This study explores the socio-demographic characteristics of pregnant women who continue to smoke during the pregnancy, and identifies the characteristics of the smokers who were likely to quit smoking during the pregnancy period.
This was secondary analysis of the New South Wales (NSW) Midwives Data Collection (MDC) 1999–2003, a surveillance system covering all births in NSW public and private hospitals, as well as home births. Bivariate and multiple logistic regression analyses were performed to explore the associations between socio-demographic characteristics and smoking behaviour during pregnancy.
Data from 426,344 pregnant women in NSW showed that 17.0% continued to smoke during pregnancy. The smoking rate was higher among teenage mothers, those with an Aboriginal (indigenous) background, and lower among more affluent and overseas-born mothers. This study also found that unbooked confinements, and lack of antenatal care in the first trimester were strongly associated with increased risk of smoking during pregnancy. About 4.0% of the smoking women reported they may quit smoking during their pregnancy. Findings showed that mothers born overseas, of higher socio-economic status, first time mothers and those who attended antenatal care early showed an increased likelihood of smoking cessation during pregnancy. Those who were heavy smokers were less likely to quit during pregnancy.
Although the prevalence of smoking during pregnancy has been declining, it remains a significant public health concern. Smoking cessation programs should target the population subgroups of women at highest risk of smoking and who are least likely to quit. Effective antismoking interventions could reduce the obstetric and perinatal complications of smoking in pregnancy.
Published estimates of Aboriginal mortality and life expectancy (LE) for the eastern Australian states are derived from demographic modelling techniques to estimate the population and extent of under-recording of Aboriginality in death registration. No reliable empirical information on Aboriginal mortality and LE exists for New South Wales (NSW), the most populous Australian state in which 29% of Aboriginal people reside.
This paper estimates mortality and LE in a large, mainly metropolitan cohort of Aboriginal clients from the Aboriginal Medical Service (AMS) Redfern, Sydney, NSW.
Identifying information from patient records accrued by the AMS Redfern since 1980 of definitely Aboriginal clients, without distinction between Aboriginal and Torres Strait Islander (n=24,035), was extracted and linked to the National Death Index (NDI) at the Australian Institute of Health and Welfare (AIHW). Age-specific mortality rates and LEs for each sex were estimated using the AMS patient population as the denominator, discounted for deaths. Directly age-standardised mortality and LEs were estimated for 1995–1999, 2000–2004 and 2005–2009, along with 95% confidence intervals. Comparisons were made with other estimates of Aboriginal mortality and LE and with the total Australian population.
Mortality declined in the AMS Redfern cohort over 1995–2009, and the decline occurred mostly in the ≤44 year age range. Male LE at birth was estimated to be 64.4 years (95%CI:62.6-66.1) in 1995–1999, 65.6 years (95%CI:64.1-67.1) in 2000–2004, and 67.6 years (95%CI:65.9-69.2) for 2005–2009. In females, these LE estimates were 69.6 (95%CI:68.0-71.2), 71.1 (95%CI:69.9-72.4), and 71.4 (95%CI:70.0-72.8) years. LE in the AMS cohort was 11 years lower for males and 12 years lower for females than corresponding all-Australia LEs for the same periods. These were similar to estimates for Australian Aboriginal people overall for the same period by the Aboriginal Burden of Disease for 2009, using the General Growth Balance (GGB) model approach, and by the Australian Bureau of Statistics (ABS) for 2005–2007. LE in the AMS cohort was somewhat lower than these estimates for NSW Aboriginal people, and higher than ABS 2005–2007 estimates for Aboriginal people from Northern Territory, South Australia, and Western Australia.
The AMS Redfern cohort has provided the first empirically based estimates of mortality and LE trends in a large sample of Aboriginal people from NSW.
Aboriginal and Torres Strait Islander peoples are under-reported in administrative health datasets in NSW, Australia. Correct reporting of Aboriginal and Torres Strait Islander peoples is essential to measure the effectiveness of policies and programmes aimed at reducing the health disadvantage experienced by Aboriginal and Torres Strait Islander peoples. This study investigates the potential of record linkage to enhance reporting of deaths among Aboriginal and Torres Strait Islander peoples in NSW, Australia.
Australian Bureau of Statistics death registration data for 2007 were linked with four population health datasets relating to hospitalisations, emergency department attendances and births. Reporting of deaths was enhanced from linked records using two methods, and effects on patterns of demographic characteristics and mortality indicators were examined.
Reporting of deaths increased by 34.5% using an algorithm based on a weight of evidence of a person being Aboriginal or Torres Strait Islander, and by 56.6% using an approach based on 'at least one report' of a person being Aboriginal or Torres Strait Islander. The increase was relatively greater in older persons and those living in less geographically remote areas. Enhancement resulted in a reduction in the urban-remote differential in median age at death and increases in standardised mortality ratios particularly for chronic conditions.
Record linkage creates a statistical construct that helps to correct under-reporting of deaths and potential bias in mortality statistics for Aboriginal and Torres Strait Islander peoples.
