K A R A B U L U N . , E R C I B . , O Z E R N . & O Z D E M I R S . ( 2 0 1 0 ) Symptom clusters and experiences of patients with cancer. Journal of Advanced Nursing 66(5), 1011–1021. doi: 10. 1111/j. 1365-2648. 2009. 05254. x Abstract Title. Symptom clusters and experiences of patients with cancer. Aim. This study is a report of a study to characterize the prevalence and severity of symptoms in patients with cancer and describing the clustering of symptoms. Background.
Patients with cancer experience multiple symptoms caused by multiple factors, including progression of the cancer, acute physiological changes associated with treatment, delayed side effects of treatment and long-term consequences of the disease. Methods. A convenience sample of 287 patients with cancer at a Turkish university hospital completed a structured questionnaire on demographical characteristics and a symptom inventory for patients with cancer. Cluster analysis, principal components and internal consistency reliability analyses were used to analyse the data. The study was conducted in 2007.
Findings. The most common symptoms experienced were fatigue, dif? culty remembering, sadness, loss of appetite, lack of enjoyment of life, pain, distress, dif? culty walking and dry mouth. The least experienced symptoms were shortness of breath and vomiting. Overall, 37? 5% of the patients experienced moderate symptoms and 12? 5% experienced severe symptoms. Among the severe symptoms were loss of appetite, fatigue, sadness, dry mouth and distress; however, 48% rated these as moderate or severe.
Conclusions. Symptom cluster research is still in its early years. Further work is needed to reach a standard de?nition of a symptom cluster and a consensus of its criteria. Additional studies are needed to examine symptom clusters in cancer survivors. As individuals are living longer with the disease, comprehensive understanding of the symptom clusters that may be unique to cancer survivors is critical. Keywords: cancer, clusters, nursing, symptom severity Introduction Patients with cancer experience multiple symptoms caused by multiple factors. The resulting symptoms of pain, dyspnoea, fatigue, depression and cognitive impairment, among others, O 2010 Blackwell Publishing Ltd affect their ability to function from day to day.
If severe enough, they can in? uence patients to forego continued treatment, and may undermine the effectiveness of cancer therapies and diminish functional status (Cleeland 2000). The interaction of multiple symptoms in? uences functional status, 1011 N. Karabulu et al. quality of life, and ultimately disease progression and survival (Cleeland & Reyes-Gibby 2002).
However, despite the importance of symptom research in cancer, the existing literature is limited. Background Cancer symptoms Cancer is often considered as the most dreaded disease, not only because of the perceived mortality but also because of the severe suffering associated with the disease and its conventional treatments, of which the most commonly reported are pain (Cleeland et al. 1994, Goudas et al. 2005), psychological distress (Ciaramella & Poli 2001, Rao & Cohen 2004) and insomnia (Davidson et al. 2002, Patrick et al. 2003).
Studies have shown that patients with cancer suffer from a variety of symptoms. A study of 200 hospice inpatients in Japan indicated that, throughout the clinical course, 94% of patients reported anorexia, 88% reported pain, 77% reported general malaise, 66% reported dyspnoea, 61% reported dry mouth, 48% reported nausea and vomiting and 48% reported cough/sputum (Morita et al. 1999). Even in newly diagnosed patients with cancer, one study found that 30–40% experienced moderate-to-severe fatigue and insomnia (Degner & Sloan 1995).
Anti-cancer treatments, such as chemotherapy and radiotherapy, are also known to cause a variety of symptoms. In a recent study of more than 500 patients undergoing active treatment, more than 20% of patients reported a variety of severe symptoms, including fatigue, anxiety, sleep disturbance, lack of appetite and dry mouth (Cleeland et al. 2000).
