Sir.—Myers et al1 showed that formula-fed infants have more gastrointestinal (GI) illness than their partially breast-fed counterparts during the first 112 days of life. There was no difference in trivial respiratory illness between feeding groups in their small cohort. This observation is not new, and its resurrection should not obscure the fact that complicated respiratory disease and other life-threatening illnesses are consistently more frequent in bottle-fed babies in any setting.2 In this connection, several points should be emphasized:
1. The authors rightly stress the need to account for associated variables (eg, social class) which presently are unfavorable in bottle-fed babies. Years ago, however, the same factors were unfavorable in breast-fed babies who were still relatively free of serious respiratory disease. Then, too, the studies linking respiratory disease to relevant factors such as social class, smoking, and day care have themselves failed to account for differences in feeding