Preliminary examination of the relations between disease activity, illness perceptions, coping strategies, and psychological morbidity in Crohn's disease guided by the common sense model of illness

Authors


Abstract

Background:

An individual's psychological adjustment to illness is influenced by disease severity, illness perceptions, and coping strategies. A more precise understanding of the contribution of each of these factors to a patient's well-being may influence the kind of psychological support required by patients. This study therefore aimed to characterize the contributors to psychological well-being in patients with Crohn's disease (CD). The design was a cross-sectional questionnaire-based study.

Methods:

Ninety-six CD patients (34 males, 62 females, mean age 38 years) attending a tertiary hospital inflammatory bowel disease outpatient clinic were studied. Disease severity was evaluated according to the Crohn's Disease Activity Index (CDAI), coping styles assessed with the Carver Brief COPE scale, illness perceptions explored with the Brief Illness Perceptions Questionnaire (BIPQ), and anxiety and depression measured using the Hospital Anxiety and Depression Scale (HADS).

Results:

Combining the questionnaire data using structural equation modeling resulted in a final model with an excellent fit (χ2 (7) = 10.42, P = 0.17, χ2/N = 1.49, root mean square error of approximation (RMSEA) < 0.07, comparative fit index (CFI) > 0.97, Goodness-of-fit index (GFI) > 0.97). Disease activity had a significant direct influence on illness perceptions (β = 51, P < 0.001). In turn, illness perceptions had a significant direct influence on depression and anxiety (β = 41, P < 0.001, β = 0.40, P < 0.001, respectively). Use of emotional coping strategies was associated significantly (P < 0.001) with the presence of anxiety and depression.

Conclusions:

There is an interrelationship between disease activity, illness perceptions, coping strategies, and depression and anxiety. These aspects of psychological processing provide a framework and direction for the psychological support that patients with CD require. (Inflamm Bowel Dis 2011;)

Psychological disturbance is a common comorbidity in inflammatory bowel disease (IBD), with reported prevalence rates as high as 50%.1 Rates of depression and anxiety are high, even when compared to other chronic illnesses, with newly diagnosed IBD patients even more likely to have depression and anxiety than individuals diagnosed with colorectal cancer.2 Further, in comparison to healthy controls (and other illness groups such as irritable bowel syndrome [IBS] and colon cancer), individuals with IBD report higher rates of psychiatric distress,3, 4 anxiety,2, 5–7 and depression.6, 8, 9 Consistent with these findings, individuals with IBD have also been found to report reduced self-esteem, increased body image concerns,10, 11 and increased sexual problems.12 It should be noted that given that Crohn's disease (CD), in contrast to ulcerative colitis (UC), is associated with pathology throughout multiple areas of the gastrointestinal tract, it is likely that this multisite pathology leads to increased psychological morbidity and impaired quality of life.

One factor likely to play a key role in mediating the impact of IBD activity on psychological well-being is that of an individual's coping strategies. Coping refers to the way an individual deals with, or manages, stress. Coping strategies can be broadly classified as positive adaptive strategies, or negative, maladaptive strategies. Strategies that have been found to be useful for ameliorating IBD symptoms and associated psychological distress include having a positive attitude (“trying to see it in a different light, to make it seem more positive”),13, 14 engaging in active coping or problem solving (“trying to come up with a strategy to deal with the problem”),15 and social support (seeking out others for emotional support and guidance).16

Negative emotion-focused coping styles such as depressive coping (ruminating about the illness and its associated problems and/or self-blame) and passive coping (not thinking about the problem) have been found to be associated with an exacerbation of IBD symptoms, distress, and reduced quality of life (QoL).15, 17–20