The presence and severity of these symptoms severely disrupt a patient’s quality of life and daily activities, and often limit the effectiveness of treatment. (Okuyama et al. 2003). Previous research has shown that 14– 100% of oncology outpatients experience pain (Goudas et al. 2005). The frequency of psychological distress, such as depression and anxiety, ranges from 0% to 44% in patients with cancer (Hosaka & Aoki 1996, Ciaramella & Poli 2001, Massie 2004). The prevalence rate for insomnia among patients with different types of cancer and measured at different courses of the disease range from 30% to 59%.
(Savard & Morin 2001, Davidson et al. 2002). These symptoms occur individually or in combination, negatively impact the patient’s quality of life, and result in increased morbidity and healthcare costs (Cleeland et al. 1994, Gureje et al. 1998, Goyal et al. 2005, Thase 2005). Reyes-Gibby et al. (2006) used a nationally representative sample of community-dwelling adults older than 50 and found a higher prevalence of pain, fatigue and depression among those who 1012 had a history of cancer compared with those who did not.
In the ? nal model, they concluded that having a history of cancer, being female, having a lower level of education, and having more comorbid conditions increased the risk for experiencing two or more of the symptoms in the cluster of fatigue, pain and depression. Numerous surveys have now documented a high prevalence of symptoms in patients with cancer in tertiary care, hospice and community settings. The prevalence of symptoms in patients with cancer varies considerably across published studies and includes nausea and vomiting (4–44%), dyspnoea (15–79%), constipation (4–65%), insomnia (7–28%), delirium (4–85%), anorexia (6–74%), weight loss (58–77%) and fatigue (13–91%).
(Vainio et al. 1996, Sarna 1998, Newell et al. 1999, Bruera et al. 2000, Chang et al. 2000a, Okuyama et al. 2001). Patients with cancer suffer from a multitude of intense physical and psychological symptoms regardless of the stage of the disease (Portenoy et al. 1994, Naughton & Homsi 2002). Some symptoms are related to progression of the disease, whereas others are associated with the early and late effects of cancer treatment, or to problems with psychosocial adjustment (Donnelly et al. 1995, Chang et al. 2000a). Symptoms such as pain, depression, fatigue and others occur in clusters and can in?uence the occurrence of other symptoms.
The concept of symptom clusters is being increasingly recognized as an important platform for symptom management for patients with cancer (Ruthledge & McGuire 2003, Paice 2004). In fact, numerous surveys have documented a high prevalence of the grouping of symptoms in patients with cancer, with a median number ranging from eight to 11 symptoms per patient (Donnelly et al. 1995, Chang et al. 2000a, 2000b, Tranmer et al. 2003).
Efforts to describe symptoms have shown that each symptom has an associated constellation of shared dimensions, including frequency, intensity and level of perceived distress (Armstrong 2003). Because cancer survivors are living longer, they may develop other chronic health problems, and the symptom clusters they experience may be unique as a consequence of their history of cancer (Dodd et al. 2001b). The majority of research on symptoms has been directed towards a single symptom, such as pain or fatigue, or towards symptoms that are correlated with a single symptom (Dodd et al. 2001a).
Although this approach has advanced the state of knowledge about symptoms, it is not always helpful in guiding clinical practice when patients present with several concurrent symptoms (Dodd et al. 2001a). Speci? c symptoms are frequently found together among patient with certain characteristics or clinical situations, such as individuals receiving adjuvant therapy or with advanced disease (Yarbro et al. 2004). The symptoms in a cluster may not O 2010 Blackwell Publishing Ltd JAN: ORIGINAL RESEARCH share the same aetiology; for instance, pain may be caused by the tumour, fatigue by the disease and treatment, and sleep insuf? ciency by anxiety or certain treatment approaches (Dodd et al.2001a).
However, symptoms in a symptom cluster can in? uence one another, and knowledge of this in? uence could direct interventions for the prevention and management of symptoms. Symptom clusters may also have a negative effect on a patient’s functional status and quality of life (Dodd et al. 2001a). It is important to identify and describe symptom clusters for accurate assessment and to develop and test interventions to prevent and manage symptom clusters associated with cancer and cancer therapy (Dodd et al. 2001b). Symptom assessment Symptom assessment tools previously used with adolescents with cancer focused on measuring single symptoms such as pain, nausea/vomiting, fatigue and health-related quality of life (Tyc et al. 1993, Hinds & Hockenberry-Eaton 2001, Varni et al. 2002).
