Chronic obstructive pulmonary disease (COPD) is an avoidable and common illness characterized by permanent airflow limitation (Agustí et al., 2020; Tamondong-Lachica et al., 2023). Risk factors such as advanced age, smoking, alcohol, occupational exposure, air pollution, infections, genetic factors, and low socioeconomic status have been associated with COPD (Adeloye et al., 2022; Bae et al., 2024). COPD, which is a substantial health problem due to its associated mortality and disease burden, causes common symptoms including dyspnea, cough, fatigue, anorexia, weight loss, anemia, sleep disorders, muscle weakness, increased sputum, anxiety, and depression (Hanania & O'Donnell, 2019; Sarkar et al., 2019). All these symptoms lead to a worsening of the general health of patients with COPD, resulting in physical limitations, social isolation, and reduced ability to perform daily living activities (Monjazebi et al., 2024). These physical, psychological, and social problems experienced by the patients may negatively affect their comfort (Kütmeç Yılmaz, 2020).

Given the multifaceted challenges faced by COPD patients, a holistic approach to care is essential, and Kolcaba's Comfort Theory provides a comprehensive framework to guide this approach. Kolcaba's Comfort Theory provides a valuable framework for understanding and improving patient comfort, particularly in the context of chronic illnesses like COPD. Kolcaba defined comfort, an important component of the holistic nursing approach, within the scope of a theory (Kolcaba et al., 2006). According to Kolcaba, comfort is defined as an expected result with a complex structure that involves addressing physical, psychospiritual, sociocultural, and environmental needs to help individuals, provide peace, and enable them to overcome problems. She emphasized that it is necessary to meet the basic human needs to be refreshed, find peace, and overcome problems (Cardoso et al., 2020; de Azevedo Ponte & da Silva, 2015). According to the comfort theory, health is defined as facilitating the optimal functioning of the individual, family, and society by increasing comfort. Kolcaba examined the individual needs that are met or unmet at three levels according to their intensity: relief, ease, and transcendence (Al-Aaraj et al., 2023; Cardoso et al., 2020). Relief is defined as the state in which individuals feel when they get rid of distress because of meeting their needs, and ease is described as the state of being calm, comfortable, or at peace. Finally, transcendence is described as the ability of individuals to overcome their problems and increase their usual strengths (Al-Aaraj et al., 2023; Ashıq Alı, 2022).

To better apply this theory in clinical practice, Kolcaba identified four key domains of comfort, each addressing a different aspect of the patient's experience. Kolcaba discusses the comfort needs of individuals in four domains: physical, psychospiritual, sociocultural, and environmental. The physical domain includes bodily perceptions and physiological factors such as symptoms, nutritional status, excretion, immune functions, and homeostatic mechanisms (Cardoso et al., 2020; Kolcaba et al., 2006). This model emphasizes that a deviation from normal in any of the physiological indicators can also affect comfort. Symptoms, especially in the physical domain, can significantly affect the comfort level of patients (Kolcaba et al., 2006). A high level of symptom severity leads to problems such as functional limitation, fatigue, insomnia, anxiety, depression, limitation in activities of daily living, and hopelessness (Janssen et al., 2015; Ozsoy et al., 2019). In addition, an increase in the severity of symptoms brings repeated hospitalizations and causes patients to withdraw from social and professional life (Correa-Gutiérrez et al., 2024).

Beyond the physical symptoms, patients also face emotional and psychological challenges that are captured within the psychospiritual domain of comfort. The psychospiritual domain is related to spiritual, cognitive, and emotional components, and includes areas such as anxiety, depression, stress, self-esteem, and spiritual state (Cardoso et al., 2020). Depression, anxiety, and stress, which are included in the psychospiritual domain, can significantly affect patients' comfort levels (Kolcaba et al., 2006). When studies on COPD patients were examined, it was seen that the frequency of anxiety varied between 10 % and 55 %, and the frequency of depression varied between 15 % and 72 % (Matte et al., 2016; Panagioti et al., 2014). Considering the high frequency of depression and anxiety in COPD patients, it is an essential area that should be evaluated in terms of psychospiritual comfort (Kolcaba et al., 2006). Loss of functional capacity, difficulties in social functioning, financial hardships, and changes in family roles reduce self-confidence and motivation. These factors cause an increase in depression, stress, and anxiety in COPD patients. Depression, anxiety, and stress result in symptoms such as restlessness, tension, and fatigue in patients, thus preventing patients from feeling relief and finding peace, and reducing comfort (Ören, 2018; Pinto et al., 2017).

