High burden of symptoms reported among patients diagnosed with chronic obstructive pulmonary disease (COPD) in Greenland after introducing the COPD Assessment Test in clinical practice

ABSTRACT

The aim was to test the internal consistency of the Greenlandic version of the COPD Assessment Test (CAT) questionnaire and to estimate the symptom burden in patients with chronic obstructive pulmonary disease (COPD) in Greenland using the CAT questionnaire. A Greenlandic version of the CAT questionnaire was developed including forward translation, reconciliation, backwards translation, and pilot test. Afterwards, a cross-sectional study of patients with COPD was conducted. The internal consistency assessed by the Cronbach α coefficient was 0.823 for the Greenlandic version of the questionnaire (n = 103). The CAT was negatively correlated to spirometry values and current smoking. In the cross-sectional study (n = 250), 81.1% of the patients experienced a high symptom burden (≥10). The main CAT score was 17 (range 0–38). The CAT was used in 9 out of 17 towns in Greenland. The Greenlandic version of the CAT questionnaire demonstrated a good internal consistency. We observed a high burden of symptoms associated with reduced lung function and active smoking status among patient diagnosed with COPD in Greenland. The questionnaire can be used in clinical practice for assessment of symptom burden in patients with COPD in Greenland and may help to increase focus on symptom control and quality of care.

KEYWORDS:

• Chronic obstructive pulmonary disease
• symptom burden
• CAT questionnaire
• COPD assessment test
• COPD

Introduction

Chronic obstructive pulmonary disease (COPD) is the third largest cause of death worldwide [1]. Globally, the burden of COPD is expected to increase in the next decades due to the continued exposure to risk factors of COPD and an ageing population [2]. In Greenland, more than 50% of the population are daily smokers [3], why it is expected that more people will be diagnosed with COPD in the future. Yet, the prevalence of diagnosed COPD in Greenland has been reported low [4]. At 31 December 2019 only 152 individuals aged between 20 and 79 years were diagnosed with COPD in Greenland [5]. The number of diagnosed individuals has increased to 839 on 19 October 2022 [6]. The increase was observed as a result of increased focus on the detection of new cases in the wake of the launching of Steno Diabetes Center Greenland (SDCG) in June 2020 as described by Brix et al [6]. Thus, SDCG aims to increase quality of management and care of diabetes, hypertension, and COPD in Greenland. However, the prevalence of diagnosed COPD is still low and the quality of care suboptimal [6]. This indicates an increased focus on the management of COPD.

COPD is a chronic disease, which reduces the capacity of breathing progressively [7]. Furthermore, the disease affects the patient’s ability to perform everyday-life activities and thereby affect the patient’s health status and health-related quality of life [8]. Symptoms of COPD include breathlessness, cough, wheeze, sputum production, and chest tightness [9] and individuals with COPD often experience a high symptom burden [10,11]. Symptom burden is important when measuring the impact of chronic disease and is a vital goal in the management of COPD [12].

Different COPD-specific questionnaires measuring symptom burden like the Respiratory Disease Questionnaire (CRQ) and St. Georges Respiratory Questionnaire (SGRQ) have been developed in an effort to find a reliable and easy questionnaire to use in clinical practice [13–17]. However, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommend the COPD assessment test (CAT), since it covers the impact of COPD on wellbeing broadly [8]. The CAT questionnaire was developed as a shorter form (8 items) of the SGRQ and is considered as a reliable and valid tool [18]. The CAT questionnaire is completed by patients in clinical practice and covers the following areas: cough, sputum production, chest tightness, breathlessness going up a stair/hill, activity limitation at home, confidence in leaving home, sleep, and energy [17]. Patients are asked to grade their response in each item using a semantic 6-point scale. The overall score of the CAT questionnaire was 0–40 points. A score higher than 30 points indicates a very high impact of the disease, between 20 and 30 points indicates a high impact, between 10 and 20 points a medium impact and a score under 10 points indicates a mild impact [19]. The CAT questionnaire was developed in English and has been translated to more than 100 languages [19]. Yet, no Greenlandic version of the CAT questionnaire has been developed.

