Analysing Chronic Diseases Affecting The Population Nursing Essay
Recent advances in medical technology have allowed more people to live with formerly fatal diseases. As such, chronic diseases are fast becoming one of the most pressing issues faced by the health care systems of today. It has been estimated that at any given point in time, at least 50% of the population have some form of long term or permanent disabilities that interfere with their normal physical, psychological, or social functioning (Hymovich & Hagopian, 1992) (Taylor, 2009). Such conditions are often permanent, caused by non-reversible pathological changes, and leave a residual degree of disability in the patient (National Commission on Chronic Illness, 1956) as cited in (Hymovich & Hagopian, 1992). Chronic patients also often require acute hospitalization exceeding thirty days, special training for rehabilitation, as well as a period of care commonly exceeding three months (Lubkin & Larsen, 2009).
Chronic diseases may range from fairly mild conditions, such as sinusitis, to severe and debilitating conditions, such as arthritis, diabetes, coronary heart disease and cancer. In this paper, the focus is on autoimmune rheumatic diseases, a group of chronic diseases that involves the immune system, musculoskeletal system, and connective tissues (Falvo, 2009) (Morrow, Nelson, Watts, & Isenberg, 1999). In these diseases, the body fails to recognize its own tissues, instead interpreting them as foreign invaders and producing antibodies to fight them. Many of these diseases are also systemic in nature, with the immune system attacking many different cells, tissues and organs of its own body. Patients predominantly experience pain, swelling and inflammation in affected parts of their bodies such as the skin, joints, muscles, and connective tissues. The most common examples include Rheumatoid Arthritis (RA), Systemic Lupus Erythematosus (SLE), Sjogren’s syndrome, Polymyositis, and Scleroderma. Rheumatic diseases are amongst the most prevalent chronic conditions in the United States of America (Huyser & Parker, Rheumatic Diseases, 2002), and are expected to become one of the leading causes of disability in Singapore due to an ageing population (Ministry of Health, 2004).
Given their widespread manifestations and effects, chronic diseases often have tremendous impacts on the society. Studies have found that chronic patients account for 80% of the days spent in hospitals, 55% of the visits to hospital emergency medicine departments, and more than 75% of America’s $2 trillion medical care costs every year (Lubkin & Larsen, 2009) (Taylor, 2009). At the level of the individual, the psychosocial challenges faced by patients with chronic diseases are often complex and challenging. With longer life expectancy comes the trade-off of longer periods of curtailed or restricted activities, which in turn affects the patient’s quality-of-life.
Due to their wide-ranging implications, a comprehensive understanding and treatment of chronic diseases requires a bio-psychosocial perspective. In this paper, the focus is on the human experience behind chronic illness. The author will be examining the relationships among illness perceptions, rumination, fatigue, and negative emotional outcomes in RA and SLE patients, with the view that such results will be useful in informing chronic illness in general.
The Self Regulation Model and Illness Perceptions
One of the most important tasks for health psychology research is to find out the factors that influence patients’ health behaviour, in order to inform chronic illness management and to identify appropriate targets for health intervention. In this study, the author is interested in predicting psychological outcomes from illness perceptions in patients with chronic illnesses.
The Self Regulation Model (SRM) by Leventhal, Nerenz and Steele (1984) examines an individual’s subjective experience of illness to understand how they develop coping strategies to manage the illness situation. It emphasizes that people play an active role in affecting their illness outcomes. The SRM specifies three phrases: Representation, coping and appraisal.
In the first phase, illness perceptions refer to an individual’s implicit beliefs about his or her illness (Taylor, 2009). These organized conceptions of illness are acquired from previous social communication and cultural knowledge of the illness, from perceived significant others or authoritative sources such as a doctor or parent, and through personal experiences (Hagger & Orbell, 2003). It includes five chief components: identity, causes, timeline, consequences and cure/controllability. Identity comprises the illness label and the signs and symptoms which the patient ascribes as being part of the disease. Causes refer to the patient’s personal ideas about aetiology of the disease. Timeline consist of the patient’s expectations about the duration of the disease and its characteristic course, while the notion of consequences refers to the expected physical, social, emotional and economic impacts and outcomes of the illness. Finally, the cure/controllability component consists of the patient’s beliefs about the extent to which the disease is amendable to control or cure (Leventhal, Leventhal, & Cameron, 2001) (Leventhal, Nerenz, & Steele, 1984) (Moss-Morris, Weinman, Petrie, Horne, Cameron, & Buick, 2002).
