Charles du V. Florey

Protective effect of breast feeding against infection.

OBJECTIVE--To assess the relations between breast feeding and infant illness in the first two years of life with particular reference to gastrointestinal disease. DESIGN--Prospective observational study of mothers and babies followed up for 24 months after birth. SETTING--Community setting in Dundee. PATIENTS--750 pairs of mothers and infants, 76 of whom were excluded because the babies were preterm (less than 38 weeks), low birth weight (less than 2500 g), or treated in special care for more than 48 hours. Of the remaining cohort of 674, 618 were followed up for two years. INTERVENTIONS--Detailed observations of infant feeding and illness were made at two weeks, and one, two, three, four, five, six, nine, 12, 15, 18, 21, and 24 months by health visitors. MAIN OUTCOME MEASURE--The prevalence of gastrointestinal disease in infants during follow up. RESULTS--After confounding variables were corrected for babies who were breast fed for 13 weeks or more (227) had significantly less gastrointestinal illness than those who were bottle fed from birth (267) at ages 0-13 weeks (p less than 0.01; 95% confidence interval for reduction in incidence 6.6% to 16.8%), 14-26 weeks (p less than 0.01), 27-39 weeks (p less than 0.05), and 40-52 weeks (p less than 0.05). This reduction in illness was found whether or not supplements were introduced before 13 weeks, was maintained beyond the period of breast feeding itself, and was accompanied by a reduction in the rate of hospital admission. By contrast, babies who were breast fed for less than 13 weeks (180) had rates of gastrointestinal illness similar to those observed in bottle fed babies. Smaller reductions in the rates of respiratory illness were observed at ages 0-13 and 40-52 weeks (p less than 0.05) in babies who were breast fed for more than 13 weeks. There was no consistent protective effect of breast feeding against ear, eye, mouth, or skin infections, infantile colic, eczema, or nappy rash. CONCLUSION--Breast feeding during the first 13 weeks of life confers protection against gastrointestinal illness that persists beyond the period of breast feeding itself.

Sample size for beginners.

The common failure to include an estimation of sample size in grant proposals imposes a major handicap on applicants, particularly for those proposing work in any aspect of research in the health services. Members of research committees need evidence that a study is of adequate size for there to be a reasonable chance of a clear answer at the end. A simple illustrated explanation of the concepts in determining sample size should encourage the faint hearted to pay more attention to this increasingly important aspect of grantsmanship.

Should obstetricians see women with normal pregnancies? A multicentre randomised controlled trial of routine antenatal care by general practitioners and midwives compared with shared care led by obstetricians.

Abstract Objective: To compare routine antenatal care provided by general practitioners and midwives with obstetrician led shared care. Design: Multicentre randomised controlled trial. Setting: 51 general practices linked to nine Scottish maternity hospitals. Subjects: 1765 women at low risk of antenatal complications. Intervention: Routine antenatal care by general practitioners and midwives according to a care plan and protocols for managing complications. Main outcome measures: Comparisons of health service use, indicators of quality of care, and womens satisfaction. Results: Continuity of carer was improved for the general practitioner and midwife group as the number of carers was less (median 5 carers v 7 for shared care group, P<0.0001) and the number of routine visits reduced (10.9 v 11.7, P<0.0001). Fewer women in the general practitioner and midwife group had antenatal admissions (27% (222/834) v 32% (266/840), P<0.05), non-attendances (7% (57) v 11% (89), P<0.01) and daycare (12% (102) v 7% (139), P<0.05) but more were referred (49% (406) v 36% (305), P<0.0001). Rates of antenatal diagnoses did not differ except that fewer women in the general practitioner and midwife group had hypertensive disorders (pregnancy induced hypertension, 5% (37) v 8% (70), P<0.01) and fewer had labour induced (18% (149) v 24% (201), P<0.01). Few failures to comply with the care protocol occurred, but more Rhesus negative women in the general practitioner and midwife group did not have an appropriate antibody check (2.5% (20) v 0.4% (3), P<0.0001). Both groups expressed high satisfaction with care (68% (453/663) v 65% (430/656), P=0.5) and acceptability of allocated style of care (93% (618) v 94% (624), P=0.6). Access to hospital support before labour was similar (45% (302) v 48% (312) visited labour rooms before giving birth, P=0.6). Conclusion: Routine specialist visits for women initially at low risk of pregnancy complications offer little or no clinical or consumer benefit. Key messages Key messages Care by general practitioners and midwives improved continuity of care: there were fewer carers, non-attendances, and hospital admissions, and marginally fewer routine visits than with specialist led shared care; incidences of hypertension, proteinuria, pre-eclampsia, and induction of labour were also lower Overall there were few deviations from the care protocol, but a greater proportion of Rhesus negative women in the general practitioner and midwife group did not have an appropriate check for antibodies The women in both trial groups were equally highly satisfied with all aspects of their care; only a small minority of women in the general practitioner and midwife group said they would have liked to have seen a hospital doctor but did not Although there was no net benefit from routine specialist antenatal visits, over half of women developed some complication during their pregnancy; in the general practitioner and midwife model of care, low risk women see a specialist when required and not at predefined routine visits

