring interventions programs used to improving quality of life in people with cystic fibrosis: A systematic review

Background

Cystic fibrosis causes mucus to build up in the lungs, digestive tract, and other areas. It is the most common chronic lung disease in children and young adults. It requires daily medical care. Before the COVID-19 pandemic, telerehabilitation and telehealth were used, but it was after this that there was a boom in these types of assistance in order to continue caring for cystic fibrosis patients.

Objective

The objective is to evaluate the effect of telemedicine programs in people with cystic fibrosis.

Methods

For the search, the PubMed, Scopus, Web of Science, PEDro, Cochrane, and CINAHL databases were used. Randomized controlled trials, pilot studies, and clinical trials have been included. The exclusion criteria have considered that the population did not have another active disease or that telemedicine was not used as the main intervention. This study follows the PRISMA statement and has been registered in the PROSPERO database (CRD42021257647).

Results

A total of 11 articles have been included in the systematic review. No improvements have been found in quality of life, forced expiratory volume, and forced vital capacity. Good results have been found in increasing physical activity and early detection of exacerbations. Adherence and satisfaction are very positive and promising.

Conclusions

Despite not obtaining significant improvements in some of the variables, it should be noted that the adherence and satisfaction of both patients and workers reinforce the use of this type of care. Future studies are recommended in which to continue investigating this topic.

Protocol for establishing a core outcome set for evaluation in studies of pulmonary exacerbations in people with cystic fibrosis

INTRODUCTION

Pulmonary exacerbations are associated with increased morbidity and mortality in people with cystic fibrosis (CF). There is no consensus about which outcomes should be evaluated in studies of pulmonary exacerbations or how these outcomes should be measured. Outcomes of importance to people with lived experience of the disease are frequently omitted or inconsistently reported in studies, which limits the value of such studies for informing practice and policy. To better standardise outcome reporting and measurement, we aim to develop a core outcome set for studies of pulmonary exacerbations in people with CF (COS-PEX) and consensus recommendations for measurement of core outcomes.

METHODS AND ANALYSIS

Preliminary work for development of COS-PEX has been reported, including (1) systematic reviews of outcomes and methods for measurement reported in existing studies of pulmonary exacerbations; (2) workshops with people affected by CF within Australia; and (3) a Bayesian knowledge expert elicitation workshop with health professionals to ascertain outcomes of importance. Here we describe a protocol for the additional stages required for COS-PEX development and consensus methods for measurement of core outcomes. These include (1) an international two-round online Delphi survey and (2) consensus workshops to review and endorse the proposed COS-PEX and to agree with methods for measurement.

ETHICS AND DISSEMINATION

National mutual ethics scheme approval has been provided by the Child and Adolescent Health Service Human Research Ethics Committee (RGS 4926). Results will be disseminated via consumer and research networks and peer-reviewed publications. This study is registered with the Core Outcome Measures in Effectiveness Trials database.

Comparative analysis of respiratory symptom scores to detect acute respiratory events in children with cystic fibrosis

BACKGROUND

Patient-reported outcomes (PROs) are important outcome measures in research and clinical practice. This study describes the longitudinal variability the Cystic Fibrosis Questionnaire-Revised (CFQ-R) Respiratory score and the Chronic Respiratory Infection Symptom Score (CRISS), as well as their ability to identify acute respiratory events in children with CF.

METHODS

In this prospective observational study, the parent-proxy (6 -13 years) and self-reported (6-18 years) CFQ-R Respiratory score and CRISS (6-18 years) were measured every 3 months over 2 years. The lung clearance index (LCI) and FEV₁ were also measured. We compared the diagnostic accuracy of the PROs in distinguishing acute respiratory events and clinically stable visits, using the minimal important difference of each PRO as the threshold.

RESULTS

A total of 98 children with CF were included. On average, the symptom scores did not change between clinically stable visits. The positive predictive value (PPV) and negative predictive value (NPV) of a ≥8.5-point worsening in the parent-proxy CFQ-R score to identify acute respiratory events (n=119) (PPV 70.2% and NPV 87.0%) were higher than for the self-reported CFQ-R score (PPV 58.9% and NPV 72.2%). The PPV and NPV of an ≥11-point change in the CRISS for acute respiratory events (n=137) was 56.5% and 79.6%, respectively. The PPV and NPV of all PROs were increased when combined with the LCI and/or FEV₁pp.

CONCLUSION

Symptoms scores differ in their ability to identify acute respiratory events in children with CF; PPV and NPV of all PROs were improved when combined with lung function outcomes.

Clinimetric analysis of outcome measures for airway clearance in people with cystic fibrosis: a systematic review

BACKGROUND

Airway clearance techniques (ACTs) are integral to cystic fibrosis (CF) management. However, there is no consensus as to which outcome measures (OMs) are best for assessing ACT efficacy.

OBJECTIVES

To summarise OMs that have been assessed for their clinimetric properties (including validity, feasibility, reliability, and reproducibility) within the context of ACT research in CF.

DESIGN AND METHODS

A systematic review was conducted according to Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA) standards. Any parallel or cross-over randomised controlled trial (RCT) investigating outcome measures for ACT in the CF population were eligible for inclusion. The search was performed in five medical databases, clinicaltrials.gov, and abstracts from international CF conferences. The authors planned to independently assess study quality and risk of bias using the COnsensus-based Standards for the selection of health status Measurement InstrumeNts (COSMIN) risk of bias checklist with external validity assessment based upon study details (participants and study intervention). Two review authors (GS and MJ) independently screened search results against inclusion criteria, and further data extraction were planned but not required.

RESULTS

No completed RCTs from the 187 studies identified met inclusion criteria for the primary or post hoc secondary objective. Two ongoing trials were identified.

DISCUSSION AND CONCLUSION

This empty systematic review highlights that high-quality RCTs are urgently needed to investigate and validate the clinimetric properties of OMs used to assess ACT efficacy. With the changing demographics of CF combined with the introduction of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies, an accurate assessment of the current benefit of ACT or the effect of ACT withdrawal is a high priority for clinical practice and future research; OMs which have been validated for this purpose are essential.

REGISTRATION

This systematic review was registered on the PROSPERO database (CRD42020206033).