EMPIRICAL STUDIES
doi: 10.1111/scs.12200
Factors associated with low physical activity in patients with chronic obstructive pulmonary disease: a cross-sectional study € dt RPt, ML (Researcher)1,2, Elisabeth Skargren RPt, PhD (Associate Professor)3, Per Jakobsson Kristina To MD, PhD2, Kersti Theander RN, PhD (Associate Professor)4 and Mitra Unosson RN, PhD (Professor Emerita)1 1
Department of Social and Welfare Studies, Link€ oping University, Norrk€ oping, Sweden, 2Department of Respiratory Medicine and Department of Medical and Health Sciences, Link€ oping University, Link€ oping, Sweden, 3Department of Medical and Health Sciences, Link€ oping University, Link€ oping, Sweden and 4Department of Health Sciences, Nursing, Faculty of Health, Science and Technology, Karlstad University, Karlstad, Sweden
Scand J Caring Sci; 2015; 29; 697–707 Factors associated with low physical activity in patients with chronic obstructive pulmonary disease: a cross-sectional study
Objectives: Low physical activity (PA) in chronic obstructive pulmonary disease (COPD) is associated with poor prognosis. In addition, physical activity seems to be low early in the disease. The aim of this study was to describe the level of PA in patients with stable COPD and to explore factors associated with low PA, with a focus on fatigue, symptom burden and body composition Methods: In a cross-sectional study, 101 patients (52 women) with COPD were classified having low, moderate or high PA according to the International Physical Activity Questionnaire – Short. Fatigue, dyspnoea, depression and anxiety, symptom burden, body composition, physical capacity (lung function, exercise capacity, muscle strength), exacerbation rate and systemic inflammation were assessed. A multiple logistic regression was used to identify independent associations with low PA.
Introduction Physical activity (PA), defined as any muscular bodily movement increasing energy expenditure, is important for promoting and maintaining optimal health not only for healthy individuals but also for individuals with chronic illnesses such as chronic obstructive pulmonary disease (COPD) (1). Patients with COPD have lower PA level than healthy controls (2) as well as lower than individuals with other chronic diseases (3). Reduced PA is reported early in the disease progression (4) and linked Correspondence to: Kristina T€ odt, Department of Social and Welfare Studies, Faculty of Health Sciences, Link€ oping University, S-601 74 Norrk€ oping, Sweden. E-mail: [email protected] © 2015 Nordic College of Caring Science
Results: Mean age was 68 (7) years, and mean percentage of predicted forced expiratory volume in 1 second was 50 (16.5). Forty-two patients reported a low PA level, while 34 moderate and 25 reported high levels. Factors independently associated with low PA, presented as odds ratio (95% confidence interval), were severe fatigue 5.87 (1.23– 28.12), exercise capacity 0.99 (0.99–1.0) and the number of pack-years 1.04 (1.01–1.07). No relationship was found between depression, anxiety, body composition, exacerbation rate or systemic inflammation and PA. Conclusions: Severe fatigue, worse exercise capacity and a higher amount of smoking were independently associated with low PA. Promoting physical activity is important in all patients with COPD. Our result suggests that patients with severe fatigue might need specific strategies to prevent physical inactivity. Keywords: physical activity, chronic obstructive pulmonary disease, fatigue, body composition, exercise tolerance, symptom burden. Submitted 21 February 2014, Accepted 3 November 2014
to an increased risk of hospital admission and mortality in patients with COPD (5, 6). Factors previously shown to be related to PA in patients with COPD include respiratory function (4, 6, 7), muscle strength (7, 8), exercise capacity (7–9) and systemic inflammation (7, 8). Except that, patients with COPD report experience of multiple symptoms (10) which may play a central role in the vicious cycle of declining physical function (11). Two distressing symptoms, dyspnoea and fatigue are major causes of disability in COPD (12). Patients experiencing those symptoms may avoid PA because of the fear increasing those symptoms. In addition, patients with COPD are commonly characterised by weight loss and reduced fat-free mass reported as predictors of mortality in these patients (13), but the impact of body composition including fat-free mass and fat mass on PA remains unclear. One main target of pulmonary rehabilitation 697
