Background
Chronic obstructive pulmonary disease (COPD) is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities usually caused by significant exposure to noxious particles or gases [
1]. Despite being a common, preventable, and treatable disease [
1], COPD is the fifth leading cause of death in China [
2]. The prevalence of COPD varies among geographic regions of China between 5 and 13% [
3], with a reported prevalence of 8.2% among people aged ≥40 years [
4].
The Chinese Thoracic Society recommends [
5] that physicians follow Global Initiative for Chronic Obstructive Lung Disease (GOLD) [
6] and national guidelines [
5], yet adherence to guidelines among Chinese physicians is low [
7]. Knowledge of COPD among Chinese physicians, including respiratory specialists, can be poor [
8]. For instance, almost a quarter (22.1%) of respiratory physicians surveyed did not consider smoking to be the most significant risk factor for the development of COPD [
8]. Furthermore, despite several large studies conducted over the last 10 years implicating biomass fuel as an important risk factor among Chinese patients with COPD [
4,
9,
10], only 20.8% of respiratory physicians surveyed believe biomass fuel plays a critical role [
8].
An observational study of respiratory diseases in the Asia-Pacific region included 210 patients with COPD from Taiwan but did not include patients from mainland China [
11,
12]. Of these Taiwanese patients, the mean age was 71 and most (85.2%) were retired, there was a high proportion (78.6%) of “ever smokers”, but only 18.8% were current smokers [
12]. Medication use was high (91.9%) in the preceding 4 weeks with mucolytics (44.8%) and methylxanthines (43.3%), the most frequently prescribed therapy, and direct medical costs were high (82.8% of direct costs) [
12]. A recent study revealed that just over a quarter (26%) of newly diagnosed COPD patients surveyed in four major Chinese cities did not use any pharmacological treatment [
13].
Many patients with COPD remain undiagnosed in China [
4]. Raising awareness of COPD is the first step to improving rates of diagnosis, yet large-scale studies of real-world outcomes, exacerbation rates, and disease severity of COPD patients in China are lacking. Furthermore, there is a paucity of data derived from large Chinese cohorts regarding COPD maintenance and exacerbation treatment patterns, non-pharmacological management and risk factors for exacerbations, disease severity, and adherence.
The REALizing and improving management of stable COPD in China (REAL) trial aims to provide reliable information on COPD management, outcomes, and risk factors in China. Here we describe the rationale and design of this 52-week multi-center, prospective, observational study (NCT03131362, registered on 20 March 2017; protocol version 1.0, 9 July 2016). The primary objective is to evaluate COPD patient outcomes (including exacerbations) following 1 year of current clinical practice. Secondary objectives are to assess disease severity, treatment patterns, adherence to medication, and investigate associated risk factors. Clinical assessments will include spirometry, bronchial dilation and induced sputum tests, fractional exhaled nitric oxide (FENO), and chest computed tomography (CT) imaging. Patient reported outcomes will include the COPD Assessment Test (CAT) [
14], modified Medical Research Council (mMRC) questionnaire [
15] and COPD knowledge questionnaire (COPD-Q) [
16]. Data on medication type, adherence, non-drug therapies, and total COPD treatment costs will also be collected.
Discussion
In China, many clinicians and patients have a low level of knowledge of the management, prevention, and risk factors for COPD [
7,
20,
21]. This represents a growing problem as COPD mortality and disease burden are predicted to increase worldwide over the coming years [
22]. The high occurrence of COPD in China may be due to greater exposure to risk factors, such as smoking [
23] and biomass fuel [
9]; however, other factors may be revealed to be important by the REAL study.
Despite the endorsement of GOLD recommendations by the Chinese Thoracic Society [
5], there have been concerns raised as to whether they are appropriate or feasible for use in Chinese clinics [
24]. With respect to diagnosis and classification of disease severity, one problem is the lack or incorrect use of spirometry testing [
24]. Studies have shown that in tertiary hospitals only 50% of patients with COPD have undergone spirometry testing, in primary and secondary hospitals the proportion was as low as 18% [
25], and in some rural areas spirometry testing is not conducted at all [
26]. Nevertheless, when spirometry testing is carried out, the prognostic validity of GOLD 2011 [
6] criteria – that differ only slightly from GOLD 2016 criteria which also take into account hospitalization for exacerbations – has been demonstrated in Asian patients with COPD [
27].
