INT J TUBERC LUNG DIS 18(12):1431–1437 Q 2014 The Union http://dx.doi.org/10.5588/ijtld.14.0195

Validation of the Mandarin Chinese version of the Leicester Cough Questionnaire in bronchiectasis Y-H. Gao,* W-J. Guan,* G. Xu,* Y. Gao,*†‡ Z-Y. Lin,* Y. Tang,* Z-M. Lin,* H-M. Li,* Q. Luo,* NS. Zhong,* S. S. Birring,§ R-C. Chen* *State Key Laboratory of Respiratory Diseases, National Clinical Research Centre for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China; †Department of Pathology and Molecular Medicine, McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, ‡Firestone Institute for Respiratory Health, St. Joseph’s Healthcare, Hamilton, Ontario, Canada; §Division of Asthma, Allergy and Lung Biology, King’s College London, London, UK SUMMARY BACKGROUND:

The Leicester Cough Questionnaire (LCQ) has been validated for assessing cough-specific health status in bronchiectasis. We translated the LCQ into Mandarin Chinese and investigated its validity, reliability and responsiveness. M E T H O D S : The LCQ was translated into Mandarin Chinese using the forward-backward translation procedure. A total of 144 out-patients completed the Mandarin Chinese version of the LCQ (LCQ-MC), the Hospital Anxiety and Depression Scale (HADS) and the St George’s Respiratory Questionnaire. Reassessments were performed during exacerbations and at 6 months. Concurrent validation, internal consistency, repeatability and responsiveness were determined. R E S U LT S : Minor cultural adaptations were made to the wording of LCQ-MC. No other difficulties were found during the translation process, with all items easily

adapted to acceptable Mandarin Chinese. The questionnaire was not changed in terms of content layout and the order of the questions. In cognitive debriefing interviews, participants reported that the questionnaire was acceptable, relevant, comprehensive and easy to complete. The LCQ-MC showed good concurrent validity, internal consistency and test-retest reliability. Responsiveness was shown by significant changes in LCQ-MC scores between steady state, the first exacerbation and following 2-week antibiotic treatment (both interval changes, P , 0.01) C O N C L U S I O N : The LCQ-MC is a valid, reliable and responsive instrument for determining cough-specific health status in Chinese bronchiectasis patients. K E Y W O R D S : LCQ; bronchiectasis; validity; cough; quality of life

BRONCHIECTASIS is a chronic progressive respiratory disease characterised by productive cough, sputum production and recurrent infective exacerbations, leading to impaired health-related quality of life (HRQoL).1 Although its prevalence in China is not precisely known, bronchiectasis has been common in clinics, possibly due to socio-economic deprivation, inadequate tuberculosis (TB) control and lower immunisation rates in rural areas.2 It has been increasingly recognised that lung function and the number of bronchiectatic lobes might not fully reflect the impact on individual patients. More

importantly, these indices are also not sensitive for the assessment of response to treatment. Proper assessment of HRQoL is therefore urgently required. As stated in the British Thoracic Society guidelines for bronchiectasis, improving health status is a major goal.1 The St George’s Respiratory Questionnaire (SGRQ) and Leicester Cough Questionnaire (LCQ) are the only two validated questionnaires for the assessment of HRQoL in bronchiectasis.3–5 The SGRQ was originally designed mainly to measure the effect of breathlessness on HRQoL in patients with chronic obstructive pulmonary disease (COPD).6 However, productive cough, and not breathlessness, is the predominant symptom of bronchiectasis.7 Well-validated cough-specific health

Footnote: YHG, WJG, GX and YG contributed equally to this paper.

Correspondence to: Rong-Chang Chen, State Key Laboratory of Respiratory Diseases, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Road, Guangzhou, Guangdong, 510120, China. Tel: (þ86) 208 306 2882. Fax: (þ86) 208 306 2718. e-mail: [email protected] Article submitted 8 March 2014. Final version accepted 7 July 2014.

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status questionnaires are therefore crucial for evaluating patient health status, both individually and in clinical trials. The LCQ is an HRQoL questionnaire originally designed for assessing chronic cough,8 and was recently validated for use in English bronchiectasis patients.5 However, there are no published data regarding the validation and translation of LCQ into Mandarin Chinese, particularly on its application in bronchiectasis patients. In the present study, we translated the original questionnaire and investigated the reliability, validity and responsiveness of the Mandarin Chinese version of the LCQ (LCQ-MC) in bronchiectasis patients.