In Greenland, from a clinician’s perspective, there is a need of a reliable and validated tool to implement in clinical practice to improve communication between the health care provider and the patient.

The aim of this study was to test the internal consistency of the Greenlandic version of the CAT questionnaire and to estimate the symptom burden of patients with COPD in Greenland using the CAT questionnaire.

Materials and methods

Study design

Completed Greenlandic versions of the CAT questionnaires were collected from March to September 2022. Furthermore, a cross-sectional study was carried out based on data extracted from the Greenlandic electronic medical record (EMR) on 14 December 2022.

Setting

Greenland, the largest island in the world, is located in the arctic region and covers 2 million km² [20]. The population consists of 56.500 inhabitants spread along the coastline in towns and small settlements. The health care system is divided into five health care regions, with a regional hospital placed in the largest town in each health care region [21]. The remaining towns and small settlements have healthcare centres and smaller healthcare units [21]. Lifestyle outpatient clinics or lifestyle outpatient clinic functions are placed at the regional hospitals and healthcare centres and are responsible for the treatment of COPD. The specialised treatment of COPD is placed physically in the capital Nuuk. Using telemedicine, it is possible to get the specialised treatment completely out in the other towns and small settlements [22]. Medication, hospital treatment and the health care service in general, are free of charge for permanent residents in Greenland [21].

Study population and variables

All patients diagnosed with COPD who visited SDCG in Nuuk or at a lifestyle clinic in the remaining parts of Greenland from March to December 2022 for a physical appointment (a COPD status) were asked to complete the CAT questionnaire as a part of their clinical appointment in either Greenlandic or Danish. The overall scores of the questionnaires were registered in the lifestyle table in the EMR. For those patients who completed the Greenlandic version of the questionnaires (n = 103) all scores from each item of the questionnaire were registered in the EMR, to be able to calculate Chronbach’s Alpha.

To investigate the symptom burden on patients diagnosed with COPD, we extracted data from the EMR by the 14^th of December 2022 on patients diagnosed with the medical diagnosis code for COPD; R95 according to International Classification of Primary Care version 2 (ICPC-2) [23,24] or diagnosis code; DJ440, DJ441 or DJ449 according to International Classification of Disease version 10 (ICD10) [25] and a registered CAT-score.

Furthermore, we extracted information on age, town, sex, height, weight, BMI, smoking status, last registered CAT-score, and last registered spirometry from the EMR. The last registered CAT-score and the last registered spirometry were performed simultaneously at the same day. Height was measured excluding shoes and weight was measured excluding shoes and outerwear. Spirometry was performed using EasyOne Air [26]. Data on spirometry included forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and the FEV1/FVC ratio. Furthermore, we included data on expected FEV1%) and expected FVC (%) based on European ethnicity as reference. The best post-bronchodilator values were added to the EMR.

Translation procedure of the CAT questionnaire

Greenlandic is an Inuit language and is similar to other native languages spoken by indigenous people in Northern Alaska and Canada [27]. A Greenlandic version of the CAT questionnaire was developed in accordance with the Linguistic Validation Guidance of a Clinical Outcome Assessment (COA) by MAPI Group [28]. The English version of the questionnaire was forward translated into two Greenlandic versions by two professional, native Greenlandic speaking interpreters who also where bilingual in English. Afterwards, a working group consisting of native speaking Greenlandic nurses, a local interpreter and the first author discussed the translations and agreed on a reconciled version. For backward translation, the reconciled version was translated into English by two professional interpreters who were bilingual in Greenlandic and English. The interpreters did not have any access or knowledge about the original version of the CAT questionnaire. After the translation, the working group met to discuss the translation. The English translation of item number 3 was discussed, and the group decided to rephrase both sentences in the Greenlandic version of the questionnaire.