The M. D. Anderson Symptom Inventory (MDASI) is a valid and reliable tool designed to assess multiple cancer-related symptoms of adults. It has been used in the United States of America (USA), Japan and Taiwan, and its psychometric properties are well-established (Cleeland et al. 2000, Okuyama et al. 2003, Mystakidou et al. 2004, Wang et al. 2004, Lin et al. 2007, Tseng et al. 2008).
The MDASI has been successfully translated into and validated in several languages, including Chinese, Japanese, Greek and Korean (Cleeland et al. 2000, Okuyama et al. 2003, Mystakidou et al. 2004, Wang et al. 2004, Lin et al. 2007, Tseng et al. 2008). It is a brief, easy-to-understand assessment tool that nonetheless is suf? ciently comprehensive to evaluate multiple symptoms accurately in patients with cancer. It assesses 13 core cancer-related symptoms: fatigue, sleep disturbance, pain, drowsiness, poor appetite, nausea, vomiting, shortness of breath, numbness, dif? culty remembering, dry mouth, distress and sadness.
It also has six items that describe how much the symptoms have interfered with various facets of the patient’s life in the past 24 hours. These include general activity, mood, work (both inside and outside the home), relations with other people, walking and enjoyment of life. This instrument offers several advantages. First, it covers multiple symptoms that commonly occur among patients with cancer, and it is capable of assessing them at one time. It also allows better understanding of the relationships between multiple symptoms and symptom clusters. We also think that a rating scale (0–10points) is easier and more user-friendly for by people with a wide variety of cognitive abilities, which potentially reduces the burden of assessment.
O 2010 Blackwell Publishing Ltd Cancer symptom experiences Such an instrument provides a truly usable framework and assessment tool for measuring cancer-related symptoms (Tseng et al. 2008). Value of symptom assessment Interference ratings for multiple symptoms would help categorize levels of symptom distress (Mendoza et al. 1999). Assessment is essential to the prevention and management of symptoms common in people with cancer.
Symptom research, necessary to promote evidence-basedclinica l management, requires the use of multidimensional instruments with proven validity and reliability in cancer populations. As the concept of symptom clusters is more clearly elucidated, symptom-related instruments need to be evaluated for their ability to provide the most valid and reliable data regarding multiple symptoms occurring concurrently. Severity of symptoms will need to be determined to establish whether a symptom should be included in a cluster (Paice 2004). Determination of cancer-related symptoms distress could assist nurses in understanding the symptoms distress when it comes to healthcare promotion.
For that reason, nurses need to know about cancer-related symptoms so that this knowledge can be used in planning of care. Although cancer is a major cause of morbidity and mortality in Turkey, with an incidence 82? 1/100,000, little is known about the status of cancer-related symptoms and management in that country (Health Ministry 2004). No previous researchers have investigated the prevalence and severity of symptoms among Turkish patients with cancer, although Turkish healthcare professionals are becoming increasingly aware of the need for symptom management.
Evaluating severity of symptom, understanding the relationship of symptom management to cancer care, and studying the barriers to symptom management are very new in Turkey. Establishment of the MDASI as an appropriate tool for theses purposes, may well open new avenues for symptom control. The study Aim The aim of the study was to characterize the prevalence and severity of symptoms in Turkish patients with cancer and describe the clustering of symptoms. Design A descriptive cross-sectional design was adopted. 1013 N. Karabulu et al. Participants The participants were 287 patients with cancer who were cared for at the medical oncology department of a university hospital in Turkey between January and October 2007. G- POWER software program (Faul et al. 2007) for windows was used to determine sample size of the study.