Australian Aboriginal children experience earlier, more frequent and more severe otitis media, particularly in remote communities, than non-Aboriginal children. Insertion of ventilation tubes is the main surgical procedure for otitis media. Our aim was to quantify inequalities in ventilation tube insertion (VTI) procedures between Australian Aboriginal and non-Aboriginal children, and to explore the influence of birth characteristics, socioeconomic background and geographical remoteness on this inequality.
Retrospective cohort study using linked hospital and mortality data from July 2000 to December 2008.
Setting and participants
A whole-of-population cohort of 653 550 children (16 831 Aboriginal and 636 719 non-Aboriginal) born in a New South Wales hospital between 1 July 2000 and 31 December 2007 was included in the analysis.
First VTI procedure.
VTI rates were lower in Aboriginal compared with non-Aboriginal children (incidence rate (IR), 4.3/1000 person-years; 95% CI 3.8 to 4.8 vs IR 5.8/1000 person-years; 95% CI 5.7 to 5.8). Overall, Aboriginal children were 28% less likely than non-Aboriginal children to have ventilation tubes inserted (age-adjusted and sex-adjusted rate ratios (RRs) 0.72; 95% CI 0.64 to 0.80). After adjusting additionally for geographical remoteness, Aboriginal children were 19% less likely to have ventilation tubes inserted (age-adjusted and sex-adjusted RR 0.81; 95% CI 0.73 to 0.91). After adjusting separately for private patient/health insurance status and area socioeconomic status, there was no significant difference (age-adjusted and sex-adjusted RR 0.96; 95% CI 0.86 to 1.08 and RR 0.93; 95% CI 0.83 to 1.04, respectively). In the fully adjusted model, there were no significant differences in VTI rates between Aboriginal and non-Aboriginal children (RR 1.06; 95% CI 0.94 to 1.19).
Despite a much higher prevalence of otitis media, Aboriginal children were less likely to receive VTI procedures than their non-Aboriginal counterparts; this inequality was largely explained by differences in socioeconomic status and geographical remoteness.
Epidemiology; Public Health
Aboriginal status has been unreliably and incompletely recorded in health and vital registration data collections for the most populous areas of Australia, including NSW where 29% of Australian Aboriginal people reside. This paper reports an assessment of Aboriginal status recording in NSW cancer registrations and estimates incidence, mortality and survival from cancer in NSW Aboriginal people using multiple imputation of missing Aboriginal status in NSW Central Cancer Registry (CCR) records.
Logistic regression modelling and multiple imputation were used to assign Aboriginal status to those records of cancer diagnosed from 1999 to 2008 with missing Aboriginality (affecting 12-18% of NSW cancers registered in this period). Estimates of incidence, mortality and survival from cancer in NSW Aboriginal people were compared with the NSW total population, as standardised incidence and mortality ratios, and with the non-Aboriginal population.
Following imputation, 146 (12.2%) extra cancers in Aboriginal males and 140 (12.5%) in Aboriginal females were found for 1999-2007. Mean annual cancer incidence in NSW Aboriginal people was estimated to be 660 per 100,000 and 462 per 100,000, 9% and 6% higher than all NSW males and females respectively. Mean annual cancer mortality in NSW Aboriginal people was estimated to be 373 per 100,000 in males and 240 per 100,000 in females, 68% and 73% higher than for all NSW males and females respectively. Despite similar incidence of localised cancer, mortality from localised cancer in Aboriginal people is significantly higher than in non-Aboriginal people, as is mortality from cancers with regional, distant and unknown degree of spread at diagnosis. Cancer survival in Aboriginal people is significantly lower: 51% of males and 43% of females had died of the cancer by 5 years following diagnosis, compared to 36% and 33% of non-Aboriginal males and females respectively.
The present study is the first to produce valid and reliable estimates of cancer incidence, survival and mortality in Australian Aboriginal people from NSW. Despite somewhat higher cancer incidence in Aboriginal than in non-Aboriginal people, substantially higher mortality and lower survival in Aboriginal people is only partly explained by more advanced cancer at diagnosis.
Heart disease is a leading cause of the gap in burden of disease between Aboriginal and non-Aboriginal Australians. Our study investigated short- and long-term mortality after admission for Aboriginal and non-Aboriginal people admitted with acute myocardial infarction (AMI) to public hospitals in New South Wales, Australia, and examined the impact of the hospital of admission on outcomes.
Admission records were linked to mortality records for 60047 patients aged 25–84 years admitted with a diagnosis of AMI between July 2001 and December 2008. Multilevel logistic regression was used to estimate adjusted odds ratios (AOR) for 30- and 365-day all-cause mortality.
Aboriginal patients admitted with an AMI were younger than non-Aboriginal patients, and more likely to be admitted to lower volume, remote hospitals without on-site angiography. Adjusting for age, sex, year and hospital, Aboriginal patients had a similar 30-day mortality risk to non-Aboriginal patients (AOR: 1.07; 95% CI 0.83-1.37) but a higher risk of dying within 365 days (AOR: 1.34; 95% CI 1.10-1.63). The latter difference did not persist after adjustment for comorbid conditions (AOR: 1.12; 95% CI 0.91-1.38). Patients admitted to more remote hospitals, those with lower patient volume and those without on-site angiography had increased risk of short and long-term mortality regardless of Aboriginal status.
