Search PubMed⌕ Search

Biomedical subjects

E A Mitchell

Publications and source records attributed to E A Mitchell.

At least 91 records · Page 5Linked to original sources
PubMed1996

Do differences in the prevalence of risk factors explain the higher mortality from sudden infant death syndrome in New Zealand compared with the UK?

AIMS: To compare the prevalence of risk factors for the sudden infant death syndrome (SIDS) in New Zealand (SIDS mortality 3.53/1000) with that in the South West Thames (SWT) region of the United Kingdom (SIDS mortality 1.36/1000). METHODS: The methodology of the study was essentially identical in New Zealand and SWT. The subjects in both countries were randomly selected from all births in the study regions. The subjects were randomly allocated an age at which to be interviewed using the same questionnaire in the two study areas. Obstetric records were also examined. Eighteen hundred subjects were selected in New Zealand and 700 subjects in SWT. RESULTS: Younger and unmarried mothers were slightly more common in New Zealand than in SWT. The prevalence of maternal smoking, prone sleeping position and infants' sharing of beds with another person were all higher in New Zealand than SWT, thus increasing the risk of SIDS (maternal smoking in pregnancy: 31.0% vs 23.8% respectively, chi 2 = 11.6, p = 0.001; prone sleeping position: 32.9% vs 25.9%, chi 2 = 18.9, p < 0.001; bed sharing: 10.5% vs 6.8%, chi 2 = 6.0, p = 0.14). However, New Zealand infants were breast fed more frequently and for longer than infants in SWT, which would tend to reduce the risk of SIDS in the New Zealand population. In combination the differences in the prevalences of these four risk factors explain only 20% of the excess risk of SIDS in New Zealand. CONCLUSIONS: The high SIDS mortality rate in New Zealand is not simply explained by a high prevalence of known and modifiable risk factors for SIDS.

Breast Feeding↗
PubMed1996

Soft cot mattresses and the sudden infant death syndrome.

AIMS: To investigate whether soft cot mattresses are a risk factor for the sudden infant death syndrome (SIDS). METHODS: A follow up postal questionnaire was sent to the subjects who were interviewed 3.8 years (range 2.2 to 5.2 years) previously as part of the New Zealand Cot Death Study, a large nationwide case-control study. RESULTS: 105 European SIDS cases were compared with 828 European controls. Soft cot mattresses were associated with an increased risk of SIDS (adjusted OR = 2.36; 95% CI = 1.06, 5,25) compared with average or hard mattresses. The firmness of the mattress did not interact with the sleeping position of infant. CONCLUSIONS: Soft cot mattresses should be avoided.

Beds↗
PubMed1996

Infant room-sharing and prone sleep position in sudden infant death syndrome. New Zealand Cot Death Study Group.

BACKGROUND: There is evidence that the risk of sudden infant death syndrome is lower among ethnic groups in which parents generally share a room with the infant for sleeping. We investigated whether the presence of other family members in the infant's sleeping room affects the risk of the sudden infant death syndrome. METHODS: The case-control study covered a region with 78% of all births in New Zealand during 1987-90. Home interviews were completed with parents of 393 (81.0% of total) babies who died from the sudden infant death syndrome aged 28 days to 1 year and 1592 (88.4% of total) controls, selected from all hospital births in the study region. FINDINGS: The relative risk of sudden infant death for sharing the room with one or more adults compared with not sharing was 0.19 (95% CI 0.08-0.45) for sharing at night during the last 2 weeks and 0.27 (0.17-0.41) for sharing in the last sleep, after control for other confounders. Sharing the room with one or more children did not affect the relative risk (1.25 [0.86-1.82] for sharing during last 2 weeks; 1.29 [0.85-1.94] for sharing in last sleep). There was a significant interaction (p = 0.033) between not sharing the room with an adult and prone sleep position in the last sleep. Compared with infants sharing the room with an adult and not prone, the multivariate relative risk was 16.99 (10.43-27.69) for infants not sharing with an adult and prone, 3.28 (2.06-5.23) for infants sharing the room and prone, and 2.60 (1.58-4.30) for infants not sharing the room and not prone. The interaction between adult room-sharing and prone sleep position suggests that both exposures may affect the risk of sudden infant death syndrome through a common mechanism. INTERPRETATION: We recommend that infants sleep in the same bedroom as their parents at night to reduce the risk of sudden infant death syndrome.

