Table 3

Agreement between self-report of RA alone, combined to the IRD questionnaire and to the medication reimbursement database with chart review

	Chart review (reference standard)			Positive predictive value, %	Negative predictive value, %	Sensitivity, %	Specificity, %	Kappa coefficient (95% CI)
	Yes	No	Total	Positive predictive value, %	Negative predictive value, %	Sensitivity, %	Specificity, %	Kappa coefficient (95% CI)
Self-report of RA
Yes	125	180	305	41.0	95.7	96.9	33.3	0.22 (0.17 to 0.28)
No	4	90	94
Total	129	270	399
Self-report of RA + IRD questionnaire
1. Confirmation by a rheumatologist or an internal medicine specialist
Yes	120	43	166	72.3	96.1	93	83	0.71 (0.65 to 078)
No	9	224	233
Total	129	270	399
2. RA medication
Yes	118	11	129	91.5	95.9	91.5	95.9	0.87 (0.82 to 0.93)
No	11	259	270
Total	129	270	399
3. Positive RF and/or ACPA
Yes	72	3	75	96.0	82.4	55.8	98.9	0.61 (0.53 to 0.70)
No	57	267	324
Total	129	270	399
4. ACR criteria
Yes	63	7	70	90.0	79.9	48.8	97.4	0.52 (0.43 to 0.61)
No	66	263	329
Total	129	270	399
Any of these four definitions
Yes	121	47	168	72.0	96.5	93.8	82.6	0.71 (0.64 to 0.78)
No	8	223	231
Total	129	270	399
Self-report of RA + medication reimbursement database
Yes	91	10	101	90.1	87.3	70.5	87.3	0.71 (0.63 to 0.78)
No	38	260	298
Total	129	270	399
Self-report of RA + IRD questionnaire + medication reimbursement database
Yes	86	2	88	97.7	86.2	66.7	99.3	0.72 (0.64 to 0.79)
No	43	268	311
Total	129	270	399

ACPA, anti-citrullinated protein autoantibody; ACR, American College of Rheumatology; IRD, inflammatory rheumatic disease; RA, rheumatoid arthritis; RF, rheumatoid factors.