Pulmonary exacerbation: towards a definition for use in clinical trials. report from the eurocarecf working group on outcome parameters in clinical trials

Journal of Cystic Fibrosis Volume 10 Suppl 2 (2011) S79-S81 Pulmonary exacerbation: Towards a definition for use in clinical trials.
Report from the EuroCareCF Working Group on outcome parameters in D. Bilton a,*, G. Canny b, S. Conway c, S. Dumcius d, L. Hjelte e, M. Proesmans f, B. Tümmler g, V. Vavrova h, K. De Boeck f a Royal Brompton Hospital, London, UK b Our Lady's Hospital for Sick Children, Crumlin, Dublin 12, Ireland c St. James' Hospital, LS9 7TF, Leeds, UK d Vilnius University, 08661, Vilnius, Lithuania e Karolinska, Stockholm CF Centre, Huddinge, 14186 Stockholm, Sweden f University Hospital Leuven, 3000 Leuven, Belgium g Medizinische Hochschule Hannover, 30625 Hannover, Germany h University Hospital Motol, Prague, 150 06 Prague 5, Czech Republic Abstract
Pulmonary exacerbations represent a key outcome variable in clinical trials of cystic fibrosis (CF). As there is variation in the trigger for use of intravenous antibiotics compared to the use of oral antibiotics or new nebulised therapy for treatment of exacerbations, the consensusview is that use of intravenous antibiotics cannot be regarded as the key defining character for an exacerbation on its own. The consensusview is that the clinical need for additional treatment as indicated by a recent change in clinical parameters provides the best definition of anexacerbation. Which parameters to include as well as the problems associated with the use of scoring systems and symptom clusters are beingdiscussed.
2011 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
Keywords: Pulmonary exacerbation; Cystic fibrosis; Outcome parameters; Definition; Consensus 1. Introduction
fibrosis (CF), including RhDNase [3], Tobramycin (TOBI)[4], Azithromycin [5] and hypertonic saline [6] Pulmonary exacerbations are a key outcome measure in iv There are significant costs associated with the requirement for intravenous antibiotic therapy at home or in hospital Pulmonary exacerbations exhibit a strong contribution in a v As a result of i-iv above, reduction in pulmonary exacerba- well validated survivorship model. Each acute pulmonary tions can be considered an important endpoint independent exacerbation had a negative impact on 5 year survival There is consensus that pulmonary exacerbations represent ii Pulmonary exacerbations have been shown to have a a key outcome variable in clinical trials of CF. profound negative impact on health related quality of life[2] 2. Definition of pulmonary exacerbation
iii Pulmonary exacerbations have been a key secondary endpoint in landmark studies of new therapies for cystic 2.1. Physician defined requirement to treat The simplest definition of pulmonary exacerbation is a * Corresponding author: D. Bilton, Royal Brompton Hospital, Respiratory Medicine, Sydney Street, London SW3 6NP, UK. Tel: +44 (0)20 7352 8121.
physician defined requirement to intervene with new antibiotic E-mail address: D.Bilton@rbht.nhs.uk (D. Bilton).
therapy, either oral or intravenous. This definition is open to 1569-1993/$ - see front matter 2011 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
D. Bilton et al. / Journal of Cystic Fibrosis Volume 10 Suppl 2 (2011) S79-S81 variability depending on clinician preference and threshold An exacerbation will be defined as the need for additional for treatment. However, this simple definition was used antibiotic treatment as indicated by a recent change in at least effectively in the Azithromycin study [5] when exacerbations were defined as the use of intravenous anti-Pseudomonal • Change in sputum volume or colour antibiotics or oral quinolones for seven or more days.
In the TOBI trial [4], use of intravenous antibiotics and • Increased malaise, fatigue or lethargy hospitalisation were used to characterise exacerbations and revealed significant benefit in favour of the active treatment.
• Decrease in pulmonary function by 10% or more / This definition is not recommended as a EuroCareCF consensus as there may be variation in the prescription of intravenous antibiotics and access to inpatient treatment indifferent countries.
2.3. Scoring system to define exacerbation As there is variation in the trigger for use of intravenous antibiotics compared to the use of oral antibiotics or new neb- Several studies have addressed the possibility of standard- ulised therapy for treatment of exacerbations, the consensus ising a symptom defined exacerbation score. However, these view is that use of intravenous antibiotics cannot be regarded are subject to the difficulty of deciding on the gold standard as the key defining character for an exacerbation on its own. for validation. If the gold standard is the physician's opinionthen variability is likely to be introduced. An Australian 2.2. Symptom defined requirement to treat survey highlighted this problem [7]. Rosenfeld et al. [8]developed two scores which were validated in the intervention Exacerbations can be usefully defined by a cluster of arm of the TOBI trial. One score included lung function as symptoms and signs as defined by Fuchs et al. [3].
a variable. The second had no requirement for lung function.
Clinical need for intravenous antibiotics as indicated by The utility of this is obvious in terms of pan-European studies presence of at least 4 of 12 possible signs or symptoms: and the algorithm produces a score where the critical value of 2.6 or above represents a physician defined exacerbation. The problem with this score is that it does not necessarily correlate with a new treatment or intervention.
• Increased dyspnoea• Increased malaise, fatigue or lethargy 2.4. Symptom cluster that defines need for treatment • Temperature over 38°C• Anorexia or weight loss Rabin et al. [9] examined patient registry data in order to predict the factors that were associated with new treatment.
The scoring system developed by Rabin et al. [9] defines • Change in physical findings on examination of the chest separate criteria for different age groups and in particular • Decrease in pulmonary function by 10% or more includes a definition of exacerbations for under 6 year olds.
The scoring system of Rabin et al. [9] appears easy to apply This definition has proven useful in the landmark DNase in clinical studies, but does not have a track record in clinical study [3] and the large trial of hypertonic saline [6].
The criteria of Fuchs et al. [3] i.e.: symptom defined (4 out The consensus view is that the scoring system of Rosenfeld of 12) can be applied regardless of treatment. It is clear from et al. [8] should not be used for European studies as the the hypertonic saline study that there is a significant difference defining score does not always correlate with a change in in exacerbations defined as per the original criteria of Fuchs treatment. The scoring system developed by Rabin et al. [9] et al. [3] and an analysis involving symptoms identified by could be used, but because it has no track record in clinical Fuchs et al. [3] (hereafter termed Fuchs symptoms) regardless trials we do not recommend it for current use. Future trials could incorporate a validation of the scoring system of Rabin The Fuchs symptoms defined exacerbation with or without et al. [9] particularly in studies of children under 6 years of requirement for treatment have shown utility in clinical trials for both children and adults with CF. We recommend that thisdefinition is adopted for future clinical trials in Europe.
Acknowledgements
The consensus view is that the clinical need for additional treatment as indicated by a recent change in clinical pa- This work was supported by the European Union rameters provides the best definition of an exacerbation. The Sixth Framework Programme (contract no. LSHM-CT-2005- clinical parameters used should be those of the criteria of Conflict of interest
The European Consensus Group wishes to validate modi- fied criteria of Fuchs et al. [3] as follows: D. Bilton et al. / Journal of Cystic Fibrosis Volume 10 Suppl 2 (2011) S79-S81 References
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