Health-related quality of life in patients with mixed connective tissue disease: a comparison with matched systemic sclerosis patients.

Objectives: Health-Related Quality of Life (HRQoL) in adult patients with mixed connective tissue disease (MCTD) has not been described so far. Therefore, we performed an explorative study to evaluate HRQoL in MCTD patients.

Methods: MCTD patients fulfilling the Kahn criteria and participating in the prospective follow-up cohort for MCTD of the Leiden University Medical Center were included; and matched to systemic sclerosis (SSc) patients based on age, sex and disease duration. Data on disease characteristics and HRQoL (SF36 and EQ-5D) were collected annually. HRQoL was compared between MCTD and SSc patients at baseline. Factors associated with HRQoL in MCTD were identified using linear regression and change in HRQoL over 3 years using linear mixed models.

Results: Thirty-four MCTD patients (121 visits) and 102 SSc patients (424 visits) were included. At baseline, MCTD patients presented with interstitial lung disease, cardiac involvement, synovitis and myositis more frequently compared to SSc patients, while use of immunosuppressive medication was less frequent. In both groups, mean SF36 scores were lower than in the general Dutch population. The SF36 subscore "general health perception" was impacted most in both groups (MCTD: 38.5 [SD:7.0], SSc: 39.9 [SD:8.9]). During follow-up, SF36 scores improved in MCTD patients, while EQ5DNL remained stable. No specific characteristics were identified that associated with baseline HRQoL or change in HRQol over time.

Conclusions: Like in SSc, HRQoL in MCTD is significantly impaired, especially the general health perception of patients. Evaluation in larger prospective cohorts is needed to identify characteristics that impact HRQol most.