Total population investigation of dental hospitalizations in indigenous children under five years in Western Australia using linked data.

BACKGROUND: The aim of this study was to compare dental hospital admissions in a total state birth population of Indigenous and non-Indigenous children aged under five years in Western Australia. METHODS: Midwives' notification data were linked to databases of deaths, admissions, birth defects and intellectual disability. Births during 1980-1995 were followed until five years of age (n = 383,665). Dental admissions were classified by ICD-9 principal diagnosis categories. RESULTS: There were 738 dental admissions for 665 children aged up to five years of Indigenous mothers (n = 20,921). Indigenous children comprised 6.3% of all children having a dental admission in this age group; 3.2% of children with Indigenous mothers had a dental admission compared with 2.7% of non-Indigenous children. Overall, 8.7% (n = 58) of Indigenous children with a dental admission had a birth defect and 5.5% (n = 23) had an intellectual disability (compared to 8.8% and 3.2%). Indigenous children were four times more likely to be diagnosed with oral soft tissue diseases than non-Indigenous children, and less likely to be categorized as having diseases of the dental hard tissues. Indigenous children were more likely to have a longer dental admission. CONCLUSIONS: These analyses provide important findings regarding hospital admissions for Indigenous children. Admissions for disorders of the soft tissues are more common in Indigenous children.

Health of caregivers in child care.

BACKGROUND: Child care workers play an important role in caring for children attending child care yet there is little research regarding their health. METHODS: The study consisted of focus groups with child care workers and a survey, conducted as part of a larger study known as the Healthy Child Care Study, which focused on children. The study investigated carers working in formal child care [long day care (LDC) and family day care (FDC)]. RESULTS: Questionnaires to caregivers in centres showed that 86% had taken sick leave in the previous year and 75% of staff had taken leave for infectious illness. Carers in FDC reported that 24% had taken sick leave in the previous year and 12% of carers had taken leave for infectious illness. Of responding caregivers from centres, 22% were cigarette smokers while in FDC homes, 8% of carers smoked. In focus groups, carers reported that their major areas of health concern were stress, infectious illness and physical trauma such as lifting injuries. CONCLUSIONS: Child care workers in LDC took more sick leave than those in FDC but this is not necessarily due to more illness. Child care workers are a diverse and important group that require further research.

Interpretation of recent sudden infant death syndrome rates in Western Australia.

The diagnosis of sudden infant death syndrome (SIDS) has undergone several changes in definition since first being recognised as a cause of death. Linked total population data from Western Australia enable investigations to determine changes in classifications of mortality for the infants of Aboriginal and non-Aboriginal mothers (Aboriginal and Torres Strait Islander people are referred to throughout this report as 'Aboriginal'). Data for recent years show a shift away from a classification of 'SIDS' towards a classification of 'unascertainable', particularly for Aboriginal infants. This has implications for the accurate translation of data into policy and practice.

Absence from childcare for respiratory illness.

BACKGROUND: This population-based study investigated prospectively collected absence for respiratory illness data in two types of formal childcare (centre day care and family day care) in Perth, Western Australia, and factors associated with such absence. METHODS: All centres (n = 11) and 95% of family day care caregivers (n = 130) selected at random from licensing lists agreed to participate. Demographic details were obtained from a parental questionnaire and absences were recorded prospectively. Characteristics of the child and family were described using univariate odds ratios (OR) with 95% confidence intervals (CI). Multivariable analysis including generalized estimating equations was used to investigate having at least one absence for respiratory illness, having two or more absences, and having six or more absences. RESULTS: No statistically significant difference between care types for having had at least one absence episode for respiratory illness (OR 1.37, 95% CI 0.92-2.04) was found. Children who attended care for more days per week (OR 1.40, 95% CI 1.26-1.56) and those in the study for more weeks (OR 1.03, 95% CI 1.01-1.05) were more likely to be absent for respiratory illness. Those children in care for a greater number of hours per day were less likely to be absent (OR 0.88, 95% CI 0.80-0.97). Family history of bronchitis was also associated with absence for respiratory illness (OR 1.86, 95% CI 1.32-2.63). CONCLUSIONS: Statistically significant factors which had an impact on absence for respiratory illness were primarily those relating to the time spent in childcare and to family history of bronchitis.

A prospective study of absence for illness and injury in childcare children.