Improving access to larger hospitals and those with specialist cardiac facilities could improve outcomes following AMI for all patients. However, major efforts to boost primary and secondary prevention of AMI are required to reduce the mortality gap between Aboriginal and non-Aboriginal people.
Hospital performance; Acute myocardial infarction; Ischaemic heart disease; Aboriginal health; Health outcomes; Multilevel modelling; Data linkage
To determine the rates of birth registration over a five-year period in New South Wales (NSW) and explore the factors associated with the rate of registration.
This is a cross-sectional study using linked population databases. The study population included all births of NSW residents in NSW between 2001 and 2005.
Birth registration rates in NSW were 82.66% in the year of birth, 93.19% in the first year, 94.02% in the second, 94.56% in the third and 95.08% in the fourth year after birth. The non-registration of births was mainly associated with such factors as neonatal and postneonatal death (adjusted OR = 3.84, 95% CI: 3.23-4.57); being Indigenous (adjusted OR = 3.26, 95% CI: 3.10-3.43); maternal age <25 or >39 years (adjusted OR = 2.81, 95% CI: 2.72-2.90); low birthweight (<2,500 grams) (adjusted OR = 1.79, 95% CI: 1.69-1.90); living in remote areas (adjusted OR = 1.57, 95% CI: 1.52-1.63); being born after the first quarter of year (adjusted OR = 1.08-1.56, 95% CI between 1.03-1.12 and 1.49-1.64); mother having more pregnancies (adjusted OR = 1.85-7.29, 95% CI between1.78-1.93 and 6.87-7.73). Mothers who were born overseas were more likely to register their births than those born in Australia (adjusted OR = 0.72, 95% CI: 0.69-0.75). Multiple births were more likely to be registered than singleton births (adjusted OR = 0.84, 95% CI: 0.76-0.92). About one-third of the non-registrations of births in NSW were explained by the risk factors. The reasons for the remaining non-registrations need to be investigated.
Of birth in NSW, 4.92% were not registered by the fourth year after birth.
Birth; Registration; Factor; Australia
The aim of this work was to determine the feasibility of improving Aboriginal and Torres Strait Islander status recording for notifiable diseases using all Invasive Pneumococcal Disease (IPD) notifications in a regional area of New South Wales, Australia.
In Australia people with IPD are nearly always admitted to hospital and their Aboriginal and Torres Strait Islander status is recorded. Aboriginal and Torres Strait Islander status was determined for IPD notifications by referring to the routine hospital admission data in a regional area of New South Wales, Australia.
There were 234 notifications in the regional area of Hunter New England during the period 2007–2009. Initially, 168 (72%) notifications had Aboriginal and Torres Strait Islander status recorded. After referring to the routine hospital admission data, the recorded status increased to 232 (99%). Updating the surveillance data required less than five minutes per notification.
Referring to routine hospital admission data proved a useful and time-efficient surveillance strategy to increase the proportion of notifications with Aboriginal and Torres Strait Islander status. These data can then be used to better understand the current epidemiology of IPD. Aboriginal and Torres Strait Islander children aged 0–4 years have a two- to threefold higher rate of invasive pneumococcal disease than non-Aboriginal children, thus high levels of timely pneumococcal immunization coverage remain important for young Aboriginal and Torres Strait Islander children.
Measuring the real burden of cardiovascular disease in Australian Aboriginals is complicated by under-identification of Aboriginality in administrative health data collections. Accurate data is essential to measure Australia's progress in its efforts to intervene to improve health outcomes of Australian Aboriginals. We estimated the under-ascertainment of Aboriginal status in linked morbidity and mortality databases in patients hospitalised with cardiovascular disease.
Persons with public hospital admissions for cardiovascular disease in Western Australia during 2000-2005 (and their 20-year admission history) or who subsequently died were identified from linkage data. The Aboriginal status flag in all records for a given individual was variously used to determine their ethnicity (index positive, and in all records both majority positive or ever positive) and stratified by region, age and gender. The index admission was the baseline comparator.
Index cases comprised 62,692 individuals who shared a total of 778,714 hospital admissions over 20 years, of which 19,809 subsequently died. There were 3,060 (4.9%) persons identified as Aboriginal on index admission. An additional 83 (2.7%) Aboriginal cases were identified through death records, increasing to 3.7% when cases with a positive Aboriginal identifier in the majority (≥50%) of previous hospital admissions over twenty years were added and by 20.8% when those with a positive flag in any record over 20 years were incorporated. These results equated to underestimating Aboriginal status in unlinked index admission by 2.6%, 3.5% and 17.2%, respectively. Deaths classified as Aboriginal in official records would underestimate total Aboriginal deaths by 26.8% (95% Confidence Interval 24.1 to 29.6%).