These illness perceptions then influence the patient’s coping process in the second phase, during which the individual adopts coping strategies to manage both the illness and their psychological well-being. The coping strategies adopted will then influence illness outcomes such as pain levels and negative affect. In the third phase, the patient evaluates his coping strategy and decides whether to continue or undertake another strategy. Feedback loops are present at all stages so that the patients can revise their strategies accordingly, and a dynamic self-regulatory mechanism is maintained (Leventhal, Leventhal, & Cameron, 2001) (Serlachius & Sutton, 2009).
Both cognitive and emotional components are present in the SRM as well. Branching out from illness perceptions, one processing arm is dedicated to cognitive processing, while the second parallel processing arm is dedicated to the processing of the emotional aspects of the illness. In sum, the SRM postulates that a patient’s cognitive and emotional construction of an illness guides his coping and appraisal, and ultimately, affects the illness outcomes.
Prior research across a range of disease populations has found that illness perceptions can influence chronic illness outcomes. For example, illness perceptions predicted health status in diabetes patients (Lange & Piette, 2006), health-related quality of life in end stage renal disease patients (Griva, Jayasena, Davenport, Harrison, & Newman, 2009), and adherence to dietary restrictions in hypercholesterolemic patients (Coutu, Dupuis, D'Antono, & Rochon-Goyer, 2003).
The impacts of such illness perceptions have also extended beyond the above-mentioned chronic disease populations to include rheumatic conditions as well.
In a 6-year longitudinal study conducted on patients with Osteoarthritis, Kaptein and colleagues (Kaptein, Bijsterbosch, Scharloo, Hampson, Kroon, & Kloppenburg, 2010) found that changes in illness perceptions were associated with changes in outcomes overtime. Patients who possessed more passive and chronic views, felt that they have lesser control over their illness, and expressed more negative emotions are more likely to have deteriorations in functional abilities over time.
In a cross-sectional study conducted by Scharloo and colleagues (Scharloo M. , et al., 1998), it was found that the illness perceptions identity and cure/control subscales accounted for an additional 35% of the variance in RA patients’ functioning, above the 6% accounted for by medical variables. Later, in a 1-year longitudinal study, Scharloo and colleagues (Scharloo M. , Kaptein, Weinman, Hazes, Breedveld, & Rooijmans, 1999) found that patients who displayed lesser emotions, and perceived themselves as having lesser control over their disease, were more likely to be admitted to the hospital. Those who believed that the disease had adverse consequences visited the outpatient clinic more frequently, and had greater levels of tiredness and anxiety. In addition, those who perceived themselves as experiencing more symptoms had greater intensities of pain, tiredness and depression. In their hierarchical multiple regression analysis, coping strategies and illness perceptions were found to contribute to health outcomes in RA patients after statistically controlling for potentially intervening medical variables.
In another longitudinal study, Groarke and colleagues (Groarke, Curtis, Coughlan, & Gsel, 2005) further reinforced the idea that illness perceptions outweighed the impact of medical disease status in predicting physical and psychological adjustments in RA patients.
Of particular interest to this study, Treharne and colleagues (Treharne, Lyons, Hale, Goodchild, Booth, & Kitas, 2008) found that baseline perceptions that RA has severe consequences and is uncontrollable significantly predicted greater fatigue after 1 year. This relationship, however, was not mediated by praying and hoping, in contrast to the mediation relationship suggested by the SRM.
In a correlational study examining the relationship between illness perceptions and depression in RA patients, Murphy and colleagues (Murphy, Dickens, Creed, & Bernstein, 1999) found that the perceived consequences and cure/control components correlated with depression, even after controlling for disability.
Sharpe and colleagues (Sharpe, Sensky, & Allard, 2001) found from a 21 month longitudinal study that perceived consequences of the illness consistently predicted subsequent depression in early RA patients, together with the initial level of depression, disability, pain and coping strategies.
Finally, in a study conducted on SLE patients, hierarchical regression analysis revealed that patients who reported a perception of their illness as having negative life consequences, an unpredictable nature and themselves possessing little understanding of lupus, reported higher levels of depression (Philip, Lindner, & Lederman, 2009).