Adult↗
PubMed1996

Marital status and births after losing a baby from sudden infant death.

UNLABELLED: To describe the change in marital status and subsequent live births of mothers who have lost a baby from sudden infant death (SID or cot death), a postal questionnaire was sent to European mothers who had been interviewed approximately 3.7 years (range 2.2-5.2 years) previously as part of a nationwide case-control study. Mothers of 105 (60.3%) cases and 828 (76.9%) controls replied. Changes in marital status between the time of interview and the time of the postal questionnaire did not differ between mothers of cases and that of controls when adjusted for marital status at the time of death/nominated date for controls. Cases were more likely to have further children than controls (P < 0.001) and had them sooner after the death than after the nominated date for control babies (P < 0.001). Case mothers were more likely than controls to have a second child after the death/nominated date, however the interval between the first and second child after the death/nominated date was the same as that for controls. CONCLUSIONS: Although the death of an infant is a major stress on marital relationships, at approximately 3.7 years marital breakdown is no higher than in the control population. After the death of her baby the mother "replaces" the child by having more children than control mothers and having the first one earlier than control mothers. Mothers who lose a baby from SID are more fertile than the control population both before and after the death.

Adult↗
PubMed1996

Sudden infant death syndrome: insulation from bedding and clothing and its effect modifiers. The National Cot Death Study Group.

BACKGROUND: Thermal stress related to excessive insulation from bedding and clothing has been postulated to be associated with sudden infant death syndrome (SIDS). METHODS: The parents of 393 (81%) of the infants who died of SIDS in the post neonatal period were interviewed at home. Interviews were also completed with the parents of 1592 (88.4% of total) controls, a representative sample of all hospital births. The study was conducted in regions of the North and South Island of New Zealand in which 78% of all New Zealand births occurred in 1987-1990. Temperatures for the infant's bedroom estimated from the outside temperature and a model were used to predict the appropriate insulation for lower critical temperature (temperature below which the metabolic rate is likely to increase). RESULTS: Sudden infant death syndrome was associated with extra thermal insulation of > 2 tog above the lower critical value, the odds ratio (OR) was 1.70 (95% confidence interval [Cl] : 1.3-2.20) after adjusting for season. After adjusting for a number of confounding factors the CR was reduced to 1.35 (95% Cl: 0.97-1.87). Also associated with SIDS was too little thermal insulation OR = 1.67(95% Cl: 1.13-2.48; and 2.63 (95% Cl: 1.61-4.30) when adjustments were made for the confounding factors. The interaction effect between infants sleeping prone and >2 tog extra thermal insulation was significant (OR = 6.07, 95% Cl: 3.83-9.60). Infants with too little thermal insulation were at increased risk if they were not tightly wrapped (OR = 3.81, 95% Cl: 2.04-7.09). There were also small additive interaction effects if the mother smoked and the infants had > 2 tog extra thermal insulation, or they were ill and had > 4 tog extra insulation. Interaction effects between thermal insulation and other factors were not significant. CONCLUSION: More thermal insulation than was necessary to maintain the lower critical temperature increased the risk of SIDS primarily among infants in the prone sleep position, and to a lesser degree in infants whose mothers smoked and in infants who were unwell.

Bedding and Linens↗
PubMed1996

Temperature and the sudden infant death syndrome.

The relationship between the days on which sudden infant death syndrome (SIDS) occurred and daily minimum and average temperature was examined for five regions of New Zealand for a three-year period beginning on 1st November 1987. There was a marked winter excess of SIDS. After adjusting for season the temperature on the days preceding SIDS deaths were negatively associated with SIDS, but the effect was not statistically significant. Further analysis, using data from the New Zealand Cot Death Study, a nation-wide case-control study was based on the mean temperature 2 to 5 days before death for the cases or a nominated day for the controls. Statistically significant interaction effects between temperature and sleep position, and temperature and the age of the infant were found. A mean temperature 2-5 days beforehand 2.5 degrees C below that on the day of death or the nominated day increased the risk of SIDS in those sleeping prone by 1.17 [95% CI 0.95 to 1.43] and in those sleeping on their side or back by 0.96 [95% CI 0.77 to 1.19]. In the same circumstances the odds ratio (OR) for infants aged 3 months or less would increase by 0.98 [95% CI 0.80 to 1.19] and that for infants older than 3 months by 1.20 [95 CI 0.97 to 1.49]. The statistically significant negative association between temperature a few days before death and SIDS has been reported previously. Most of the effect of temperature can be attributed to seasonal variations, and minor fluctuations in day to day temperatures make only a very small contribution to SIDS.

