Relative Risks of Adverse Perinatal Outcomes in Three Australian Communities Exposed to Per- and Polyfluoroalkyl Substances: Data Linkage Study.

INTRODUCTION: Firefighting foams containing per- and polyfluoroalkyl substances (PFAS) have caused environmental contamination in several Australian residential areas, including Katherine in the Northern Territory (NT), Oakey in Queensland (Qld), and Williamtown in New South Wales (NSW). We examined whether the risks of adverse perinatal outcomes were higher in mothers living in these exposure areas than in selected comparison areas without known contamination. METHODS: We linked residential addresses in exposure areas to addresses collected in the jurisdictional Perinatal Data Collections of the NT (1986-2017), Qld (2007-2018), and NSW (1994-2018) to select all pregnancies from mothers who gave birth while living in these areas. We also identified one comparison group for each exposure area by selecting pregnancies where the maternal address was in selected comparison areas. We examined 12 binary perinatal outcomes and three growth measurements. For each exposure area, we estimated relative risks (RRs) of adverse outcomes and differences in means of growth measures, adjusting for sociodemographic characteristics and other potential confounders. RESULTS: We included 16,970 pregnancies from the NT, 4654 from Qld, and 7475 from NSW. We observed elevated risks of stillbirth in Oakey (RR = 2.59, 95% confidence interval (CI) 1.25 to 5.39) and of postpartum haemorrhage (RR = 1.94, 95% CI 1.13 to 3.33) and pregnancy-induced hypertension (RR = 1.88, 95% CI 1.30 to 2.73) in Williamtown. The risks of other perinatal outcomes were not materially different from those in the relevant comparison areas or were uncertain due to small numbers of events. CONCLUSIONS: There was limited evidence for increased risks of adverse perinatal outcomes in mothers living in areas with PFAS contamination from firefighting foams. We found higher risks of some outcomes in individual areas, but these were not consistent across all areas under study and could have been due to chance, bias, or confounding.

Psychological distress in three Australian communities living with environmental per- and polyfluoroalkyl substances contamination.

BACKGROUND: Environmental chemical contamination is a recognised risk factor for psychological distress, but has been seldom studied in the context of per- and polyfluoroalkyl substances (PFAS) contamination. We examined psychological distress in a cross-sectional study of three Australian communities exposed to PFAS from the historical use of aqueous film-forming foam in firefighting activities, and three comparison communities without environmental contamination. METHODS: Participation was voluntary following recruitment from a PFAS blood-testing program (exposed) or random selection (comparison). Participants provided blood samples and completed a survey on their exposure history, sociodemographic characteristics, and four measures of psychological distress (Kessler-6, Distress Questionnaire-5, Patient Health Questionnaire-15, and Generalised Anxiety Disorder-7). We estimated prevalence ratios (PR) of clinically-significant psychological distress scores, and differences in mean scores: (1) between exposed and comparison communities; (2) per doubling in PFAS serum concentrations in exposed communities; (3) for factors that affect the perceived risk of living in a community exposed to PFAS; and (4) in relation to self-reported health concerns. RESULTS: We recruited 881 adults in exposed communities and 801 in comparison communities. We observed higher levels of self-reported psychological distress in exposed communities than in comparison communities (e.g., Katherine compared to Alice Springs, Northern Territory: clinically-significant anxiety scores, adjusted PR = 2.82, 95 % CI 1.16-6.89). We found little evidence to suggest that psychological distress was associated with PFAS serum concentrations (e.g., Katherine, PFOS and anxiety, adjusted PR = 0.85, 95 % CI 0.65-1.10). Psychological distress was higher among exposed participants who were occupationally exposed to firefighting foam, used bore water on their properties, or were concerned about their health. CONCLUSION: Psychological distress was substantially more prevalent in exposed communities than in comparison communities. Our findings suggest that the perception of risks to health, rather than PFAS exposure, contribute to psychological distress in communities with PFAS contamination.

