Table 3

Summary of measurement properties of HRQoL instruments used in SLE

Instrument	Floor/ceiling effect	Internal consistency	Test–retest reliability	Convergent validity	Discriminant validity	Known-group validity	Responsiveness	MID	Generalisability	Cross-cultural validation	Responsiveness in RCTs
SF36	Present in some domains.	Cronbach’s α≥0.71.	Not assessed.	Valid.	Valid.	Some evidence but effect size not reported.	Poor in most domains and inconsistent across anchors.	Available.	Yes.	Chinese, French and Turkish versions.	Changes from baseline were ≥MID in most studies but between-arm differences did not reach MID.
EQ5D	None reported.	Not assessed.	Not assessed.	Valid.	Valid.	Inconclusive evidence; effect size not reported.	Not responsive.	Not available.	Yes.	Chinese version.	Current evidence is limited and inconclusive.
FACIT-Fatigue	Not assessed.	Cronbach’s α≥0.95.	Not assessed.	Valid.	Valid.	Partially.	Medium responsiveness to clinical improvements but not deteriorations; responsive to patient-reported changes in health.	Available.	No indication of clinical disease activity, damage or disease duration.	None.	Current evidence is limited and inconclusive.
PROMIS item-bank	Ceiling effects reported for 29-item profile but not PROMIS CATs.	Cronbach’s α≥0.88.*	ICC>0.7.	Valid.	Valid.	Demonstrated.	Not reported.	Not available.	Yes.	None.	Not used in RCTs.
LupusQoL	Present in some domains.	Cronbach’s α≥0.85.	ICC≥0.68.	Valid.	Valid.	Some evidence but effect size not reported.	Poor in most domains and inconsistent across anchors.	Available.	Yes.	Italian, French, Spanish, Chinese, Turkish and Farsi versions.	Used in one RCT but data not reported.
LupusPRO	Present in some domains.	Cronbach’s α≥0.60.	ICC≥0.55.	Valid.	Valid.	Some evidence but effect size not reported.	Scores changed significantly in response to longitudinal changes in health but effect size has not been reported.	Not available.	Yes.	Tagalog, Turkish, Spanish, French, Italian, Japanese, and Chinese versions.	Not used in RCTs.
LIT	Not assessed.	Cronbach’s α≥0.84.	ICC≥0.83.	Valid.	Valid.	Some evidence but effect size not reported.	Some evidence for medium responsiveness to clinical improvements but not deteriorations.	Available.	Yes.	German, Italian, Spanish, Swedish and French versions.	Not used in RCTs.

*Internal consistency of PROMIS CATs remains to be established.
CAT, Computer Adaptive Tests; EQ5D, EuroQol-5D; FACIT-Fatigue, Functional Assessment of Chronic Illness Therapy-Fatigue;ICC, intraclass correlation; LIT, Lupus Impact Tracker; LupusPRO, Lupus Patient Reported Outcomes; LupusQoL, Lupus Quality of Life questionnaire; MID, minimally important differences; RCTs, Patient Reported Outcomes Measurement Information System item-bank; RCTs, randomised controlled trials; SF36, Medical Outcomes Study Short-Form 36.