Table 2.

Meta-analysis (effect sizes) of studies measuring challenge bacteria concentrations following application of phage in pigs

Parameter	I2, %	Effect size	Effect significance, P-value	Power, %	No. observations, Treatment	No. observations, Control	Total observations
All observations together	64.2	−1.06	<0.0001	100	336	240	576
Sampling Time
Samples collected ≤24 h post-phage treatment	57.4	−0.82	0.0007	96.96	252	156	408
Samples collected 48–96 h post-phage treatment	36.6	−1.78	0.022	99.72	84	84	168
Age of Pig
Piglets	62.8	−1.31	0.0001	100	216	174	390
Piglets, samples collected ≤24 h post-phage treatment	65.8	−1.075	0.0037	99.97	132	90	222
Piglets, samples collected 48–96 h post-phage treatment	36.6	−1.78	0.022	99.72	84	84	168
Market Weight Pigs, samples collected ≤24 h post-phage treatment	0	−0.50	0.0138	99.76	120	66	186
Targeted Bacteria
Salmonella	64.2	−0.95	<0.0001	100	312	216	528
Salmonella, samples collected ≤24 h post-phage treatment	59.3	−0.77	0.002	100	240	144	384
Salmonella, samples collected 48–96 h post-phage treatment1	0	−1.53	0.002	99.22	72	72	144
E. coli	69.1	−1.89	0.1084	71.46	24	24	48
E. coli, samples collected ≤24 h post-phage treatment1	66.5	−1.29	0.3743	43.15	12	12	24
E. coli, samples collected 48–96 h post-phage treatment	82.7	−2.68	0.3622	431.5	12	12	24
Frequency of Phage Application
Single Dose1	0.0	−0.25	0.0202	80.67	72	18	90
Multiple Doses	63.4	−1.21	<0.0001	100	264	222	486
Multiple Doses, samples collected ≤24 h post-phage treatment	60.9	−0.98	0.0011	100	180	138	318
Multiple Doses, samples collected 48–96 h post-phage treatment	36.6	−1.78	0.022	99.72	84	84	168
Prophylaxis vs. Treatment
Prophylaxis	0.0	−0.72	0.0017	99.99	144	102	270
Prophylaxis, samples collected ≤24 h post-phage treatment	0.0	−0.24	0.0017	99.99	144	102	246
Treatment	71.0	−1.31	0.0025	100	192	138	330
Treatment, samples collected ≤24 h post-phage treatment	78.4	−0.93	0.0748	99.28	108	54	162
Treatment, samples collected 48–96 h post-phage treatment	36.6	−1.78	0.022	99.72	84	84	168
Sample Site
Ileum2	30.4	−0.40	0.0008	99.77	96	78	174
Cecum	50.6	−0.92	0.0133	99.97	120	102	222
Cecum, samples collected ≤24 h post-phage treatment	79.2	−0.60	0.2709	99.77	96	78	174
Feces	69.4	−1.58	0.0062	99.97	120	102	222
Feces, samples collected ≤24 h post-phage treatment	81.4	−1.28	0.1078	95.28	60	42	102
Feces, samples collected 48–96 h post-phage treatment	50.6	−1.94	0.0617	97.91	60	60	120
Administration Route
Gavage	68.9	−1.00	0.0002	100	270	216	486
Gavage, samples collected ≤24 h post-phage treatment	67.6	−0.82	0.0061	100	198	144	342
Gavage, samples collected 48–96 h post-phage treatment1	0	−1.53	0.002	99.22	72	72	144
Feed	62.7	−1.35	0.0631	98.72	66	66	132
Feed, Gavage, samples collected ≤24 h post-phage treatment	25.5	−0.81	0.0966	96.64	54	54	108
Feed, samples collected 48–96 h post-phage treatment1	82.7	−2.68	0.3622	43.15	12	12	24
Phage Protection
Protected	43.2	−1.027	0.0029	100	168	126	294
Protected, samples collected ≤24 h post-phage treatment	10	−0.80	0.0011	100	156	114	270
Protected, samples collected ≤24 h post-phage treatment1	82.7	−2.68	0.3622	43.15	12	12	24
Unprotected	75.7	−1.13	0.0112	100	144	90	234
Unprotected, samples collected ≤24 h post-phage treatment	85.0	−0.79	0.2307	97.82	96	42	138
Unprotected, samples collected ≤24 h post-phage treatment1	0.0	−1.53	0.002	99.22	72	72	144

¹Only one study; ²Data same as ileum <24 h.