Of 66 general practice antenatal clinic clusters in the primary care trust, 33 were randomly allocated to the peer support service (intervention group) and 33 to standard antenatal care (figure). One small intervention practice closed after randomisation but before intervention. During the six months of the study 2511 women delivered in the three hospitals; 1140 (45.4%) received antenatal care in the 32 intervention practices and 1371 (54.6%) in the 33 control practices. Data on initiation of breast feeding were available for 2398 women (95.5%); 1083 (95.0%) in the intervention group and 1315 (96.0%) in the control group.
Patient flow through trial
Table 1 shows the hospital, month of delivery, and other characteristics of women by trial group. Although there were generally no clinically important differences between the groups, the intervention group did have more deliveries in one of the three hospitals and fewer African-Caribbean women than the control group.
Table 1 Variables of women allocated to peer support for breast feeding or to standard antenatal care by a midwife. Values are numbers (percentages) of women
Initiation rates for breast feeding did not differ between intervention and control groups; 69.0% and 68.1%. The cluster adjusted odds ratio was 1.11 (95% confidence interval 0.87 to 1.43, P=0.40, interpractice correlation coefficient 0.07; table 2). These rates excluded women with missing data on initiation of breast feeding. If missing data were assumed to be for women who had not initiated breast feeding then initiation rates would be 65.5% and 65.4%. Multiple imputation techniques provided a similar result to the analysis using complete data: cluster adjusted odds ratio 1.10 (0.86 to 1.42, P=0.44).
Table 2 Breastfeeding status in women allocated to peer support for breast feeding or to standard antenatal care by a midwife
Effects of mothers’ characteristics
Initiation of breast feeding varied according to several sociodemographic and delivery characteristics (table 3). Initiation was lower in Heartlands Hospital, younger and older women, those who had a Caesarean section, and multiparous women. Differences were large according to ethnic group, with the lowest initiation of breast feeding among white British women and the highest among African-Caribbean women. Substantial variation was found among Asian ethnic groups, with the lowest initiation of breast feeding among Bangladeshi women and the highest among women of Indian (subcontinent) origin. No difference was found for deprivation score, but 70% of the sample was in the lowest 10th. Multivariable analysis with adjustment for cluster showed that being from an ethnic minority group compared with being white British, and being primiparous were independently associated with an increased likelihood of initiating breast feeding (table 4). Accounting for confounding factors in the multivariable model, however, had little effect on the primary outcome.
Table 3 Initiation of breast feeding and variables for women. Values are numbers (percentages) of women
Table 4 Multiple logistic regression for initiation of breast feeding
Peer support worker logs
Logs completed by the peer support worker were analysed for women in the intervention group with a recorded expected date of delivery between 1 February and 31 July 2007. Records of a contact were available for 912 women (80.0% of deliveries during the period), and 846 (74.2%) had a support session. Of the women contacted, 64 (7%) refused a support session because they had already decided to bottle feed (n=21) or breast feed (n=43). The mean duration of the first support session was 13.1 (SD 10.2) minutes, and 799 (94.4%) took place in the clinic, with only 11 (1.3%) at home. Of the 846 women who accepted a first support session, 351 (41.5%) had a second session, again predominantly in the clinic, and 25 (3.0%) a third. The first support session took place at a mean of 28 (SD 6.5) weeks’ gestation and the second at 34.5 (SD 3.6) weeks.
Before the start of the first support session the women were asked whether they had made any plans about feeding: 500 (59.1%) planned to breast feed, 174 (20.6%) were considering breast feeding, 35 (4.1%) planned to use both breast and bottle, 51 (6%) planned to bottle feed, and 64 (7.6%) were undecided. The issues discussed in the first support session included health benefits for the baby of being breast fed (n=809, 95.6%), health benefits for the mother (n=794, 93.9%), convenience of breast feeding (n=689, 81.4%), cost of feeding (n=603, 71.3%), perceived difficulties of breast feeding (n=499, 59.0%), partner’s attitudes towards breast feeding (n=362, 42.8%), family attitudes towards breast feeding (n=309, 36.5%), discard of colostrum (n=265, 31.3%), and other cultural issues (n=56, 6.6%).