OBJECTIVES: This population-based study investigated prospectively collected absence episodes to describe patterns and rates of absences for illness and other reasons in two types of formal childcare. DESIGN: Centre day care and family day care homes were selected at random from licensing lists. All centres (n = 11) and 95% of family day care caregivers (n = 130) agreed to participate. The results are based on absence information from carers and on questionnaires to the parents of participating children (n = 846). RESULTS: The major reason for absence was respiratory illness with 48% of all children absent at least once during the year with some form of respiratory illness. Although the absence rate for children in centre care was higher than that in family care (3.34 episodes per 52 child-weeks compared with 2.41), the difference was not statistically significant. CONCLUSION: Investigating patterns of absences from childcare allows a better understanding of needs in childcare. The major reason for absence for illness was respiratory illness.

Perinatal and postneonatal mortality among Indigenous and non-Indigenous infants born in Western Australia, 1980-1998.

OBJECTIVE: To describe cause-specific perinatal and postneonatal mortality for Indigenous and non-Indigenous infants using a new classification system. DESIGN: Total population retrospective cohort study. PARTICIPANTS AND SETTING: All registered births in Western Australia of birthweight greater than 399 g from 1980 to 1998, inclusive. MAIN OUTCOME MEASURES: Rates and time trends for all births 1980-1998, and cause-specific rates for births 1980-1993 of fetal, neonatal and postneonatal mortality among Indigenous and non-indigenous infants, using a classification system designed for use in perinatal, postneonatal and childhood deaths. RESULTS: For Indigenous infants born 1980-1998, the mortality rate before the first birthday was 2.7 times (95% CI, 2.5-2.9 times) that for non-Indigenous infants. Indigenous infants born 1980-1993 had a higher mortality rate in all cause-of-death categories. The highest relative risk was for deaths attributable to infection (8.1; 95% CI, 6.5-10.0) which occurred primarily in the postneonatal period; the source of the infection was less likely to be identified in Indigenous deaths. From 1980-1998, the rate of neonatal deaths decreased at a greater rate for Indigenous than for non-Indigenous infants. However, while stillbirth and sudden infant death syndrome rates for non-Indigenous births fell, they remained static for Indigenous births. CONCLUSIONS: The new classification system, which considers the underlying rather than immediate cause of death, enables investigation of the causes of all deaths, from stillbirths to childhood. This system has highlighted the comparative importance of infection as a cause of death for Indigenous infants, particularly in the postneonatal period.

Parental attitudes to health of children in child-care centres and options when children are ill.

OBJECTIVE: To determine parental attitudes regarding the health of children attending child-care centres, to explore concerns when children who normally attend child care are ill, and to investigate options in these circumstances. METHODOLOGY: Focus groups conducted with parents whose children attended child-care centres. Ten focus groups were conducted. RESULTS: Many parents encountered difficulty when children who normally attend child care were ill and there was a lack of options for care. Parents were concerned about the spread of infections among children but considered that there were also many health and other advantages for their children in attending child care. Child-care centres were perceived as providing a valuable support role for families. CONCLUSIONS: Many parents lack adequate options for care when their children are ill. Parents' concerns regarding health in child care are important in policy decisions regarding the health of children in child care, and the development of alternative care services for children.

Association between breast feeding and asthma in 6 year old children: findings of a prospective birth cohort study.

OBJECTIVES: To investigate the association between the duration of exclusive breast feeding and the development of asthma related outcomes in children at age 6 years. DESIGN: Prospective cohort study. SETTING: Western Australia. SUBJECTS: 2187 children ascertained through antenatal clinics at the major tertiary obstetric hospital in Perth and followed to age 6 years. MAIN OUTCOME MEASURES: Unconditional logistic regression to model the association between duration of exclusive breast feeding and outcomes related to asthma or atopy at 6 years of age, allowing for several important confounders: sex, gestational age, smoking in the household, and early childcare. RESULTS: After adjustment for confounders, the introduction of milk other than breast milk before 4 months of age was a significant risk factor for all asthma and atopy related outcomes in children aged 6 years: asthma diagnosed by a doctor (odds ratio 1.25, 95% confidence interval 1.02 to 1.52); wheeze three or more times since 1 year of age (1.41, 1.14 to 1.76); wheeze in the past year (1.31, 1.05 to 1.64); sleep disturbance due to wheeze within the past year (1.42, 1.07 to 1.89); age when doctor diagnosed asthma (hazard ratio 1.22, 1.03 to 1.43); age at first wheeze (1.36, 1.17 to 1.59); and positive skin prick test reaction to at least one common aeroallergen (1.30, 1.04 to 1.61). CONCLUSION: A significant reduction in the risk of childhood asthma at age 6 years occurs if exclusive breast feeding is continued for at least the 4 months after birth. These findings are important for our understanding of the cause of childhood asthma and suggest that public health interventions to optimise breast feeding may help to reduce the community burden of childhood asthma and its associated traits.

The Bibbulung Gnarneep Project: practical implementation of guidelines on ethics in indigenous health research.