Case-Control Studies↗
PubMed1996

Symptoms, sweating and reactivity of infants who die of SIDS compared with community controls. New Zealand National Cot Death Study Group.

OBJECTIVE: To describe the symptoms of illness reported by the parents of infants who have died of sudden infant death syndrome (SIDS) compared with those reported by community controls. METHODOLOGY: A nationwide case-control study involving regions of New Zealand with 78% of all births between 1987 and 1990. Home interviews were completed with parents of 393 (81% of total) infants who died from SIDS in the post neonatal age group, and 1592 (88.4% of total) controls who were a representative sample of all hospital births in the study region. RESULTS: Symptoms of infection were common in both cases and controls, but were not significantly different. Infants dying of SIDS, however, were likely to have symptoms suggestive of more severe illness in the 2 days before death (odds ratio [OR] = 3.02, 95% confidence interval [CI] 1.69-5.38). After adjusting for potential confounding this was still statistically significant (adjusted OR 2.36, 95% Cl 1.14-4.90). Also, babies dying of SIDS were more likely to have been less reactive to their environment in the 2 weeks before death compared with the controls (univariate OR 0.88, 95% Cl 0.55- 1.39, adjusted OR 0.55, 95% CI 0.29-0.88). 'Drenching' sweats at least weekly were reported for 15.6% of case infants compared with 5.9% of control infants (adjusted OR 2.12, 95% CI 1.53-3.39). Forty per cent of these infants had this symptom in the first 4 weeks of life when it was also associated with a significantly raised risk of SIDS. Apnoea lasting more than 20 s was reported for 13.2% of case infants compared with 5.3% of control infants (adjusted OR 1.93, 95% CI 1.17-3.17). Similarly, 71.8% of case infants' faces were reported to never turn red while awake compared to 49.8% of control infants (adjusted OR 2.98, 95% CI 2.19-4.07). CONCLUSIONS: Only a small number (6.4%) of babies who die of SIDS have symptoms of serious illness in the 2 days before death. There is support for the hypothesis that there is a group of babies dying of SIDS who have subtle abnormalities in autonomic control or arousal ability.

Apnea↗
PubMed1996

Life events, social support and the risk of sudden infant death syndrome.

The effects of a lack of maternal social support and stressful life events on the risk of Sudden Infant Death Syndrome (SIDS) were examined by case-control design: 390 cases and 1592 control infants. A seven item index of mother's social support was used. A possible 21 life events experienced by each family were summed and then put into one of three categories: 0-2, 3-5, and 6 or more life events. Similar levels of maternal social support were found for both groups. SIDS families experienced significantly more stressful life events than control families, but once social factors had been taken into account this association was lost.

Analysis of Variance↗
PubMed1996

Growth and the sudden infant death syndrome.

OBJECTIVE: To compare the growth curves based on measurements of body weight for male and female infants dying of sudden infant death syndrome (SIDS) with those of male and female controls. METHODS: The data were drawn from a large case control study of SIDS carried out in New Zealand between 1987 and 1990. RESULTS: The mean birthweight for the cases was 3049 g and for the controls 3526 g. The mean growth curves for the male and female controls were close to the 50th centile of growth charts used in New Zealand. The growth curve for the male cases diverged from that of the controls, being closer to the 25th percentile. The differences between the female cases and controls were less pronounced. The differences in weekly weight increments derived from the curves for the cases and controls for nine 4-week periods were not statistically significant after taking into account race, manner of feeding and maternal smoking for any 4-week period. CONCLUSIONS: SIDS cases were lighter at birth, but their growth velocity was normal postnatally.