Rumination in Chronic Physical Illness
In this paper, rumination is defined as the tendency to focus on maladaptive self-referential thoughts following stressful events (Robinson & Alloy, 2003) (Smith & Alloy, 2009). According to the Stress-Reactive Rumination model by Robinson and Alloy (Robinson & Alloy, 2003), when faced with a negative life stressor such as a physical illness, people tend to ruminate and focus their thoughts on three main areas: Negative attributions and inferences associated with the illness, hopeless cognitions induced by the illness, as well as active coping strategies and problem-solving solutions associated with the illness.
Traditionally, rumination as a recurrent thought has been investigated in depression and other psychopathologies like post-traumatic stress and anxiety disorders (Morrow & Nolen-Hoeksema, 1990) (Nolen-Hoeksema & Morrow, 1991). It has been found to be an important maintaining factor of trauma-related emotional disorders (Ehring, Frank, & Ehlers, 2007).
Recent research has moved beyond psychopathologies and began to explore the relationship between rumination and physical health outcomes.
Lyubomirsky and colleagues (Lyubomirsky, Kasri, Chang, & Chung, 2006) found that women who have a tendency to ruminate were significantly less likely to intend to contact a physician right away after finding an imaginary breast lump as compared to non-ruminators. Women breast cancer survivors who ruminated more were also delayed in seeking a diagnosis for their breast cancer symptoms by an additional 39 days.
In a study conducted by Roger and Najarian (1998), rumination was found to be associated with cortisol secretion levels in subjects undergoing a stressful written examination. Rumination has also been found to be positively related to sleep disturbances (Carney, Edinger, Meyer, Lindman, & Istre, 2006), and strongly related to bodily pain in patients with Chronic Fatigue Syndrome (Nijs, Van de Putte, Louckx, Truijen, & De Meirleir, 2008).
In a study by Thomsen and colleagues (Thomsen, et al., 2004), the authors concluded that rumination is associated with poorer self-reported physical health, but the association depends on the age of the individual as well as the time span studied. Additionally, in a study exploring the effects of rumination on immunity, rumination was found to be positively associated with total leukocyte count, total lymphocyte count, and the number of B cells among the elderly (Thomsen, et al., 2004).
In an exploratory study examining the generalizability of rumination to groups with non-mood symptomatology, individuals with SLE were found to ruminate more than healthy individuals, and less than depressed individuals (Siegle, Moore, & Thase, 2004).
Although these studies have considerably advanced our knowledge about the impact that recursive negative thinking may have on physical health, there is a lack of theoretical direction and application. In an article postulating the role that rumination may play in the context of chronic physical illness, Soo and colleagues (Soo, Burney, & Basten, 2009) proposed that chronic illness may trigger such ruminative thought processes via two mechanisms: Through the experience of the symptoms and treatment associated with the illness, and the activation of the individual’s illness schemas and perceptions.
Thus, in view of the SRM, rumination may be selected as a coping mechanism in response to the physical and emotional demands of RA on the patient. The SRM posits that coping mediates the effect of illness perceptions on illness outcomes. Therefore, according to the model, rumination would contribute unique variance to illness outcomes beyond illness perceptions.
Fatigue in Chronic Illness
Fatigue is a very common complaint among patients who live with chronic illness (Kralik, Telford, Price, & Koch, 2005) (Small & Lamb, 1999) (Swain, 2000). It can be measured objectively using physiological methods, or behaviorally via physical or mental performance (Huyser, Parker, Thoreson, Smarr, Johnson, & Hoffman, 1998). However, as objective measurements of fatigue do not always correlate with subjective fatigue (Swain, 2000), measuring patient’s subjective perceptions is still the best way to understand their illness experiences. In this paper, fatigue is defined as the extreme and persistent tiredness, weakness or exhaustion experienced in the absence of any excessive expenditure of effort as the cause (Dittner, Wessely, & Brown, 2004).
Fatigue is an extremely common symptom in patients with autoimmune rheumatic diseases. According to prior studies, about 53% to 81% of SLE patients have complaints of fatigue (Krupp, LaRocca, Muir, & Steinburg, 1990) (Omdal, Waterloo, Koldingsnes, Husby, & Mellgren, 2003) (Tench, McCurdie, White, & D'Cruz, 2000). The prevalence rate of fatigue in RA patients is as high as 98%, with clinically important levels of fatigue present in about 42% of RA patients (Belza, Henke, Yelin, Epstein, & Gilliss, 1993) (Belza B. L., 1995) (Repping-Wuts, Fransen, van Achterberg, Bleijenberg, & van Riel, 2006) (Wolfe, Hawley, & Wilson, 1996). Fatigue has been described as the most severe symptom experienced by SLE patients (Krupp, LaRocca, Muir, & Steinburg, 1990), and is second only to pain for RA patients (Wolfe, Hawley, & Wilson, 1996).
