Psychometrics of HRQoL questionnaires in bronchiectasis: A systematic review and meta-analysis

INTRODUCTION: Understanding the psychometric properties of health related quality of life (HRQoL) questionnaires can help inform selection in clinical trials. OBJECTIVE: To assess the psychometric properties of HRQoL questionnaires in bronchiectasis. METHODS: A literature search was conducted. HRQoL questionnaires were assessed for psychometric properties (reliability, validity, minimal clinically important difference (MCID), floor/ceiling effects). Meta-analyses assessed the associations of HRQoL with clinical measures and responsiveness of HRQoL in clinical trials. RESULTS: 166 studies and 12 HRQoL questionnaires were included. The BHQ, LCQ, CAT and SF-36 had good internal consistency in all domains reported (Cronbach's α≥0.7) across all studies and the QoL-B, SGRQ, CRDQ and SOLQ had good internal consistency in all domains in the majority of (but not all) studies. The BHQ, SGRQ, LCQ and CAT had good test-retest reliability in all domains reported ((intraclass correlation coefficient) ICC ≥0.7) across all studies and the QoL-B, CRDQ and SOLQ had good test-retest reliability in all domains in the majority of (but not all) studies. HRQoL questionnaires were able to discriminate between demographics, important markers of clinical status, disease severity, exacerbations and bacteriology. For HRQoL responsiveness, there was a difference between the treatment and placebo effect. CONCLUSION: SGRQ was the most widely used HRQoL questionnaire in bronchiectasis studies and it had good psychometric properties, however good psychometric data are growing on bronchiectasis specific HRQoL questionnaires, QoL-B and BHQ. Future studies should focus on the medium-long term test-retest reliability, responsiveness and MCID in these HRQoL questionnaires which show potential in bronchiectasis

Quality control for multiple breath washout tests in multicentre bronchiectasis studies:Experiences from the BRONCH-UK clinimetrics study

Multiple Breath Washout (MBW) to measure Lung Clearance Index (LCI) is increasingly being used as a secondary endpoint in multicentre bronchiectasis studies. LCI data quality control or “over-reading” is resource intensive and the impact is unclear. Objectives: To assess the proportion of MBW tests deemed unacceptable with over-reading, and to assess the change in LCI (number of turnovers), LCI coefficient of variation (CV%) and tidal volume (VT) CV% results after over-reading. Methods: Data were analysed from 250 MBW tests (from 98 adult bronchiectasis patients) collected as part of the Bronch-UK Clinimetrics study in 5 UK centres. Each MBW test was over-read centrally using pre-defined criteria. MBW tests with <2 technically valid and repeatable trials were deemed unacceptable to include in analysis. In accepted tests, values for LCI, LCI CV% and VT CV% before and after over-reading, were compared. Results: Insufficient data was collected in 10/250 tests. With over-reading, 30/240 (12%) were deemed unacceptable to include in analysis. In those accepted tests, overall the change in LCI, LCI CV% and VT CV% with over-reading was not statistically significant. When MBW new sites were compared to MBW expert sites, the change in LCI with over-reading was significantly greater in MBW new sites (p = 0.047). Data suggests that over-reading could be important up to at least 12 months post initiation of MBW activity. Conclusion: MBW over-reading was important in this study as 12% of tests were considered unacceptable. Over-reading improved test result accuracy in sites new to MBW

Measurements of Flavour Dependent Fragmentation Functions in Z^0 -> qq(bar) Events

Fragmentation functions for charged particles in Z -> qq(bar) events have been measured for bottom (b), charm (c) and light (uds) quarks as well as for all flavours together. The results are based on data recorded between 1990 and 1995 using the OPAL detector at LEP. Event samples with different flavour compositions were formed using reconstructed D* mesons and secondary vertices. The \xi_p = ln(1/x_E) distributions and the position of their maxima \xi_max are also presented separately for uds, c and b quark events. The fragmentation function for b quarks is significantly softer than for uds quarks.Comment: 29 pages, LaTeX, 5 eps figures (and colour figs) included, submitted to Eur. Phys. J.

Bronchiectasis in yellow nail syndrome

BACKGROUND AND OBJECTIVE: Yellow nail syndrome (YNS) is a rare and poorly described disease process. In this case-control study, clinical features and findings on HRCT were compared with idiopathic bronchiectasis (IBx). METHODS: A review of all patients attending an adult bronchiectasis clinic between 2007 and 2013 identified 25 YNS patients. IBx patients were matched in a 2:1 ratio for age, duration of symptoms and gender. RESULTS: Median age of onset was 53 years. There were 12 male and 23 Caucasian YNS patients. Respiratory manifestations included chronic productive cough (100%), chronic rhinosinusitis (88%), pleural effusions (20%) and lymphoedema (12%). Chest symptoms preceded yellow nails in the majority (68%). Abnormal nails persisted at follow-up in 23 of 25 patients but improved in 14. In both disorders, there was symmetrical, predominantly lower lobe bronchiectasis on HRCT. Extent (P = 0.04), severity (P = 0.03) and bronchial wall thickness (P = 0.05) scores were lower in YNS, with less upper and middle lobe disease. Multivariate analysis showed an independent association with increased mucus plugging in YNS. There was a similar prevalence of Pseudomonas aeruginosa infection and mild lung function abnormalities. CONCLUSION: Bronchiectasis in YNS is less severe than IBx but is associated with increased mucus plugging, onset is in middle age and there is no female predominance. Treatment targeted at improved secretion clearance may improve both chest and nail symptoms, with consideration of long-term macrolide antibiotics

