Table 2

Zinc compared with no zinc (all outcomes)

OutcomesTrialsPeopleES (95% CI), fixed effectsHeterogeneity
I2; χ2 (p Value)
Zinc vs no zinc
Mortality
 All-cause13 (16%)138 302 (67%)Risk=0.95 (0.86 to 1.05)0%; 10.57 (p=0.65)
 Due to diarrhoea4 (5%)132 321 (64%)Risk=0.95 (0.69 to 1.31)0%; 0.82 (p=0.84)
 Due to LRTI3 (4%)132 063 (64%)Risk=0.86 (0.64 to 1.15)0%; 0.07 (p=0.96)
 Due to malaria2 (3%)42 818 (21%)Risk=0.90 (0.77 to 1.06)0%; 0.01 (p=0.94)
Hospitalisation
 All-cause7 (9%)92 872 (45%)Risk=1.04 (0.97 to 1.11)44%; 14.41 (p=0.07)
 Due to diarrhoea4 (5%)74 039 (36%)Risk=1.03 (0.87 to 1.22)42%; 6.91 (p=0.14)
 Due to LRTI3 (4%)74 743 (36%)Risk=1.10 (0.93 to 1.30)0%; 0.35 (p=0.95)
Diarrhoea
 Incidence (all-cause)35 (44%)15 042 (7%)Risk=0.87 (0.85 to 0.89)88%; 295.56 (p<0.00001)
 Prevalence (all-cause)13 (16%)8519 (4%)Rate=0.88 (0.86 to 0.90)88%; 118.88 (p<0.00001)
 Incidence (severe)5 (6%)4982 (2%)Risk=0.89 (0.84 to 0.95)56%; 13.54 (p=0.04)
 Incidence (persistent)7 (9%)6216 (3%)Risk=0.73 (0.62 to 0.85)61%; 20.47 (p=0.009)
 Prevalence (persistent)1 (1%)666 (0%)Rate=0.70 (0.64 to 0.76)91%; 11.76 (p=0.0006)
LRTI
 Incidence12 (15%)9610 (5%)Risk=1.00 (0.94 to 1.07)1%; 17.16 (p=0.44)
 Prevalence3 (4%)1955 (1%)Rate=1.20 (1.10 to 1.30)97%; 89.87 (p<0.00001)
Malaria
 Incidence4 (5%)2407 (1%)Risk=1.05 (0.95 to 1.15)0%; 2.04 (p=0.84)
 Prevalence1 (1%)661 (0%)Rate=0.88 (0.47 to 1.64)Not applicable
Growth
 Height51 (64%)13 669 (7%)SMD=0.09 (0.06 to 0.13)86%; 407.92 (p<0.00001)
 Weight44 (55%)12 305 (6%)SMD=0.10 (0.07 to 0.14)76%; 216.64 (p<0.00001)
 Weight-to-height ratio24 (30%)7901 (4%)SMD=0.05 (0.01 to 0.10)20%; 34.96 (p=0.17)
 Prevalence of stunting6 (8%)3838 (2%)Risk=0. 94 (0.86 to 1.02)59%; 19.43 (p=0.01)
AEs
 Participants with one AE2 (3%)850 (0%)SMD=1.13 (1.00 to 1.27)0%; 0.49 (p=0.78)
 Study withdrawal6 (8%)4263 (2%)Risk=1.75 (0.93 to 3.32)21%; 5.07 (p=0.28)
 Vomiting (incidence)5 (6%)4095 (2%)Risk=1.68 (1.61 to 1.75)85%; 34.28 (p<0.00001)
 Vomiting (prevalence)4 (5%)35 192 (17%)Rate=1.29 (1.14 to 1.46)37%; 6.31 (p=0.18)
Biological indicators
 Zn concentration46 (58%)9810 (5%)SMD=0.62 (0.58 to 0.67)91%; 582.45 (p<0.00001)
 Zn deficiency (prevalence)15 (19%)5434 (3%)Risk=0.49 (0.45 to 0.53)86%; 144.77 (p<0.00001)
 Haemoglobin concentration27 (34%)6024 (3%)SMD=−0.05 (−0.10 to 0.00)45%; 63.96 (p=0.002)
 Anaemia (prevalence)13 (16%)4287 (2%)Risk=1.00 (0.95 to 1.06)37%; 28.52 (p=0.05)
 Fe concentration19 (24%)4474 (2%)SMD=0.07 (0.00 to 0.13)95%; 480.50 (p<0.00001)
 Fe deficiency (prevalence)10 (13%)3149 (2%)Risk=0.99 (0.89 to 1.10)15%; 16.44 (p=0.29)
 Cu concentration11 (14%)3071 (1%)SMD=−0.22 (−0.29 to 0.14)68%; 37.47 (p=0.0002)
 Cu deficiency (prevalence)3 (4%)1337 (1%)Risk=2.64 (1.28 to 5.42)59%; 4.94 (p=0.08)
  • AE, adverse event; ES, effect size; LRTI, lower respiratory tract infection; SMD, standardised mean difference.