Identifying long-term psychological distress from single measures: evidence from a nationally representative longitudinal survey of the Australian population.

BACKGROUND: Single time-point assessments of psychological distress are often used to indicate chronic mental health problems, but the validity of this approach is unclear. The aims of this study were to investigate how a single assessment of distress relates to longer-term assessment and quantify misclassification from using single measures to indicate chronic distress. METHODS: Data came from the Household, Income and Labour Dynamics in Australia Survey, a nationally representative study of Australian adults. Psychological distress, measured with the Kessler10 and categorised into low (scores:10- < 12), mild (12- < 16), moderate (16- < 22) and high (22-50), has been assessed in the Survey biennially since wave 7. Among respondents who were aged ≥25 years and participated in all waves in which distress was measured, we describe agreement in distress categories, and using a mixed linear model adjusting for age and sex we estimate change in scores, over a two-, four-, six- and eight-year follow-up period. We applied weights, benchmarked to the Australian population, to all analyses. RESULTS: Two-years following initial assessment, proportions within identical categories of distress were 66.0% for low, 54.5% for mild, 44.0% for moderate and 50.3% for high, while 94.1% of those with low distress initially had low/mild distress and 81.4% with high distress initially had moderate/high distress. These patterns did not change materially as follow-up time increased. Over the full eight-year period, 77.3% of individuals with high distress initially reported high distress on ≥1 follow-up occasion. Age-and sex- adjusted change in K10 scores over a two-year period was 1.1, 0.5, - 0.7 and - 4.9 for low, mild, moderate and high distress, respectively, and also did not change materially as follow-up time increased. CONCLUSION: In the absence of repeated measures, single assessments are useful proxies for chronic distress. Our estimates could be used in bias analyses to quantify the magnitude of the bias resulting from use of single assessments to indicate chronic distress.

Body mass index and incident hospitalisation for cardiovascular disease in 158 546 participants from the 45 and Up Study.

OBJECTIVE: To investigate the relationship between fine gradations in body mass index (BMI) and risk of hospitalisation for different types of cardiovascular disease (CVD). DESIGN, SUBJECTS AND METHODS: The 45 and Up Study is a large-scale Australian cohort study initiated in 2006. Self-reported data from 158 546 individuals with no history of CVD were linked prospectively to hospitalisation and mortality data. Hazard ratios (HRs) of incident hospitalisation for specific CVD diagnoses in relation to baseline BMI categories were estimated using Cox regression, adjusting for age, sex, region of residence, income, education, smoking, alcohol intake and health insurance status. RESULTS: There were 9594 incident CVD admissions over 583 100 person-years among people with BMI≥20 kg m(-2), including 3096 for ischaemic heart disease (IHD), 1373 for stroke, 411 for peripheral vascular disease (PVD) and 320 for heart failure. The adjusted HR of hospitalisation for all CVD diagnoses combined increased significantly with increasing BMI (P(trend) <0.0001)). The HR of IHD hospitalisation increased by 23% (95% confidence interval (95% CI): 18-27%) per 5 kg m(-2) increase in BMI (compared to BMI 20.0-22.49 kg m(-2), HR (95% CI) for BMI categories were: 22.5-24.99=1.25 (1.08-1.44); 25-27.49=1.43 (1.24-1.65); 27.5-29.99=1.64 (1.42-1.90); 30-32.49=1.63 (1.39-1.91) and 32.5-50=2.10 (1.79-2.45)). The risk of hospitalisation for heart failure showed a significant, but nonlinear, increase with increasing BMI. No significant increase was seen with above-normal BMI for stroke or PVD. For other specific classifications of CVD, HRs of hospitalisation increased significantly with increasing BMI for: hypertension; angina; acute myocardial infarction; chronic IHD; pulmonary embolism; non-rheumatic aortic valve disorders; atrioventricular and left bundle-branch block; atrial fibrillation and flutter; aortic aneurysm; and phlebitis and thrombophlebitis. CONCLUSION: The risk of hospitalisation for a wide range of CVD subtypes increases with relatively fine increments in BMI. Obesity prevention strategies are likely to benefit from focusing on bringing down the mean BMI at the population level, in addition to targeting those with a high BMI.

Identifying young Aboriginal and Torres Strait Islander children in linked administrative data: A comparison of methods.

BACKGROUND: In the ongoing debate on optimum methods for identification of Indigenous people within linked administrative data, few studies have examined the impacts of method on population counts and outcomes in family-based linkage studies of Aboriginal children. OBJECTIVE: To quantify differences between three algorithms in ascertaining Aboriginal and Torres Strait Islander children in linked administrative data. METHODS: Linked administrative health data for children born in Western Australia (WA) from 2000-2013, were used to examine the cohorts identified by three methods: A) the Indigenous Status Flag (ISF, derived by the WA Data Linkage Branch using a multistage-median approach) for the children alone; B) the ISF of the children, their parents and grandparents; and C) Indigenous status of the child, mother or father on either of the child's perinatal records (Midwives or birth registration), to determine differing characteristics of each cohort. RESULTS: Method B established a larger cohort (33,489) than Method C (33,306) and Method A (27,279), with all methods identifying a core group of 26,790 children (80-98%). Compared with children identified by Method A, additional children identified by Methods B or C, were from less-disadvantaged and more urban areas, and had better perinatal outcomes (e.g. lower proportions of small-for-gestational age, 10% vs 16%). Differences in demographics and health outcomes between Methods C and B were minimal. CONCLUSIONS: Demographic and perinatal health characteristics differ by Aboriginal identification method. Using perinatal records or the ISF of parents and grandparents (in addition to the ISF of the child) appear to be more inclusive methods for identifying young Indigenous children in administrative datasets. KEYWORDS: Aboriginal health, identification, data linkage, Indigenous, child, methodology.

