Sleep Quality in Lung Cancer Patients

Lung cancer is the third most common cancer diagnosed among men and women (after prostate cancer and breast cancer), the annual burden of disease is larger than that of any other cancer. In 2012, the American Cancer Society estimates that lung cancer will account for 160,340 deaths, which is approximately 28% of all deaths from cancer in the United State (Wender et al., 2013). The quantity and quality of sleep comprise an important factor that affects the life quality of both healthy and sick individuals (Mercadante et al., 2004). A great deal of symptoms occurs in association with cancer and the treatment (Lutz et al., 2001; Aynur et al., 2010). Majority of problems such as pain, fatigue, anxiety and depression, which develops in association with cancer and the treatment, affect the quality of sleep (Theobald, 2004; Mercadante et al., 2010). Sleep disturbances, such as difficulty in falling asleep, maintaining sleep, poor sleep efficiency, early awakening, and excessive daytime sleepiness, are common in patients with cancer (Zarogoulidis et al., 2013). Developed in patients with lung cancer fatique, anxiety and depression affects patients’ sleep and causes mental status (Shuanglan et al., 2013). Sleep problem is among the adverse effects that is experienced by cancer patients most frequently (Davidson et al., 2002; O’Donnell, 2004; Berger et al., 2005; Kvale and Shuster, 2006; Whıtmer et al., 2006). There are results indicating that sleep problems are experienced by cancer patients more, compared to the other population (Mercadante et al., 2004; Vena et al., 2006; Mystakidou


Introduction
Lung cancer is the third most common cancer diagnosed among men and women (after prostate cancer and breast cancer), the annual burden of disease is larger than that of any other cancer. In 2012, the American Cancer Society estimates that lung cancer will account for 160,340 deaths, which is approximately 28% of all deaths from cancer in the United State (Wender et al., 2013). The quantity and quality of sleep comprise an important factor that affects the life quality of both healthy and sick individuals (Mercadante et al., 2004). A great deal of symptoms occurs in association with cancer and the treatment (Lutz et al., 2001;Aynur et al., 2010). Majority of problems such as pain, fatigue, anxiety and depression, which develops in association with cancer and the treatment, affect the quality of sleep (Theobald, 2004;Mercadante et al., 2010). Sleep disturbances, such as difficulty in falling asleep, maintaining sleep, poor sleep efficiency, early awakening, and excessive daytime sleepiness, are common in patients with cancer (Zarogoulidis et al., 2013). Developed in patients with lung cancer fatique, anxiety and depression affects patients' sleep and causes mental status (Shuanglan et al., 2013).
Sleep problem is among the adverse effects that is experienced by cancer patients most frequently (Davidson et al., 2002;O'Donnell, 2004;Berger et al., 2005;Kvale and Shuster, 2006;Whıtmer et al., 2006). There are results indicating that sleep problems are experienced by cancer patients more, compared to the other population (Mercadante et al., 2004;Vena et al., 2006;Mystakidou et al., 2009). However, sleep problem is perceived as a normal and temporary reaction that develops in association with the cancer treatment and has not been analysed adequately yet (Davidson et al., 2002;Fortner et al., 2002;Mercadante et al., 2004;Roscoe et al., 2007;Mystakidou et al., 2009;Savard et al., 2011).
Sleep problems are also considered important for patients with lung cancer. As a result of the studies performed, it was determined that patients with lung cancer suffer from sleep problems and this affects the life quality (Chen et al., 2004;O'Donnell, 2004;Vena et al., 2006;Gooneratne et al., 2007;Yale et al., 2007;Joyce et al., 2008;Lis et al., 2008).
Among the sleep problems, there are problems such as difficulty in falling asleep, early wakings, restless sleep, and frequent wakings at night and waking dreams (Lianqi, 2008). Sleep problems experienced by cancer patients cause the poor quality of sleep. The poor quality of sleep cause the development or increase of various physical, cognitive and psychological symptoms, such as impairment of concentration, fatigue, pain, anxiety, irritability, depression, hallucinations, poor apettite, constipation, increase of accident rate (Savard et al., 2004;Myastakidou et al., 2007;Mercadante et al., 2010;Guay et al., 2011).
Among the factors affecting the sleep disorder in cancer patients are gender, age, former sleep history, cancer diagnosis and treatment period, stage of cancer, disease and symptoms experienced in association with the treatment (O'Donnell, 2004;Berger et al., 2005;Kvale and Shuster, 2006;Myastakidou et al., 2007). It was determined that the symptoms observed on the patient, such as pain, fatigue, dyspnea and cough affect the sleep of the patient. The implemented studies indicated that sleep quality is in association with pain (Mystakidou et al., 2007;, fatigue (Roscoe et al., 2007), dyspnea (Gooneratne et al., 2007) and depression (Chen et al., 2004;Akechi et al., 2007;Mystakidou et al., 2009).
In our country, it is seen that there is a limited number of studies aimed at the sleep problem experienced by patients with lung cancer and its affecting factors (Albayrak, 2006). In his study where she researched sleep disorders in patients with lung cancer, Albayrak (2006) stated that 54.9% of the hospitalized patients (n:87) have sleep problems. Besides, sleep problem is also frequently observed on patients in association with the adverse effects experienced during the chemotherapy and radiotherapy treatments used for lung cancer (Görgüner, 2007). If the sleep problems of the patient and their reasons are diagnosed, the interventions required to increase the sleep quality of the patient can be planned. As well as determining the factors affecting the sleep quality of patients with advanced stage lung cancer, the findings obtained in this study emphasize the importance for nurses to make accurate diagnosis and planning aimed at these problems.

