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(CNS), hematological, glandular, constitutional, lymphadenopathic, and biological
( Appendix 1 ). The ESSDAI is now in use as a gold standard, as the SLEDAI is in
lupus. In addition, ESSDAI started to be used as an outcome measure in randomized
controlled trials (RCTs) in SS, and even as the primary outcome measure in cur-
rently ongoing RCTs. Both ESSDAI and ESSPRI were reported sensitive to change
in response to therapeutic interventions. Recently, the defi nition of disease activity
levels and thresholds of minimal clinically important improvement (MCII) have
been proposed for that tool: a moderately active disease being defi ned as an
ESSDAI ≥ 5 and an MCII as a decrease of at least three points. These cut-offs have
started to be used, respectively, as entry criteria and primary end points for RCTs.
In this setting, enhancing the accuracy and the reliability of disease activity scoring
to correctly classify patients at study entry but also at fi nal evaluation is a crucial
point to determine the effi cacy of the drug under investigation [ 20 ].
Health-Related Quality of Life Measures in Sjögren’s Syndrome
Health-related quality of life ( HRQOL ) handles the patients’ physical and psycho-
logical well-being aspects as well as the impact of ill-health on the patient’s social
relationships. On the other hand, the term “quality of life” (QOL) is used to describe
the general well-being of individuals and societies [ 21 ]. Therefore, QOL studies
emphasize mainly the economic well-being. Assessment of HRQOL in SS is impor-
tant as it addresses the unique contribution of sicca manifestations as well as oral
health to more general measures of health and well-being, including activities of
daily living and social functioning. Tools for HRQOL assessment can be stratifi ed
into either generic or specifi c tools:
Generic Tools
The World Health Organization (WHO) developed a generic questionnaire to assess
QOL (the initial WHOQOL-100) [ 22 ]. This was further shorte ned into 26-items, the
WHOQOL-BREF [ 23 ]. The WHOQOL-BREF is composed of four domains,
namely: physical health, psychological, social relationships, and environment. In
comparison to the control group, primary SS patients were found to have reduced
QOL across the four WHOQOL-BREF domains [ 24 ]. In comparison to the other
chronic musculoskeletal infl ammatory conditions, while the pattern of affection in
primary SS patients showed similar pattern to systemic lupus erythematosus
patients, there were signifi cant differences in contrast to the rheumatoid arthritis
subgroup. RA patients had signifi cantly lower scores on the physical function
domain scale. The Short Form-36 (SF-36) [ 25 ] is another generic questionnaire that
has been used widely in different chronic disorders. The WHOQOL-BREF physical
scale scores correlated well with SF-36 vitality and physical domain scores.
M.O. Hegazi et al.