Human rights and ethical principles justify Indigenous control of health research conducted in Indigenous communities, but also emphasise the need for scientific rigour, knowledge and expertise, much of which currently resides with the non-Indigenous community. In 1994, we began development of the Bibbulung Gnarneep Project on Aboriginal maternal and child health in Perth, Western Australia. We describe the process of developing a protocol to ensure ethical conduct of this research through consultation and negotiation between Aboriginal and non-Aboriginal people involved in the project.

Cumulative mortality in children aged 1 to 6 years born in Western Australia from 1980-89.

PURPOSE: To investigate cumulative mortality for children aged 1-6 years born in Western Australia from 1980 to 1989. STUDY DESIGN: Births and deaths were ascertained from a linked total population database supplemented by information from postmortem records. Deaths were classified according to the underlying cause, and mortality rates, including factor specific rates, were calculated. Trends were investigated and comparisons were made using relative risks with 95% confidence intervals. RESULTS: Cumulative mortality was 2.2/1000 infant survivors, with a significant decrease during the years studied. Mortality was almost four times higher for Indigenous children, with no decrease. Accidents comprised 45.6% of all deaths, birth defects 17.3%, cancer and leukaemias 12.5%, and infections 11.0%. Low birth weight, preterm birth, and young maternal age significantly increased the risk of death in both Indigenous and non-Indigenous children; single marital status was also a significant risk factor for non-Indigenous children. CONCLUSION: High quality data and appropriate classification systems are essential to enable effective monitoring of childhood deaths and the planning of preventive programmes. Further decreases in mortality rates might be dependent on ensuring that resources are directed towards improving social and economic conditions for Indigenous and other disadvantaged families.

Infant care practices in a metropolitan aboriginal population Bibbulung Gnarneep Team.

OBJECTIVE: To describe sleeping position, room and bed-sharing, tobacco smoke exposure and infant feeding for a sample of Australian Aboriginal infants from a metropolitan area. METHODS: Interviews with Aboriginal mothers who resided in the Perth metropolitan area and had given birth during a continuous 15-month study period. The interviews took place when the infants were approximately 6-12 weeks old and efforts were made to contact all eligible mothers. Results are presented as proportions with 95% confidence intervals. RESULTS: Of all the eligible mothers (n = 515), 87% were contacted and 53% (n = 273) completed the interview. Of all the infants, 11% slept prone, 96% shared a room and 68% shared a bed; 65% of mothers smoked during pregnancy and 65% were smokers at the time of interview; 66% of the partners were smokers and 80% of the infants were regularly exposed to tobacco smoke; 89% of mothers initiated breast-feeding and 70% were breast-feeding at time of interview. CONCLUSION: Prevalences of non-prone sleeping and breast-feeding are similar to the overall Western Australian population, whilst tobacco smoke exposure of the infants is markedly higher. Programs of community and family education and support are required urgently to decrease this exposure.

The use of medication in children attending childcare in Western Australia.

OBJECTIVE: This paper reports on medication use and factors affecting use in a cohort of preschool children attending long daycare in centres and family daycare in homes. METHODOLOGY: A survey of parents representing 846 children under 6 years old in two types of childcare in Perth, Western Australia. The data were analysed using descriptive and logistic regression techniques to elucidate factors associated with use of medication. RESULTS: Seventy-three per cent of the children were reported to have used over-the-counter medication at some time, whilst current regular use of prescribed medication was 11%. This proportion is comparable to the limited available data for children of similar ages in Western Australia. For both medication categories, the use of medication was higher in long daycare than family daycare. In addition, many other characteristics differed between children in long daycare and family daycare. Initial analysis showed a number of significant associations between child and family factors and both categories of medication. Multivariable analyses indicated that the most important associations with medication use were with children's illnesses. There was no significant difference between long daycare and family daycare for use of over-the-counter medication but attending long daycare was significantly associated with increased use of prescribed medication (OR=2.13; 95% CI 1.24-3.67) after illnesses had been taken into account. CONCLUSION: Medication use in children attending childcare is closely related to reported illness in the child.

Data linkage methods used in maternally-linked birth and infant death surveillance data sets from the United States (Georgia, Missouri, Utah and Washington State), Israel, Norway, Scotland and Western Australia.