A sample size of 308 patients was estimated using power analysis based on an alpha of 0? 01, power of 0? 99, assumed effect size was 0? 30 and standard deviation was 4? 2 for the sample size estimation. The response rate was 93? 2%. Twenty-one potential patients did not participate because they were too busy or unwilling; their characteristics were similar to those included in the study.
The patients were selected consecutively. The eligibility criteria were: (i) being registered with a primary diagnosis of cancer in the oncology clinic, (ii) aged 18 years or more, (iii) able to read and understand Turkish and (iv) no history of psychiatric illness. Data collection Data were collected using a questionnaire that included demographical characteristics and the MDASI. We visited the oncology clinic on 5 days every week and collected the data. After receiving an explanation of the study, participants read the questionnaire and marked their answers. The questionnaire took approximately 20 minute to complete.
It was administered in a separate quiet room of the oncology clinic. All participants completed the questionnaire. for severe symptoms in this study comes from our previous research on pain and fatigue, which suggested that, on a 1–10 scale, 5–6 is the optimum range for moderate symptoms and 7–10 is optimum for severe symptoms (Benedetti et al. 2000; Mock et al. 2000). The mean of all of these interference symptom items was used as a measure of overall symptom distress. The inventory’s alpha was reported by Cleeland et al. (2000) as 0? 87. Initially, the inventory was translated into Turkish and reviewed by two experts for clarity and cultural sensitivity; recommended changes related to wording were implemented.
Three individuals, expert in both languages, back-translated the Turkish instrument into English, achieving agreement. Factor analysis showed that 13 items constituted the symptom severity factor and six items comprised the symptoms interference factor. These factors were the same as two factors in the original inventory, with eigenvalues >1, and together accounted for 39? 7% of the total variance.
Thus, no item was extracted from the questionnaire because factor loading was adequate. Internal reliability coef?cients (Cronbach’s alpha) for the two factors ranged from 0? 84 to 0? 77, and total alpha of the inventory was 0? 85. Pearson’s productmoment inter-item correlations ranged from 0? 36 to 0? 79, and test-retest of the inventory was 0? 76. These analyses showed that the inventory had statistically acceptable levels of reliability and validity (Table 1). Ethical considerations The study was approved by a university review board. Validity and reliability The MDASI was developed by Cleeland et al. (2000) and consists of two factors. First, it is a brief measure of the severity and impact of cancer-related symptoms.
Each symptom is rated on an 11-point scale (0–10) to indicate the presence and severity of the symptom, with 0 meaning ‘not present’ and 10 meaning ‘as bad as you can imagine’. The 11point rating scale maximizes the trade-off between ease of responding and the marginal increase in reliability associated with a greater number of response choices. Each symptom is rated at its worst in the last 24 hours. The second factor includes ratings of how much symptoms interfered with different aspects of a patient’s life in the last 24 hours.
These interference items include general activity, mood, work (includes both work outside the home and housework), relations with other people, walking and enjoyment of life. The interference items also are measured on a scale of 0–10, with 0 meaning ‘did not interfere’, and 10 meaning ‘interfered completely’. The rationale of using a cut-off point of ‡7 1014 Data analysis All statistical procedures were performed using the SPSS program for Windows. Construct validity of the MDASI was tested with principal factor analysis using oblimin rotation to explore the underlying structure that explains the overall observed variation while reducing the complexity of the data.
The number of factors was identi? ed using the number of factors against the eigenvalues. The results determined whether or not the factor analysis reproduced the same factor-loading pattern seen during the original MDASI development in the USA. Reliability was evaluated by calculating Cronbach’s alpha coef? cient, which is a measure of the internal consistency of responses to a group of items. Hierarchical cluster analysis was used to establish symptom clusters. The analysis gave us additional information about the structure of patient responses to the total set of items by showing which items were more closely related to others.