Combining Aboriginal determinations in morbidity and official death records increases ascertainment of unlinked cardiovascular morbidity in Western Australian Aboriginals. Under-identification of Aboriginal status is high in death records.
Missing or incorrect Indigenous status in health records hinders monitoring of Indigenous health indicators. Linkage of administrative data has been used to improve the ascertainment of Indigenous status. Data linkage was pioneered in Western Australia (WA) and is now being used in other Australian states. This systematic review appraises peer-reviewed Australian studies that used data linkage to elucidate the impact of under-ascertainment of Indigenous status on health indicators.
A PubMed search identified eligible studies that used Australian linked data to interrogate Indigenous identification using more than one identifier and interrogated the impact of the different identifiers on estimation of Indigenous health indicators.
Eight papers were included, five from WA and three from New South Wales (NSW). The WA papers included a self-identified Indigenous community cohort and showed improved identification in hospital separation data after 2000. In CVD hospitalised patients (2000–05), under-identification was greater in urban residents, older people and socially more advantaged Indigenous people, with varying algorithms giving different estimates of under-count. Age-standardised myocardial infarction incidence rates (2000–2004) increased by about 10%-15% with improved identification. Under-ascertainment of Indigenous identification overestimated secular improvements in life expectancy and mortality whereas correcting infectious disease notifications resulted in lower Indigenous/ non-Indigenous rate ratios. NSW has a history of poor Indigenous identification in administrative data systems, but the NSW papers confirmed the usefulness of data linkage for improving Indigenous identification and the potential for very different estimates of Indigenous disease indicators depending upon the algorithm used for identification.
Under-identification of Indigenous status must be addressed in health analyses concerning Indigenous health differentials – they cannot be ignored or wished away. This problem can be substantially diminished through data linkage. Under-identification of Indigenous status impacts differently in different disease contexts, generally resulting in under-estimation of absolute and relative Indigenous health indicators, but may perversely overestimate Indigenous rates and differentials in the setting of stigma-associated conditions such as sexually-transmitted and blood-borne virus infections. Under-numeration in Census surveys also needs consideration to address the added problem of denominator undercounts.
Lower breast cancer survival has been reported for Australian Aboriginal women compared to non-Aboriginal women, however the reasons for this disparity have not been fully explored. We compared the surgical treatment and survival of Aboriginal and non-Aboriginal women diagnosed with breast cancer in New South Wales (NSW), Australia.
We analysed NSW cancer registry records of breast cancers diagnosed in 2001–2007, linked to hospital inpatient episodes and deaths. We used unconditional logistic regression to compare the odds of Aboriginal and non-Aboriginal women receiving surgical treatment. Breast cancer-specific survival was examined using cumulative mortality curves and Cox proportional hazards regression models.
Of the 27 850 eligible women, 288 (1.03%) identified as Aboriginal. The Aboriginal women were younger and more likely to have advanced spread of disease when diagnosed than non-Aboriginal women. Aboriginal women were less likely than non-Aboriginal women to receive surgical treatment (odds ratio 0.59, 95% confidence interval (CI) 0.42-0.86). The five-year crude breast cancer-specific mortality was 6.1% higher for Aboriginal women (17.7%, 95% CI 12.9-23.2) compared with non-Aboriginal women (11.6%, 95% CI 11.2-12.0). After accounting for differences in age at diagnosis, year of diagnosis, spread of disease and surgical treatment received the risk of death from breast cancer was 39% higher in Aboriginal women (HR 1.39, 95% CI 1.01-1.86). Finally after also accounting for differences in comorbidities, socioeconomic disadvantage and place of residence the hazard ratio was reduced to 1.30 (95% CI 0.94-1.75).
Preventing comorbidities and increasing rates of surgical treatment may increase breast cancer survival for NSW Aboriginal women.
Australia/epidemiology; Breast Neoplasms/epidemiology; Female health services; Indigenous; Survival rate
Population-based patterns of care studies are important for monitoring cancer care but conducting them is expensive and resource-intensive. Linkage of routinely collected administrative health data may provide an efficient alternative. Our aim was to determine the accuracy of linked routinely collected administrative data for monitoring prostate cancer care in New South Wales (NSW), Australia.
The NSW Prostate Cancer Care and Outcomes Study (PCOS), a population-based survey of patterns of care for men aged less than 70 years diagnosed with prostate cancer in NSW, was linked to the NSW Cancer Registry, electronic hospital discharge records and Medicare and Pharmaceutical claims data from Medicare Australia. The main outcome measures were treatment with radical prostatectomy, any radiotherapy, external beam radiotherapy, brachytherapy or androgen deprivation therapy, and cancer staging. PCOS data were considered to represent the true treatment status. The sensitivity and specificity of the administrative data were estimated and relevant patient characteristics were compared using chi-squared tests.
The validation data set comprised 1857 PCOS patients with treatment information linked to Cancer Registry records. Hospital and Medicare claims data combined described treatment more accurately than either one alone. The combined data accurately recorded radical prostatectomy (96% sensitivity) and brachytherapy (93% sensitivity), but not androgen deprivation therapy (76% sensitivity). External beam radiotherapy was rarely captured (5% sensitivity), but this was improved by including Medicare claims for radiation field setting or dosimetry (86% sensitivity). False positive rates were near 0%. Disease stage comparisons were limited by one-third of cases having unknown stage in the Cancer Registry. Administrative data recorded treatment more accurately for cases in urban areas.
