Inclusion and exclusion criteria
The selected studies used for this meta-analysis had to match the
following criteria:
(1) All infants born after <32 weeks of gestation and birth
weight < 1500g; (2) Randomized controlled studies; (3) A group
exposed to prophylactic caffeine citrate therapy (0-3 days of life), a
control group of infants not receiving caffeine until they develop AOP,
and a comparison between the two groups; (4) At least one of the
parameters was included in the outcome measures: The primary outcomes of
interest were apnea of prematurity (AOP), duration of mechanical
ventilator(days) and duration of oxygen therapy(h); Secondary outcomes
included: biparietal diameter (BPD), patent ductus arteriosus (PDA),
retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC),
intra-ventricular hemorrhage (IVH) and death before hospital discharge.
All diseases diagnosis relied on the recording of patient charts or
surgical data.
Any study that met a specific exclusion criterion was removed from the
meta-analysis:
Case reports, reviews, or animal trials; (2) The studies with unclear
or inadequate exposure/outcome definitions; and (3) The studies with
insufficient information for extraction data.