Factors associated with pain coping and catastrophising in patients with systemic lupus erythematosus: a cross-sectional study of the LuLa-cohort

Introduction

Patients with systemic lupus erythematosus (SLE) suffer from possible involvement of numerous organ systems, and often from pain,1–3 fatigue,1 ,4–6 sleep disorders,1 ,5 ,7 ,8 fear,9 depression9–13 and cognitive deficits.14–19 These complaints, either as an independent condition or associated or aggravated by the disease, are frequently linked to physical and mental restraints. Coping describes a set of intentional, goal-directed efforts people engage in to minimise physical, psychological or social harm of an event or a situation.20 It encompasses behavioural and psychological strategies. These strategies can help in dealing with stress caused by the disease and are associated with a better health related quality of life (HRQoL) in patients with SLE.21 In this work we subsume the beneficial effects of coping with pain under the term ‘coping’. In contrast catastrophising represents a maladaptive cognitive style employed by patients and is associated with an irrationally negative forecast of future events.

Coping is more efficient in an existing reliable social network, which may provide socioemotional support.22 The latter has a high impact on disease activity, damage and quality of life.23 As patients with SLE frequently report a poorer social support than healthy controls,24 it represents a modifiable option to enhance coping behaviour. Former studies demonstrated positive influence of physical activity on fatigue in SLE25–27 and pain as well as physical function in other rheumatic diseases.28 Referring to these results we hypothesised that physical activity might have an influence on coping strategies as well.

In contrast it is known that catastrophising may have serious impact on chronically ill patients in general and patients with SLE in particular.29 Maladaptive coping characterised by catastrophising is associated with increased pain experience30 and predicts higher levels of pain in patients with chronic rheumatic diseases (eg, fibromyalgia syndrome and rheumatoid arthritis).31 Furthermore, catastrophising and maladaptive coping strategies are linked to higher levels of functional impairment and depression in rheumatoid arthritis32 and SLE.33 Numerous other studies verified the negative influence of catastrophising, respectively, suboptimal coping strategies on the outcome of various other chronic diseases by occurrence of depressive symptoms,34 ,35 reduced cognitive performance36 or even an increased risk for suicide.37

As psychological interventions and education are able to increase coping abilities in patients with SLE and can thus improve their quality of life,38 it is of major importance to explore the main stressors that affect coping behaviour.

The aim of this study was to identify factors that are associated with our outcomes pain coping and catastrophising in patients with long-standing SLE and to detect possible susceptible targets for intervention. Therefore, we analysed several demographic parameters, disease related outcomes, physical activity, physical and mental functioning, social participation and their impact on pain coping and catastrophising.

Methods

The data was collected within the lupus erythematosus long-term study (LuLa-study), a prospective, patient-centred study investigating the long-term management and course of disease as well as quality of life in patients with SLE. Data collection started in 2001 with annual postal questionnaires among members of the German Lupus Erythematosus Self-Help Organisation. Inclusion criteria were a reported diagnosis of SLE, being a member of the German Lupus Erythematosus Self-Help Organisation and having returned the completed questionnaire. Prior evaluation of the LuLa cohort showed that its data is comparable to physician-reported data and thereby is representative of patients with SLE in Germany.39 In 2009 we surveyed for 18 comorbidities (hypertension, myocardial infarction, stroke, chronic kidney damage, diabetes, cancer, chronic respiratory disease, chronic liver damage, chronic gastrointestinal disorders, hypercholesterolaemia, mental illness, arthrosis, scarring changes of skin, osteoporosis, fibromyalgia, thrombosis, miscarriages, early menopause), lupus-specific drugs, sociodemographic characteristics, inability to work, degree of disability (%), HRQoL measured by the Short Form 12 Health Survey (SF-12),40 ‘pain in the last 7 days’ (NRS 0–10), ‘impairment in the last 7 days’ (NRS 0–10), disease flares during the last 3 months, disease activity measured by the Systemic Lupus Activity Questionnaire (SLAQ),41 health related physical activity assessed by the Freiburg Questionnaire for Physical Activity (FFkA),42 situation-specific aspects of the patients’ cognitive coping with pain (‘catastrophising’ and ‘coping’), measured by the Pain-Related Self Statements Scale (PRSS),43 fatigue measured by the Vanderbilt Fatigue Score (VFS),44 and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI).45–47 Most assessments were self-reported, only for the SLICC/ACR DI patients were asked to let their physician complete the questionnaire. All questionnaire items were assessed at the same time. Due to the questionnaire's length specific instruments regarding socioemotional support had to be omitted. Therefore we used a construct using other variables.