Body Weight↗
PubMed1996

Allergy and the risk of sudden infant death syndrome. The Members of the New Zealand Cot Death Study Group.

BACKGROUND AND OBJECTIVE: There are several sources that suggest that there is a link between allergy and sudden infant death syndrome. We endevavoured to look for evidence of an association between allergic disease and the risk of sudden infant death syndrome (SIDS). METHODS: A nationwide case-control study covering a region with 78% of all births in New Zealand during 1987-90. Interviews were completed with the parents of 393 (81.0% of total) infants who died from the sudden infant death syndrome (SIDS), and 1592 (88.4% of total) control families who were a representative sample of all hospital births in the study region. RESULTS: Eczema was reported in 13.9% control infants compared with only 8.0% of the SIDS infants, univariate odds ratio for this in terms of risk for SIDS was 0.56 (95% confidence interval 0.37, 0.84) for infants with eczema compared with those without. This lesser risk for SIDS was unchanged when adjusted for potential confounding factors. The risk of SIDS was not associated with reported cow's milk reactions or a family history of allergic symptoms once adjustments were made for possible confounding factors. CONCLUSION: Infants with skin disorders identified by their parents as eczema had a low risk for SIDS. Families can be reassured that atopy is not a risk factor for SIDS.

Asthma↗
PubMed1995

Public health policy on bed sharing and smoking in the sudden infant death syndrome.

AIMS: Further develop New Zealand public health policy on infant bed sharing by quantifying the number of sudden infant death syndrome (SIDS) cases attributable to bed sharing among infants of smoking and nonsmoking mothers. METHODS: A large nation-wide case control study covering a region with 78% of all births in New Zealand during 1987-90. Interviews were completed with parents of 393 (81.0% of total) cases who died from the sudden infant death syndrome in the postneonatal age group, and 1592 (88.4% of total) controls who were a representative sample of all hospital births in the study region. RESULTS: The proportion of control infants who usually bed shared in the last 2 weeks was 65.7% in Maori, 73.7% in Pacific Island people and 35.5% in Europeans (44.5% in all ethnic groups combined, and half of these for less than 2 hours per night). There was an interaction between maternal smoking and infant bed sharing on the risk of sudden infant death separately in Maori, Pacific Island and European infants with the risk being highest in infants exposed to both risk factors. 26% of SIDS deaths were explained by bed sharing among infants of smoking mothers (who comprised 16% of the total infant population) and 3% by bed sharing among infants of non-smoking mothers (28% of total infant population). CONCLUSION: Infant bed sharing is common. The majority of SIDS deaths that are attributed to be sharing occur among infants of smoking mothers. A policy which advises all infants not to bed share is estimated to potentially save an extra 3% of SIDS compared to a policy targeted only on infants of smoking mothers. If public attitudes are favorable to bed sharing, there could be a marginal cost (against its acceptance) by including infants of non-smoking mothers in the recommendation not to bed share. These findings should not be interpreted as indicating that bed sharing where the mother is a nonsmoker is safe or protective against SIDS.

Beds↗
PubMed1995

An audit of the sudden infant death syndrome prevention programme in the Auckland region.

AIM: An audit of the sudden infant death syndrome (SIDS) prevention programme in the Auckland region. METHODS: 107 health professionals working in antenatal classes, postnatal wards, domiciliary midwifery and the Plunket Society were interviewed. RESULTS: Maternal smoking and infant sleeping position were considered to be the most important risk factors for SIDS; lack of breast feeding and cosleeping were rated less important. Many other putative risk factors were also mentioned. There was no difference in the evaluation of the relative importance of risk factors for SIDS by health professionals working in south Auckland, where SIDS mortality has declined only slightly, compared with the evaluation by health professionals in the rest of Auckland, where SIDS mortality has declined considerably. The most important source of information for health professionals was the pamphlet "Cot death: you can reduce the risks", which is designed for parents. CONCLUSION: Differences in the SIDS prevention message by health professionals do not explain differences in SIDS mortality within Auckland. Health professionals were knowledgeable about risk factors for SIDS, but knowledge could be improved further by regular updates. New resource material including posters and pamphlets for families is also required.

Attitude of Health Personnel↗