Materials and Methods
The study was performed for determining the factors affecting the sleep quality of patients with advanced stage lung cancer. Sample The population of the study is constituted of patients, who were hospitalized in Chest Diseases Service of a university hospital in the Province of İzmir, due to the diagnosis of lung cancer. The population of the study is constituted of 100 patients diagnosed with stage three and four lung cancer, who are older than 18 and have no perceptional problem.

Procedures and measurements
In the study, the data were collected by using three forms were prepared by using the literature: Personal Information Form, Visual Analogous Scale-Pain (VAS-Pain), Visual Analogous Scale-Sleep (VAS-Sleep). The data were filled by the researcher by interviewing with the participants. The pre-application of the study was performed on 10 patients with lung cancer, who were convenient for the election criteria.
Personal Information Form includes the personal characteristics of patients (age, gender, educational status, income state), and their information about the disease (respiration problem, existence of cough and pain, state of receiving chemotherapy and radiotherapy, state of depression) (Foley et al., 2006).
In the VAS-Pain form, the patients were required to evaluate the level of their pain on the visual analogous scale that shows the consecutive numbers from 0 to 10 (Yıldırım et al., 2006).
In the VAS-Sleep form, the patients were required to evaluate the quality of their quality of sleep on the visual analogous scale that shows the consecutive numbers from 0 to 10 (Herbert et al., 1976;Parrot and Hindmarch,1980;Lui and Lo, 2002).

Statistical analysis
During the evaluation of the data, Kruskal Wallis analysis was used for the relation between the frequency and percentage distributions of definitive variables of patients, average of VAS-Pain and VAS-Sleep scores in patients with lung cancer, maximum, minimum and standard deviation values, cough and respiration problem and sleep quality; Mann-Whitney U test was used for the relation between adverse effects caused by the treatment (nausea, vomiting, fatigue) and sleep quality; and Pearson correlation statistical analysis was used for the relation between the VAS-Pain score and VAS-Sleep score.

Ethics
Permission was obtained from the ethics committee of the university hospital in order to implement the study. In addition to this, patients were informed about the object and method of the study by the researcher and patients who accepted to participate in the study were included in the study.

Results
Defining characteristics about the patients who were included in the study are given in Table 1. While 82% of  the patients are consisted of male patients, their average age was found as 61.9. It was determined that while 43% of the patients were diagnosed 12-23 months ago, 85% receive chemotherapy and 45% receive radiotherapy (Table 1). It was determined that while the pain level average of patients varies between 4.6±3.5, their average of sleep quality score varies between 3.8±2.4. As is seen in Table 2, the relation between the cough, respiration problems of patients, the existing depression in the patient and averages of sleep quality score was not found statistically significant (p<0.05, KW: 0.872, p=0.646, KW: 3.174, p=0.205, u: 441.000, p=0.916). It was revealed that nausea and loss of appetite experienced by patients do not affect the sleep quality score (p>0.05), whereas, sleep quality score averages of patients suffering from problems such as vomiting, fatigue/weakness are affected (p<0.01) ( Table 2).

