The quality of evidence is downgraded by inconsistency (unexplained variability in results)
The recommendation is strong because the intervention has potential benefits without any harms.
Several studies have shown that short-lasting breastfeeding or none at all predispose to otitis media «Teele DW, Klein JO, Rosner B. Epidemiology of otit...»1, «Alho OP, Koivu M, Sorri M, Rantakallio P. Risk fac...»2, «Pukander J, Luotonen J, Timonen M, Karma P. Risk f...»3, «Owen MJ, Baldwin CD, Swank PR, Pannu AK, Johnson D...»4, «Kero P, Piekkala P. Factors affecting the occurren...»5, «Chandra RK. Prospective studies of the effect of b...»6, «Saarinen UM. Prolonged breast feeding as prophylax...»7 but this relationship could not be shown in all studies «Fleming DW, Cochi SL, Hightower AW, Broome CV. Chi...»8, «Tainio VM, Savilahti E, Salmenperä L, Arjomaa P, S...»9, «Rubin DH, Leventhal JM, Krasilnikoff PA, Kuo HS, J...»10. A meta-analysis by Uhari et al «Uhari M, Mäntysaari K, Niemelä M. A meta-analytic ...»11 showed that breastfeeding for at least three months reduced the risk of acute otitis media (risk ratio 0.87; 95% CI 0.79 - 0.95). Paradise et al «Paradise JL, Elster BA, Tan L. Evidence in infants...»12 reported that children with a cleft palate who had been given breast milk had middle-ear effusion for a shorter time than children who had received milk substitute.
Duncan et al «Duncan B, Ey J, Holberg CJ, Wright AL, Martinez FD...»13 report that children who received only breast milk for at least four months had fewer episodes of otitis media during their first year of life compared with those who had received no breast milk at all or were only partly breast-fed. Correspondingly, Aniansson et al «Aniansson G, Alm B, Andersson B, Håkansson A, Lars...»14 concluded that children who had been breast-fed exclusively during their first year of life had fewer episodes of otitis, partly breast-fed children had slightly more and weaned children had the most episodes of acute otitis.
An U.S. based study «...»15 included infants who were fully breastfed for 4 to < 6 months (n = 223) and infants who were fully breastfed for > or = 6 months (n = 136). Adjusting for demographic variables, childcare, and smoke exposure revealed statistically significant increased risk for both pneumonia (OR 4.27; 95% CI 1.27 to14.35) and > or = 3 episodes of OM (OR 1.95; 95% CI 1.06 to 3.59) in those who were fully breastfed for 4 to < 6 months compared with > or = 6 months.
An U.S. based randomized study «...»16 included 338 low-income, mother-infant dyads (n = 163 for the intervention group and n = 175 for the control group). The women were randomized to a prenatal and postpartum lactation support intervention vs. usual care. End-points included otitis media-, respiratory tract-, or gastrointestinal-related visits. The mothers and infants were followed until the child was 12 months old. Only the number of otitis media visits was reduced in the intervention group. Other endpoints did not differ by treatment group. At 2 weeks, 87% of the mothers in intervention group were breastfeeding vs. 66% of controls. At 5 months, responding numbers were 53% vs. 39%. In intervention group, 39.4% of infants had at least one period of AOM vs. 47.1% in the control group (P</=.03).