Dyspnea is characteristic of COPD but it is now accepted as only one of several symptoms that affect patients, and comprehensive assessments are required to give a full picture of disease burden [
28]. As commentators have noted, high patient volumes and staff shortages in Chinese clinical practice mean that simple methods of assessment are preferred and often judged to be the best [
24]. The REAL study has opted to use the mMRC [
15] and the CAT [
14] to assess the level of health status impairment. The mMRC provides a simple yet reliable way to categorize the levels of disability due to breathlessness experienced by patients with COPD [
29]. The CAT is an 8-item measure of health status impairment in COPD, in which questions are scored from 0 to 5 [
14]. The CAT has been used in many trials [
30], it shows good agreement with the more complex and time consuming St George’s Respiratory Questionnaire (SGRQ) [
31,
32], and in a large study of Chinese patients it correlated moderately with the mMRC dyspnea score [
33]. The COPD-Q [
16] is a reliable tool that can be used to test disease knowledge among with patients with limited health literacy [
34]. As the questionnaire is composed of only 13 simple questions with “true or false” answers, the COPD-Q can be easily translated into other languages [
35].
The majority of recent studies of health-related costs among Chinese patients with COPD have focused on specific interventions such as mechanical intervention [
36], vaccination [
37], or specific risk factor such as pollutants [
38,
39]. One study conducted in 2011 in four Chinese cities among 678 patients with COPD found that poorer quality of life as determined by the EuroQol-5 dimensions (EQ-5D) health questionnaire was significantly linked to increased medical costs [
40]. A further analysis of this cohort showed the mean annual direct medical (DMC), direct non-medical (DNMC), and indirect (IC) costs per COPD patient were 11,968 yuan (US$ 1853), 539 yuan (US$ 83), and 2087 yuan (US$ 323), respectively, with over half (56.7%) of total costs due to hospitalization [
41]. While these data are somewhat dated, they do offer some degree of insight into the high cost burden of COPD in China and will be interesting to compare with the results from the larger REAL cohort.
The Adelphi respiratory disease-specific program (DSP) utilized surveys conducted in 2010 in China (
N = 511) and 2013 in Europe (
N = 1242) and the United States (
N = 413) to provide information on pharmacological management of COPD [
42]. In the Chinese sample, the most prescribed maintenance treatment was inhaled corticosteroid/long-acting β
2-agonist (ICS/LABA) dual therapy (25.9%), followed by ICS/LABA plus xanthines (20.2%), other (unspecified) therapies (16.5%), xanthines only (11.2%), and ICS/LABA plus leukotriene receptor antagonist (LTRA) (10.6%) [
42]. The level of ICS/LABA use was comparable to that of the American cohort (25.9%) and higher than that of the European cohort (15.7%); however, less than 1% of the American and European patients used ICS/LABA plus xanthines, xanthines only, or ICS/LABA plus LTRA, with 4.4 and 5.6% using ‘other’ treatments, respectively [
42]. The high use of ‘other’ therapies among the Chinese patients may, in part, be attributable to the high rate of non-prescription medicine use that has been observed [
43]. The most common maintenance therapy among American and European patients was triple therapy (long-acting muscarinic antagonist [LAMA] plus ICS/LABA or LAMA plus ICS plus LABA) in 33.2 and 33.1% of patients, respectively, but only 1.6% of Chinese patients reported triple therapy use [
42]. Triple therapy is recommended by GOLD for group D patients (high symptom burden and high exacerbation risk) [
1]. The Adelphi respiratory DSP survey in China was carried out in 2010 [
42], before the endorsement of the GOLD guidelines by the Chinese Thoracic Society in 2013 [
5]. The REAL study will be the first major investigation of treatment patterns since the introduction of the new guidelines; however, as adherence to guidelines among Chinese physicians is low [
6], it remains to be seen what level of impact this will have.
One strength of the REAL study is the 52-week duration and large sample size which, to our knowledge, is unprecedented among prospective observational studies of COPD conducted in mainland China to date. A steering committee of respiratory experts (TY, BCai, BCao, JK, FW, JZ, XL, and CW) was consulted on protocol design and data collection, and will oversee operational aspects of the study. Multi-stage random sampling and selection of sites will ensure study participants are representative of the six regions. Over half of exacerbations may be unreported [
44], so the use of investigator-led telephone follow-ups during the REAL study may prompt participants to provide a more complete picture of the pattern of their exacerbations. Potential limitations include the fact that since patients will be enrolled only from secondary and tertiary hospitals, the sample may not be representative of Chinese COPD patients as a whole. Patients from secondary and tertiary hospitals are less likely to be lost to follow-up over the course of the trial than patients in primary care. However, as with any observational study, withdrawal of patients and missing data may introduce bias and there may be further unidentified or unmeasured confounding variables.
In conclusion, the REAL study should help to provide reliable information on COPD management, outcomes, and risk factors that may help improve the standard of care in China.
Trial status
ClinicalTrials.gov identifier: NCT03131362. Registered on 20 March 2017; protocol version 1.0, 9 July 2016. The first patients were recruited to REAL on 30 June 2017 and the estimated primary completion date is 31 January 2020.
