Table 2.

Characteristics of newborns screened by HPLC-tandem mass spectrometry.

	Newborns without acyl-CoA hydrogenase deficiencies N = 352,099	Newborns with false positive result for acyl-CoA hydrogenase deficiency, N = 754	Newborns with acyl-CoA hydrogenase deficiencies N = 20	p#	P*
Age at initial testing (days, median)	3 (3–20)	3 (3–20)	4 (3–16)	ND	0.085
Gender
Male	184,917	347	9	0.501	0.563
Female	167,182	326	11
No record	40	0	0
Gestational age (weeks)
<32	1,519	1	0	0.548	0.451
32–36	17,263	28	2
>37	334,449	638	18
No record	1,132	6	0
Birth Weight (g)
<1,500	559	0	0	0.857	0.813
1,500–1,999	1,741	1	0
2,000–2,499	7,893	18	1
>2,500	331,601	650	19
No record	10,305	4	0
Number of fetus
Singleton	349,350	665	19	0.097	0.138
Twins	2,720	8	1
Triplet	19	0	0
Register region
Suzhou	201,259	384	12	0.797	0.793
Others	150,840	289	8
No record	0	0	0
Household registration
Urban	214,647	408	12	0.930	0.955
Rural	137,452	265	8
No record	0	0	0

^#Comparison between group of newborns with acyl-CoA hydrogenase deficiencies and group of newborns without acyl-CoA hydrogenase deficiencies.

*Comparison between group of newborns with acyl-CoA hydrogenase deficiencies and group of newborns with false positive result for acyl-CoA hydrogenase deficiency.

ND, not done.