METHODS This study was part of a prospective cohort study used to assess the effects of anxiety and depression on bronchiectasis exacerbations (Clinicaltrials.gov, number NCT01688180). The study was approved by the Ethics Committee of the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. Written informed consent was provided by all participants. Translation of the LCQ A three-step linguistic validation procedure was employed.

Forward translation The original English version of the LCQ was translated into Mandarin Chinese independently by two bilingual Mandarin Chinese and English PhD students (YHG and WJG) specialised in respiratory medicine. A committee consisting of these two translators and another bilingual Chinese (GX) critically reviewed the two Mandarin Chinese versions, harmonised discrepancies and created a consensus version. Back translation The consensus Mandarin Chinese version was backtranslated into English by another translator (YG), who was blinded to the original English version. The same committee then assessed and corrected the back translation to produce a comprehensible and acceptable formulation of the concept. SSB, the author of the English LCQ, also checked the linguistic and conceptual equivalence of the back translation against the original English version. Cognitive debriefing interviews and final review Cognitive debriefing interviews of 10 Chinese bronchiectasis patients were conducted in out-patient clinics to test the applicability, comprehensiveness and relevance of the LCQ-MC. During the cognitive debriefing interviews, patients were asked to comment on questionnaire items and instructions. The

final revision of the LCQ-MC was adapted accordingly to ensure item clarity and relevance. The final version was then reviewed by a pulmonologist in China, and used for further psychometric assessments. The final LCQ-MC (see Appendix)* for the assessment of the impact of cough in the past 2 weeks consisted of 19 items divided into three domains: physical (8 items), psychological (7 items) and social (4 items).8 A 7-point Likert scale was used for scoring individual domains. The total scores ranged from 3 to 21, with higher scores representing better health status.8

Subjects Bronchiectasis patients aged 718 years were eligible to participate. Bronchiectasis was defined as a history compatible with evidence of bronchial dilatation on high-resolution computed tomography (HRCT). Exclusion criteria were 1) acute exacerbation within 4 weeks; 2) uncontrolled asthma; 3) active allergic bronchopulmonary aspergillosis; 4) active TB; and 5) poor understanding. Outcome measures Two health-related questionnaires, the Chinese version of the SGRQ and the hospital anxiety and depression scale (HADS),4,9 were simultaneously applied to the study population along with the LCQ-MC. The SGRQ, which assesses the impact of symptoms in the past 4 weeks, consisted of 50 items divided into three domains: symptoms (8 items), activity (16 items) and impact (26 items).6 Total scores and scores for the three individual domains range from 0 to 100, with higher scores indicating poorer HRQoL.6 The HADS, used to assess the impact of symptoms in the previous 2 weeks, consisted of 7 items for depression and 7 for anxiety, each of which was scored on a scale of 0 to 3.10 Both questionnaires have previously been validated for use in Chinese.4,9 Spirometry was performed using a standardised protocol according to American Thoracic Society/ European Respiratory Society guidelines.11 Dyspnoea was assessed using the 4-grade Medical Research Council (MRC) scale.12 The number of exacerbations in the past year and sputum culture reports were extracted by meticulous history taking and review of clinical records. The severity of bronchiectasis was scored using the modified Reiff score.13 The 6-min walking test (6MWT) was performed to assess the exercise capacity of patients per the guidelines.14

* The Appendix is available in the online version of this article, at http://www.ingentaconnect.com/content/iuatld/ijtld/2014/ 00000018/00000012/art00009.