Results

The LuLa 2009 cohort included 620 patients of whom 173 reported no pain (86,1%) or did not answer the PRSS questionnaire (13,9%). This resulted in 447 cases (94.9% female) with a mean age of 52.0 years (SD 12.5) and mean disease duration of 16.1 years (SD 8.1), which were included in the analyses. The analysis of the PRSS subscales showed a mean catastrophising score of 1.1 (SD 0.8) and a mean coping score of 2.8 (SD 0.9). Details and further results of self-reported disease activity, damage, current treatment, employment status, assessments of general health and physical functioning are listed in table 1.

Table 2 opposes four groups of different catastrophising and coping levels. Higher catastrophising centiles (upper quartile) are associated with higher experienced pain, current lupus activity (SLAQ score), fatigue (VFS score), damage (SLICC/ACR DI scores) and a decrease of HRQoL domains (SF-36-pfi, SF-12 PCS and SF-12 MCS) whereas they present inversely for coping (table 2).

Nine out of the 18 acquired comorbidities showed significant association to the PRSS subscale catastrophising with higher catastrophising means in presence of comorbidities than in absence (table 3).

A relationship between coping and comorbidities was not observed. Three of the nine comorbidities with significant association remained significant after Bonferroni correction (p value <0.003). These three comorbidities ‘chronic gastrointestinal disorders’ (p value 0.002), ‘mental illness’ (p value <0.001) and ‘scarring changes of skin’ (p value <0.001) were included in the MVA but did not show significant association to catastrophising any more.

In total, 52 patients (11.6%) participated in the bowling and dancing activities, whereby 31 (7.0%) participated in dancing, 13 (2.9%) in bowling and 8 (1.8%) in both. This was considered as social participation.

As shown in table 4, coping presented statistical significance for ‘social participation’ in the UVA (p value 0.001) and the MVA (p value 0.006). Mean coping was significantly higher in participants with social participation than without (mean 3.2 vs 2.8). ‘SF-12 MCS’ was significant for both PRSS subscales in the UVA (p value catastrophising <0.001; p value coping 0.001) but only significant for catastrophising in the MVA (p<0.001). Catastrophising demonstrated a multitude of significant correlations with different disease parameters and conditions among others SF-12, SLAQ, SLICC/ACR DI and disease flares during last 3 months. The variables ‘pain in the last 7 days’ (correlation coefficient 0.420), ‘impairment in the last 7 days’ (correlation coefficient 0.388), fatigue (VFS score) (correlation coefficient 0.367) and disease activity (SLAQ score) (correlation coefficient 0.475) evinced the highest correlation coefficients (table 4).

After Bonferroni correction all significant variables of the UVA were included in the MVA. Four variables reached statistical significance regarding catastrophising (‘number of lupus-specific drugs’ (p value 0.004), ‘pain in the last 7 days’ (p value 0.034), ‘SF-12 MCS’ (p value <0.0001), and ‘SLAQ score’ (p value 0.042)), and one (‘social participation’; p value 0.006) regarding coping.

Parameters for basic, sports and leisure activities, assessed by the FFkA, were also compared with the two PRSS subscales. However, none of the activity parameters or the extent of health related physical activity showed a coherent statistical significance regarding pain coping and catastrophising.

