Table 3.
Comparison between EPISER2000 and EPISER2016 studies.
| EPISER2000 | EPISER2016 | |
|---|---|---|
| Sample, n | 2192 | 4916 |
| RA classification criteria used | 1987 ACR | 1987 ACR, 2010 ACR/EULAR and previous diagnosis by a rheumatologist |
| Positive screening resulta, n (%) | 186 (8) | 289 (5.9) |
| Confirmed RA cases, n | 11 | 39 |
| Screening questionnaire PPV (%) | 5.9 | 12.77 |
| Screening questionnaire NPV (%) | 100 | 100 |
| RA prevalence based on ACR 1987 criteria, % (95% CI) | 0.5 (0.3–0.9) | 0.69 (0.47–0.99) |
| Estimation of total RA cases in Spainb, n | 80,000–271,000 | 220,000–430,000 |
| Diagnosis of RA prior to EPISER study, n (%) | 8 (72.7) | 39 (100) |
| Sociodemographic characteristics | ||
| Females, n (%) | 9 (81.8) | 24 (61.5) |
| Prevalence in females, % (95% CI) | 0.8 (0.4–1.3) | 0.9 (0.6–1.3) |
| Prevalence in males, % (95% CI) | 0.2 (0.0–0.5) | 0.8 (0.4–1.3) |
| Mean age, years ± SD | 59.27 ± 22.01 | 60.48 ± 14.85 |
| Residence (%) | ||
| Urban | – | 74.4 |
| Rural | – | 25.6 |
| Educational level (%) | ||
| Basic | 63.6 | 56.4 |
| Medium | 18.2 | 23.1 |
| High | 18.2 | 20.5 |
RA rheumatoid arthritis, SD standard deviation, CI confidence interval, PPV positive predictive value, NPV negative predictive value.
aScreening questionnaire: EPISER2000 used a questionnaire administered by a rheumatologist in a face-to-face interview, while EPISER2016 used a phone questionnaire administered by the call centre interviewers.
bThese estimates were calculated considering the lower and upper limits of the confidence intervals of the prevalence and the figures of the population aged 20 years old or over in Spain in the years 2000 and 2016. The confidence interval used for EPISER2016 was that corresponding to the prevalence of 0.82%.