Interventional radiology in obstetric patients: A population-based record linkage study of use and outcomes.

INTRODUCTION: Interventional radiology (IR) is a technique for controlling hemorrhage and preserving fertility for women with serious obstetric conditions such as placenta accreta spectrum (PAS) or postpartum hemorrhage. This study examined maternal, pregnancy and hospital characteristics and outcomes for women receiving IR in pregnancy and postpartum. MATERIAL AND METHODS: A population-based record linkage study was conducted, including all women who gave birth in hospital in New South Wales or the major tertiary hospital in the neighboring Australian Capital Territory, Australia, between 2003 and 2019. Data were obtained from birth and hospital records. Characteristics and outcomes of women who underwent IR in pregnancy or postpartum are described. Outcomes following IR were compared in a high-risk cohort of women: those with PAS who had a planned cesarean with hysterectomy. Women were grouped by those who did and those who did did not have IR and were matched using propensity score and other factors. RESULTS: We identified IR in 236 pregnancies of 1 584 708 (15.0 per 100 000), including 208 in the delivery and 26 in a postpartum admission. Two-thirds of women receiving IR in the birth admission received a transfusion of red cells or blood products, 28% underwent hysterectomy and 12.5% were readmitted within 6 weeks. Other complications included: severe maternal morbidity (29.8%), genitourinary tract trauma/repair (17.3%) and deep vein thrombosis/pulmonary embolism (4.3%). Outcomes for women with PAS who underwent planned cesarean with hysterectomy were similar for those who did and did not receive IR, with a small reduction in transfusion requirement for those who received IR. CONCLUSIONS: Interventional radiology is infrequently used in pregnant women. In our study it was performed at a limited number of hospitals, largely tertiary centers, with the level of adverse outcomes reflecting use in a high-risk population. For women with PAS undergoing planned cesarean with hysterectomy, most outcomes were similar for those receiving IR and those not receiving IR, but IR may reduce bleeding.

Interaction effects of multimorbidity and frailty on adverse health outcomes in elderly hospitalised patients.

We quantified the interaction of multimorbidity and frailty and their impact on adverse health outcomes in the hospital setting. Using aretrospective cohort study of persons aged ≥ 75 years, admitted to hospital during 2010-2012 in New South Wales, Australia, and linked with mortality data, we constructed multimorbidity, frailty risk and outcomes: prolonged length of stay (LOS), 30-day mortality and 30-day unplanned readmissions. Relative risks (RR) of outcomes were obtained using Poisson models with random intercept for hospital. Among 257,535 elderly inpatients, 33.6% had multimorbidity and elevated frailty risk, 14.7% had multimorbidity only, 19.9% had elevated frailty risk only and 31.8% had neither. Additive interactions were present for all outcomes, with a further multiplicative interaction for mortality and LOS. Mortality risk was 4.2 (95% CI 4.1-4.4), prolonged LOS 3.3 (95% CI 3.3-3.4) and readmission 1.8 (95% CI 1.7-1.9) times higher in patients with both factors present compared with patients with neither. In conclusion, multimorbidity and frailty coexist in older hospitalized patients and interact to increase the risk of adverse outcomes beyond the sum of their individual effects. Their joint effect should be considered in health outcomes research and when administering hospital resources.

Differences in the pre-hospital management of women and men with stroke by emergency medical services in New South Wales.