Validation of LCQ-MC in bronchiectasis

Validation Concurrent validity, internal consistency, floor and ceiling effects, repeatability, and responsiveness were used to validate the LCQ-MC in bronchiectasis. Concurrent validity of LCQ-MC was evaluated by comparing the component and total scores with the baseline SGRQ and HADS scores. Internal consistency, i.e., the degree of homogeneity of an individual domain, was calculated by determining the Cronbach’s a coefficient, with a value of 70.7 representing sufficient acceptability. LCQ-MC scores at baseline were used to assess internal consistency. Floor and ceiling effects were determined if .15% of patients achieved the best or worst possible score, respectively. Absence of floor and ceiling effects represented satisfactory content validity.15 Test-retest reliability is a measure of the stability of LCQ-MC scores over time. In our study, repeatability was determined by comparing LCQ-MC scores at baseline with those measured at 6 months in clinically stable bronchiectasis, defined as no significant changes in treatment and cough symptoms following study entry. Responsiveness was evaluated by changes in LCQMC scores corresponding to changes in exacerbations. LCQ-MC questionnaires were filled at steady state, immediately before commencing antibiotic treatment and 1 week after completion of treatment. The questionnaire was adapted for the assessment at the end of the exacerbation period for information on symptoms in the preceding week.5 The standardised response mean (SRM) was calculated as the mean change in LCQ-MC between steady state and exacerbation or after a 2-week course of antibiotic treatment, divided by the standard deviation (SD) of mean change. An SRM of 70.5 indicated a moderate-to-large change.16 Exacerbation was defined as persistent deterioration in respiratory symptoms requiring antibiotic treatment. For patients who had experienced one or more exacerbations, only the first was analysed. All patients received a 14-day course of oral or intravenous antibiotics based on previous culture profiles. Fluoroquinolone was administered where sputum bacteriology results were unavailable. Statistical analysis The results were displayed as number (%), mean 6 SD or ranges, where appropriate. Pearson’s correlation or Spearman’s rank correlation was used to assess the correlation of LCQ-MC with SGRQ and HADS. Concurrent validity was demonstrated by moderate (empirically .0.3) to strong (empirically .0.5) correlations between LCQ-MC scores and other measurements that were expected to measure similar or related concepts. For example, we would expect strong correlation between the LCQ-MC

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psychological and social domains and SGRQ impact domains.17 Internal consistency and reliability was evaluated by calculating Cronbach’s alpha coefficients and the intraclass correlation coefficient (ICC) for the three domains and total LCQ scores, respectively. The Bland-Altman plot of the LCQ total score was used to demonstrate repeatability over time.18 Responsiveness was analysed by calculating the 95% confidence interval for the three domains and total LCQ-MC scores during steady state, exacerbation and following 2 weeks of antibiotic treatment. All comparisons were two-sided, with P 6 0.05 being considered as statistically significant. Statistical analyses were performed using SPSS 16.0 (Statistical Package for the Social Sciences, Chicago, IL, USA) and Graphpad Prism Version 5.0 (Graphpad Software, San Diego, CA, USA).

RESULTS Translation of LCQ-MC and cognitive debriefing interviews No major difficulties were experienced during the forward translation process, and discrepancies were easily harmonised after discussion by the committee. Minor adaptations made to the wording of LCQ-MC (back-translated version) are listed in Appendix Table A.1. There were no significant differences in the conceptual contents between the back translation and the original English version as verified by SSB. In our cognitive debriefing interviews, none of the patients reported any difficulty in understanding or answering the questions. Baseline characteristics and health status Table 1 shows the characteristics of 144 patients (mean age 45.2 6 SD 13.8 years; 87 females [60.4%]) with clinically stable bronchiectasis. All patients had a mean forced expiratory volume in 1 s (FEV1) of 67.13% predicted (SD 22.55%), and were eligible for the cross-sectional analysis (concurrent validity, floor and ceiling effects, and internal consistency). The total LCQ-MC score was 12.59 6 3.90, indicating severely impaired health status, which was consistent with Birring et al.’s study in patients with chronic cough.8 All health domains of LCQ-MC, including physical, psychological and social, are given in Table 1. Concurrent validity The LCQ-MC individual domain and total scores correlated significantly with SGRQ and HADS scores (Table 2). The psychological and social domains of LCQ-MC showed a strong correlation with the corresponding impact domains of SGRQ-MC (r ¼ 0.587 and 0.585, respectively) (Table 2). LCQ-MC physical domains correlated moderately with the corresponding SGRQ-MC symptoms and activity

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Table 1

Clinical characteristics of 144 bronchiectasis patients

Characteristic Age, years Sex ratio, male/female Body mass index, kg/m2

All patients mean 6 SD

Range

45.15 6 13.82 57/87 20.41 6 3.01

18.00–74.00 — 13.80–30.60

5 (3.5) 11 (7.6)

— —

Smoking status, n (%) Current Former Spirometry FEV1, l FEV1 % predicted FVC, l FVC % predicted FEV1/FVC % 6-min walk test 6-min walk distance, m Minimal SaO2, % Borg’s scale for dyspnoea, median [IQR] HRCT bronchiectasis score Chronically colonised with Pseudomonas aeruginosa, n (%) MRC dyspnoea score (0–4 scale), median [IQR] Number of infective exacerbations in previous year

1.90 67.13 2.57 76.26 72.64

0.76 22.55 0.87 20.13 13.52

0.41–3.97 16.80–125.56 0.75–4.49 23.20–126.44 29.90–96.60

501.91 6 82.46 95.05 6 5.85 1.00 [0.00–2.00] 7.28 6 3.97 41 (28.5) 1.00 [0.00–1.00] 1.78 6 1.34