A native-speaking Greenlandic pulmonologist read the Greenlandic version and gave inputs to minor improvements of the questionnaire. As an example, the statement “I never cough” – in Greenlandic: “Quersorneq ajorpunga” was modified to “Quersunngisaannarpunga”. Afterwards The Language Secretariat of Greenland read the modified Greenlandic version and suggested minor improvements. The working group discussed inputs from the pulmonologist and The Language Secretariat of Greenland and all parts agreed on an interim Greenlandic version.

Pilot test

The interim Greenlandic version of the CAT questionnaire was pilot-tested on 10 native Greenlandic speaking patients with COPD. Clinicians supervised the completion of the questionnaire by the patients and asked questions to ensure that the Greenlandic version of the questionnaire was acceptable and understandable. The final step in the translation process was external proofreading of the final version (see appendix 1) by a professional Greenlandic translator. Ten patients (five men and five women) with COPD and who were fluent in Greenlandic participated in the pilot test. All patients understood all items in the questionnaire and the pilot test did not result in further modifications of the questionnaire. MAPI Group approved the final Greenlandic version of the CAT.

Implementation of the CAT questionnaire

The implementation of the CAT in clinical practice was initiated in Nuuk in March 2022. In the following months, health care providers working at the lifestyle outpatient clinics in the remaining parts of Greenland were trained in the use of the CAT questionnaire. The patients fulfilled the CAT questionnaire as a part of their clinical appointment regarding their COPD.

The CAT questionnaire was used in nine different clinical practices in Greenland, but primarily in Nuuk (see Figure 1).

Figure 1. Map illustrating the places where the CAT has been used.

Statistical analysis

CAT scores and other normally distributed parameters were described using means and standard deviation (SD) and were compared using t-tests. Check for normal distribution was performed using QQ-plots.

The internal consistency of the Greenlandic version of the CAT questionnaire was examined using Cronbach’s alpha coefficient. A coefficient above 0.70 was considered as acceptable.

A p-value below 0.05 was considered to be statistically significant. All analyses were carried out in R version 4.1.2.

Correlation analysis between CAT score and other parameters was performed using Pearson Correlation Coefficient.

Ethics

The study fulfils the Helsinki Declaration II and was approved by the Ethics Committee for Scientific Research in Greenland (reference no. 2022–4). Permission to review data from the EMR was given by the Agency for Health and Prevention in Greenland.

Results

Internal consistency of the Greenlandic CAT

In total, 103 patients answered the Greenlandic version of the CAT questionnaire with a mean age of 63 years (43–80 years). Of them, 67.0% were women and 33.0% were men. Their overall CAT score ranged from 1 to 35. The internal consistency of the CAT was high (Chronbach’s Alpha = 0.823 (95% CI: 0.769–0.866)).

Symptom burden in patients with COPD in Greenland

In total, 250 patients (130 men and 120 women) from Nuuk and eight other places of residence with a mean age of 63 years completed the CAT questionnaire in either Greenlandic (n = 103 from above) or Danish (n = 147) from March to December 2022. Mean CAT score was 17 (range 0–38). 65.2% (CI: 59.30–71.10) of the patients were daily smokers (data not shown). Characteristics of the participants are summarised in Table 1. As expected, men had a higher FEV1 and FVC compared to women, however women had higher FEV1/FVC-ratio compared to men, 64% vs. 58% (p = <0.001). Figure 2 shows a frequency distribution histogram of total CAT scores. The number of individuals with a CAT score of 10 or greater than 10 was 201 (81.1%). CAT scores were negatively correlated with lung function (Table 1, Figure 3 and 4). The correlation coefficient between CAT score and FEV1 (L) was −0.200 (p = 0.002), between CAT score and FEV1%) −0.220 (p = <0.001), between CAT score and FVC (L) −0.130 (p = 0.041), between CAT score and FVC (%) −0.150 (p = 0.018), and between CAT score and FEV1/FVC (%) −0.170 (p = 0.008).

Figure 2. Frequency distribution histogram of CAT score (n = 250).

Figure 3. Scatter plot of the correlation between the CAT score and FEV1/FVC (n = 250).