One of the best-validated social-cognitive models used to explore the interrelationship between illness, illness perceptions, coping processes, and health outcomes is the Common Sense Model (CSM) (Fig. 1), as described by Leventhal et al.21 The CSM predicts that an individual's illness outcomes, such as anxiety and depression, are determined by several factors. The first is illness stimuli or illness activity. In the case of CD this would include symptoms associated with the disease such as diarrhea and abdominal pain. Based on these symptoms, the CSM predicts that individuals generate their own perceptions or cognitive and emotional representation of the illness. For example, how CD affects their own sense of self, the perceived ability to control and/or manage CD symptoms and activity, and the disease course such as timing of episodes. An individual's perception of an illness, according to the CSM, influences the choice and engagement in various coping styles, such as avoiding thinking about the illness or seeking help from friends. This in turn influences illness outcomes, such as psychological distress. According to the original description, at each stage of the CSM there are feedback loops to each of the previous stages, allowing for appraisal and evaluation.21 Another key feature of the CSM involves parallel-processing, suggesting that individuals make simultaneous emotional and cognitive representations and actions related to their illness.22

Figure 1.

The Common Sense Model (modified from Hagger and Orbell, 2003).

Several studies have explored the validity of the CSM in various illness populations including human immunodeficiency virus, diabetes, arthritis, and hypertension.22 In a recent review and meta-analysis of 45 studies utilizing CSM, Hagger and Orbell22 found strong evidence for the CSM and the ability to predict interrelationships between disease activity, illness perceptions, coping styles, and psychological morbidity. Research involving individuals with IBD have also provided evidence for the influence of illness perception on psychological morbidity. For example, using 38 adults with IBD, Kiebles et al23 found that poorer illness perceptions were associated with increased disease activity and psychological distress and reduced QoL. With regard to coping, Hagger and Orbell22 identified that illness perceptions correlated significantly with both coping styles and psychological morbidity. For example, chronic disease activity and negative illness perceptions in serious disease consequences were associated with poorer psychological well-being. Strong illness perceptions such as reduced perceived disease control were found to have significant correlations with maladaptive coping styles such as avoidance and adaptive coping styles such as seeking social support. As noted by Dorrian et al,24 only a small number of studies have evaluated directly the possible influence of coping on the relationship between illness perceptions and psychological morbidity. Of those studies that have explored coping as a mediator in the CSM, limited evidence has been identified.22

To date, only one study has explored the utility of applying the CSM in an IBD sample. In 81 adults diagnosed with CD or UC, Dorrian et al24 provided partial evidence for the role of disease activity, illness representations, and coping on individual outcomes such as psychological distress and QoL. Two measures of QoL were used, the Inflammatory Bowel Disease Questionnaire and the Functional Limitations Profile. The authors demonstrated that illness representation (illness perceptions) had a significant adverse impact on psychological distress and QoL. No evidence was found that emotion-focused coping styles would adversely influence psychological distress and QoL, or that problem-focused coping-style would reduce psychological distress and improve QoL.

Using Structural Equation Modeling (SEM), the aim of the current study was to explore the utility and value of the CSM in patients with CD. We hypothesized that disease activity, that is, illness stimuli, would have an adverse correlation with illness perceptions and psychological distress, specifically anxiety and depression. It was also hypothesized that an interrelationship would exist between disease activity, coping style, illness perceptions, and psychological distress.

PATIENTS AND METHODS

Patients

Ninety-six adults (34 males, 62 females) with CD from the IBD clinic in one teaching hospital were studied. The average age was 37.80 (SD = 13.70). Of the 96 participants, 45% were married or living together with a partner, 34% were single, and 6% were divorced; 15% did not identify relationship status. Patients' mean disease duration was 11 years, 46% had active disease (as defined by a Crohn's Disease Activity Index [CDAI] score over 150) at the time of interview, 42% reported no history of surgery, 58% reported an average of 2 (SD = 1) surgical procedures, 6% had an ileostomy or colostomy, and 39% had past or present fistulizing disease.

Inclusion criteria included: definite diagnosis of CD and age between 18 and 40 years. Ethical approval to conduct this research was obtained from the St Vincent's Hospital and Swinburne University of Technology Human Ethics Research Committees.