144.00–661.00 54.00–100.00 0.00–8.00 2.00–17.00 — 0.00–4.00 0.00–6.00

6 6 6 6 6

LCQ scores Physical Psychological Social Total

4.22 3.85 4.53 12.59

6 6 6 6

1.22 1.46 1.48 3.90

1.00–6.88 1.00–7.00 1.00–7.00 3.00–20.88

SGRQ scores Symptoms Activity Impact Total

41.09 30.01 34.50 34.11

6 6 6 6

21.82 22.03 20.00 18.62

5.00–97.00 0.00–92.00 0.00–80.00 2.00–83.00

HADS scores Depression Anxiety Total

5.33 6 3.63 7.06 6 3.78 12.38 6 6.73

0.00–16.00 0.00–17.00 0.00–32.00

SD ¼ standard deviation; FEV1 ¼ forced expiratory volume in 1 s; FVC ¼ forced volume capacity; IQR ¼ interquartile range; HRCT ¼ high-resolution computed tomography; SaO2 ¼ arterial blood oxygen; MRC ¼ Medical Research Council; LCQ ¼ the Leicester Cough Questionnaire; SGRQ ¼ St George’s Respiratory Questionnaire; HADS ¼ Hospital Anxiety and Depression Scale.

domains (r ¼0.474 and 0.367) (Table 2). The total score also correlated with the SGRQ-MC total score (r ¼ 0.600) (Table 2). The LCQ-MC correlated better with SGRQ than with HADS (Table 2). Table 2 baseline

Floor and ceiling effect, and internal consistency At baseline (Table 3), the internal consistency of the three domains and the whole questionnaire was acceptable (.0.7), with the Cronbach’s a coefficients

Concurrent validity of LCQ-MC in 144 patients with clinically stable bronchiectasis at LCQ-MC*

HADS Anxiety Depression Total SGRQ Symptoms Activity Impact Total

Physical

Psychological

Social

Total

0.302*

0.385*

0.306*

0.354*

0.275† 0.318*

0.279† 0.381*

0.271† 0.313*

0.308* 0.361*

0.474* 0.367*

0.446* 0.295*

0.498* 0.428*

0.493* 0.388*

0.590* 0.564*

0.587* 0.535*

0.585* 0.589*

0.627* 0.600*

* P , 0.001. † P ¼ 0.01. LCQ-MC ¼ Leicester Cough Questionnaire in Mandarin-Chinese; HADS ¼ Hospital Depression and Anxiety Scale; SGRQ ¼ St George’s Respiratory Questionnaire.

Validation of LCQ-MC in bronchiectasis

Table 3 Floor and ceiling effect, and internal consistency of LCQ-MC in 144 patients with clinically stable bronchiectasis at baseline LCQ-MC at baseline Physical Psychological Social Total Floor and ceiling effect, %* Data at floor (lowest) Data at ceiling (highest) Cronbach’s a coefficient Birring et al.† The present study‡

0.7 0.0

2.8 2.8

0.79 0.83

0.89 0.88

0.7 12.5

0.7 0.0

0.85 0.92 0.82 0.93

* Percentage of patients with the lowest or highest possible scores. † Patients with chronic cough.8 ‡ Patients with non-cystic fibrosis bronchiectasis. LCQ-MC ¼ Leicester Cough Questionnaire in Mandarin-Chinese.

ranging from 0.82 to 0.93. Our results were comparable with studies among patients with chronic cough.8 Although 12.5% of patients achieved the best possible score in the LCQ-MC social domain, no floor or ceiling effects were present in the three domains and the whole questionnaire. Repeatability Table 4 shows the ICC of LCQ-MC of 40 patients who repeated the questionnaire at month 6. All domain and total scores had excellent test-retest reliability (ICC . 0.80). Our results were comparable with findings reported by Murray et al. and Birring et al.5,8 The Bland-Altman plot of LCQ-MC total scores is shown in the Figure; the difference between the total scores over time was 0.33 6 2.17. Spirometry results did not differ (all P , 0.05) (Appendix Table A.2). Responsiveness Thirty patients who experienced an exacerbation during the study period and had been assessed before and after a 2-week course of antibiotic treatment were included in the final analysis. The mean LCQMC scores deteriorated significantly between steady state and the first exacerbation (P , 0.01, Table 5). However, the LCQ-MC scores improved significantly following the 2-week course of antibiotics (P , 0.01). The SRMs of the domain and total scores were moderate to significant (.0.6). However, overall

