USEFULNESS OF A NONEXPERIMENTAL 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 se rvice developments, and the usefulness of non-experimental study desig ns need to be assessed. This is examined with reference to a study car ried out to evaluate the appointment of a baby feeding adviser (BFA) a nd other policy changes for infant feeding at a district general hospi tal (DGH). Surveys of Maternity Unit staff attitudes and practices, an d of mothers' experiences were carried out in 1988 (prior to the chang es) and afterwards in 1990. Service changes were; appointment of a BFA , removal from the postnatal wards of dextrose, seminars on baby feedi ng for midwifery staff, and a reduction of night-only shifts. There wa s 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 w ho stopped breast feeding by 6 weeks fell from 30% in 1988 to 22% in 1 990; P=0.11. Mothers who did not see the BFA (1990 only) were signific antly less likely to begin breast feeding (P=0.03), independent of soc ial 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 sup plements for breast-fed babies (P<0.001). Women having Caesarian secti ons were more likely to give up breast feeding in 1988 and in 1990, an d this was partly explained by continued use of supplements. It is con cluded that the service initiatives have been associated with some fav ourable changes in attitudes and practices of staff, and in the outcom e for mothers and babies as measured by breast feeding at 6 weeks and satisfaction with advice. The limitations and value of the study desig n are discussed in the light of the results. While cause and effect wi ll inevitably remain difficult to establish in a non-experimental situ ation, there are some characteristics of the study which aid interpret ation. Of particular importance is the observation that some key socia l and service factor associations persisted after the intervention, th ereby highlighting issues requiring continued attention.