Disease Assessment and Questionnaires

CDAI (Best et al26)

The CDAI is an 8-item questionnaire used to evaluate the severity of CD that is completed by the patient and clinician. The CDAI is regarded as the standard for evaluating disease severity. It evaluates a patient's health in relation to their CD and includes measurement of their pain, diarrhea, general well-being, the presence of extraintestinal symptoms such as arthralgia, fever, fistula, or fever, and concurrent use of antidiarrheal medication. Clinicians record the weight, hematocrit, and the presence of abdominal masses. A CDAI score less than 150 is regarded as representing clinical remission, while a score over 300 indicates severe disease activity.26

Brief Illness Perceptions Questionnaire (BIPQ; Broadbent et al27)

The BIPQ is a 9-item questionnaire exploring the emotional and cognitive representations of illness. The BIPQ is a shortened version of the widely used 80-item Illness Perception Questionnaire – Revised (IPQ-R) by Weinman, Petrie, Moss-Morris, and Horne (1996, cited in Broadbent et al27). Consistent with the IPQ, the BIPQ explores perception of illness across eight dimensions: consequences, timeline, personal control, treatment control, identity, concern, understanding, and emotional response. Each item is assessed on an 11-point Likert scale. For example, “How much does your illness affect your life: 0 [not at all] – 10 [severely affects my life].”

To further improve model fit and internal consistency, all four questionnaires were evaluated in a confirmatory factor analyses (CFA) using the Amos statistical package (v. 16) and Cronbach alpha with item-if-deleted analyses. Illness perception was found to have a good model fit (χ2P > 0.05; χ2/N = 1–3, CFI > 0.095, RMSEA < 0.07, CFI > 0.95, GFI > 0.95) and strong internal consistency (0.76) using 5 items: “How much does your illness affect your life,” “How much do you experience symptoms from your illness?,” “How concerned are you about your illness?, “How well do you feel you understand your illness?,” “How much does your illness affect you emotionally?.” Illness perceptions scores were attained by averaging the items, subscale ranges 0–10, with higher scores reflecting a poorer emotional and cognitive representation of illness.

Carver Brief Coping Questionnaire (Brief-COPE; Carver28)

The Brief-COPE is a 28-item questionnaire exploring the ways in which individuals tend to cope with a stressor. Traditionally, the brief-COPE has 14 subscales, each scored using two subitems, scored on a 4-point Likert scale: 0 (I haven't been doing this at all) to 3 (I've been doing this a lot). Consistent with Carver et al,29 a Principal Component Analysis (PCA) with an Oblim rotation was performed using all 28 items. Review of the scree plot (eigenvalues over 1) and component pattern matrix (minimum of 2 items in each component), suggested a four component structure solution. To further improve model fit and internal consistency, all four components were evaluated in a CFA and Cronbach alpha with item-if-deleted analyses. Only two coping styles were found to have a good fit and strong internal consistency (Cronbach alpha >0.7), these were identified as emotion-focused and problem-focused coping.

Emotion-focused coping had 7 items: “I've been giving up trying to deal with it,” “I've been refusing to believe that it has happened,” “I've been saying things to let my unpleasant feelings escape,” “I've been criticizing myself,” “I've been giving up the attempt to cope,” “I've been expressing my negative feelings,” and “I've been blaming myself for things that happened,” with an internal consistency of 0.76.

Problem-focused coping had 9 items: “I've been turning to work or other activities to take my mind off things,” “I've been concentrating my efforts on doing something about the situation I'm in,” “I've been taking action to try to make the situation better,” “I've been trying to see it in a different light, to make it seem more positive,” “I've been trying to come up with a strategy about what to do,” “I've been looking for something good in what is happening,” “I've been doing something to think about it less, such as going to movies, watching TV, reading, daydreaming, sleeping, or shopping,” “I've been accepting the reality of the fact that it has happened,” and “I've been thinking hard about what steps to take,” and an internal consistency of 0.82. Each of the subscale scores were attained by averaging the items, subscale ranges 0–3, with higher scores indicating a greater engagement in emotion- or problem-focused coping.