Table 4 Test-retest reliability (repeatability) of the LCQ-MC in 40 stable patients with bronchiectasis (6 months apart) LCQ-MC† Physical Psychological Social Total

Birring et al.*

Murray et al.†

ICC (95%CI)

0.93 0.9 0.88

NA NA NA

0.84 (0.70–0.92) 0.82 (0.67–0.91) 0.89 (0.79–0.94)

0.96

0.89 (0.80–0.94)

0.96 8

* Patients with chronic cough. † Patients with non-cystic fibrosis bronchiectasis.5 LCQ-MC ¼ Leicester Cough Questionnaire in Mandarin-Chinese; ICC ¼ intraclass correlation coefficient; CI ¼ confidence interval; NA ¼ not available.

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spirometry results were not different in the aforementioned conditions (all P . 0.05), with the exception of FEV1 predicted % before and after treatment (P ¼ 0.002) (Appendix Table A.3). Of 30 exacerbations, 17 potentially pathogenic microorganisms were identified: 14 Pseudomonas aeruginosa, 3 Haemophilus influenzae and 1 Klebsiella pneumonae.

DISCUSSION To our knowledge, this is the first study to translate and validate the LCQ for use in Chinese bronchiectasis patients. As in the case of the validated English version,5 our results also demonstrated highly acceptable concurrent validity, internal consistency and repeatability. Furthermore, the LCQ-MC was more sensitive than spirometry in capturing and assessing response to antibiotic treatment for exacerbations. As previously reported in COPD patients with chronic cough,17 we found that the LCQ-MC individual domain and total scores correlated significantly with those of SGRQ. Notably, the SGRQ activity score had low-to-moderate correlation coefficients with all LCQ-MC scores. This may be because the SGRQ focuses on dyspnoea and limitation of activity, unlike the LCQ, which focuses on cough.6,8 Concurrent validity was reinforced by significant correlations between LCQ-MC scores and degree of anxiety and depression. A weaker correlation with the HADS suggests that LCQ and HADS measure different aspects of well-being in bronchiectasis patients. Specifically, the LCQ focused mainly on the distress associated with cough as opposed to a patient’s general mental health. Construct analysis of LCQ-MC showed a preferable internal consistency for the three domains and total score similar to the validated English version.5 Test-retest reliability, as indicated by the ICC, was highly acceptable over 6 months in clinically stable bronchiectasis patients. There were no changes in spirometry results in these patients over the 6 months. Agreement was assessed according to the methods described by Bland and Altman.18 The mean change in steady-state bronchiectasis over time was 0.33 6 2.17 units, slightly higher than that reported in a study of the English version (0.23 6 1.1).5 Both were less than the minimal clinically important difference (MCID) of LCQ total score reported in chronic cough (1.3 units),19 suggesting that the difference was not clinically significant. Changes in LCQ scores among stable patients could have arisen due to the lengthy duration of test-retest reliability studies, as the conventional interval for assessing repeatability is often 2 weeks. Disease characteristics and cultural influences might, at least partially, have contributed to the aforementioned discrepancy in changes in LCQ score between Chinese and English

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Figure Repeatability of the LCQ. Bland-Altman plot of the LCQ total score repeated over 6 months in 40 patients with stable bronchiectasis whose cough and treatment remained unchanged. ––– ¼ mean difference between the two scores (0.33); - - - - ¼ 95% limits of agreement (3.93 to 4.59). LCQ ¼ Leicester Cough Questionnaire.

patients. Of note, the results for assessing the agreement of LCQ were comparable to those in COPD patients with chronic cough, although data were captured 2 weeks apart.17 Nevertheless, our analyses for agreement assessment need to be reproduced in a larger cohort of bronchiectasis patients at a shorter interval for a more definitive conclusion. There was significant deterioration across all domains and in LCQ-MC total scores between the steady state and the first exacerbation, and an improvement following completion of the 2-week course of antibiotics, with changes in total scores ranging from 2.73 to 3.66. Changes were higher than the MCID,19 indicating considerable responsiveness of the LCQ-MC. However, there were no significant changes in spirometric indices under the aforementioned conditions, except for an improve-

