Disability, fatigue, pain and their associates in early diffuse cutaneous systemic sclerosis: the European Scleroderma Observational Study

Abstract

Objectives: Our aim was to describe the burden of early dcSSc in terms of disability, fatigue and pain in the European Scleroderma Observational Study cohort, and to explore associated clinical features.

Methods: Patients completed questionnaires at study entry, 12 and 24 months, including the HAQ disability index (HAQ-DI), the Cochin Hand Function Scale (CHFS), the Functional Assessment of Chronic Illness Therapy-fatigue and the Short Form 36 (SF36). Associates examined included the modified Rodnan skin score (mRSS), current digital ulcers and internal organ involvement. Correlations between 12-month changes were also examined.

Results: The 326 patients recruited (median disease duration 11.9 months) displayed high levels of disability [mean (s.d.) HAQ-DI 1.1 (0.83)], with 'grip' and 'activity' being most affected. Of the 18 activities assessed in the CHFS, those involving fine finger movements were most affected. High HAQ-DI and CHFS scores were both associated with high mRSS (ρ = 0.34, P < 0.0001 and ρ = 0.35, P < 0.0001, respectively). HAQ-DI was higher in patients with digital ulcers (P = 0.004), pulmonary fibrosis (P = 0.005), cardiac (P = 0.005) and muscle involvement (P = 0.002). As anticipated, HAQ-DI, CHFS, the Functional Assessment of Chronic Illness Therapy and SF36 scores were all highly correlated, in particular the HAQ-DI with the CHFS (ρ = 0.84, P < 0.0001). Worsening HAQ-DI over 12 months was strongly associated with increasing mRSS (ρ = 0.40, P < 0.0001), decreasing hand function (ρ = 0.57, P < 0.0001) and increasing fatigue (ρ = -0.53, P < 0.0001).

Conclusion: The European Scleroderma Observational Study highlights the burden of disability in early dcSSc, with high levels of disability and fatigue, associating with the degree of skin thickening (mRSS). Impaired hand function is a major contributor to overall disability.

Keywords: disability; early diffuse cutaneous systemic sclerosis; fatigue; hand function; pain.

Fig. 1

Baseline distribution of disability indicators CHFS: Cochin Hand Function Scale; FACIT: Functional Assessment of Chronic Illness Therapy; HAQ-DI: HAQ disability index; MCS: mental component summary; PCS: physical component summary; SF36: Short Form 36 Health Survey; sHAQ: Scleroderma HAQ.

Fig. 2

Composition of disability indicators at baseline For each questionnaire item, the distribution of answers is displayed based on the number of respondents for each individual question. CHFS: Cochin Hand Function Scale; FACIT: Functional Assessment of Chronic Illness Therapy; HAQ-DI: HAQ disability index.

Fig. 3

Associates of HAQ disability index For the relation between HAQ-DI and binary variables (here current digital ulcers and pulmonary fibrosis), box plots (with median and interquartile ranges) summarize the distribution of the index within each level of the binary variable. In addition, a strip plot shown next to each box plot gives more detail on the dispersion of all individual points. For the relation between HAQ-DI and continuous variables (here mRSS, CHFS and sHAQ Pain VAS), a scatter plot is shown for each pair and superimposed with a linear regression line to describe the correlation direction. CHFS: Cochin Hand Function Scale; mRSS: modified Rodnan skin score; sHAQ: Scleroderma HAQ.

Fig. 4

Associates of Cochin hand function scale For the relation between CHFS and binary variables (here current digital ulcers and pulmonary fibrosis), box plots (with median and interquartile ranges) summarize the distribution of the index within each level of the binary variable. In addition, a strip plot shown next to each box plot gives more detail on the dispersion of all individual points. For the relation between CHFS and continuous variables (here mRSS and sHAQ Pain VAS), a scatter plot is shown for each pair and superimposed with a linear regression line to describe the correlation direction. CHFS: Cochin Hand Function Scale; mRSS: modified Rodnan skin score; sHAQ: Scleroderma HAQ.

Fig. 5

Co-movements of skin score and disability indicators in first 12 months These four scatter plots describe the 12 month changes in mRSS (overall and in fingers and hand dorsum) with respect to the change in HAQ-DI and CHFS. In each axis, the symbol Δ denotes change. A regression line shows in each case the marginal effect of a 1 unit increase in the skin score, equal to the regression coefficient (β), shown here alongside its significance P-value. CHFS: Cochin Hand Function Scale; HAQ-DI: HAQ disability index; mRSS: modified Rodnan skin score.