Hospital Anxiety and Depression Scale (HADS; Zigmond and Snaith30)

The HADS is a 14-item self-report questionnaire assessing levels of anxiety (ANX; 7 items) and depression (DEP; 7 items) over the past week. Each question is assessed on a 4-point Likert Scale: “I feel tense or ‘wound up’” 0 = not at all 3 = most of the time). Traditionally, using the 7-item subscales, mean subscale values are interpreted as 0–7 (normal), 8–10 (mild), 11–15 (moderate), and 16–21 (severe) (31), this cutoff of 8/9 to differentiate normal from mild to severe distress has been validated recently.32

Confirmatory factor analyses and Cronbach alpha with item-if-deleted analyses for anxiety and depression were conducted. Anxiety was found to have a good model fit and strong internal consistency (0.78) using 4 items: “I get a sort of frightened feeling as if something awful is about to happen,” “I get a sort of frightened feeling like ‘butterflies’ in the stomach,” “I get sudden feelings of panic,” and “I feel restless as if I have to be on the move.” Depression was also found to have good model fit and strong internal consistency (0.87) using 6 items: “I still enjoy the things I used to enjoy,” “I can laugh and see the funny side of things,” “I feel cheerful,” “I have lost interest in my appearance,” “I look forward with enjoyment to things,” and “I can enjoy a good book or radio or TV program.” Each of the subscale scores were attained by averaging the subscale items (subscale ranges 0–3), with higher scores indicating a greater severity.

Methods

Patients attending the outpatient IBD clinic were invited to participate in the study. Attending gastroenterologists were asked to complete the CDAI score. Patients could complete the questionnaire at a time and place convenient to them and were asked to return the questionnaire using a prepaid envelope. All questionnaires were used in their original and unaltered form.

Statistical Analyses

Exploratory analysis and visual inspection of the data indicated that all of the study variables met the necessary assumptions for statistical analysis (e.g., normality, linearity). With the exception of the CDAI, initial CFA and Cronbach alpha analyses were undertaken for all questionnaires. Correlational analyses were undertaken to compare the relationship between the study variables: disease severity (CDAI), illness perceptions (BIPQ), emotion-focused coping and problem-focused coping (COPE), and anxiety and depression (HADS). Consistent with the CSM, a saturated structural equation model was specified using the Amos statistical package. The final model was derived by an iterative process of removing nonsignificant pathways or variables that did not add significantly to the model's fit.

RESULTS

The demographic and disease characteristics of the 96 participants in this study were similar to previous research undertaken in the same department.33 Overall, 46% reported active IBD activity (CDAI score greater than 150). Regarding levels of psychological distress, 55% reported mild anxiety symptoms while 10% reported severe anxiety symptoms. Forty-one percent reported mild depression symptoms while 3% reported severe depressive symptoms.

As shown in Table 1 (descriptive and correlational analyses), disease severity had a significant positive correlation with illness perceptions, anxiety and depression suggesting that individuals with greater illness symptoms reported lower positive perceptions relating to their illness and greater anxiety and depression symptoms. Disease severity also had a significant positive correlation with problem-focused coping, suggesting that as the disease severity increased, so did the engagement in problem-focused coping strategies. There was no significant correlation found between disease severity and emotion-focused coping.

Table 1. Pearson's Correlations (and Significance Values) and Descriptive Values of CSM Variables
 Disease SeverityIllness PerceptionsEmotion- focused CopingProblem- focused CopingAnxietyDepressionMean (SD)
  • a

    Based on the traditional HADS scoring procedure with all 7 subscale items, the mean anxiety score was 8.96 (SD=3.6) and mean for depression was 7.65 (SD=3.66), the total mean HADS was 16.61, (SD=6.04).

Disease severity157.20 (109.48)
Illness perceptions0.46 (<.001)6.98 (1.41)
Emotion-focused coping0.12 (.26)0.35 (<0.001)0.77 (0.60)
Problem-focused coping0.24 (<0.05)0.28 (<0.01)0.31 (<0.01)1.59 (0.63)
Anxiety0.25 (<0.05)0.43 (<0.001)0.37 (<0.001)0.18 (>0.05)1.15 (0.71)a
Depression0.25 (<0.05)0.47 (<0.001)0.52 (<0.001)−0.01 (>0.05)0.44 (<0.001)1.12 (0.70)a

Illness perceptions were found to have a significant positive correlation with emotion- and problem-focused coping and psychological distress. These results suggest that as an individual's perceptions become more hopeless, so did their engagement in both emotion- and problem-focused coping and severity of psychological distress.