ment in FEV1 % predicted following the 2-week course of antibiotics for exacerbation. LCQ-MC might thus be more useful than spirometry in capturing information on exacerbation and in assessing response to antibiotic treatment. Several limitations should be considered. First, the study was conducted at a single centre with patients who were younger than those in miscellaneous cohorts, restricting extensive application. Second, the small sample size precluded the possibility of reliably calculating the MCID; further studies are therefore necessary. Furthermore, the SGRQ, rather than other cough-specific QoL questionnaires, was employed as the reference standard. To date, the SGRQ is the only QoL questionnaire to have been validated for bronchiectasis. Polley et al. also demonstrated significant concurrent validity (r ¼ 0.88) for total scores of LCQ and the CoughSpecific Quality of Life Questionnaire in bronchiectasis.20 In summary, the LCQ-MC is a reliable, valid and responsive instrument applicable to Chinese bronchiectasis patients for assessment of HRQL, both at steady state and during infective exacerbations. Our validated LCQ-MC should thus be incorporated into future research. Acknowledgements The study was funded by Changjiang Scholars and Innovative Research Team in University ITR0961 and National Key Scientific & Technology Support Program: Collaborative Innovation of Clinical Research for Chronic Obstructive Pulmonary Disease and Lung Cancer, No 2013BAI09B09. The authors thank M Jiang (State Key Laboratory of Respiratory Diseases, Guangzhou Medical University, Guangzhou, China) for her assistance in statistical analysis; and J Li, X-Q Chen, Z-G Zheng, J-P Zheng, C-L Tang, C-R Ju and Y-Q Zhan (State Key Laboratory of Respiratory Diseases, Guangzhou Medical University) for their assistance in enrolling patients; and P Jones (St George’s Hospital, London, UK) for his kind permission to use the St George’s Respiratory Questionnaire.

Table 5 Changes in LCQ-MC scores between steady-state and infective exacerbations and after 2 weeks of antibiotic treatment in 30 exacerbation events in adults with bronchiectasis LCQ-MC Parameter

Physical

Psychological

Social

Total

LCQ scores at steady state 4.58 6 1.19 4.10 6 1.43 4.90 6 1.32 13.58 6 3.75 LCQ scores before treatment 3.63 6 0.78 3.36 6 1.23 3.86 6 1.31 10.85 6 2.99 LCQ scores after treatment 4.93 6 1.10 4.52 6 1.36 5.07 6 1.37 14.51 6 3.63 Mean difference from stable stage* to the first exacerbation, (95%CI) 0.95 (1.35 to 0.55) 0.74 (1.14 to 0.34) 1.04 (1.52 to 0.56) 2.73 (43.88 to 1.59) P value for paired t-test ,0.001 0.001 ,0.001 ,0.001 0.89 0.69 0.81 0.89 SRM† Mean improvement after 2-week antibiotic treatment, (95%CI) 1.30 (0.91 to 1.68) 1.16 (0.73 to 1.58) 1.21 (0.74 to 1.67) 3.66 (2.50 to 4.82) P value for paired t-test ,0.001 ,0.001 ,0.001 ,0.001 † 1.26 1.01 0.97 1.18 SRM * Stable stage at baseline. † Mean change/SD of mean change. LCQ-MC ¼ Leicester Cough Questionnaire in Mandarin-Chinese; CI ¼ confidence interval; SRM ¼ standardised response mean; SD ¼ standard deviation.

Validation of LCQ-MC in bronchiectasis

Conflict of interest: none declared.

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10 Zigmond A S, Snaith R P. The hospital anxiety and depression scale. Acta Psychiatr Scand 1983; 67: 361–370. 11 Miller M R, Hankinson J, Brusasco V, et al. Standardisation of spirometry. Eur Respir J 2005; 26: 319–338. 12 Mahler D A, Wells C K. Evaluation of clinical methods for rating dyspnea. Chest 1988; 93: 580–586. 13 Pasteur M C, Helliwell S M, Houghton S J, et al. An investigation into causative factors in patients with bronchiectasis. Am J Respir Crit Care Med 2000; 162: 1277–1284. 14 ATS Committee on Proficiency Standards for Clinical Pulmonary Function. ATS statement: guidelines for the sixminute walk test. Am J Respir Crit Care Med 2002; 166: 111– 117. 15 Terwee C B, Bot S D, de Boer M R, et al. Quality criteria were proposed for measurement properties of health status questionnaires. J Clin Epidemiol 2007; 60: 34–42. 16 Liang M H, Fossel A H, Larson M G. Comparisons of five health status instruments for orthopedic evaluation. Med Care 1990; 28: 632–642. 17 Berkhof F F, Boom L N, ten Hertog N E, et al. The validity and precision of the Leicester Cough Questionnaire in COPD patients with chronic cough. Health Qual Life Outcomes 2012; 10: 4. 18 Bland J M, Altman D G. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; 1: 307–310. 19 Raj A A, Pavord D I, Birring S S. Clinical cough IV: what is the minimal important difference for the Leicester Cough Questionnaire? Handb Exp Pharmacol 2009: 311–320. 20 Polley L, Yaman N, Heaney L, et al. Impact of cough across different chronic respiratory diseases: comparison of two cough-specific health-related quality of life questionnaires. Chest 2008; 134: 295–302.