Discussion

Despite the numerous recent advances in research and clinical treatment, SLE keeps being an incurable chronic disease with a huge impact on persons’ lives by affecting patients’ physical and mental functioning. Former studies illustrated that coping capacities help in dealing with the disease and are associated with a better HRQoL.21

The PRSS results from our cross-sectional study in SLE depicted significantly worse catastrophising and coping scores than reported from healthy controls.43 Coping presented worse in our cohort compared with patients with chronic pain but was similar to patients suffering from TMPD.43 In contrast our cohort presented significantly less catastrophising.43 As pain related catastrophising differs in younger and older adults55 these differences may partly be explained by the younger age in Flor's cohort43 (42.4 years vs 52.1 years). Compared with patients with fibromyalgia56 our SLE cohort showed lower amount of catastrophising and coping. This might be attributed to a high rate of depression in the fibromyalgia cohort and to the inclusion of patients participating in pain management programmes.56

We identified valuable parameters that seem to influence the occurrence of either catastrophising or coping in patients with SLE. Yet it should be noted that cross-sectional studies limit the ability to make causal assumptions between the predictors and outcomes.

First, our results demonstrated that patients with SLE with our above mentioned comorbidities catastrophise more than those without, which emphasises the impact of these specific comorbidities in patients with SLE. Studies from other chronic diseases support our findings.57 ,58 Thus it is of importance that ‘scarring changes of skin’,59 ‘mental illness’60 and ‘gastrointestinal disorders’61 might also be attributable to lupus and are preventable by an early and optimised lupus therapy.

Second, we found statistically significant associations between the number of lupus-specific drugs, pain, ‘SF-12 MCS’, damage and catastrophising. In detail the high correlation between the ‘experienced pain in the last 7 days’ and catastrophising (Table 4) confirms findings from former studies depicting that the experience of pain in rheumatological disorders is closely related to catastrophising.29 ,31 ,62

The moderate correlation between ‘SF-12 MCS’ (a proxy for depression and anxiety) and catastrophising presented in our work substantiates the fact that suboptimal mental health is associated with catastrophising, which has already been demonstrated in former studies.34–37

Besides, we showed that the ‘number of lupus-specific drugs’ significantly increases with a higher catastrophising score. Yet, it has not been clarified whether a rising amount of medication leads to increased catastrophising or vice versa. Consequently, physicians should be aware of possible aggravations and ought to apply objective criteria for the choice of medication.

Third, referring to coping, the variable ‘social participation’ reached statistical significance in the MVA. This is allegeable by the numerous positive effects associated with an existing social network and the provided socioemotional support.22 An obviously anticipated reciprocal correlation between the amount of pain coping and catastrophising could likewise be shown in our work. This indicates that a sufficient manner of coping (eg, by increasing social participation/activity) might be helpful to reduce catastrophising and consequently improve physical and mental functioning in SLE (Table 2).

In addition, it needs to be considered that catastrophising, pain, disability and mood-emotional functioning might bias the questionnaire's response behaviour. Patients might indicate a poorer health condition than it actually is because of their tendency to catastrophise, their experienced severity of pain, their physical functioning and/or psychological condition. Our results depicted in table 2 support this hypothesis, as the group of the strongest catastrophiser (upper quartile) showed poorer values for all mentioned variables than the others (lower quartile, 25–50%, 50–75%). A similar observation was published by Mancuso et al63 who detected that patients with asthma with more depressive symptoms reported worse HRQoL than patients with asthma with similar disease activity but fewer depressive symptoms. These findings emphasise that psychological conditions might have an impact on patients’ response behaviour.

Most of our identified key factors that interact with pain coping strategies (number of lupus-specific drugs, pain, mental health, disease activity) have been identified as disease aggravating factors in the SLE treat-to-target recommendations published in 2014.64 They can be modified by an effective therapy which is regularly adjusted to lupus manifestations and individual needs. Furthermore pain and mental health as well as pain coping and catastrophising can effectively be improved by using psychological or psychoeducational interventions,38 ,65–68 which among others aim at increasing the self-efficacy of patients.

Conclusion

Our work points out that in order to optimise pain coping and catastrophising in the care of patients with SLE and to affect patients’ physical and mental functioning, positive factors should be protected and promoted and negative factors need to be prevented. In this context social participation represents an essential positive factor whereas negative ones include disease activity, pain, impairments and an extensive lupus-specific medication. Further studies are necessary to determine which patients benefit most from a psychoeducation and to identify the impact of revised modifiable parameters on coping strategies.