The data were standardized and the cluster analysis O 2010 Blackwell Publishing Ltd JAN: ORIGINAL RESEARCH Cancer symptom experiences Table 1 Details of the inventory: number of items, Cronbach’s alpha, explained variance and eigenvalue M. D. Anderson Symptom Inventory Items Cronbach’s alpha Factor loading Variance (%) Correlation Eigenvalue Severity symptoms Interference symptoms Total symptoms 13 6 19 0? 84 0? 77 0? 85 0? 537–0? 734 0? 483–0? 709 0? 483–0? 734 28? 4 11? 3 39? 7 0? 461–0? 700 0? 555–0? 796 0? 367–0? 682 4? 5 2? 1 3? 6 was based on the distance between symptom ratings, whichwas calc ulated using squared Euclidian distances.
Regression analysis was performed to identify the predictors of interference and severity symptoms. All P values reported are twotailed. Results The socio-demographical and clinical characteristics of the patients are shown in Table 2. More than half were men, the majority of the sample was at Stage II of cancer and 92% of the patients were married; 42? 2% had graduated from primary school. The mean duration of cancer since diagnosis was 2? 9 ± 2? 5 years and the majority of patients had received chemotherapy (Table 2).
The most commonly experienced symptoms were fatigue (95? 5%), dif? culty remembering (90? 9%), sadness (90? 2%), loss of appetite (88? 2%), enjoyment of life (88? 8%), pain (87? 8%), distress (87? 8%), dif? culty walking (87? 5%) and dry mouth (86? 8%). The least commonly experienced symptoms were shortness of breath (65? 2%) and vomiting (64? 5%) (Table 3). Overall, 37? 5% of the participants had experienced moderate symptoms and 12? 5% experienced severe symptoms. The ratings of symptom severity and interference using the MDASI are presented in Table 3. Mean scores on the 13 symptom items and six interference items of the MDASI were 5 and 4?
4 respectively. The symptom items were ranked in terms of mean severity, along with the per cent of patients rating each symptom as moderate (5–6) or severe (7–10). Loss of appetite, fatigue, sadness, dry mouth and distress were the most severe symptoms; more than 48% of patients rated these as moderate or severe. Loss of appetite was the most prevalent severe symptom, with more than half of the sample having experienced severe loss of appetite. Based on the interference items of the MDASI, symptoms interfered most with work, followed closely by walking and enjoyment of life (Table 3).
Loss of appetite, fatigue, sadness, dry mouth and distress were the primary symptoms for patients with digestive system cancer and those having chemotherapy. The result of the cluster analysis is shown in Figure 1. General activity, mood, work, relations with other people, O 2010 Blackwell Publishing Ltd Table 2 Demographical and disease/treatment characteristics of participants (n = 287) Characteristics Age (years) 0? 05 >0? 05 >0? 05 >0? 05 0? 05 A0? 381 A0? 024 A0? 205 0? 040 A0? 094 A0? 085 0? 207 0? 086 A0? 030 A0? 096 t 4? 133 A2? 720 A0? 425 A2? 653 0? 600 A1? 468 A1? 326 3? 251 1? 409 A0? 522A1?
501 0? 422 0? 178 4? 142 0? 05 0? 05 >0? 05 >0? 05 All independent variables selected are added to a single regression model. d. f. = 14. treatment characteristics (b = A0? 133, P < 0? 05) and stage of cancer (b = 0? 175, P < 0? 01) were important predictors for severity of symptoms (Table 4). To identify the independent signi? cance of each variable according to the interference of symptoms, demographical and disease/treatment variables were put together in a linear regression.
These variables together explained 10? 6% of this variance (R = 0? 326, F = 2? 27, P < 0? 01). Age (b = A0? 411, P < 0?05), stage of cancer (b = 0? 179, P < 0? 01) and cancer site (b = 0? 183, P < 0? 01) were found to be independent predictors of symptom interference (Table 4). Overall the variables predicted 17? 8% of the variance in total symptoms (R = 0? 422, F = 4? 14, P < 0? 001). Additionally, age (b = A0? 381, P < 0? 01), educational level (b = A0? 205, P < 0? 01) and stage of cancer (b = 0? 207, P < 0? 001) were important predictors for total symptoms (Table 4).