Variations in cotinine levels in smokers during and after pregnancy

OBJECTIVE To compare the antenatal and postnatal cotinine levels in smoking women after controlling for the differences in smoking practices. STUDY DESIGN A paired comparison of two measurements of cotinine concentration was conducted in 40 smoking women voluntarily recruited in a prenatal education program held in La Fe Hospital, Valencia, Spain, during 1990 and 1991. Cotinine concentration was assayed by gas chromatography in samples of saliva obtained during and after pregnancy. The Wilcoxon matched-pairs test and multiple linear regression analysis were used. RESULTS The cotinine per cigarette ratio during pregnancy (median 3.53 ng/ml per cigarette) was significantly lower than the ratio in the postnatal testing (median 9.87 ng/ml per cigarette). This difference persisted after allowing for differences in reported cigarette consumption. CONCLUSION These findings suggest that the available equivalencies between cotinine level and nicotine intake obtained from adult nonpregnant populations cannot be directly applied during pregnancy.

UK study of intrapartum care for low risk primigravidas: a survey of interventions.

STUDY OBJECTIVE: To determine the extent of intrapartum intervention received by primigravidas. DESIGN: Cross sectional survey of NHS hospitals in the UK. SETTING: One hundred and one randomly selected hospital maternity units. PARTICIPANTS: Forty consecutive primigravid women, judged to be at low risk at the start of labour, in each hospital. MAIN OUTCOME MEASURES: Seven groups of interventions or monitoring procedures were identified from the first, second, and third stages of labour: fetal monitoring, vaginal examinations, artificial rupture of membranes, augmentation of labour, pain relief, type of delivery, and episiotomy. Data were collected during 1993. MAIN RESULTS: Ninety eight hospitals took part in the study and data were collected on 3160 low risk primigravidas. Seventy four per cent of these women had continuous cardiotocography. The proportion of women having restrictive or invasive fetal monitoring showed appreciable geographical variation for both the first and second stages of labour. Using the criterion of a vaginal examination every four hours and allowing for the length of each womans labour, 72% had more vaginal examinations than expected; there was a significant geographical variation in the number of women receiving more than five examinations. Fifty three per cent had artificial rupture of membranes; the procedure was performed over a wide range of cervical dilatations (0 cm-10 cm). Thirty eight per cent of labours were augmented, most commonly by intravenous syntocinon; the procedure showed significant geographical variation. Twenty eight per cent had a spinal block or epidural analgesia for the relief of pain; this intervention varied by geographical region only for the second stage of labour. Over one quarter of the women required instrumental delivery. Forty six per cent had an episiotomy; the frequency of this intervention varied substantially by region. There were no infant deaths. Twelve babies were recorded at birth as having a congenital anomaly. CONCLUSIONS: The rates of several interventions seem high for this low risk group and there was substantial geographical variation in the use of six interventions. Clinical trials are needed to evaluate the optimum criteria for using these interventions from which guidelines should be drawn up by local groups and the Royal College.

The influence of availability of free school milk on the height of children in England and Scotland.

The effect is investigated of availability of free school milk on height gain in one year of six- and seven-year-old primary schoolchildren in England and Scotland, using data collected annually from 1972 to 1976. The height gain of children for whom milk was available for the whole year of observation was compared with that of children who had no milk. Out of 16 sex-country-year-specific analyses for children from manual social classes only, 13 showed no significant evidence of greater height gain in children who had milk. Comparison of children from Social Classes IV and V (semi-skilled and unskilled) showed no greater increase in height for those who had milk, nor was there a difference in height gain between manual social class children according to the number of glasses of milk they drank a day at home or at school. We concluded that, given the standard of living at the time of the survey, the drinking of free school milk did not increase the growth rate of six- and seven-year-old children.

Cognitions associated with initial medical consultations concerning recurrent breathing difficulties: A community-based study

Abstract A two-stage community survey identified 568 respondents reporting recurrent breathing difficulties over a one-year period. Subsequent interviews allowed comparison of (i) 21 respondents who had never consulted a doctor about frequent wheezing (i.e., on more than 30 days) or serious breathing difficulties (i.e., disrupting everyday activities) over the past year with (ii) a randomly selected group of 22 who had seen their doctor concerning breathing difficulties in the past year. These groups were found to be similar with respect to demographic and lung function measures. An extended health belief model framework including causal attributions for breathing difficulties and consulting self-efficacy was used to explore cognitions which might distinguish between the two groups. Logistic regression suggested that lower perceived relative severity of symptoms (in relation to other problems). attribution of wheezing to smoking and lower self-efficacy in relation to explaining breathing difficulties to a...