Human sperm acrosome function assays are predictive of fertilization rate in vitro: a retrospective cohort study and meta-analysis

Table 6 Summary of SMD values for AE assay

Subgroup		N	SMD (95% CI)	Test(s) of heterogeneity		Significance test(s) of SMD = 0		P ^a
Subgroup		N	SMD (95% CI)	I² (%)	P	Z	P
Overall		16	0.79 (0.53–1.05)	74.5	0.000	5.97	0.000
Four experiments excluded		12	0.75 (0.57–0.93)	26.5	0.184	8.19	0.000
Geographic areas
Asia		3	0.50 (0.15–0.85)	2.3	0.359	2.77	0.006	0.026
North America		7	0.81 (0.39–1.22)	74.2	0.001	3.80	0.000
Europe		6	0.92 (0.48–1.36)	80.8	0.000	4.08	0.000
Storage method
Cryopreservation		2	0.20 (−0.11–0.52)	0.0	0.425	1.27	0.204	< 0.001
Fresh		14	0.89 (0.63–1.15)	69.3	0.000	6.73	0.000	< 0.001
Preparation method
No preparation		10	0.82 (0.50–1.13)	63.1	0.004	5.14	0.000	0.023
Swim up		4	0.57 (0.20–0.94)	53.6	0.091	3.04	0.002
Discontinuous gradient		2	1.07 (−0.10–2.25)	95.1	0.000	1.79	0.074
FR cut-off value combined with AE assay method
≥ 70% vs. < 70%	Spectrophotometry							NC
	Spectrophotometry/BAPNA	1	0.86 (0.30–1.41)	–^b	–	3.03	0.002
≥ 50% vs. < 50%	Spectrophotometry
	Spectrophotometry/BAPNA	2	0.94 (0.18–1.71)	72.5	0.056	2.41	0.016
> 50% vs. = 0%	Spectrophotometry
	Spectrophotometry/BAPNA	1	0.82 (0.26–1.38)	–	–	2.87	0.004
> 0% vs. = 0%	Fluorometry
	PAb-acrosin	1	1.68 (1.29–2.07)			8.45	0.000
	PAb-hyaluronidase	1	0.48 (0.13–0.82)			2.68	0.007
	MAb 4D4-proacrosin	2	0.72 (0.32–1.13)	0.0	0.600	3.50	0.000
	Spectrophotometry
	Spectrophotometry/BAPNA	2	1.23 (−0.74–3.19)	93.5	0.000	1.22	0.221
	Accu-Sperm spectrophotometry/BAPNA	5	0.70 (0.41–0.99)	22.5	0.271	4.70	0.000
	Spectrophotometry/BAEE	1	−0.04 (−0.72–0.64)	–	–	0.12	0.908

SMD standardized mean difference, CI confidence interval, BAPNA N-α-benzoyl-dl-arginine-p-nitroanilide, BAEE N-benzoyl-l-arginine ethyl ester, NC not compared
^aComparison between subgroups with the Q test for heterogeneity
^bNot calculated

ISSN: 1477-7827