Validation of LCQ-MC in bronchiectasis

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APPENDIX Table A.1 Cultural adaptation for back-translated version of LCQ-MC by SSB Back-translated version of LCQ-MC 2 In the past 2 weeks, have you been bothered with sputum production when coughing? (1) Every time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) Occasionally (6) Seldom (7) Never 7 In the past 2 weeks, has cough interfered with your work or other daily affairs? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time 8 In the past 2 weeks, has cough interfered with your entire life enjoyment? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time 11 In the past 2 weeks, how many times a day have you had cough bouts? (1) Constantly (2) Most times (3) Several times (4) Some times (5) Occasionally (6) Seldom (7) Never 13 In the past 2 weeks, has cough made you feel fed up? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time 14 In the past 2 weeks, have you suffered from hoarseness as a result of cough? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time 15 In the past 2 weeks, have you felt full of energy? (1) None of the time (2) Hardly any of the time (3) A little of the time (4) Some of the time (5) A good bit of the time (6) Most of the time (7) All of the time 16 In the past 2 weeks, have you been worrying that you might have a serious disease as a result of cough? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time

Cultural adaptation by SSB 2 In the past 2 weeks, have you been bothered with sputum (phlegm) when coughing? (1) Every time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) Occasionally (6) Seldom (7) Never 7 In the past 2 weeks, has cough interfered with your work or other daily tasks? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time 8 In the past 2 weeks, has cough interfered with your overall life enjoyment? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time 11 In the past 2 weeks, how many times a day have you had cough bouts? (1) Constantly (2) Most times (3) Several times (4) Some times (5) Occasionally (6) Rarely (7) Never 13 In the past 2 weeks, has cough made you feel fed up? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time 14 In the past 2 weeks, have you suffered from hoarse voice as a result of cough? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time 15 In the past 2 weeks, have you had a lot of energy? (1) None of the time (2) Hardly any of the time (3) A little of the time (4) Some of the time (5) A good bit of the time (6) Most of the time (7) All of the time 16 In the past 2 weeks, have you been worrying that you might have a serious illness as a result of cough? (1) All of the time (2) Most of the time (3) A good bit of the time (4) Some of the time (5) A little of the time (6) Hardly any of the time (7) None of the time

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Table A.2 Spirometric indices in 40 patients with clinically stable bronchiectasis measured 6 months apart Baseline Mean 6 SD

Parameters FVC % predicted FEV1 % predicted FEV1/FVC MMEF % predicted

76.07 67.95 73.61 47.29

6 6 6 6

6 months Mean 6 SD

21.13 24.59 13.50 25.84

77.06 68.14 72.33 45.99

6 6 6 6

P value

22.44 26.83 14.13 27.42

0.39 0.88 0.08 0.4

SD ¼ standard deviation; FEV1 ¼ forced expiratory volume in 1 s; FVC ¼ forced volume capacity; MMEF ¼ maximum mid-expiratory flow.

Table A.3 Spirometric indices among adult patients with steady-state and exacerbated bronchiectasis and after a 2-week course of antibiotic treatment Parameter FVC % predicted FEV1 % predicted FEV1/FVC MMEF % predicted

Steady state 70.68 58.35 67.78 35.08

6 6 6 6

22.89 24.67 12.98 22.56

P value* 0.66 0.08 0.21 0.08

Exacerbation Mean 6 SD 70.02 55.94 65.85 32.41

6 6 6 6

23.52 25.84 14.40 21.96

P value†

After 2 weeks of antibiotics Mean 6 SD

0.06 0.002 0.82 0.07

* Paired t-test between steady state and exacerbation. † Paired t-test between exacerbation and after 2 weeks of antibiotics. ‡ Paired t-test between steady state and after 2 weeks of antibiotics. FEV1 ¼ forced expiratory volume in 1 s; FVC ¼ forced volume capacity; MMEF ¼ maximum mid-expiratory flow.