Determination of alpha_s using Jet Rates at LEP with the OPAL detector

Hadronic events produced in e+e- collisions by the LEP collider and recorded by the OPAL detector were used to form distributions based on the number of reconstructed jets. The data were collected between 1995 and 2000 and correspond to energies of 91 GeV, 130-136 GeV and 161-209 GeV. The jet rates were determined using four different jet-finding algorithms (Cone, JADE, Durham and Cambridge). The differential two-jet rate and the average jet rate with the Durham and Cambridge algorithms were used to measure alpha(s) in the LEP energy range by fitting an expression in which order alpah_2s calculations were matched to a NLLA prediction and fitted to the data. Combining the measurements at different centre-of-mass energies, the value of alpha_s (Mz) was determined to be alpha(s)(Mz)=0.1177+-0.0006(stat.)+-0.0012$(expt.)+-0.0010(had.)+-0.0032(theo.) \.Comment: 40 pages, 17 figures, Submitted to Euro. Phys. J.

W+W- production and triple gauge boson couplings at LEP energies up to 183 GeV

A study of W-pair production in e+e- annihilations at Lep2 is presented, based on 877 W+W- candidates corresponding to an integrated luminosity of 57 pb-1 at sqrt(s) = 183 GeV. Assuming that the angular distributions of the W-pair production and decay, as well as their branching fractions, are described by the Standard Model, the W-pair production cross-section is measured to be 15.43 +- 0.61 (stat.) +- 0.26 (syst.) pb. Assuming lepton universality and combining with our results from lower centre-of-mass energies, the W branching fraction to hadrons is determined to be 67.9 +- 1.2 (stat.) +- 0.5 (syst.)%. The number of W-pair candidates and the angular distributions for each final state (qqlnu,qqqq,lnulnu) are used to determine the triple gauge boson couplings. After combining these values with our results from lower centre-of-mass energies we obtain D(kappa_g)=0.11+0.52-0.37, D(g^z_1)=0.01+0.13-0.12 and lambda=-0.10+0.13-0.12, where the errors include both statistical and systematic uncertainties and each coupling is determined setting the other two couplings to the Standard Model value. The fraction of W bosons produced with a longitudinal polarisation is measured to be 0.242+-0.091(stat.)+-0.023(syst.). All these measurements are consistent with the Standard Model expectations.Comment: 48 pages, LaTeX, including 13 eps or ps figures, submitted to European Physical Journal

Bose-Einstein Correlations in e+e- to W+W- at 172 and 183 GeV

Bose-Einstein correlations between like-charge pions are studied in hadronic final states produced by e+e- annihilations at center-of-mass energies of 172 and 183 GeV. Three event samples are studied, each dominated by one of the processes W+W- to qqlnu, W+W- to qqqq, or (Z/g)* to qq. After demonstrating the existence of Bose-Einstein correlations in W decays, an attempt is made to determine Bose-Einstein correlations for pions originating from the same W boson and from different W bosons, as well as for pions from (Z/g)* to qq events. The following results are obtained for the individual chaoticity parameters lambda assuming a common source radius R: lambda_same = 0.63 +- 0.19 +- 0.14, lambda_diff = 0.22 +- 0.53 +- 0.14, lambda_Z = 0.47 +- 0.11 +- 0.08, R = 0.92 +- 0.09 +- 0.09. In each case, the first error is statistical and the second is systematic. At the current level of statistical precision it is not established whether Bose-Einstein correlations, between pions from different W bosons exist or not.Comment: 24 pages, LaTeX, including 6 eps figures, submitted to European Physical Journal

Bose-Einstein Correlations of Three Charged Pions in Hadronic Z^0 Decays

Bose-Einstein Correlations (BEC) of three identical charged pions were studied in 4 x 10^6 hadronic Z^0 decays recorded with the OPAL detector at LEP. The genuine three-pion correlations, corrected for the Coulomb effect, were separated from the known two-pion correlations by a new subtraction procedure. A significant genuine three-pion BEC enhancement near threshold was observed having an emitter source radius of r_3 = 0.580 +/- 0.004 (stat.) +/- 0.029 (syst.) fm and a strength of \lambda_3 = 0.504 +/- 0.010 (stat.) +/- 0.041 (syst.). The Coulomb correction was found to increase the \lambda_3 value by \~9% and to reduce r_3 by ~6%. The measured \lambda_3 corresponds to a value of 0.707 +/- 0.014 (stat.) +/- 0.078 (syst.) when one takes into account the three-pion sample purity. A relation between the two-pion and the three-pion source parameters is discussed.Comment: 19 pages, LaTeX, 5 eps figures included, accepted by Eur. Phys. J.