Figure 4. Scatter plot of the correlation between the CAT score and FEV1% of expected (n = 250).

Table 1. Basic characteristics of patients with COPD with a registered CAT-score.

	Men		Women			Total		Correlation coefficient (R) with CAT-score
	N	Mean (SD)	N	Mean (SD)	p	N	Mean (SD)	R	p
Age (years)	130	64 (7.4)	120	62 (8.4)	0.016	250	63 (8.0)	−0.085	0.180
Weight (kilo)	130	81 (21.1)	120	67 (17.3)	<0.001	250	74 (20.6)	−0.200	0.002
Height (cm)	130	172 (8.5)	120	156 (7.1)	<0.001	250	164 (11.2)	−0.046	0.470
BMI (kg/m^2)	130	27 (6.8)	120	27 (6.5)	0.989	250	27 (6.6)	−0.210	0.001
CAT score	130	16 (7.9)	120	17 (8.1)	0.410	250	17 (8.0)	-	-
FEV1 (L)	130	2.2 (0.8)	120	1.6 (0.5)	<0.001	250	1.9 (0.7)	−0.200	0.002
FEV1%)	130	67 (22.3)	120	69 (18.9)	0.301	250	68 (20.7)	−0.220	<0.001
FVC (L)	130	3.6 (1.0)	120	2.5 (0.6)	<0.001	250	3.1 (1.0)	−0.130	0.041
FVC (%)	130	86 (21.6)	120	84 (17.3)	0.463	250	85 (19.6)	−0.150	0.018
FEV1/FVC-ratio (%)	130	58 (11.0)	120	64 (10.7)	<0.001	250	61 (11.3)	−0.170	0.008

N = number of patients, SD = standard deviation, P = p-values.

P values below 0.05 are in bold.

Furthermore, smokers had a significantly higher CAT score compared to non-smokers, 17.6 vs. 14.7, (p = 0.07). We did not observe any difference in CAT score between men and women.

Discussion

This study shows a high symptom burden since 81.1% of the patients had a CAT-score above 10.

Furthermore, this study shows that the newly developed official Greenlandic version of the CAT questionnaire has good internal strength and can be used both in Nuuk and a number of smaller towns on the coast in Greenland. Within just 8 months it was used on 250 patients with COPD (28% of all patients with COPD in Greenland) and used in 9 out of 17 towns.

A Chronbach’s Alpha coefficient at 0.823 was observed in our study, which is above the acceptable of 0.70, indicating a good correlation between items. The result in our study is comparable to findings in other studies from Europe [17,29,30]. The first validation study of the CAT questionnaire showed an excellent internal validity with Chronbach’s Alpha Coefficient at 0.880 [17]. In a study from Iran testing the Iran version of the CAT questionnaire, Chronbach’s Alpha Coefficient was calculated to be 0.732 [29] and in a study from Serbia testing the Serbian version of the CAT questionnaire found a Chronbach’s Alpha Coefficient at 0.880 [30].

The mean CAT score in our study was 17, demonstrating that the patients with COPD in our study are experiencing many symptoms in their everyday life. The impact level of the patients in our study was similar to the findings reported in other studies [17,29–31]. In the first validation study of the CAT questionnaire they measured mean CAT scores from six different countries (mean CAT score); Belgium (21.5), France (18.5), Germany (18.2), The Netherlands (16.0), Spain (16.4) and USA (17.8) [17]. The study testing the Iran version of the CAT questionnaire showed a mean CAT score at 24.87 [29] while the study testing the Serbian version of the CAT questionnaire found a mean CAT score at 19.5 [30]. The mean CAT score of the Arabic version of the CAT questionnaire among 808 individuals was measured to be 16.16 and the mean CAT score of the Turkish version was measured among 229 individuals to be 20.90 [31]. Mean CAT score was generally higher in Saudi Arabia, Lebanon, and Egypt and lower in the North African countries [31]. A study from United Kingdom investigating 224 individuals found a mean CAT score at 23.1 [32]. These results suggest that the majority of patients with COPD experience a high symptom burden of their disease.

