Inequality in infant morbidity: causes and consequences in England in the 1990s. ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood.
STUDY OBJECTIVE: To examine the effect of deprivation, crowding, maternal smoking, and breast feeding on morbidity from wheeze and diarrhoea in the first six months after birth. DESIGN: A geographically located population survey using maternal responses on self completion questionnaires. SETTING: The three health districts of Bristol. SUBJECTS: 8501 infants from the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) in which all women expecting a baby between April 1991 and December 1992 in Bristol were invited to participate. MAIN OUTCOME MEASURES: The prevalence and severity of wheeze at six months after birth. The prevalence of diarrhoea and the duration of the worst bout at six months after birth. RESULTS: Logistic regression analyses using a conceptual hierarchical framework showed that wheeze was significantly more likely to be reported for infants if they lived in rented accommodation (OR = 1.20, 95% CI = 1.04, 1.39), if they lived in crowded housing conditions (OR = 1.26, 95% CI = 1.06, 1.49), if they were one of a number of siblings (OR = 1.78, 95% CI = 1.52, 2.07), and if their mothers smoked (OR = 1.38, 95% CI = 1.21, 1.58). They were significantly less likely to have wheeze if they were breast fed (OR = 0.68, 95% CI = 0.59, 0.79). Each of these factors was independently related to the prevalence of wheeze. For infants with wheeze those who were breast fed for three or more months were significantly less likely to have three or more episodes in the first six months after birth (OR = 0.76, 95% CI = 0.58, 0.99). A higher prevalence of diarrhoea in infancy was associated with living in rented accommodation (OR = 1.25, 95% CI = 1.10, 1.41) and lower maternal education (OR = 0.76, 95% CI = 0.69, 0.84) and a lower prevalence with breast feeding (OR = 0.42, 95% CI = 0.37, 0.48). An episode of diarrhoea was significantly less likely to last for six or more days if an infant lived in mortgaged accommodation (OR = 1.34 95% CI = 1.03, 1.75) and was breast fed for three or more months (OR = 1.34 95% CI = 1.03, 1.75). CONCLUSION: Deprivation was associated with heightened morbidity from common conditions such as wheeze and diarrhoea for this geographical cohort of infants in England in the 1990s. Results supported evidence suggesting that breast feeding is protective against such conditions and is particularly associated with reduced severity and duration. Implications for future research and policy are discussed.