Cancer Registry and hospital inpatient data accurately captured radical prostatectomy and brachytherapy treatment, but not external beam radiotherapy or disease stage. Medicare claims data substantially improved the accuracy with which all major treatments were recorded. These administrative data combined are valid for population-based studies of some aspects of prostate cancer care.
Severe perineal trauma occurs in 0.5-10% of vaginal births and can result in significant morbidity including pain, dyspareunia and faecal incontinence. The aim of this study is to determine the risk of recurrence, subsequent mode of birth and morbidity for women who experienced severe perineal trauma during their first birth in New South Wales (NSW) between 2000 – 2008.
All singleton births recorded in the NSW Midwives Data Collection between 2000–2008 (n=510,006) linked to Admitted Patient Data were analysed. Determination of morbidity was based upon readmission to hospital within a 12 month time period following birth for a surgical procedure falling within four categories: 1. Vaginal repair, 2. Fistula repair, 3. Faecal and urinary incontinence repair, and 4. Rectal/anal repair. Women who experienced severe perineal trauma during their first birth were compared to women who did not.
2,784 (1.6%) primiparous women experienced severe perineal trauma during this period. Primiparous women experiencing severe perineal trauma were less likely to have a subsequent birth (56% vs 53%) compared to those not who did not (OR 0.9; CI 0.81-0.99), however there was no difference in the subsequent rate of elective caesarean section (OR 1.2; 0.95-1.54), vaginal birth (including instrumental birth) (OR 1.0; CI 0.81-1.17) or normal vaginal birth (excluding instrumental birth) (OR 1.0; CI 0.85-1.17). Women were no more likely to have a severe perineal tear in the second birth if they experienced this in the first (OR 0.9; CI 0.67-1.34). Women who had a severe perineal tear in their first birth were significantly more likely to have an ‘associated surgical procedure’ within the ≤12 months following birth (vaginal repair following primary repair, rectal/anal repair following primary repair, fistula repair and urinary/faecal incontinence repair) (OR 7.6; CI 6.21-9.22). Women who gave birth in a private hospital compared to a public hospital were more likely to have an ‘associated surgical procedure’ in the 12 months following the birth (OR 1.8; CI 1.54-1.97), regardless of parity, birth type and perineal status.
Primiparous women who experience severe perineal trauma are less likely to have a subsequent baby, more likely to have a related surgical procedure in the 12 months following the birth and no more likely to have an operative birth or another severe perineal tear in a subsequent birth. Women giving birth in a private hospital are more likely to have an associated surgical procedure in the 12 months following birth.
Severe perineal trauma; Subsequent birth; Postpartum morbidities; Risk of recurrence
Monitoring treatment patterns is crucial to improving cancer patient care. Our aim was to determine the accuracy of linked routinely collected administrative health data for monitoring colorectal and lung cancer care in New South Wales (NSW), Australia.
Colorectal and lung cancer cases diagnosed in NSW between 2000 and 2002 were identified from the NSW Central Cancer Registry (CCR) and linked to their hospital discharge records in the NSW Admitted Patient Data Collection (APDC). These records were then linked to data from two relevant population-based patterns of care surveys. The main outcome measures were the sensitivity and specificity of data from the CCR and APDC for disease staging, investigative procedures, curative surgery, chemotherapy, radiotherapy, and selected comorbidities.
Data for 2917 colorectal and 1580 lung cancer cases were analysed. Unknown disease stage was more common for lung cancer in the administrative data (18%) than in the survey (2%). Colonoscopies were captured reasonably accurately in the administrative data compared with the surveys (82% and 79% respectively; 91% sensitivity, 53% specificity) but all other colorectal or lung cancer diagnostic procedures were under-enumerated. Ninety-one percent of colorectal cancer cases had potentially curative surgery recorded in the administrative data compared to 95% in the survey (96% sensitivity, 92% specificity), with similar accuracy for lung cancer (16% and 17%; 92% sensitivity, 99% specificity). Chemotherapy (~40% sensitivity) and radiotherapy (sensitivity≤30%) were vastly under-enumerated in the administrative data. The only comorbidity that was recorded reasonably accurately in the administrative data was diabetes.
Linked routinely collected administrative health data provided reasonably accurate information on potentially curative surgical treatment, colonoscopies and comorbidities such as diabetes. Other diagnostic procedures, comorbidities, chemotherapy and radiotherapy were not well enumerated in the administrative data. Other sources of data will be required to comprehensively monitor the primary management of cancer patients.
Linked data; Validation; Colorectal cancer; Lung cancer; Investigative procedures; Disease stage; Surgery; Chemotherapy; Radiotherapy; Comorbidities
In recent years there has been an increase in the use of population-based linked data. However, there is little literature that describes the method of linked data preparation. This paper describes the method for merging data, calculating the statistical variable (SV), recoding psychiatric diagnoses and summarizing hospital admissions for a perinatal psychiatric study.