Ethics approval and consent to participate
The Ethics Committee of the China-Japan Friendship Hospital, the leading site, approved the study protocol and informed consent form (ICF) prior to study initiation (approval number 2016–97). All patients participating in this study voluntarily signed the ICF and received a copy of the ICF before study initiation.
Ethics approval was also gained from all other sites involved in the study, including: the Chinese Academy of Medical Sciences & Peking Union Medical College Hospital Ethics Committee (B193), the Peking University Third Hospital Medical Science Research Ethics Committee (D2016071), the First Affiliated Hospital of China Medical University Medical Science Research Ethics Committee (2017–127), the First Affiliated Hospital of Guangzhou Medical College Science Project Review Ethics Committee (2016–71), the Sichuan University West China Hospital Biology Medical Ethics Committee (2016–303), the Ethics Committee Of The Fourth Affiliated Hospital Of China Medical University (EC-2017-KS-038), the First Hospital Of Qiqihar – Clinical Trials Ethics Committee (2017–004), The Beijing Chao-Yang Hospital/Capital Medical University Ethics Committee (2017-8-7-2), the Tangshan People’s Hospital Drug Clinical Trials Ethics Committee (2017–001), the Beijing Huairou Hospital Medical Ethics Committee (2017-NA; site did not participate in the study), the Beijing Mentougou District Hospital Ethics Committee (NA), the Hospital of Yutian County Ethics Committee (NA), the Shanghai Jiaotong University School of Medicine/Renji Hospital Ethics Committee (2017–044), the Hangzhou Red Cross Hospital Clinical Study Ethics Committee (2017–02), the Shanghai Tongji Hospital Ethics Committee (Tong - 398), the Shanghai Yangpu District Central Hospital Ethics Committee (LL-2017-DZX-010), the Tongxiang First People’s Hospital Ethics Committee (NA), the Quzhou People’s Hospital Drug Clinical Trials Ethics Committee (2017-1-1), the Central Hospital of Minhang District/Shanghai Ethics Committee (2017–2), the Tonglu First People’s Hospital Medical Ethics Committee (2017–1; site did not participate in the study), the Shanghai Pudong Gongli Hospital Ethics Committee (20I7-0I-004-FOI), the Shanghai Pudong District People’s Hospital Drug Clinical Trials Ethics Committee (2017–002), the Hospital of Haiyan County Medical Ethics Committee (2017–1), the First People’s Hospital of Chunan County Ethics Committee (2017–1), the People’s Hospital of Changshan County Medical Ethics Committee (NA), the First Affiliated Hospital of Xinjinag Medical University Medical Ethics Committee (2017–0605-01), the Baoji Central Hospital Drug Clinical Trials Ethics Committee (2017–03), the Shaanxi Sengong Hospital Biology Medical Ethics Committee (2017–1), the Hospital of Qishan County Medical Ethics Committee (2017–1), the Second People’s Hospital of Yibin National Drug Clinical Trials Ethics Committee (2017–005-01), the Chengdu Fifth People’s Hospital Ethics Committee (2017-01-01), the Chengdu Pidu District People’s Hospital Medical Ethics Committee (2017–07), the People’s Hospital of Pengan County Ethics Committee (2017–002), the Sichuan Forestry Central Hospital Medical Ethics Committee (2017–001), the First People’s Hospital of Foshan Ethics Committee (2017–1), the Third Affiliated Hospital of Zhongshan Medical University Clinical Medical Research Ethics Committee (2017–2-165), the Second Hospital/University of South China Drug Clinical Trials Ethics Committee (201704–06), the Medical Ethics Committee of Xiangya Hospital Central South University (201708101), the Guangzhou Baiyun District People’s Hospital Ethics Committee (2017–1), the Wuhan Red Cross Hospital Biology Medical Ethics Committee (2017–1), the Guangzhou Panyu District Ho Hsien Memorial Hospital Ethics Committee (NA), the Luoyang New District People’s Hospital Ethics Committee (NA), the Yueyang Yuehua Hospital Ethics Committee (2017–01), the Shengjing Hospital Dalian Hospital of China Medical University Ethics Committee (2017–1), the People’s Hospital of Qinlai County Medical Ethics Committee (2017–01), the Liaoning Electric Power Hospital Medical Ethics Committee (2017–01), the Changchun Second Hospital Ethics Committee (2017–01), the Longkou People’s Hospital Ethics Committee (NA), the Xuzhou Mine Hospital Ethics Committee (2018–01), Independent Ethics Committee for Clinical Research of Zhongda Hospital/Affiliated to Southeast University (2017ZDSYLL021-YOI; site did not participate in the study), the 180th Hospital of PLA Medical Ethics Committee (2017–1; site did not participate in the study), and the General Hospital of Shenyang Military Medical Ethics Committee (2017–18; site did not participate in the study).
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