698
K. T€odt et al.
programs is to increase daily PA (14). To develop more efficient rehabilitation programs, a comprehensive knowledge on the factors that are associated with daily PA is needed. This study will focus on the association between PA and subjective experience of fatigue, symptom burden of multiple symptoms and body composition. According to the middle-range theory of unpleasant symptoms (TUS) (15), symptoms can occur alone or in combination with other symptoms. The experience of a symptom is described as multidimensional with regard to intensity (strength or severity), timing (duration or frequency of occurrence), distress (degree of discomfort) and quality (15). These dimensions are distinct and related and can be measured separately or in combination. The consequences or impact of the symptoms are described as changes on physical or cognitive performance, the former measured as PA (15). The two most prevalent symptoms in patients with COPD are dyspnoea and fatigue (10). Dyspnoea is the most common and characteristic symptom in patients with COPD and is seen as the central symptom limiting exercise capacity and PA in these patients (11). However, the relation between dyspnoea and PA is inconsistent, with no relation being found in some studies (7, 9, 16) and a negative relation found by others (8, 17, 18). Fatigue is a highly prevalent symptom among patients with COPD (71%) (10) and is experienced every day by nearly 50% of the patients (19). Fatigue is a complex phenomenon which is best seen as a subjective sensation that can impact on various functions of daily life (20). Although there is no universally accepted definition of fatigue, Ream and Richardsson defined fatigue as a ‘a subjective, unpleasant symptom which incorporates total body feelings ranging from tiredness to exhaustion, creating an unrelenting overall condition which interferes with individuals’ ability to function to their normal capacity’ (21). Subjective fatigue has a significant impact on functional performance in people with COPD (22, 23). In contrary to one previous study (9), two recent studies found fatigue to be inversely related to PA in patients with COPD (8, 16). On the other hand, these studies used scales including items to assess both the experience of fatigue and the impact of fatigue on functioning in daily life (8, 9, 16). One researcher studying fatigue in patients with COPD found a relationship between the severity of fatigue and physical function (22). However, this study only considered the severity dimension of the symptom. For the purpose of the current study, experience of fatigue was defined as the subjective perception of frequency, duration and severity during the previous month and analysed in relation to the level of PA. In patients with COPD, several symptoms are often experienced simultaneously (24). The experience of concurrent symptoms are suggested to result in a
multiplicative rather than additive experience (15) which may hamper engagement in physical activity and increase sedentary behaviour. The experience of frequency, severity and distress of concurrent symptoms has been computed and used for description of symptom burden (25). However, the degree to which symptom burden contribute to PA in patients with COPD is unclear. Another potential restrictor of PA is malnutrition including both underweight and overweight or obesity. Although low body mass index (
doi: 10.1111/scs.12200
Factors associated with low physical activity in patients with chronic obstructive pulmonary disease: a cross-sectional study € dt RPt, ML (Researcher)1,2, Elisabeth Skargren RPt, PhD (Associate Professor)3, Per Jakobsson Kristina To MD, PhD2, Kersti Theander RN, PhD (Associate Professor)4 and Mitra Unosson RN, PhD (Professor Emerita)1 1
Department of Social and Welfare Studies, Link€ oping University, Norrk€ oping, Sweden, 2Department of Respiratory Medicine and Department of Medical and Health Sciences, Link€ oping University, Link€ oping, Sweden, 3Department of Medical and Health Sciences, Link€ oping University, Link€ oping, Sweden and 4Department of Health Sciences, Nursing, Faculty of Health, Science and Technology, Karlstad University, Karlstad, Sweden
Scand J Caring Sci; 2015; 29; 697–707 Factors associated with low physical activity in patients with chronic obstructive pulmonary disease: a cross-sectional study
Objectives: Low physical activity (PA) in chronic obstructive pulmonary disease (COPD) is associated with poor prognosis. In addition, physical activity seems to be low early in the disease. The aim of this study was to describe the level of PA in patients with stable COPD and to explore factors associated with low PA, with a focus on fatigue, symptom burden and body composition Methods: In a cross-sectional study, 101 patients (52 women) with COPD were classified having low, moderate or high PA according to the International Physical Activity Questionnaire – Short. Fatigue, dyspnoea, depression and anxiety, symptom burden, body composition, physical capacity (lung function, exercise capacity, muscle strength), exacerbation rate and systemic inflammation were assessed. A multiple logistic regression was used to identify independent associations with low PA.
