Abstract
Background and aims To compare specific health-related quality of life (HR-QoL) questionnaire (SLE-QoL) with a generic HRQoL questionnaire (SF-36) and to examine their sensitivity to changes defined by the global rating for change (GRC).
Methods Patients attending a single-centre lupus clinic in Thailand completed both validated SLE-QoL and SF-36 questionnaires, and rated their global change in QoL compared to previous visit using a 7-point Likert scale (GRC). Patients were grouped into either ‘no change’ (control group), ‘deterioration’ or ‘improvement’ categories (GRC status). Physician global assessment (PGA, 0–3) scores were collected for clinician-assessed disease activity. Associations between GRC status and SLE-QoL/SF-36 scores were examined using generalised estimating equations. Cohen’s d effect sizes were estimated to compare mean changes in SLE-QoL and SF-36 scores.
Results The analysis included 248 patients with 1265 visits. Patients reported improvement in ˜59%, deterioration in ˜16% and no change in QoL in ˜25% of visits. PGA demonstrated statistically significant (p<0.01), negative correlations with GRC (r=−0.49), SLE-QOL (r=−0.49), SF-36PCS (r=−0.50) and SF-36MCS (r=−0.36) scores. In contrast, SLE-QoL scores correlated positively and significantly (p<0.01) with SF-36PCS (r=0.56) and SF-36MCS (r=0.60) scores. Compared to control group, mean scores of SF-36PCS, SF-36MCS and SLE-QoL surveys were significantly lower in the deterioration group (mean change –4.96,–3.21, and −6.51, respectively, p<0.01) but SF-36PCS and SLE-QoL were significantly higher in the improvement group (mean change 1.22 and 1.35 respectively, p<0.01). Cohen’s d effect sizes were similar for both questionnaires.
Conclusions Both SLE-QoL and SF-36 demonstrated similar, strong associations with GRC-based deterioration or improvement.