Emotion-focused coping had a significant positive correlation with problem-focused coping and psychological distress, suggesting that engagement in emotion-focused coping was associated with increased engagement in problem-focused coping and increased psychological distress. Problem-focused coping had a significant positive correlation with anxiety and a nonsignificant correlation with depression. These results suggest that while engagement in problem-focused coping was associated with increased anxiety, it had no significant impact on depression. Finally, anxiety was found to have a significant positive correlation with depression, indicating that individuals with higher levels of anxiety also reported higher levels of depression.

Consistent with the CSM, disease severity, illness perceptions, emotion- and problem-focused coping and psychological distress (anxiety and depression symptoms) were specified in a structural equation model. The initial model was saturated and included the addition of demographic details (age, gender, age at onset). Based on CFA, the validated measurement models of each variable were represented as latent variables. To reduce for measurement error in the model, single indicator latent variables were specified with subscale internal consistency and variance.

The final model was derived by removing nonsignificant pathways or variables that did not add significantly to the model's fit. As recommended by Hu and Bentler,34 criteria used to specify paths or variables to be removed were based on inspection of standardized residuals, modification indices, and a significant improvement in fit (i.e., significant change in χ2/N and an increase in standard goodness of fit measures [χ2P > 0.05; χ2/N = 1–3, RMSEA < 0.07, CFI > 0.95, GFI > 0.95]). After the path or variable with the poorest fit was removed the change in standard goodness of fit measures were assessed. This process of removal continued until the final model was both parsimonious, theoretically valid, and provided the best fit. Based on this iterative process, several paths and variables were identified as being nonsignificant contributors to the model, including all of the demographic variables and the pathway between disease severity and emotion- and problem-focused coping and depression and anxiety. The pathway between problem-focused coping and anxiety was also found to be nonsignificant and was removed. The final model (Fig. 2) is presented.

Figure 2.

Final CSM solution (note: only latent variables presented with error terms removed; ***P < 0.001, **P < 0.01, *P < 0.05).

Despite the small sample size, the final model had an excellent fit (χ2 (7) = 10.42, P = 0.17, χ2/N = 1.49, RMSEA < 0.07, CFI > 0.97, GFI > 0.97). The total amount of variance accounted for each of the variables was also good, 26% of illness perceptions, 21% of emotion-focused coping, 13% of problem-focused coping, 66% of depression symptoms, and 39% of anxiety symptoms.

Consistent with the CSM and the study hypotheses, disease activity had a significant direct influence on illness perceptions (β = 51, P < 0.001). Illness perceptions had a significant direct influence on depression and anxiety (β = 41, P < 0.001, β = 0.40, P < 0.001, respectively). Also consistent with the CSM and study hypotheses were the findings of several indirect (mediating) pathways: illness perceptions mediated the correlation between disease severity and emotion-focused and problem-focused coping; emotion-focused coping mediated the correlation between illness perceptions and depression and anxiety; and problem-focused coping mediated the correlation between illness perceptions and depression. Not supporting the study hypotheses was failure to attain a mediating correlation between problem-focused coping and anxiety. There was a positive correlation between depression and anxiety (P < 0.05).