The data preparation techniques described in this paper are based on linked birth data from the New South Wales (NSW) Midwives Data Collection (MDC), the Register of Congenital Conditions (RCC), the Admitted Patient Data Collection (APDC) and the Pharmaceutical Drugs of Addiction System (PHDAS).
The master dataset is the meaningfully linked data which include all or major study data collections. The master dataset can be used to improve the data quality, calculate the SV and can be tailored for different analyses. To identify hospital admissions in the periods before pregnancy, during pregnancy and after birth, a statistical variable of time interval (SVTI) needs to be calculated. The methods and SPSS syntax for building a master dataset, calculating the SVTI, recoding the principal diagnoses of mental illness and summarizing hospital admissions are described.
Linked data preparation, including building the master dataset and calculating the SV, can improve data quality and enhance data function.
Data preparation; Method; Psychiatric study; Australia
Background: There is little information on the detailed patterns of cervical screening uptake in older migrant women in Australia. This linkage study was performed to assess cervical screening participation in older migrants.
Methods: We linked year 2000-2001 records for 14,228 Middle Eastern/Asian-born women 40-64 years of age, and an age and area matched random sample of 13,939 Australian-born women in the New South Wales (NSW) Admitted Patients Data Collection (APDC), which records country of birth, to screening register records. Screening behaviour after 1st July 2001 was assessed in women without a recorded prior cervical abnormality
Results: Compared to Australian-born women, women born in South Central Asia had a lower screening participation rate (odds ratio for being screened at least once within a 3 year period 0.78, 95% CI 0.70-0.88). However, participation appeared relatively higher (17%-25%) in women born in the Middle East or other parts of Asia. Screening increased with increasing socioeconomic status (SES) in Australian-born women, but this trend was not observed in the migrant women. When we broadly corrected for hysterectomy, the apparent excess of screening in women from the Middle East and other parts of Asia was substantially eliminated and in contrast, the apparent deficiency in screening in women from South Central Asia increased.
Conclusions: Older women from the Middle East, and North East and South East Asian countries appeared to have similar overall screening participation to that of Australian-born women. Women from South Central Asia appeared less likely than Australian-born women to participate in cervical screening at the recommended interval.
Cervical cancer; Cervical screening; Record linkage; Screening in migrants
Statistical time series derived from administrative data sets form key indicators in measuring progress in addressing disadvantage in Aboriginal and Torres Strait Islander populations in Australia. However, inconsistencies in the reporting of Indigenous status can cause difficulties in producing reliable indicators. External data sources, such as survey data, provide a means of assessing the consistency of administrative data and may be used to adjust statistics based on administrative data sources.
We used record linkage between a large-scale survey (the Western Australian Aboriginal Child Health Survey), and two administrative data sources (the Western Australia (WA) Register of Births and the WA Midwives’ Notification System) to compare the degree of consistency in determining Indigenous status of children between the two sources. We then used a logistic regression model predicting probability of consistency between the two sources to estimate the probability of each record on the two administrative data sources being identified as being of Aboriginal and/or Torres Strait Islander origin in a survey. By summing these probabilities we produced model-adjusted time series of neonatal outcomes for Aboriginal and/or Torres Strait Islander births.
Compared to survey data, information based only on the two administrative data sources identified substantially fewer Aboriginal and/or Torres Strait Islander births. However, these births were not randomly distributed. Births of children identified as being of Aboriginal and/or Torres Strait Islander origin in the survey only were more likely to be living in urban areas, in less disadvantaged areas, and to have only one parent who identifies as being of Aboriginal and/or Torres Strait Islander origin, particularly the father. They were also more likely to have better health and wellbeing outcomes. Applying an adjustment model based on the linked survey data increased the estimated number of Aboriginal and/or Torres Strait Islander births in WA by around 25%, however this increase was accompanied by lower overall proportions of low birth weight and low gestational age babies.
Record linkage of survey data to administrative data sets is useful to validate the quality of recording of demographic information in administrative data sources, and such information can be used to adjust for differential identification in administrative data.
Objective. To determine the risks of induced term delivery to the mother and neonate at different gestational ages in the absence of obstetric indications. Study Design. All deliveries in New South Wales (NSW) between 1998 and 2008 were reviewed from the MDC. Uncomplicated pregnancies which were induced for non-obstetric reasons after 37 completed weeks were reviewed. This was a retrospective, historical cohort study, and both maternal and neonatal outcomes were analysed and compared between different gestational age groups. Results. An analysis of the data shows that induction of labour after 37 completed weeks exposes the fetus and mother to different levels of risk at different gestations. Conclusion. In an uncomplicated pregnancy, induction of labour is associated with the highest rate of neonatal complication at 37 weeks as compared with rates at later gestations. With each ensuing week, the neonatal outcome improves. At 40 weeks the likelihood of neonatal intensive care admission, low Apgar scores, and perinatal death rate is at its lowest, and then there is a slight but not significant rise after 41 weeks. The likelihood of caesarean section is the lowest when inductions are carried out at 39 weeks and is the highest at 41 weeks and over.