In addition to internal experiences, external living conditions also play a significant role in shaping comfort, which is addressed under the environmental domain. The environmental domain includes external factors such as place of residence and physical characteristics of the house (Boudiab & Kolcaba, 2015; Eijkelenboom & Bluyssen, 2022). Whether the house is in a rural or urban area affects the comfort levels of individuals (Wang et al., 2021). Individuals living in rural areas may face difficulties in accessing social facilities and health services, and this may reduce their comfort level (Wang et al., 2022). Comfort is also influenced by social and cultural factors, as reflected in the sociocultural domain of the theory. The sociocultural sub-dimension deals with variables such as income level and marital status (Boudiab & Kolcaba, 2015; Cardoso et al., 2020; Krinsky et al., 2014). It is emphasized that individuals who are married, have a good income, and a higher education level tend to have higher comfort levels (DiNicola et al., 2013; Kütmeç Yılmaz, 2020). The social support that married individuals receive from their spouses contributes to the increase in their overall comfort (DiNicola et al., 2013). In addition, individuals with a high income level can meet their needs during the disease process, have access to all treatment opportunities for the treatment of COPD, and are not significantly affected by the economic losses experienced during the disease process (Siboni et al., 2019). Patients with a certain level of education can take an active role in planning and implementing their care, and this positively affects their comfort level (Kütmeç Yılmaz, 2020).

Ultimately, addressing comfort holistically across all these domains is critical for improving health outcomes in individuals with COPD. The importance of comfort in COPD management is not only limited to alleviating the symptoms of the individual, but it is also a fundamental element that directly affects the patient's quality of life and participation in the care process. Ensuring the comfort of patients in long-term care processes in chronic and progressive diseases such as COPD increases compliance with treatment, reduces hospitalizations and improves overall health outcomes (Cardoso et al., 2020; Kolcaba et al., 2006). In addition, the World Health Organization (WHO) and many international health organizations define patient-centered care as a fundamental component of 21st century health systems and recommend that the physical, psychological, social, and environmental needs of individuals be addressed holistically (World Health Organization, 2016; Institute of Medicine, 2001). In this context, comfort has become an indispensable component in improving the quality of nursing practices and health services. Therefore, in this study, the holistic assessment of comfort in COPD patients reflects an important necessity at the level of both individual patient care and health systems.

This study makes an innovative contribution to the field by combining Kolcaba's Comfort Theory with Structural Equation Modeling (SEM) to quantitatively assess the comfort levels of patients with COPD. Although the importance of comfort in patients with COPD has been emphasized previously (Nuccio & Nuccio, 2009; Wu, 2023), existing research is often based on qualitative approaches (Nuccio & Nuccio, 2009; Wu, 2023) or simple correlational studies (Kütmeç Yılmaz, 2020). Such studies are limited in explaining causal relationships between variables and producing generalizable findings. In this study, testing a multidimensional model developed based on Kolcaba's theory with SEM method enables to reveal the complex relationships between the factors affecting comfort. This approach enables a holistic and statistically powerful analysis of the physical, psychospiritual, sociocultural and environmental dimensions of comfort, thus filling an important gap in the literature and providing more comprehensive and explanatory results compared to previous studies.

The primary objective of this study is to investigate the overall comfort level in patients diagnosed with COPD using Kolcaba's Theory of Comfort within a SEM framework. The secondary aim of the study is to explore how various dimensions, namely physical, psychospiritual, sociocultural, and environmental factors, affect the general comfort level of patients with COPD. Additionally, this study sought answers to the following research questions (Fig. 1):1.

What is the general comfort level in patients with COPD?

2.

How do physical factors affect the general comfort level of patients with COPD?

3.

How do psychospiritual factors influence the general comfort level of patients with COPD?

4.

How do sociocultural factors affect the general comfort level of patients with COPD?

5.

How do environmental factors affect the general comfort level of patients with COPD?