OBJECTIVES: To examine whether pre-hospital emergency medical service care differs for women and men subsequently admitted to hospital with stroke. DESIGN, SETTING, PARTICIPANTS: Population-based cohort study; analysis of linked Admitted Patient Data Collection and NSW Ambulance data for people admitted to New South Wales hospitals with a principal diagnosis of stroke at separation, 1 July 2005 - 31 December 2018. MAIN OUTCOME MEASURES: Emergency medical service assessments, protocols, and management for patients subsequently diagnosed with stroke, by sex. RESULTS: Of 202 231 people hospitalised with stroke (mean age, 73 [SD, 14] years; 98 599 women [51.0%]), 101 357 were conveyed to hospital by ambulance (50.1%). A larger proportion of women than men travelled by ambulance (52.4% v 47.9%; odds ratio [OR], 1.09; 95% CI, 1.07-1.11), but time between the emergency call and emergency department admission was similar for both sexes. The likelihood of being assessed as having a stroke (adjusted OR [aOR], 0.97; 95% CI, 0.93-1.01) or subarachnoid haemorrhage (aOR, 1.22; 95% CI, 0.73-2.03) was similar for women and men, but women under 70 years of age were less likely than men to be assessed as having a stroke (aOR, 0.89; 95% CI, 0.82-0.97). Women were more likely than men to be assessed by paramedics as having migraine, other headache, anxiety, unconsciousness, hypertension, or nausea. Women were less likely than men to be managed according to the NSW Ambulance pre-hospital stroke care protocol (aOR, 0.95; 95% CI, 0.92-0.97), but the likelihood of basic pre-hospital care was similar for both sexes (aOR, 1.01; 95% CI, 0.99-1.04). CONCLUSION: Our large population-based study identified sex differences in pre-hospital management by emergency medical services of women and men admitted to hospital with stroke. Paramedics should receive training that improves the recognition of stroke symptoms in women.

Maternal factors and risk of spontaneous preterm birth due to high ambient temperatures in New South Wales, Australia.

BACKGROUND: Exposure to high ambient temperatures has been shown to increase the risk of spontaneous preterm birth. Determining which maternal factors increase or decrease this risk will inform climate adaptation strategies. OBJECTIVES: This study aims to assess the risk of spontaneous preterm birth associated with exposure to ambient temperature and differences in this relationship between mothers with different health and demographic characteristics. METHODS: We used quasi-Poisson distributed lag non-linear models to estimate the effect of high temperature-measured as the 95th percentile of daily minimum, mean and maximum compared with the median-on risk of spontaneous preterm birth (23-36 weeks of gestation) in pregnant women in New South Wales, Australia. We estimated the cumulative lagged effects of daily temperature and analyses on population subgroups to assess increased or decreased vulnerability to this effect. RESULTS: Pregnant women (n = 916,678) exposed at the 95th percentile of daily mean temperatures (25ºC) had an increased risk of preterm birth (relative risk 1.14, 95% confidence interval 1.07, 1.21) compared with the median daily mean temperature (17℃). Similar effect sizes were seen for the 95th percentile of minimum and maximum daily temperatures compared with the median. This risk was slightly higher among women with diabetes, hypertension, chronic illness and women who smoked during pregnancy. CONCLUSIONS: Higher temperatures increase the risk of preterm birth and women with pre-existing health conditions and who smoke during pregnancy are potentially more vulnerable to these effects.

Sex differences in emergency medical services management of patients with myocardial infarction: analysis of routinely collected data for over 110,000 patients.

Emergency medical services (EMS) activation is an integral component in managing individuals with myocardial infarction (MI). EMS play a crucial role in early MI symptom recognition, prompt transport to percutaneous coronary intervention centres and timely administration of management. The objective of this study was to examine sex differences in prehospital EMS care of patients hospitalized with Ml using data from a retrospective population-based cohort study of linked health administrative data for people with a hospital diagnosis of MI in Australia (2001-18).

Are newly introduced criteria for the diagnosis of gestational diabetes mellitus associated with improved pregnancy outcomes and/or increased interventions in New South Wales, Australia? A population-based data linkage study.

