Usefulness of a nondashexperimental study design in the evaluation of service developments for infant feeding in a general hospital

There are likely to be many situations in which it is not possible to use a randomized controlled trial (RCT) for the evaluation of local service developments, and the usefulness of nondashexperimental study designs need to be assessed. This is examined with reference to a study carried out to evaluate the appointment of a baby feeding adviser (BFA) and other policy changes for infant feeding at a district general hospital (DGH). Surveys of Maternity Unit staff attitudes and practices, and of mothersʹ experiences were carried out in 1988 (prior to the changes) and afterwards in 1990. Service changes were; appointment of a BFA, removal from the postnatal wards of dextrose, seminars on baby feeding for midwifery staff, and a reduction of night-only shifts. There was no change in the initial breast feeding rate of about 80%, but there was an increase in breast feeding at 6 weeks postnatally from 57% (95% CI; 51–64) to 64% (95% CI; 59–69); P = 0.15. The percentage of women who stopped breast feeding by 6 weeks fell from 30% in 1988 to 22% in 1990; P = 0.11. Mothers who did not see the BFA (1990 only) were significantly less likely to begin breast feeding (P = 0.03), independent of social class and age, but a similar association was not seen at 6 weeks. There were significant reductions in the percentage of midwifery staff viewing feeding policy as unimportant (P = 0.02), and in the use of supplements for breast-fed babies (P < 0.001). Women having Caesarian sections were more likely to give up breast feeding in 1988 and in 1990, and this was partly explained by continued use of supplements. It is concluded that the service initiatives have been associated with some favourable changes in attitudes and practices of staff, and in the outcome for mothers and babies as measured by breast feeding at 6 weeks and satisfaction with advice. The limitations and value of the study design are discussed in the light of the results. While cause and effect will inevitably remain difficult to establish in a nondashexperimental situation, there are some characteristics of the study which aid interpretation. Of particular importance is the observation that some key social and service factor associations persisted after the intervention, thereby highlighting issues requiring continued attention.