In the subgroup analysis for the first hour, including only the studies with a low bias risk, no heterogeneity was observed I2 = 0% and Q − p = 0.75; there was an important difference in pain intensity between the two groups mean difference = 2.11; 95% CI 1.75 and 2.45 with p < 0.00001 in favour of epidural analgesia.
Al analizar por subgrupo la hora 1, incluyendo solo los estudios con bajo riesgo de sesgo, no se observó heterogeneidad I=0% y Q-p= 0,75; allí se presentó una importante diferencia en la intensidad del dolor entre los 2 grupos diferencia media = 2,11 IC 95%: 1,75 a 2,45, con una p < 0,00001 a favor de epidural.