There is concern that the rate of planned births (by pre-labour caesarean section or induction of labour) is increasing and that the gestation at which they are being conducted is decreasing. The aim of this study was to describe trends in the distribution of gestational age, and assess the contribution of planned birth to any such changes.
We utilised the New South Wales (NSW) Perinatal Data Collection to undertake a population-based study of all births in NSW, Australia 1994–2009. Trends in gestational age were determined by year, labour onset and plurality of birth.
From 1994–2009, there was a gradual and steady left-shift in overall distribution of gestational age at birth, with a decline in the modal gestational age from 40 to 39 weeks. For singletons, there was a steady but significant reduction in the proportion of spontaneous births. Labour inductions increased in the proportion performed, with a gradual and changing shift in the distribution from a majority at 40 weeks to an increase at both 37–39 weeks and 41 weeks gestation. The proportion of pre-labour caesareans also increased steadily at each gestational age and doubled since 1994, with most performed at 39 weeks in 2009 compared with 38 weeks up to 2001.
Findings suggest a changing pattern towards births at earlier gestations, fewer births commencing spontaneously and increasing planned births. Factors associated with changing clinical practice and long-term implications on the health and well-being of mothers and babies should be assessed.
Caesarean section (CS) rates around the world have been increasing and in Australia have reached 30% of all births. Robson's Ten-Group Classification System (10-group classification) provides a clinically relevant classification of CS rates that provides a useful basis for international comparisons and trend analyses. This study aimed to investigate trends in CS rates in New South Wales (NSW), including trends in the components of the 10-group classification.
We undertook a cross-sectional study using data from the Midwives Data Collection, a state-wide surveillance system that monitors patterns of pregnancy care, services and pregnancy outcomes in New South Wales, Australia. The study population included all women giving birth between 1st January 1998 and 31st December 2008. Descriptive statistics are presented including age-standardised CS rates, annual percentage change as well as regression analyses.
From 1998 to 2008 the CS rate in NSW increased from 19.1 to 29.5 per 100 births. There was a significant average annual increase in primary 4.3% (95%CI 3.0-5.7%) and repeat 4.8% (95% CI 3.9-5.7%) CS rates from 1998 to 2008. After adjusting for maternal and pregnancy factors, the increase in CS delivery over time was maintained. When examining CS rates classified according to the 10-group classification, the greatest contributors to the overall CS rate and the largest annual increases occurred among nulliparae at term having elective CS and multipara having elective repeat CS.
Given that the increased CS rate cannot be explained by known and collected maternal or pregnancy characteristics, the increase may be related to differences in clinical decision making or maternal request. Future efforts to reduce the overall CS rate should be focussed on reducing the primary CS rate.
A linked data file of birth records and hospital admissions was used to investigate inpatient hospital morbidity before 2 years of age for all non-Aboriginal and Aboriginal children born in Western Australia in 1986. Of the non-Aboriginal children, 31.8% were admitted to hospital at least once before the age of 2 years, with an overall admission rate of 526/1000 live births; the corresponding figures for Aboriginal children were 68.7% and 2797. The mean number of days in hospital for each non-Aboriginal child admitted was 7.4, and 26.5 for Aboriginal children. Of the total cohort, 21% of non-Aboriginal and 20% of Aboriginal children were admitted only once, and 4% of non-Aboriginal and 36% of Aboriginal children were admitted at least three times; 23% of non-Aboriginal and 24% of Aboriginal children were admitted for only one major disease category, and 1% of non-Aboriginal and 16% of Aboriginal children were in at least four categories. The highest admission rates and highest percentages of the cohort admitted were for gastrointestinal and respiratory diseases and social admissions. These results illustrate the importance for both descriptive and analytical research of relating admissions to hospital for the total population to the individual child, and of using clinically relevant disease classifications.
Dental caries remains one of the most common chronic diseases of adolescents. In Australia there have been few epidemiological studies of the caries experience of adolescents with most surveys focusing on children. The New South Wales (NSW) Teen Dental Survey 2010 is the second major survey undertaken by the Centre for Oral Health Strategy. The survey is part of a more systematic and efficient approach to support State and Local Health District dental service planning and will also be used for National reporting purposes.
Data for the NSW Teen Dental Survey were collected in 2010 from a random sample of Year 9 secondary school students aged 14 to 15 years from metropolitan and non-metropolitan schools under the jurisdiction of the NSW Department of Education and Training, the Catholic Education Commission and Independent Schools in New South Wales. Nineteen calibrated examiners performed 1269 clinical examinations at a total of 84 secondary schools across NSW. The survey was accompanied by a questionnaire looking at oral health related behaviours, risk factors and the usage of the Medicare Teen Dental Plan.
