Table 3. Subgroup analysis of the sensitivity and specificity of serum IgG4 for the diagnostic performance of IgG4-RD.

Parameter	Category	No. of study	Sensitivity	p	Specificity	p
Period	Before 2011	9	78% (67–90%)	0.00	95% (92–98%)	0.00
	After 2011	14	88% (82–94%)		91% (87–95%)
Study design	Prospective	6	83% (74–93%)	0.04	90% (86–94%)	0.00
	Retrospective	10	85% (77–92%)		93% (91–96%)
Sample size	Less than 150	13	88% (82–94%)	0.35	91% (87–95%)	0.00
	More than 150	10	79% (67–90%)		95% (92–98%)
Ethnicity	Asian	15	88% (83–93%)	0.63	94% (92–97%)	0.00
	Caucasian	8	73% (61–86%)		90% (84–95%)
Assay	Nephelometry	15	83% (75–91%)	0.02	92% (89–95%)	0.00
	Other method	8	87% (78–96%)		94% (90–98%)