Effectiveness of cognitive behavioural therapy for chronic obstructive pulmonary disease patients: A systematic review and meta‐analysis

Highlights

• Anxiety, depression, and quality of life were improved in COPD patients.

• Fatigue, exercise capacity, self-efficacy, and sleep quality were not improved.

• Cognitive behavioural therapy is a promising complementary therapeutic approach.

Abstract

Background

and purpose: Cognitive behavioural therapy (CBT) has gained increasing attention for the treatment of psychological disorders. This study aims to establish the effectiveness of CBT on psychological and physical outcomes in patients with chronic obstructive pulmonary disease (COPD).

Methods

Two waves of electronic searches of the PubMed, Cochrane library, EMBASE, Web of Science and China National Knowledge Infrastructure databases were conducted. Statistical analyses were performed using Revman Manager 5.3 and Stata 12.0 software.

Results

Sixteen randomized controlled trials were eligible. There were significant improvements in anxiety (SMD = −0.23; 95% CI: −0.42 to −0.04; P = 0.02), depression (SMD = −0.29, 95% CI: −0.40 to −0.19, P < 0.01), quality of life (MD = −5.21; 95% CI: −10.25 to −0.17; P = 0.04), and mean visits to emergency departments in the CBT groups. No statistically significant differences were observed in fatigue (SMD = 0.88, 95% CI: −0.58 to 2.35, P = 0.24), exercise capacity (MD = 28.75, 95% CI: −28.30 to 85.80, P = 0.32), self-efficacy (SMD = 0.15, 95% CI: −0.05 to 0.34, P = 0.14), or sleep quality (MD = 1.21, 95% CI: −0.65 to 3.06, P = 0.20).

Conclusion

This meta-analysis suggests that CBT can serve as a complementary therapy to improve anxiety, depression, and quality of life in COPD patients and deserves more widespread application in clinical practice.

Introduction

Chronic obstructive pulmonary disease (COPD) is a chronic progressive lung disease that is characterized by largely irreversible airway obstruction, which is associated with persistent respiratory symptoms, including dyspnoea, cough and excessive sputum production [1,2]. COPD has exhibited a rising trend in morbidity and mortality, and it is estimated that COPD will become the third leading cause of death in the world by 2020 [3]. Anxiety disorder and depressive disorder are the main comorbidities observed in COPD patients, and these disorders more commonly occur in COPD patients than in patients with other chronic diseases, such as cancer, diabetes or heart disease [4,5]. The prevalence rate of anxiety in patients with COPD is approximately 50% [6], and the rate of depression ranges from 10% to 42% in stable patients and up to 86% in patients with acute exacerbation [7,8]. The current focus tends to be on the physical symptoms experienced by those with COPD; thus, mental health symptoms could go unnoticed and therefore untreated. However, mental disorders seriously impair a patient's adherence to treatment and can have a considerable impact on health-related quality of life (HRQoL), exercise capacity, readmission rates and mortality [[9], [10], [11]].

The exact mechanism of the development of mental disorders is still unclear, but it likely involves many factors [12]. Pathophysiological factors are complex and may include hypoxemia and chronic inflammation, while behavioural factors may include active smoking and tobacco addiction. Other factors include social isolation, comorbidities, reduced physical functioning and frequent rehospitalization. Furthermore, more than 70% of COPD patients have sleep disturbances [13], which are related to nocturnal oxygen desaturation and can, in turn, further aggravate anxiety and depressive symptoms [14]. In addition, the presence of psychological symptoms is often associated with a reduction in self-efficacy, which may lead to a decline in the ability to cope with diseases [15,16]. Increasing evidence has shown that the relationship between emotional disorders and COPD is bidirectional: the development of COPD exacerbates anxiety and depression, and the presence of mental disorders also worsens COPD outcomes [4,10,17]. The high prevalence of anxiety and depression in patients with COPD, as well as the adverse impacts of these mental disorders on the prognoses of disease and patient-centred outcomes, prompted us to investigate effective therapies for the identification and management of patients' mood disorders in clinical practice.

Pharmacotherapy is the mainstream treatment for mental disorders among COPD patients, although there is some controversy regarding its effectiveness, and it is often accompanied by some side effects [9,18]. In addition, some studies have focused on the efficacy of nonpharmacological interventions, such as yoga, exercises, and psychological interventions, as complementary and alternative therapies in the treatment of anxiety and depression [[19], [20], [21]]. Cognitive behavioural therapy (CBT) is a type pf psychotherapy that is used for the treatment of psychiatric disorders [18] and is a collaborative psychological approach that is based on experimental and scientific psychology and neuroscience [22]. CBT is a patient-centred and personalized therapy that is usually provided by psychologists or psychiatrists; the contents of the therapy vary and mainly include psychological education, cognitive reconstruction and behavioural activation [23]. The purpose of CBT is to teach patients skills to change their emotional state and behaviour in order to address their current dysfunctional thoughts, beliefs and negative behaviours [12,24]. This mode of psychotherapy emphasizes the effects of cognition on emotion and behaviour, and it theorizes that distorted thinking patterns can lead to "negative" emotions and maladaptive behaviours [25]. Therefore, the treatment focuses on changing a patient's cognitive pattern to improve psychological and physical outcomes.

In recent years, CBT has attracted the attention of researchers who are investigating chronic diseases. Several studies have investigated the effect of CBT on COPD patients; however, the results have been inconsistent. For example, a randomized controlled trial (RCT) [26] showed that CBT reduced depressive disorders but did not reduce anxiety after an 8-week intervention. Conversely, another study showed that although patients exhibited a lesser degree of anxiety symptoms after CBT, there was no significant difference in the degree of depression between the two groups [27]. A direct comparison is hindered by many factors, such as the duration of the intervention, the different sample sizes, and the outcome assessment tools used. Previous systematic reviews have investigated various psychological interventions within a single review, such as meditation, mindfulness, relaxation and CBT; the results showed that psychological therapies might be beneficial for reducing the severity of mental disorders [[28], [29], [30], [31]]. However, due to the varying methodological qualities of the studies included in these reviews, more high-quality studies in this area are clearly warranted. Furthermore, the results concerning CBT interventions presented in the current reviews are inconsistent. Some reviews showed that CBT is effective for improving psychological outcomes [28,29], while other reviews found no conclusive evidence of an effect [[30], [31], [32]]. Meanwhile, the outcomes of these reviews are not comprehensive; most of these studies have not focused on physical outcomes.

It is worth noting that combining various psychological interventions in one review may mask or exaggerate the effects of each intervention included. Therefore, despite the similarities that exist among the different psychological therapies; there is still a need to examine the literature that has focused specifically on CBT. Considering the lack of a systematic review and meta-analysis that focuses solely on the efficacy of CBT regarding psychological and physical health outcomes in COPD patients, we believe it is necessary to quantify the effects of CBT alone. We did not include third-wave CBT methods, such as mindfulness-based cognitive therapy, because the components of the treatment and the overall aim of the interventions are different [33]. This study only included RCTs to further clarify the effectiveness of CBT for COPD patients, and to provide a reference for future research.