Thus, linear regression analysis indicated that age, educational level, treatment characteristics, stage of cancer and cancer site were statistically signi?cant predictors for the symptoms experienced by patients with cancer and its speci? ed dimensions. Discussion Study limitations Limitations of the study include its cross-sectional design and volunteer sample. Therefore, generalizations must be made O 2010 Blackwell Publishing Ltd with caution. The sample re? ects only one area of Turkey and therefore cannot be generalized to all patients with cancer in the country. Future studies should include larger samples from different regions in Turkey.
Patients with cancer are especially in need of symptom control, since symptoms greatly in? uence their functional status and may even cause them to change or abandon an active treatment plan (Cleeland et al. 2000). Frequency of symptoms In the current study, commonly experienced symptoms were fatigue, dif? culty remembering, sadness, appetite loss, enjoyment of life, pain, distress, dif? culty walking and dry mouth. The least experienced symptoms were shortness of breath and vomiting. Overall, 37? 5% of the patients experienced moderate symptoms and 12? 5% experienced severe symptoms. Wang et al. (2004) determined fatigue, sleep disturbance, distress and pain were reported to be the four most severe symptoms in general. In the study by Hadi et al.
(2008), the three areas most frequently interfered with by symptoms were general activity (91? 0%), normal work (89? 0%) and enjoyment of life (88? 6%). In a study carried out in China, the mean score for the interference items of the MDASI was 3? 1 (SD : 2? 5). The highest level of interference was reported for work, followed by enjoyment of life, mood, walking ability, general activity and relations with others (Wang et al. 2004). Other studies 1017 N. Karabulu et al. What is already known about this topic • Patients with cancer suffer from a multitude of intense physical and psychological symptoms, regardless of the stage of the disease.
• Some symptoms are related to progression of the disease, whereas others are associated with the early and late effects of treatment, or to problems with psychosocial adjustment. We investigated the frequency of symptoms. Loss of appetite, fatigue, sadness, dry mouth and distress were the most severe symptoms experienced; loss of appetite was the most prevalent severe symptom, with more than half of the sample having experienced severe loss of appetite (Table 3). Other studies have shown that fatigue, drowsiness and distress were the most common symptoms; more than 30% of patients rated these symptoms as moderate or severe.
(Okuyama et al. 2003, Wang et al. 2004, Bender et al. 2008). What this paper adds • The most common symptoms experienced were fatigue, dif? culty remembering, sadness, loss of appetite, lack of enjoyment of life, pain, distress, dif? culty walking and dry mouth. • The least experienced symptoms were shortness of breath and vomiting. Overall, 37? 5% of the patients experienced moderate symptoms and 12? 5% experienced severe symptoms. • Demographical characteristics and disease/treatment characteristics have an effect on experience of symptoms of the disease. Implications for practice and/or policy.
• The information gained from this study should increase awareness among cancer care professionals about the range of symptoms experienced and may help them to target patients in cancer groups for particular interventions. • The long-term aim is to use the data from this research to produce a standardized pro? le of symptoms to enable nurses to focus their approach to patients according to their predicted symptoms. • Carers should evaluate the frequency and severity of symptoms as well as whether cancer survivors attribute their symptoms to cancer or to other conditions. have shown that fatigue was the most prevalent severe symptom, with more than half of the sample having experienced moderate-to-severe fatigue (Cleeland et al. 2000, Okuyama et al. 2003, Ivanova et al. 2005).
The other severe symptoms of sleep disturbance, pain, distress and sadness were present in two-thirds of the patients. Based on the interference items of the MDASI, symptoms interfered most with work and general activity followed closely by mood, enjoyment of life and walking, according to Ivanova et al. (2005). Our results are compatible with all these ?ndings. 1018 Clusters of symptoms We found three main clusters of symptoms. The six interference symptoms comprised a cluster.