175 schools were contacted, with 84 (48%) accepting the invitation to participate in the study. A total of 5,357 student consent forms and parent information packages were sent out and 1,256 students were examined; leading to a student participation rate of 23%. The survey reported a mean DMFT for 14 and 15 year olds of 1.2 and it was identified that 45.4% of students had an experience of dental caries. Major variations in caries experience reported occurred by remoteness, water fluoridation status, socio-economic status and household income levels.
The NSW Teen Dental Survey provided state-wide data that will contribute to the national picture on adolescent oral health. The mean DMFT score of 1.2 is similar to the national caries experience data for this age group from the Australian Child Dental Health Survey in 2009.
Teen dental survey; School children; Adolescents; Caries experience
To explore the relationship between child injury morbidity and socioeconomic status.
A cross‐sectional analysis of routinely collected hospital separation data for unintentional injury for the period 1999/2000–2004/2005.
All statistical local areas of New South Wales (NSW), Australia
110 549 unintentional injury‐related hospital separations for NSW children aged 0–14 years.
Main outcome measure
Adjusted incidence rate ratios (IRRs) for hospital separations for unintentional injury (for all injury and by individual injury mechanisms) by quintile of socioeconomic disadvantage for children aged 0–14 years.
There was no clear relationship between socioeconomic status and injury when all injury mechanisms were combined. However, children in the more disadvantaged quintiles were more likely to be hospitalized than children in the least disadvantaged quintile for the following injury mechanisms: motor cycle (point estimates for IRRs across the socioeconomic status quintiles ranged from 2.95 to 4.02 relative to the least disadvantaged quintile), motor‐vehicle occupant (IRR range 1.33–2.27), pedestrian (IRR range 1.43–2.54 for ages 0–4 years), pedal cyclist (IRR range 1.30–1.50), fire and burns (IRR range 1.37–2.00), and poisoning (IRR range 1.32–1.91). Similarly, hospital separation rates for foreign body, other transport, and pedestrian (aged 5–9 years) injuries were also greater, but the differences were not statistically significant across all quintiles. These injury mechanisms accounted for about 25% of the hospital separations.
The relationship between relative socioeconomic disadvantage and injury risk in NSW children is strongest for transport‐related injuries, fires and burns, and poisoning. Interventions that address these specific injury mechanisms may help to reduce the disparity between high and lower socioeconomic groups.
social class; socioeconomic factors; wounds and injuries; child; morbidity
It is unclear if podiatric foot care for people with rheumatoid arthritis (RA) in New South Wales (NSW) meets current clinical recommendations. The objective of this study was to survey podiatrists’ perceptions of the nature of podiatric foot care provision for people who have RA in NSW.
An anonymous, cross-sectional survey with a web-based questionnaire was conducted. The survey questionnaire was developed according to clinical experience and current foot care recommendations. State registered podiatrists practising in the state of NSW were invited to participate. The survey link was distributed initially via email to members of the Australian Podiatry Association (NSW), and distributed further through snowballing techniques using professional networks. Data was analysed to assess significant associations between adherence to clinical practice guidelines, and private/public podiatry practices.
86 podiatrists participated in the survey (78% from private practice, 22% from public practice). Respondents largely did not adhere to formal guidelines to manage their patients (88%). Only one respondent offered a dedicated service for patients with RA. Respondents indicated that the primary mode of accessing podiatry was by self-referral (68%). Significant variation was observed regarding access to disease and foot specific assessments and treatment strategies. Assessment methods such as administration of patient reported outcome measures, vascular and neurological assessments were not conducted by all respondents. Similarly, routine foot care strategies such as prescription of foot orthoses, foot health advice and footwear were not employed by all respondents.
The results identified issues in foot care provision which should be explored through further research. Foot care provision in NSW does not appear to meet the current recommended standards for the management of foot problems in people who have RA. Improvements to foot care could be undertaken in terms of providing better access to examination techniques and treatment strategies that are recommended by evidence based treatment paradigms.
Rheumatoid arthritis; Foot health; Podiatry; Footwear; Care access; Web survey
Objectives: To examine factors that impact on breastfeeding duration among Western Australian Aboriginal children. We hypothesised that Aboriginal children living in remote locations in Western Australia were breastfed for longer than those living in metropolitan locations. Methods: A population-based cross-sectional survey was conducted from 2000 to 2002 in urban, rural and remote settings across Western Australia. Cross-tabulations and multivariate logistic regression analyses were performed, using survey weights to produce unbiased estimates for the population of Aboriginal children. Data on demographic, maternal and infant characteristics were collected from 3932 Aboriginal birth mothers about their children aged 0–17 years (representing 22,100 Aboriginal children in Western Australia). Results: 71% of Aboriginal children were breastfed for three months or more. Accounting for other factors, there was a strong gradient for breastfeeding duration by remoteness, with Aboriginal children living in areas of moderate isolation being 3.2 times more likely to be breastfed for three months or more (p < 0.001) compared to children in metropolitan Perth. Those in areas of extreme isolation were 8.6 times more likely to be breastfed for three months or longer (p < 0.001). Conclusions: Greater residential isolation a protective factor linked to longer breastfeeding duration for Aboriginal children in our West Australian cohort.
breastfeeding duration; Australian Aboriginal children; isolation