The experience of fatigue is not limited to the physical extent. Cognitive, emotional and psychological elements are present in fatigue as well. Patients categorized their fatigue as different from normal tiredness (Repping-Wuts, Uitterhoeve, van Riel, & van Achterberg, 2008), describing it as being extreme, undeserved, and almost permanently present (Hewlett, et al., 2005). There is a wide variation in intensity and duration, and its sudden onset and exhausting nature results in frustrations and anger for the patients (Hewlett, et al., 2005).
It is important to study fatigue because its consequences are overwhelming, and there are far-reaching effects on patients’ everyday tasks, physical activities, emotions, attitudes, relationships, and social and family roles (Hewlett, et al., 2005) (Repping-Wuts, Uitterhoeve, van Riel, & van Achterberg, 2008). A study by Cross and colleagues (Cross, Lapsley, Barcenilla, Brooks, & March, 2008) had found fatigue to be significantly correlated with poorer health-related quality of life for patients. Rupp and colleagues (Rupp, Boshuizen, Jacobi, Dinant, & van den Bos, 2004) had further reported that different aspects of fatigue selectively accounted for different aspects of health-related quality of life in chronic patients.
Patients who reported more fatigue made more visits to their doctors than patients who reported less fatigue (Belza, Henke, Yelin, Epstein, & Gilliss, 1993). Yet, because many patients believe that professional support is rare and that the physician’s emphasis is on physical problems and disease activity, fatigue is not communicated to healthcare professionals explicitly (Hewlett, et al., 2005) (Repping-Wuts, Hewlett, van Riel, & van Achterberg, 2009).
Although considered by professionals to be a general symptom of disease activity, fatigue is rarely addressed as a treatment target in its own right (Hewlett, et al., 2005). Up till now, the mechanisms generating fatigue in these disorders are unknown and, thus treatment is still an issue (Kozora, 2005).
In this paper, the author is looking at fatigue as a chronic illness outcome that is influenced by patients’ illness perception and ruminative thoughts.
Negative Emotional Outcomes in Chronic Illness
Many chronic illnesses require a substantial amount of psychological adaptation as patients have to come to terms with a prolonged and debilitating condition. Patients need to deal with fatigue, pain, changes in lifestyle, and a potential loss of role, independence and financial stability. Negative emotions, which can be manifested in the form of depressive, anxiety and stress symptoms, may occur when patients are unable to cope with their conditions.
Patients with chronic illness also tend to have higher levels of emotional distress than healthy individuals. In a longitudinal study conducted by McCabe and Battista (2004), it was found that patients with Multiple Sclerosis had higher levels of anxiety and depression than the general population.
Negative emotions are often prevalent in patients with chronic illness. In a study (Kagee, 2008) examining the occurrence of depressive symptoms in diabetes and hyper-tension patients receiving treatment in semi-rural community health care clinics, 26.1% of the sample fell in the moderate mild to moderate range, 15.3% in the moderate to severe range, and 4.5% in the severe range. On average, the sample also reported experiencing elevated symptoms of anxiety.
In addition to merely symptomatic manifestations, the prevalence rates of co-morbid depression in chronic illness typically range from 10% to 80%, depending on the illness population being studied (Blazer, 2003) (Lee, Chan, Chronister, Chan, & Romero, 2009).
Given the chronic and debilitating nature of autoimmune rheumatic diseases, it is no surprise that negative emotions are commonly experienced by such patients as well. A meta-analysis conducted by Dickens and colleagues (Dickens, McGowan, Clark-Carter, & Creed, 2002) had found that depression is more common in patients with RA than in healthy individuals.
Pincus and colleagues (Pincus, Griffith, Pearce, & Isenberg, 1996)found that patients with RA were four times more likely to be anxious than controls and twice as likely to have depressive symptoms. Typically, about 15% of RA patients also meet the clinical cut-off for depression (Pincus, Griffith, Pearce, & Isenberg, 1996) (Wolfe & Michaud, 2009).