Appetite loss was related to mental health issues and pain. Nausea was linked to vomiting (Figure 1). Okuyama et al. (2003) found 5 common components in Japanese and US studies: (i) nausea and vomiting, (ii) shortness of breath and remembering things, (iii) mood (distress and sadness) and mood-related symptoms (fatigue, drowsiness and sleep disturbance); (iv) pain and (v) dry mouth. In another study, the symptom cluster was anorexia, nausea, vomiting, abdominal pain or fatigue (Majumdar et al. 1999). Our ? ndings that these patients suffer from various symptoms such as fatigue, drowsiness and emotional distress indicate an urgent need for symptom management.
Predictors of symptoms The regression analysis showed that, collectively, the independent variables were predictors of 19% of the variance of symptom severity, 10? 6% of the variance in interference and 17? 8% of the variance in total symptoms; age, educational level, treatment characteristics and stage of cancer were powerful predictors of the severity of symptoms. Overall, the analysis indicated that age, educational level, treatment characteristics, stage of cancer and cancer site were statistically signi? cant predictors of the symptoms experienced.
Younger patients with cancer had less symptom distress because it might be said that most of them were at an earlier stage of cancer. Those with low educational level suffered more from symptoms because these patients were in later stage of cancer and they were receiving chemotherapy. Patients perceiving radiotherapy + chemotherapy had further symptom distress. Those at stage IV of cancer had more severe symptoms than others.
Those with gynaecological cancer experienced more interference symptoms since they were all having chemotherapy. In the study by Cleeland et al. (2000), the chemotherapy group demonstrated statistically O 2010 Blackwell Publishing Ltd JAN: ORIGINAL RESEARCH signi? cantly greater mean symptom interference than the group not currently receiving any anticancer therapy.
The mean loss of appetite score also was higher for patients receiving chemotherapy than for patients who were not treated in the study by Wang et al. 2004). Bender et al. (2008) found that lower level of education increased the risk of experiencing two or more symptoms in the fatigue, pain and depression cluster. Wang et al. (2004) showed advanced stage disease to be a second statistically signi? cant predictor of the interference component score.
The results of the present study were some similar to the ? ndings of the other researches. Cancer symptom experiences Author contributions ? NK, BE and SO were responsible for the study conception ? ? and design; NK, NO and SO performed the data collection; BE performed the data analysis; NK and BE were responsible for the drafting of the manuscript; NK and BE made critical revisions to the paper for important intellectual content; BE ? provided statistical expertise; NK and NO provided administrative, technical or material support; BE supervised the study.
References Conclusion The information gained from this study should increase awareness among cancer care professionals about a range of experienced symptoms and may help them target patients in cancer groups for particular care interventions. The longterm aim is to use the data from this research to produce a standardized pro? le of symptoms. This would enable care nurses to focus their approach to the patients according to their predicted symptoms. Assessment is essential to the prevention and management of symptoms common in people with cancer. Interventions should be designed to address these clusters, rather than isolated symptoms, to match the experiences of people with cancer.
Assessments should evaluate the frequency and severity of symptoms, as well as whether cancer survivors attribute their symptoms to cancer or to other conditions. Understanding the unique contributions of chronic health problems to the symptom experiences of cancer survivors is important. The information will guide the development of interventions to manage symptoms. Additional prospective studies are needed to examine symptom clusters in cancer survivors. As individuals are living longer with the disease, a comprehensive understanding of the symptom clusters that may be unique to cancer survivors with comorbid conditions is critical.
Assessments should evaluate the frequency and severity of symptoms, as well as whether cancer survivors attribute their symptoms to cancer or to other conditions. Funding This research received no speci? c grant from any funding agency in the public, commercial, or not-for-pro? t sectors. Con? ict of interest No con? ict of interest has been declared by the authors. O 2010 Blackwell Publishing Ltd Armstrong T. S. (2003) Symptoms experience: a concept analysis. Oncology Nursing Forum 30, 601–606. Bender C. M. , Engberg S. J. , Donovan H. S. , Cohen S. M. , Houze M. P. , Rosenzweig M. Q. , Mallory G.
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