Ethnic differences in the natural progression of nephropathy among diabetes patients in New Zealand: hospital admission rate for renal complications, and incidence of end-stage renal disease and renal death.

AIMS/HYPOTHESIS: We estimated the incidence of chronic renal failure, the incidence of end-stage renal disease (ESRD) and renal mortality rates among New Zealand European and Maori patients with diabetes and estimated the ethnic difference in the risk of developing renal failure. METHODS: A renal complication-free cohort of adult diabetes patients registered with Waikato regional diabetes service, diagnosed with diabetes before 2003, were retrospectively followed for 4 years. Events of interest were renal hospital admission, ESRD and death coded with renal disease. Incidences of renal hospital admission, ESRD and death from renal disease were calculated for NZ Europeans and Maori patients with diabetes. Ethnic and sex differences in the risks of these renal outcomes were estimated using a Cox proportional hazards model. RESULTS: Of the 7,900 patients followed up, 116 (1.5%) had a renal admission, 42 (0.5%) started dialysis/transplantation and 21 (0.27%) died from renal disease. Maori diabetes patients had significantly higher incidences of dialysis or transplantation and rates of renal admission and renal death. Adjusted hazard ratios indicate that, compared with NZ Europeans with diabetes, Maori diabetes patients had a significantly higher risk of ESRD, renal admission and renal death (46-fold, seven-fold and four-fold increases, respectively). Maori patients progressed at a significantly faster rate from first hospital admission for chronic renal disease to ESRD. CONCLUSIONS/INTERPRETATION: There were huge ethnic disparities in outcomes from renal disease. Screening for early kidney disease among Maori diabetes patients, intensive management of risk factors and further research on the aetiology of renal disease among Maoris is recommended.

Dental health in rural Victoria: the Crossroads Household Survey.

BACKGROUND: The aims of this study were to describe dental health and perceived barriers to dental care in a regional centre and surrounding smaller towns in rural Victoria. METHODS: A stratified, randomized, face-to-face household survey was undertaken to assess levels of edentulism and access to oral health services. A study response rate of 70.3 per cent (6316/9260) was achieved. RESULTS: When compared with those in the regional centre, people living in the shire capitals were more likely to travel greater distances to see a dentist and were less likely to have seen a dentist within the past 12 months. While there was little difference in the edentulous proportion living in shire capitals compared with the regional centre, the level of edentulousness over the entire region was greater than overall Australian estimates. Differences in perceived barriers to care within the region were less than expected. Existing perceived barriers were lack of need, time until available appointments, attitudes of dentists and lack of public dental facilities. Differences in these barriers existed between socio-economic groups. CONCLUSIONS: This study shows that the prevalence of edentulism was higher in the areas studied relative to the Australian population. Significant patient perceived barriers to care exist which may contribute to the problem.

Prevalence of diabetes in New Zealand general practice: the influence of ethnicity and social deprivation.

BACKGROUND: The prevalence of diagnosed diabetes among different ethnic groups and the influence of deprivation on the prevalence of diabetes among Maori and New Zealand Europeans was investigated. METHODS: This was a cross-sectional survey on all patients registered with 10 practices in the Rotorua General Practice Group on 1 July 2007. Patients diagnosed with diabetes were identified though diagnostic codes for diabetes, prescriptions for diabetes medications and laboratory tests for glycosylated haemoglobin (HbA(1c)). Prevalence of diabetes by ethnicity, age group, gender and NZDep2001 quintiles was calculated. Adjusted ORs for the risk of diabetes were obtained from logistic regression analysis. RESULTS: Of the 45 500 patients registered, 1819 had been diagnosed with diabetes mellitus. In the 40+ age groups, the prevalence of diabetes in Maori and Pacific people was around three times that in Europeans. With increasing deprivation, the age-standardised prevalence of diagnosed diabetes increased among European males (2.7-5.0%) and females (2.1-3.1%). However, the prevalence of diabetes was highest among the least deprived Maori (males 9.7%, females 6.2%). The adjusted risk of diabetes for the most deprived Maori is not significantly different from that for the least deprived Maori. The most deprived Europeans had nearly twice the risk of having diabetes than the least deprived Europeans. CONCLUSIONS: Although the rising prevalence of diabetes with increasing deprivation among Europeans shows a similar trend to results from national and international studies, the trend among Maori seems to be different because the least deprived are equally at risk of diabetes. Diabetes interventions aimed at Maori should be tailor-made to include the least deprived groups.