Table 2.

Comparison with previous studies.

Countries	Equipment	Age (y)	C3 (g/L)		C4 (g/L)
			Males	Females	Males	Females
Present studya	Deling BN-II specific protein analyser		0.83–1.58			0.15–0.40
Francea	Optilite® turbidimetric analyser		0.89–1.87			0.15–0.45
Russiaa	Beckman AU5800		0.78–1.34			0.15–0.45
SE Africa	UniCel DxC (BC)		0.82–1.57	0.80–1.48	0.14–0.41	0.14–0.40
Japan	UniCel DxC (BC)		0.74–1.35	0.71–1.26	0.12–0.31	0.11–0.30
Indiaa	Beckman Coulter Immage 800		0.85–1.82			0.16–0.55
Chinese multicentre studya	Beckman AU5800	<45 y	0.76–1.27			0.15–0.45
		≥45 y	0.81–1.34			0.17–0.51

Abbreviations: y, years old

^aOne range indicates no sex difference in this group, while the RIs for males and females are the same.