DISCUSSION

The current study aimed to explore the extent to which psychological factors, individual coping styles, and disease activity contributed to CD patients' anxiety and depression. Almost half the patients had active CD at the time of the study. Based on the HADS scores, 55% of the sample reported mild levels of anxiety, and 41% of the sample reported mild levels of depression, while the levels of severe anxiety and depression, 10%, and 3%, respectively, were lower than the 33% reported by Dorrian et al24 in other conditions, our results are consistent with previous studies in IBD that have reported moderate to high levels of psychological distress.2–9

Disease activity, that is, illness stimuli, had an adverse relationship with illness perceptions and psychological distress. As the symptoms of CD become more severe, so did the negative perceptions relating to CD-related illness perceptions and levels of psychological distress. These findings accord with previous research indicating a strong adverse relationship between illness activity and anxiety and depression,22 and between illness perceptions and psychological distress and QoL.22, 23, 35, 36

Poor illness perceptions were related to increased coping activity, both problem- and emotion-focused. Emotion-focused coping activity had an adverse, while problem-focused coping activity had a beneficial, relationship with anxiety and depression. These findings are similar to previous findings22 and suggest that engagement in emotion-focused coping, such as denial, or venting emotions, is associated with increased anxiety and depression, while engagement in problem-focused coping, such as thinking positively, or planning, is associated with reduced anxiety and depression.

To address previous recommendations22 regarding the improved specificity of CSM within illness samples, this study first sought to ensure that each variable (with the exception of disease severity; CDAI) specified in the structural equation CSM were statistically validated using both CFA and Cronbach alpha analyses. The CFA led to a reduction in the number of items in each scale, resulting in each subscale becoming more parsimonious, valid for the sample being evaluated, and with improved psychometric properties. Consequently, the final CSM evaluated by the SEM was found to have a good fit. The utilization of the SEM also provided several other advantages including the ability to statistically evaluate all the variables, and direct and indirect (mediation) relationships, simultaneously.

A major finding of this study, which confirms one of the main tenets of the CSM,21, 22 is that disease activity indirectly impacts anxiety and depression, via illness perceptions, and, in turn, coping strategies. Dorrian et al24 found that, after accounting for disease severity, illness perceptions added significantly to the prediction of both psychological distress and quality of life.

Emotion- and problem-focused coping styles acted as mediators between illness perceptions and depression. Emotion-focused coping exacerbated or led to depression and anxiety, while problem-focused coping reduced depression, but not anxiety. These results are consistent with previous studies demonstrating that problem-focused coping styles are associated with increased well-being and reduced psychological distress,13–16 while emotional focused coping is associated with reduced well-being and increased psychological distress.15, 17–20

Our findings indicate the importance of understanding and taking into account in the therapeutic relationship psychological aspects of illness in this group of patients. Identification of specific perceptions and coping strategies, especially those that are emotionally oriented, may be critical to effective clinical management. By identifying and assessing these important mediators of psychological outcomes, physicians and counselors may be better able to help individuals cope with the strong emotional demands associated with the intense long-term effects of CD. A strong focus on taking into account a patients illness perceptions, and on minimizing emotional coping strategies while enhancing problem-solving skills, may provide an important means of reducing the anxiety and depression associated with this chronic condition.

A sample size of over 200 is sometimes suggested for this type of study.37 However, as we were testing a previously proven model with strong theoretical underpinnings, a smaller sample seemed to be appropriate. Further, with the exception of the CDAI, we statistically validated all variables specified in the model to improve model specificity and reduce measurement error. Our study did not include or measure pain impairment, occupation, or educational status.24 Lastly, only two psychological outcomes—depression and anxiety—were measured. Future studies could include other illness outcome measures such as QoL, work-life balance, and social and role functioning. Given the differences between CD and UC, future research should also compare the possible differences between UC and CD on the CSM. Future research could also extend upon the CSM by adding factors that have been identified in the IBD literature that influence illness or QoL outcomes, including personality,38, 39 self-efficacy and self-esteem,40 and coping strategies such as yoga, meditation, mindfulness, and relaxation.41

In conclusion, our study has elucidated aspects of the interrelationship, in this serious chronic condition, between disease activity, illness perceptions, coping strategies, and depression and anxiety. Illness severity directly influences illness perceptions, which, in turn, influences coping strategies. The nature of coping mechanisms influences the development of psychological morbidity, namely, depression and anxiety. These findings provide direction for the psychological support that patients with CD require.

Acknowledgements

The authors thank all the participants for the support and interest in our research. We also thank Dr. Denny Meyer and Dr. Jason Skues for statistical advice regarding SEM used in this study.

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