In this paper we describe the methods used to link birth and infant mortality and morbidity surveillance data sets into sibships using deterministic or multistage probabilistic linkage methods. We describe nine linked data sets: four in the United States (Georgia, Missouri, Utah and Washington State), and four elsewhere (Scotland, Norway, Israel and Western Australia). Norway and Israel use deterministic methods to link births and deaths into sibships. The deterministic linkage is usually dependent on the availability of national identification numbers. In both countries they assign these numbers at birth. Deterministic linkage is usually highly successful, and the major problem is the validation of linkages. In the United States, Western Australia and UK linkage is multistage and probabilistic. This approach is usually dependent on the calculation linkage weights from sociodemographic variables. The success rates of probabilistic methods are above 80%. Maternally-linked perinatal data open new vistas for epidemiological research. Recurrence of poor perinatal outcomes is more appropriately studied using longitudinally-linked data sets. In addition, the emergence of risk factors and the recurrence of risk factors can be studied.

An analysis of sudden infant death syndrome in aboriginal infants.

The purpose of this case-control study was to identify antenatal and perinatal risk factors for sudden infant death syndrome (SIDS) in Aboriginal infants in Western Australia (WA). Cases were all Aboriginal infants born in WA from 1980 to 1990 inclusive and classified as dying from SIDS in WA. Controls consisted of a matched group and a random group both selected from liveborn Aboriginal infants born from 1980 to 1990. Multivariate modelling showed that SIDS in Aboriginal infants was strongly related to young maternal age (< 20 years, odds ratio (OR) = 2.89), high parity (parity > 3, OR = 4.40) and being small-for-gestational age (OR = 3.36) but was not associated with single marital status (OR = 0.95) or male sex (OR = 0.97). Although the study was based on routinely collected data, results do highlight some important groups for SIDS prevention. To gain further knowledge in terms of SIDS in Aboriginal infants, there is an urgent need to collect information concerning infant care practices in the Aboriginal community.

Sudden infant death syndrome in Australian aboriginal and non-aboriginal infants: an analytical comparison.

Our previous research has shown that the sudden infant death syndrome (SIDS) rate for Aboriginal infants in Western Australia (WA) is markedly higher than that for non-Aboriginal infants. The aim of this study was to identify factors that may be important in explaining this disparity. A case-control study was conducted based on routinely collected data for the population of WA singleton births from 1980 to 1990 inclusive. Cases were infants born and classified as dying from SIDS in WA (Aboriginal n = 88, non-Aboriginal n = 409). Controls were infants born in WA and not classified as dying from SIDS; 2% samples of both Aboriginal and non-Aboriginal infants were included. The risk of dying from SIDS in Aboriginal infants was 3.86 times [95% confidence interval (CI) = 2.98 to 5.02] that in non-Aboriginal infants. Statistically significant univariable risk factors for SIDS in Aboriginal infants were preterm birth, low birthweight and small-for-gestational-age; for non-Aboriginal infants they included these factors as well as single marital status, young maternal age, parity of one or greater and male sex. Comparing Aboriginal with non-Aboriginal controls, most of the risk factors were more common in the Aboriginal population. Multiple logistic regression analysis indicated that Aboriginal infants were 1.43 times [95% CI = 1.04 to 1.95] more likely to die from SIDS than non-Aboriginal infants. Differences in the risk factor profile for Aboriginal and non-Aboriginal infants were sought using interaction terms. The only important differences were that the risk of SIDS in Aboriginal infants, unlike that in non-Aboriginal infants, appeared not to be strongly related to male sex or to single marital status. Thus, the results show that the disparity between the incidence of SIDS in the Aboriginal and non-Aboriginal populations can be explained largely, although not totally, by the high prevalence of routinely recorded risk factors in the Aboriginal population. A limitation of this study is that data on the postnatal risk factors of prone sleeping, maternal smoking and non-breastfeeding were unavailable. The residual excess risk for Aboriginal infants may be a result of these recognised postnatal risk factors and/or other infant care practices that are not routinely recorded in our data base, or to underlying social and economic conditions. Further study of all these potential risk factors is warranted.

Hospital admissions for lower respiratory tract illness before the age of two years in western Australia.

In this study, hospital admissions for lower respiratory tract illness before two years of age have been documented for all children born in Western Australia in 1986. Admissions data were linked to birth and death records for individual children. Of the total cohort, 5% of non-Aboriginal and 17% of Aboriginal children were hospitalised only once for lower respiratory tract illness; 1% of non-Aboriginal and 11% of Aboriginal children had repeated admissions. Perinatal conditions comprised the greatest proportion of the admissions for non-Aboriginal children, and pneumonia for Aboriginal children. Non-Aboriginal children had decreasing admission rates from the neonatal period onwards, whereas those for Aboriginal children increased. For all children, those of low or high birthweight, male sex and those with young or unmarried mothers or residing in country regions were more likely to be admitted. This research has highlighted potential risk factors for serious respiratory illness in early childhood and has shown the feasibility of using linked data for the total population to formulate and test hypotheses relating to respiratory morbidity.