It is important to study negative emotional outcomes because they may have various consequences on the lives of chronic patients. In older adults with chronic illnesses, having low levels of negative mood was found to be associated with lower levels of symptom distress, higher daily activity scores, and higher perceived physical and mental health-related quality of life (Hu & Gruber, 2008).
A study conducted on SLE patients found that depression, anxiety, stress, as well as anger are associated with, and may exacerbate, the illness symptoms of SLE patients (Adams, Dammers, Saia, Brantley, & Gaydos, 1994). In another study conducted on RA patients, Zautra and colleagues (Zautra, et al., 1995) also found that arthritis patients with higher levels of negative mood tend to experience more activity limitations and pain.
In a review of the best practices and research in the psychology of rheumatic diseases, it was recommended that more research be done on mood states other than depression, especially anxiety (Newman & Mulligan, 2000). Thus, in this paper, the author is looking at depression, anxiety and stress as outcomes that are influenced by patients’ illness perception and ruminative thoughts.
The purpose of the current study was to investigate the associations between illness perceptions, rumination, fatigue and negative emotional outcomes patients with chronic illness. To date, only a relatively small number of studies have adopted the SRM to investigate illness outcomes in RA and SLE patients. Research has also largely neglected the role that rumination can play in the context of chronic physical illness. Finally, to the best of my knowledge, this is also the first study on illness perceptions in Asian RA and SLE samples.
We seek to answer the following questions:
Are there any differences in the illness experience of RA and SLE patients?
Are illness perceptions related to fatigue and negative emotional outcomes in chronic patients? Although considered partially exploratory in nature, guided by the SRM and previous research, it was hypothesized that illness perceptions predict psychological outcomes in chronic patients such that: perceived timeline will be positively associated with fatigue and negative emotional states; perceived consequences will be positively associated with fatigue and negative emotional states; and perceived cure/controllability will be negatively associated with fatigue and negative emotional states.
Is rumination related to fatigue and negative emotional outcomes in chronic patients? It was hypothesized that rumination predicts psychological outcomes in chronic patients such that: rumination focused on the negative inferences associated with the illness will be positively associated with fatigue and negative emotional states; rumination focused on hopeless cognitions induced by the illness will be positively associated with fatigue and negative emotional states; and rumination focused on problem-solving solutions associated with the illness will be negatively associated with fatigue and negative emotional states.
Is the mediation hypothesis in the SRM supported? It was hypothesized that the effect of illness perceptions on fatigue and negative emotional states will be completely mediated by rumination.
Sixty adult patients diagnosed with RA (n =??) and SLE (n =??) according to the American College of Rheumatology (ACR) classification criteria were recruited from a rheumatology outpatient clinic at the National University of Singapore Hospital. Eligibility criteria for the study will include the following: (a) 21 years old and above; (b) able to understand and respond to questions in English and/or Mandarin; (c) absence of intellectual impairment; and (d) absence of psychiatric disorders.
Socio-Demographic Questionnaire. Participants filled in a questionnaire with information on their condition, gender, age, ethnicity, educational level, marital status, and employment status.
Illness Perceptions Questionnaire-Revised (IPQ-R). Participants responded to the
IPQ-R (Moss-Morris, Weinman, Petrie, Horne, Cameron, & Buick, 2002) specially modified for RA and SLE patients. In the instruction, the word “illness” was substituted by either “Rheumatoid Arthritis” or “Systemic Lupus Erythematosus”. The questionnaire contained 70 items that measured five chief components of illness perceptions. Patients rated on a five-point scale ranging from (1) strongly disagree to (5) strongly agree, except for the identity subscale which is indicated on a binomial of (0) no and (1) yes. Specifically, the questionnaire assessed patients’ beliefs about (1) the identity of the disease (14 items, score ranges from 0 to 14); (2) whether the timeline is acute or chronic (6 items, score ranges from 0 to 30); (3) the consequences of the illness (6 items, score ranges from 0 to 30); (4) the degree of personal control over the illness (6 items, score ranges from 0 to 30); (5) the degree that their treatment control the illness (5 items, score ranges from 0 to 25); (6) illness coherence (5 items, score ranges from 0 to 25); (7) the cyclical nature of the illness (4 items, score ranges from 0 to 20); (8) their emotional representations of the illness (6 items, score ranges from 0 to 30); and (9) their perceived causes of the illness (18 items, score ranges from 0 to 90). Items were coded so that higher scores represent stronger beliefs for each dimension.
