Table 1.
Epidemiological Features of subjects with incident primary Sjögren’s Syndrome diagnosed in Olmsted County, Minnesota from 2000 to 2015, and age- and sex-matched controls without Sjögren’s Syndrome
| Baseline Characteristic | Cases (N=106) | Controls (N=318) | p value |
|---|---|---|---|
| Age, years, mean (SD) | 59.7 (15.8) | 59.7 (15.7) | >0.999 |
| Sex, female | 88 (83%) | 264 (83%) | >0.999 |
| Ocular symptoms | 95/106 (90%) | - | |
| Oral symptoms | 89/106 (84%) | - | |
| Antinuclear antibody positivity | 77/104 (74%) | - | |
| SSA (anti-La) positivity | 78/101 (77%) | - | |
| SSB (anti-Ro) positivity | 61/100 (61%) | - | |
| Rheumatoid factor positivity | 50/90 (56%) | - | |
| Hypergammaglobulinemia present | 42/85 (49%) | - | |
| Abnormal ocular staining† | 10/15 (67%) | - | |
| Schirmer’s test ≤5/5 minutes | 7/9 (78%) | - | |
| Abnormal salivary scintigraphy or parotid sialography | 7/9 (78%) | - | |
| Unstimulated salivary flow ≤0.1 ml/minute | 1/1 (100%) | - | |
| Histopathology positivity$ | 9/14 (64%) | - | |
| Met AECG criteria, no. (%)†† | 19 (18%) | - | |
| Met 2012 ACR criteria, no. (%)†† | 18 (17%) | - | |
| ESSDAI score, no. (%) | |||
| Low disease activity (≤5) | 42 (70%) | - | |
| Moderate disease activity (5–13) | 13 (22%) | - | |
| High disease activity (≥14) | 5 (8%) | - | |
| Smoking status at index date* | 0.012 | ||
| Never smoker | 49 (46%) | 140 (45%) | |
| Former smoker | 51 (48%) | 117 (38%) | |
| Current smoker | 6 (6%) | 51 (17%) | |
| Smoking status one year prior to index date* | 0.005 | ||
| Never smoker | 48 (46%) | 138 (45%) | |
| Former smoker | 52 (50%) | 116 (38%) | |
| Current smoker | 5 (5%) | 51 (17%) | |
| BMI at index date, kg/m2**, mean (SD) | 27.9 (7.2) | 29.2 (7.4) | 0.062 |
| Obesity (BMI≥30 kg/m2) at index date** | 33 (32%) | 113 (37%) | 0.318 |
Values are the number/total number (%) unless indicated otherwise.
Abbreviations: AECG=American–European Consensus Group; ACR=American College of Rheumatology; ESSDAI=European League Against Rheumatism Sjögren’s Syndrome Disease Activity Index; BMI=Body mass index; SD=standard deviation.
According to the report of the revising pathologist
Van Bijsterveld score ≥4 or Rose Bengal test.
A minority of the patients fulfilled AECG (18%) and ACR (17%) classification criteria, since the requisite tests were not performed, not because they were negative.
Among cases, smoking status at date of diagnosis and one year prior to diagnosis date was available in all (100%) and in 105 (99%) subjects respectively, and among controls in 308 (97%) and 305 (96%) subjects, respectively.
BMI within 1 year before to 1 year after date of diagnosis was available for 104 cases (98%) and 304 controls (96%).