INTRODUCTION: The incidence of gestational diabetes mellitus (GDM) is increasing in Australia, influenced by changed diagnostic criteria. We aimed to identify whether the diagnostic change was associated with improved outcomes and/or increased obstetric interventions using state-wide data in New South Wales (NSW), Australia. RESEARCH DESIGN AND METHODS: Perinatal and hospital data were linked for singleton births, 33-41 weeks' gestation, 2006-2015, NSW. An adjusted Poisson model was used to split pregnancies from 2011 onwards into those that would have been diagnosed under the old criteria ('previous GDM') and newly diagnosed cases ('additional GDM'). We compared actual rates of total and early (<39 weeks) planned births, cesareans, and maternal and neonatal adverse outcomes for GDM-diagnosed pregnancies using three predicted scenarios, where the 'additional GDM' group was assumed to have the same rates as: the 'previous GDM' group <2011 (scenario A); the 'non-GDM' group <2011 (scenario B); or the 'non-GDM' group ≥2011 (scenario C). RESULTS: GDM incidence more than doubled over the study period, with an inflection point observed at 2011. For those diagnosed with GDM since 2011, the actual incidence of interventions (planned births and cesareans) and macrosomia was consistent with scenario A, which meant higher intervention rates, but lower rates of macrosomia, than those with no GDM. Incidence of neonatal hypoglycemia was lower than scenario A and closer to the other scenarios. There was a reduction in perinatal deaths among those with GDM, lower than that predicted by all scenarios, indicating an improvement for all with GDM, not only women newly diagnosed. Incidence of maternal and neonatal morbidity indicators was within the confidence bounds for all three predicted scenarios. CONCLUSIONS: Our study suggests that the widely adopted new diagnostic criteria for GDM are associated with increased obstetric intervention rates and lower rates of macrosomic babies, but with no clear impacts on maternal or neonatal morbidity.

Multiple Peri-Operative Complications are Associated with Reduced Long Term Amputation Free Survival Following Revascularisation for Lower Limb Peripheral Artery Disease: A Population Based Linked Data Study.

OBJECTIVE: To determine, in a population based linked data study, the relationship between peri-operative multiple complications and longer term outcomes, specifically the combined outcome of two year amputation or death, after lower limb revascularisation for peripheral artery disease (PAD). METHODS: State wide health administrative data and death records were probabilistically linked for all patients who had lower limb artery surgery between 2010 and 2012 in New South Wales, Australia. Multivariable Cox regression modelled the impact of medical and surgical complications on the combined outcome of amputation or death two years after discharge. RESULTS: Open surgery was performed on 3004 patients (26.7%), and endovascular on 8263 (73.3%). Of the 10 971 patients discharged alive, 3747 (34.1%) experienced at least one complication, and 2113 (19.3%) had multiple complications. Older patients, those with high comorbidity scores, or those with chronic limb threatening ischaemia were at increased risk of multiple complications. After adjusting for procedure type, patients with multiple complications experienced more than three times the hazard ratio (HR) of amputation or death two years after the procedure than those without complications (adjusted HR 3.4, 95% confidence interval 3.1-3.7), and increasing complications progressively multiplied the risk. In particular, non-surgical complications such as stroke, acute renal failure, delirium, and cardiac events were associated with the highest rates of two year amputation or death. CONCLUSION: Multiple complications after surgery for lower limb PAD carried a compounding risk of reduced long term amputation free survival. Patients experiencing at least one complication form a high risk group that requires increased attention to prevent the potential development of further complications.

Gestational age, morbidity and mortality among twin births in New South Wales, Australia 2003-2014: A cohort study.