In our study, 81.1% of the study population had a CAT score ≥ 10 indicating a good opportunity for improvement of symptom burden among people with COPD in Greenland. In this study, a high CAT score was correlated to active smoking. This is in line with the international trend. Thus, a higher symptom burden among smokers compared to non-smokers was also found in Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria and United Arab Emirates [31]. The study from United Kingdom did not observe any difference in mean CAT score between smokers (23.8) and non-smokers (22.9) [32].

In our study population, 65.2% were daily smokers, which is more than the general population in Greenland, where around half of the population are daily smokers [3,33]. This underlines the need for an increased focus on smoking cessation among COPD patients in Greenland and in the general population. Backe & Pedersen investigated the effect of a diabetes initiative in Greenland, and found a significant decrease in the prevalence of smokers among people with diabetes following the initiative [34].

In our study, we observed significant, although weak, correlations between the CAT score and spirometry measurements. The same tendency has been reported in other studies comparing CAT scores with pulmonary function values [35–41]. This might represent an inconsistency between patient reported outcome measurements and the degree of respiratory dysfunction. Furthermore, the results indicates, that the individual’s spirometry values does not necessarily determine the individuals symptom burden of the disease by itself. The spirometry are performed by healthcare professionals who has been trained in performing spirometry at annually courses organised by SDCG for healthcare professionals which for example sees patients with COPD in the clinic. We therefore expect the healthcare professionals to have the necessary competencies to perform spirometry.

The CAT questionnaire was used in 9 out of 17 towns and around 28% (n = 250) of the patients diagnosed with COPD in Greenland (n = 900) fulfilled the CAT questionnaire from March to December 2022, assuming that our results is representative for the entire Greenlandic COPD population. We expect that the use of the CAT questionnaire in clinical practice in Greenland will improve the communication between health care providers and patients and enable a common understanding of the impact and severity of COPD at individual level.

Strengths and limitations

This is the first study to report symptom burden among patients diagnosed with COPD in Greenland and the introduction of the Greenlandic version of CAT, potentially, can led to increased focus on symptom control and quality of care. Yet, the sample size is still small, which limits the statistical power in some of the analysis performed. Furthermore, correlations of CAT scores and lung function observed in this study were poor. It would also be preferable if other clinical variables such as COPD related quality of life (QOL), acute exacerbations of COPD (AECOPD) rates, or health care utilisation could have been correlated with CAT scores. This data was unfortunately not available. Test-retest reliability for the Greenlandic version of the CAT questionnaire was not assessed in this study.

However, our results are much in line with the trend in international studies and provide a good baseline for the continued monitoring of prevalence of COPD and quality of care in Greenland in the coming years.

Conclusions

The symptom burden among patients with COPD in Greenland is high. The Greenlandic version of the CAT questionnaire had an acceptable internal consistency and was an applicable instrument for evaluating the symptom burden in patients with COPD. We observed weak correlations between CAT score and spirometry measurements. This version of the questionnaire should be recommended for the assessment of COPD in clinical practice in all parts of Greenland.

Authors’ contributions

MHN, ARL and MLP conceived the study idea. MHN cleaned the data, conducted the analysis and wrote the first draft of the manuscript. ARL assisted in setting up the questionnaire and the implementation. All authors revised the manuscript and approved the final manuscript. MLP supervised the overall project.

Disclosure statement

The authors wish to thank pulmonologist Sequssuna Olsen for discussion and revision of the Greenlandic version of the CAT questionnaire. Furthermore, we would like to thank the Language Secretariat of Greenland for proofreading the CAT questionnaire. At least, we would like to thank the healthcare providers from the lifestyle outpatient clinics in Greenland and from Steno Diabetes Center Greenland.

Supplementary Material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/22423982.2023.2220476

Additional information

Funding

Steno Diabetes Centre Greenland is partly funded by the Novo Nordisk Foundation (NNF20SA0064190).