Introduction Physical activity (PA), defined as any muscular bodily movement increasing energy expenditure, is important for promoting and maintaining optimal health not only for healthy individuals but also for individuals with chronic illnesses such as chronic obstructive pulmonary disease (COPD) (1). Patients with COPD have lower PA level than healthy controls (2) as well as lower than individuals with other chronic diseases (3). Reduced PA is reported early in the disease progression (4) and linked Correspondence to: Kristina T€ odt, Department of Social and Welfare Studies, Faculty of Health Sciences, Link€ oping University, S-601 74 Norrk€ oping, Sweden. E-mail: [email protected] © 2015 Nordic College of Caring Science
Results: Mean age was 68 (7) years, and mean percentage of predicted forced expiratory volume in 1 second was 50 (16.5). Forty-two patients reported a low PA level, while 34 moderate and 25 reported high levels. Factors independently associated with low PA, presented as odds ratio (95% confidence interval), were severe fatigue 5.87 (1.23– 28.12), exercise capacity 0.99 (0.99–1.0) and the number of pack-years 1.04 (1.01–1.07). No relationship was found between depression, anxiety, body composition, exacerbation rate or systemic inflammation and PA. Conclusions: Severe fatigue, worse exercise capacity and a higher amount of smoking were independently associated with low PA. Promoting physical activity is important in all patients with COPD. Our result suggests that patients with severe fatigue might need specific strategies to prevent physical inactivity. Keywords: physical activity, chronic obstructive pulmonary disease, fatigue, body composition, exercise tolerance, symptom burden. Submitted 21 February 2014, Accepted 3 November 2014
to an increased risk of hospital admission and mortality in patients with COPD (5, 6). Factors previously shown to be related to PA in patients with COPD include respiratory function (4, 6, 7), muscle strength (7, 8), exercise capacity (7–9) and systemic inflammation (7, 8). Except that, patients with COPD report experience of multiple symptoms (10) which may play a central role in the vicious cycle of declining physical function (11). Two distressing symptoms, dyspnoea and fatigue are major causes of disability in COPD (12). Patients experiencing those symptoms may avoid PA because of the fear increasing those symptoms. In addition, patients with COPD are commonly characterised by weight loss and reduced fat-free mass reported as predictors of mortality in these patients (13), but the impact of body composition including fat-free mass and fat mass on PA remains unclear. One main target of pulmonary rehabilitation 697
698
K. T€odt et al.
programs is to increase daily PA (14). To develop more efficient rehabilitation programs, a comprehensive knowledge on the factors that are associated with daily PA is needed. This study will focus on the association between PA and subjective experience of fatigue, symptom burden of multiple symptoms and body composition. According to the middle-range theory of unpleasant symptoms (TUS) (15), symptoms can occur alone or in combination with other symptoms. The experience of a symptom is described as multidimensional with regard to intensity (strength or severity), timing (duration or frequency of occurrence), distress (degree of discomfort) and quality (15). These dimensions are distinct and related and can be measured separately or in combination. The consequences or impact of the symptoms are described as changes on physical or cognitive performance, the former measured as PA (15). The two most prevalent symptoms in patients with COPD are dyspnoea and fatigue (10). Dyspnoea is the most common and characteristic symptom in patients with COPD and is seen as the central symptom limiting exercise capacity and PA in these patients (11). However, the relation between dyspnoea and PA is inconsistent, with no relation being found in some studies (7, 9, 16) and a negative relation found by others (8, 17, 18). Fatigue is a highly prevalent symptom among patients with COPD (71%) (10) and is experienced every day by nearly 50% of the patients (19). Fatigue is a complex phenomenon which is best seen as a subjective sensation that can impact on various functions of daily life (20). Although there is no universally accepted definition of fatigue, Ream and Richardsson defined fatigue as a ‘a subjective, unpleasant symptom which incorporates total body feelings ranging from tiredness to exhaustion, creating an unrelenting overall condition which interferes with individuals’ ability to function to their normal capacity’ (21). Subjective fatigue has a significant impact on functional performance in people with COPD (22, 23). In contrary to one previous study (9), two recent studies found fatigue to be inversely related to PA in patients with COPD (8, 16). On the other hand, these studies used scales including items to assess both the experience of fatigue and the impact of fatigue on functioning in daily life (8, 9, 16). One researcher studying fatigue in patients with COPD found a relationship between the severity of fatigue and physical function (22). However, this study only considered the severity dimension of the symptom. For the purpose of the current study, experience of fatigue was defined as the subjective perception of frequency, duration and severity during the previous month and analysed in relation to the level of PA. In patients with COPD, several symptoms are often experienced simultaneously (24). The experience of concurrent symptoms are suggested to result in a
multiplicative rather than additive experience (15) which may hamper engagement in physical activity and increase sedentary behaviour. The experience of frequency, severity and distress of concurrent symptoms has been computed and used for description of symptom burden (25). However, the degree to which symptom burden contribute to PA in patients with COPD is unclear. Another potential restrictor of PA is malnutrition including both underweight and overweight or obesity. Although low body mass index (