Stress Reactive Rumination Scale (SRRS). Participants responded to the SRRS (Robinson & Alloy, 2003), a 25-item questionnaire assessing individuals’ ruminations in response to their illness in the past week. In the instruction, patients were asked to refer to the “stressful event” as their physical illness, either “Rheumatoid Arthritis” or “Systemic Lupus Erythematosus”. The Chinese version of the questionnaire was obtained via a forward-backward-forward translation, verified by recent graduate who majored in Chinese Studies, and pilot-tested on the current sample. Participants filled in their answers along a one hundred-point scale, ranging from (0) never to (100) always. The three dimensions of rumination measured are: (1) negative attributions and inferences associated with the illness (9 items, score ranges from 0 to 900); (2) hopeless cognitions induced by the illness (6 items, score ranges from 0 to 600); (3) and active coping strategies and problem-solving solutions associated with the illness (10 items, score ranges from 0 to 1000). The total extent of rumination was obtained from the summation of all scores, with higher scores denoting more rumination. The internal consistency of the scale is adequate (α = .89), and it has a 1-month test-retest reliability of .71 (Smith & Alloy, 2009).
Multidimensional Assessment of Fatigue (MAF) Questionnaire. The MAF (Tack, 1991) contains 16 items and measures four dimensions of fatigue: (1) severity (2 items); (2) distress (1 item); (3) the degree of interference in activities of daily living (10 items); and (4) timing (2 items). Fourteen items contain eight-point rating scales ranging from (1) not at all to (8) a great deal, while the last two items have multiple-choice responses. Patients filled up this questionnaire based on the perceptions of fatigue for the past week. The Global Fatigue Index was obtained by the summation of all scores, with greater scores denoting higher levels of fatigue.
Depression, Anxiety and Stress Scale- 21(DASS- 21). Participants responded to the DASS-21 (Henry & Crawford, 2005) (Lovibond & Lovibond, 1995) which measures three types of negative emotional states: (1) depression; (2) anxiety; and (3) stress (7 items per scale). The Depression scale assesses “dysphoria, hopelessness, devaluation of life, self-deprecation, lack of interest, anhedonia, and inertia”. The Anxiety scale assesses “autonomic arousal, skeletal muscle effects, situational anxiety, and subjective experience of anxious affect”. The Stress scale assesses “difficulty relaxing, nervous arousal, and being easily agitated, over-reactive and impatient”. Patients are asked to use a four-point scale ranging from (0) never to (3) all the time to rate the extent to which they have experienced each emotion over the past week. Scores for Depression, Anxiety and Stress are calculated by summing the scores for the relevant items and multiplying it by two. A total score for negative emotional outcomes was obtained by the summation of all scores, with greater scores denoting higher levels of emotional distress.
Disease Activity. Upon written consent, patients’ medical files and routine blood samples were reviewed to obtain the necessary indicators of their disease activity. A rheumatologist calculated the Disease Activity Score (DAS28; (Fuchs & Pincus, 1994) (Prevoo, Van'T Hof, Kuper, Van Leeuwen, Van De Putte, & Van Riel, 1995) for RA patients. This score is made up by tender and swollen joint counts, erythrocyte sedimentation rate, and patient-rated assessment of disease activity. As for SLE patients, the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI; (Bombardier, Gladman, Urowitz, Caron, & Chang, 1992)) was calculated. It is a “weighted index of 9 organ systems for disease activity in SLE, as follows: 8 for central nervous system and vascular, 4 for renal and musculoskeletal, 2 for serosal, dermal, immunologic, and 1 for constitutional and hematologic”.
The study protocol was approved by the relevant hospital ethics review board. Individuals who met the inclusion criteria were approached and briefed about the aims and objectives of the study. Those who agreed to be part of the study signed a consent form, and were given the questionnaires. To obtain reliable responses, participants were told to complete the questionnaires alone. To decrease social desirability bias, participants were told that all responses will be kept confidential, and that there were no right or wrong answers. All participants were subsequently debriefed and thanked for the time spent in this study.
Statistical analyses in this study were conducted using PASW 18.0 software. Descriptive statistics on the socio-demographics variables were explored. Pearson correlation analyses were conducted to examine the associations among illness perceptions, rumination, and fatigue. Finally, hierarchical multiple regressions were performed to examine the amount of unique variance that rumination contribute to fatigue outcomes beyond illness perceptions, after controlling for disease activity.