71.89 58.95 66.21 35.26

6 6 6 6

21.93 24.84 12.63 22.74

P value‡ 0.4 0.61 0.29 0.91

Validation of LCQ-MC in bronchiectasis

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Validation of LCQ-MC in bronchiectasis

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RESUME C O N T E X T E : Le questionnaire de Leicester relatif a` la toux (LCQ) a e´ t´e valid´e pour l’´evaluation de l’´etat de sant´e en mati`ere de toux chez les patients atteints de bronchiectasies. Nous avons traduit ce LCQ en chinois mandarin et v´erifi´e sa validit´e, sa fiabilit´e et sa r´eactivit´e. M E´ T H O D E S : Le LCQ a e´ t´e traduit en chinois mandarin grace ˆ a` la proc´edure d’aller-retour. En total, 144 patients externes ont rempli la version chinoise du LCQ (LCQMC), l’´echelle d’anxi´et´e et de d´epression a` l’hopital ˆ et le questionnaire respiratoire de St Georges. Des r´ee´ valuations ont e´ t´e r´ealis´ees lors d’exacerbations de la toux et a` 6 mois. Ceci a permis de d´eterminer la validation concurrente, la coh e´ rence interne, la r´ep´etabilit´e et la r´eactivit´e. R E´ S U LT A T S : Des adaptations culturelles mineures ont port´e sur le vocabulaire du LCQ-MC. Il n’y a pas eu d’autres difficult´es au cours du processus de traduction,

tous les items s’´etant ais´ement adapt´es a` du chinois mandarin acceptable. Par contre, le plan du contenu et l’ordre des questions n’ont pas e´ t´e modifi´es. Lors des entretiens cognitifs de d´ebriefing, les participants ont affirm´e que le questionnaire e´ tait acceptable, pertinent, complet et facile a` remplir. Le LCQ-MC a d´emontr´e une bonne validit´e concurrente, une bonne coh´erence interne et une fiabilit´e d’un test a` l’autre. La r´eactivit´e a e´ t´e d´emontr´ee par des modifications significatives des scores du LCQ-MC entre les rendez-vous r´eguliers, la premi`ere exacerbation et la consultation suivant 2 semaines de traitement antibiotique (les deux modifications, P , 0,01) C O N C L U S I O N : Le LCQ-MC est un instrument valide, fiable et r´eactif pour d´eterminer l’´etat de sant´e en mati`ere de toux chez les patients chinois atteints de bronchectasies. RESUMEN

El cuestionario de Leicester (LCQ) sobre la tos se ha validado para evaluar el estado de salud, espec´ıficamente con relacion ´ a la tos, en los casos de bronquiectasias. El cuestionario se tradujo al chino mandar´ın y se investigo´ su validez, fiabilidad y sensibilidad. M E´ T O D O S: El LCQ se tradujo al chino mandar´ın mediante un procedimiento de traducci on ´ y retrotraduccion. ´ Ciento cuarenta y cuatro pacientes ambulatorios completaron la version ´ en mandar´ın del LCQ (LCQ-MC), la escala hospitalaria de ansiedad y depresion ´ y el cuestionario respiratorio Saint George. La evaluacion ´ se repitio´ durante las exacerbaciones y a los 6 meses. Se determino´ la validez convergente, la concordancia interna, la reproducibilidad y la sensibilidad del cuestionario. R E S U L T A D O S: A la formulaci on ´ del LCQ-MC se introdujeron adaptaciones culturales menores. No se observaron otras dificultades durante la traduccion ´ y M A R C O D E R E F E R E N C I A:

todos los elementos se adaptaron sin problema en una versi on ´ aceptable en chino mandar´ın. Este procedimiento no modific o´ la disposici on ´ del contenido ni el orden de las preguntas del cuestionario. En entrevistas cognitivas de ana´lisis, los participantes afirmaron que el cuestionario era aceptable, pertinente, exhaustivo y fa´cil de completar. El LCQ-MC ofrecio´ validez convergente, concordancia interna adecuada y fiabilidad al repetir la prueba. La sensibilidad del LCQMC se puso en evidencia con las modificaciones significativas de puntuacion ´ que se obtuvieron del estado basal, a la primera exacerbacion ´ y despu´es de 2 semanas de tratamiento antibiotico ´ (P , 0,01 para los cambios en ambos intervalos). ´ N: El LCQ-MC representa un instrumento CONCLUSIO va´lido, fiable y sensible para determinar el estado de salud con relacion ´ a la tos en los pacientes chinos que presentan bronquiectasias.

Validation of the Mandarin Chinese version of the Leicester Cough Questionnaire in bronchiectasis.

The Leicester Cough Questionnaire (LCQ) has been validated for assessing cough-specific health status in bronchiectasis. We translated the LCQ into Ma...
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