Table 3.
Correlations between Pittsburgh Sleep Quality Index and clinical variables
| Variable | Spearman’s coefficient | p value |
|---|---|---|
| Age | 0.189 | 0.043 |
| EQ-5D score | –0.418 | 3.22 × 10–6 |
| Overall oral dryness VAS | 0.214 | 0.022 |
| XI score | 0.206 | 0.027 |
| Overall eye dryness VAS | 0.246 | 0.009 |
| Eyeball pain VAS | 0.192 | 0.043 |
| OSDI score | 0.246 | 0.008 |
| ESS | 0.288 | 0.002 |
| Arthralgia VAS | 0.312 | 0.001 |
| Myalgia VAS | 0.300 | 0.001 |
| Anxiety VAS | 0.278 | 0.003 |
| PGA VAS | 0.366 | 5.87 × 10–5 |
| FSS score | 0.402 | 8.58 × 10–6 |
| BDI-II score | 0.507 | 7.34 × 10–9 |
| ESSPRI | 0.432 | 1.44 × 10–6 |
| WBC counts | 0.236 | 0.011 |
| ANC | 0.234 | 0.012 |
| IgG levels | –0.218 | 0.019 |
| ESSDAI | –0.259 | 0.005 |
p values by the Spearman rank correlation test.
EQ-5D, EuroQol 5-dimensional questionnaire; VAS, visual analogue scale; XI, xerostomia inventory; OSDI, Ocular Surface Disease Index; ESS, European League Against Rheumatism (EULAR) sicca score; PGA, patient global assessment for Sjögren’s syndrome (SS); FSS, fatigue severity score; BDI, Beck Depression Inventory; ESSPRI, EULAR SS Patient Reported Index; WBC, white blood cell; ANC, absolute neutrophil counts; IgG, immunoglobulin G; ESSDAI, EULAR SS Disease Activity Index.