The study was conducted according to the provisions of Good Clinical Practice, local laws, EU-Directive 2001/20, and the International Conference on Harmonization and the World Medical Association Declaration of Helsinki guidelines. Prior its initiation, study protocol and all relevant documentation was submitted to and approved by the Institutional Review Board/ Ethics Committees of the following institutions: “Agios Savvas” General Oncology Hospital of Athens, “Sotiria” General Hospital of Thorax Diseases of Athens, “Metropolitan” Hospital of Athens, “Attikon” University General Hospital of Athens, University General Hospital of Heraklion, “Evangelismos” University General Hospital of Athens, “G. Papanikolaou” General Hospital of Thessaloniki, “Euromedica” Hospital of Thessaloniki, University General Hospital of Ioannina and University General Hospital of Larisa. Given the sensitive nature of data processed in the frame of the study, all parties involved undertook adequate safety measures (physical, logical, organisational, technical, etc.) to warrant that data would always be processed safely and in compliance with the EU Data Privacy Directive 95/46/EC.
Patients needed to fulfil all of the following criteria for being included into the study: (1) have an age ≥ 40 years, (2) established or new diagnosis of COPD, (3) do not undergo any exacerbations treatment neither at baseline visit nor in the previous month (i.e., have a stable COPD), (4) be able and willing to give informed consent and comply with study procedures. Male and female patients were recruited. Patients were excluded from the study if: (1) undergoing pregnancy or lactation (in case of female subjects), (2) they had a previous diagnosis of asthma, sleep apnea syndrome, other chronic respiratory disease other than COPD, or were classified as asthma-COPD overlapping patients (3) they had any acute or chronic condition that would limit the patient’s ability to complete questionnaires or participate in the study, or (4) they were participating in another study. Subjects were able to withdraw from the study at any time without explanation, without losing the right to medical care.
The primary objectives of the study were to (1) record the stage of COPD patients according to GOLD 2017 and (2) record the treatment of COPD patients in relation to COPD stage in Greece and to correlate the data with GOLD 2017 suggestions. Secondary objectives of the study were to (3) describe the patients’ characteristics in relation to GOLD categories, (4) determine the comorbidities of the patients, treated or not, (5) record COPD exacerbations during the last year, (6) record information related to vaccination habits of that population, and (7) evaluate the compliance to the recommended treatment.
Study structure and workflow
This was a cross-sectional observational study. Fifteen hospitals and 340 private practice respiratory physicians collaborated for this project across the Greek state; within a period of 5 months (March–August 2017), each investigator was scheduled to record sequentially 10 COPD patients, and each healthcare site was scheduled to record sequentially 20 COPD patients. The predefined standardised workflow of the study included the following steps: (1) recruitment of sequentially presenting patients with COPD diagnosed by a pulmonologist and stable disease at the time of enrollment (see inclusion criteria), (2) signing and dating of the informed consent form by the patient, (3) implementation of the complete initial medical examination and completion of the rest of the standardised case report form of the study, including (4) documentation of compliance to the treatment for COPD, by reporting how many doses they miss on average on a weekly basis (independent of the current study, which was not an interventional study), (5) end of recruitment, (6) data anonymisation, storing and locking, (7) data processing and statistical analysis respecting data integrity and safety (Additional file 1: Figure S1).
Demographics participants were registering their age (in years), gender (male, female), height (in cm) and weight (in kg).
Vital sign measurements investigators were recording the diastolic and systolic blood pressure of the subjects (in mmHg) as well as their heart rate (beats per minute) and respiratory rate (breaths per minute.)
Medical history related to COPD participants were asked to provide the following pieces of information: (1) date of initial COPD diagnosis (otherwise unknown), (2) current COPD treatment (multiple choice among thirteen categories; short-acting β adrenoreceptor agonists/SABA, long-acting β adrenoreceptor agonists/LABA, short-acting muscarinic receptor antagonists/SAMA, long-acting muscarinic receptor antagonists/LAMA, methylxanthines, inhaled corticosteroids/ICS, oral glucocorticoids, phosphodiesterase-4 (PDE4) inhibitors, antibiotics, antioxidants, mucolytic agents, combination of LAMA + LABA, combination of LABA + ICS), date of initiation and frequency of missing doses (never, once monthly, twice monthly, once weekly, twice weekly) per pharmacological category, (3) number of COPD exacerbations during the last 12 months and number of them having led to the emergency department or having required hospitalization.
Comorbidities participants were asked to provide information on any comorbidities, indicate the date of diagnosis and whether they receive any concomitant medication.
Vaccination data participants were asked to confirm whether they were vaccinated for influenza (during the running year) and/or pneumococcus.
Spirometric assessment of pulmonary function available data of the most recent pre- and post-bronchodilation spirometry according to common clinical practice were utilised [forced expiratory volume in 1s (FEV1) (in L and % predicted) and the FEV1 to forced vital capacity (FEV1/FVC) ratio]. No date-limit was set; 60.8% of subjects underwent spirometry on the date of recruitment, 2.8% underwent spirometry after that date, 33.8% provided data up to 1 year old, and 2.6% provided data older than that. Finally, subjects were kindly requested to complete the CAT. CAT consists of 8 items, each of which describes the best to worst case of a state on a 0–5 scale (for instance, for the state “coughing” the best case is “I never cough”, corresponding to 0, and the worst case is “I cough all the time”, corresponding to 5. Values 2–4 represent intermediate cases between the two extremes). CAT score comprises the sum of scale values for all 8 items, thus ranges from 0 to 40.
After checking the collected data for completeness, they were double entered into Epi-data version 3.1 and exported into SPSS version 21 for analysis. In this study sample, any missing values were not replaced by others and the calculations were based on the number of cases for which there is information. The data were processed by using descriptive analysis, including frequency distribution, cross tabulation, and summary measures.
For the comparison of quantitative characteristics with normal distribution of values between the different groups that will be compared, t-test was used for independent test observations pairs or analysis of variance, if comparisons took place between more than 3 groups or multiple categorical factors existed. Two-tailed tests were performed for all analyses, and P was set to 0.05. All results shown in the corresponding tables and figures are mean ± standard deviation (SD). Bonferroni correction has been applied to account for multiple comparisons.