Discussion
In accordance with the findings obtained in the study, it was determined that there is no relation between cough, respiration problem, nausea, depression and sleep quality; on the other hand, there is a positive relation between pain, vomiting and fatigue.
Dyspnea is an important problem for cancer patients that affect the daily life of the individual (Tanaka et al., 2002;Redy et al., 2009). In our study, it was determined that there is no relation between the respiration problem and sleep quality (p>0.05). In their study performed on patients with lung cancer, Gooneratne and colleagues (2007) determined that uncontrollable dyspnea and cough affect the sleep quality of patients negatively.
Pain is a symptom that is experienced by cancer patients and causes insomnia most frequently (Savard and Morin, 2001;Theobald, 2004). It is specified in literature that sleep quality is negatively affected by pain (Moore and Dimsdale, 2002;Lianqi, 2008;McMillan et al., 2008;Mystakidou et al., 2009). It is specified in our study that 60.3% of the patients suffer from pain and their sleep is affected negatively. While the VAS-pain score average of patients was determined to be 4.6±3.5, their average of VAS-sleep score was determined as 3.18±2.11. A negative and medium-level relation was observed between the score averages of pain and sleep quality. In many of the studies, it was determined that cancer pain affects the sleep quality of patients negatively (Beck et al., 2005;Whıtmer et al., 2006;Gooneratne et al., 2007;Myastakidou et al., 2007;Mystakidou et al., 2009;Eyigör et al., 2010;Cheng and Lee, 2011;Guay et al., 2011).
Nausea and vomiting are observed in association with the cancer treatment Nausea and vomiting are usually specified by patients as one of the symptoms causing physical and psychological stress (Faubert andVaessen, 2005). While no relation was observed between the nausea and sleep quality in our study, a relation was determined between vomiting and sleep quality. Sleep quality of patients with vomiting was determined to be lower. Since vomiting is the process of throwing out the stomach contents by using a force, it might cause the interruption of an individual's sleep.
In their study, Bergkvist and colleagues (2006) indicated that 60% of patients receiving chemotherapy suffer from nausea and vomiting and this condition affects the life quality and sleep routine of the patient negatively. The study performed by Foubert and colleagues (2005) supports this data.
Fatigue is one of the most frequently encountered symptoms of the cancer patients (Sela et al., 2005;Whıtmer et al., 2006;Donovan and Jacobsen, 2007;Hsiang et al., 2008). The perception of sleep quality is poor among newly diagnosed lung cancer patients and is correlated with fatigue (Zarogoulidis et al., 2013). In our study, fatigue was determined to be a factor affecting the sleep quality. Fatigue can affect the sleep quality negatively by causing snoozes within the day. In the studies, a relation was observed between fatigue and insomnia (Moore and Dimsdale, 2002;Berger et al., 2005;Israel, 2005;Rosco et al., 2007;Aynur et al., 2010;Shuanglan et al., 2013). Cancer patients indicated that their sleep problems increase other symptoms including fatigue and fatigue increases the insomnia (Anderson et al., 2003;Beck et al., 2005;Donovan and Jacobsen, 2007;Cheng and Lee, 2011).
In their studies, Davidson and colleagues 2002 indicated that among the patients diagnosed with lung cancer, 56.1% suffer from fatigue and 46.5% suffer from insomnia; on the other hand, Donnell and colleagues (2004) indicated that 50% of the cancer patients complain about insomnia and that complaints about fatigue, pain, nausea and vomiting experienced during the treatment cause insomnia.
In one of his studies performed on cancer patients of palliative stage, Sela and colleagues (2005)   lung cancer, Görgüner (2007) also explained that adverse effects experienced in association with treatments affect the daily activities, psychological conditions and sleep qualities of patients negatively. Depression is one of the most frequently encountered symptoms of the cancer patients. In our study, no relation was observed between depression and sleep quality. However, many studies indicate that psychological problems such as anxiety, depression and stress affect the sleep quality of cancer patients negatively (Sela et al., 2005;Akechi et al., 2007;Donovan and Jacobsen, 2007;Cheng and Lee, 2011). While insomnia could be caused by depression, there is also a possibility that insomnia might cause depression (Okuyama et al., 2000). Cancer patients might suffer from depression or anxiety, since they feel themselves desperate and can not cope with it in a convenient way (Theobald, 2004). In the study performed by Mystakidou et al. (2009), 96% of the patients indicated that they suffer from sleep problem. A statistically significant relation was determined between sleep and depression, desperateness and life quality (Mystakidou et al., 2009;Shuanglan et al., 2013).
In a study performed by Mystakidou and colleagues (2007) with 102 cancer patients; it was determined that patients suffering from depression and desperateness experience sleep problems as well. Redeker and colleagues (2004), on the other hand, indicated that there is a positive relation between insomnia and depression in cancer patients. A relation was observed between psychological stress and sleep problems.
In conclusion, the patients with advanced stage lung cancer suffer from sleep problems and other symptoms also affect their sleep quality negatively (Yavuzşen and Kömürcü, 2008). It is well known that sleep is an important factor for individuals to sustain their life quality. Consequently, the nurse is supposed to handle all symptoms, rather than just one symptom such as pain, fatigue and evaluate their relation with one another (Redeker and Lev, 2000;Beck et al., 2005). After chemotherapy, self-reported sleep impairment is present and sleep efficiency is reduced, without significant change in sleep architecture (Zarogoulidis et al., 2013). The nurse is also supposed to plan interventions that would restrain other symptoms such as pain, vomiting, fatigue, which affect the sleep of the patient. Regular discussion with and referral to medical team on detection of any new symptom or rapid worsening of condition (Moore et al., 2002).