BACKGROUND: Evidence suggests that the trend toward early planned births observed among singletons may be evident among twin pregnancies. AIMS: To describe trends in gestational age at birth, pregnancy characteristics, neonatal morbidity and mortality among twin pregnancies. MATERIALS AND METHODS: Population-based data linkage study of twin births of ≥30 weeks of gestation without a major congenital anomaly born in 2003-2014 in New South Wales (NSW), Australia. Linked pregnancy and birth, hospital and mortality data were used. Generalised linear regression was used to assess linear trends. Risk difference (RD) and 95% confidence intervals were estimated. RESULTS: Among 28 076 eligible twin births (14 038 pregnancies), 49% of births occurred prior to 37 weeks and 69% of births were planned (pre-labour caesarean or induction of labour). There were increases over time in the proportion of twin births at preterm gestations (30-34 weeks (RD 2.1, 95% CI 0.1, 4.0), 35-36 weeks (RD 7.5, 95% CI 5.4, 9.7)) and in the rates of planned births (pre-labour caesarean (RD 6.4, 95% CI 4.0, 8.8), induction (RD 4.6, 95% CI 2.6, 6.6)). There was no significant change in stillbirth or neonatal death rates, but there was an increase in neonatal morbidity over the study period. Concurrently, there were increases in the prevalence of gestational diabetes; and decreases in pregnancy hypertension, assisted reproductive technology use, small-for-gestational age and birthweight discordance. CONCLUSIONS: Gestational age at birth among twin births is decreasing and birth intervention is increasing. There are increasing rates of neonatal morbidity, but no overall change in perinatal mortality.

The association between haemoglobin levels in the first 20 weeks of pregnancy and pregnancy outcomes.

BACKGROUND: Low haemoglobin has been linked to adverse pregnancy outcomes. Our study aimed to assess the association of haemoglobin (Hb) in the first 20 weeks of pregnancy, and restoration of low Hb levels, with pregnancy outcomes in Australia. METHODS: Clinical data for singleton pregnancies from two tertiary public hospitals in New South Wales were extracted for 2011-2015. The relationship between the lowest Hb result in the first 20 weeks of pregnancy and adverse outcomes was determined using adjusted Poisson regression. Those with Hb <110 g/L were classified into 'restored' and 'not restored' based on Hb results from 21 weeks onwards, and risk of adverse outcomes explored with adjusted Poisson regression. RESULTS: Of 31,906 singleton pregnancies, 4.0% had Hb <110 and 10.2% had ≥140 g/L at ≤20 weeks. Women with low Hb had significantly higher risks of postpartum haemorrhage, transfusion, preterm birth, very low birthweight, and having a baby transferred to higher care or stillbirth. High Hb was also associated with higher risks of preterm, very low birthweight, and transfer to higher care/stillbirth. Transfusion was the only outcome where risk decreased with increasing Hb. Risk of transfusion was significantly lower in the 'restored' group compared with the 'not restored' group (OR 0.39, 95% CI 0.22-0.70), but restoration of Hb did not significantly affect the other outcomes measured. CONCLUSIONS: Women with both low and high Hb in the first 20 weeks of pregnancy had higher risks of adverse outcomes than those with normal Hb. Restoring Hb after 20 weeks did not improve most adverse outcome rates but did reduce risk of transfusion.

Haemoglobin trajectories during pregnancy and associated outcomes using pooled maternity and hospitalization data from two tertiary hospitals.

BACKGROUND AND OBJECTIVES: This study aimed to describe how haemoglobin trajectories in pregnant Australian women were associated with subsequent postpartum haemorrhage, blood transfusion and other outcomes. MATERIALS AND METHODS: The study was conducted in two tertiary public hospitals in Australia, using routinely collected maternity and hospital data on singleton pregnancies (2011-2015). Latent class growth modelling defined trajectories among those with at least one haemoglobin in each of three antenatal time periods (0-15, 16-30 and 31+ weeks; n = 7104). Observed over expected ratios were calculated after predicting expected outcomes with adjusted logistic regression. RESULTS: The mean minimum haemoglobin levels across the three periods were 127·9, 116·5 and 119·3 g/l. We identified seven groups of women with similar haemoglobin trajectories: five with parallel U-shaped trajectories, one with increasing and one with decreasing trajectory. Thirty-eight women (0.5%) had very low haemoglobin across the pregnancy and the highest adverse outcomes, including higher than expected blood transfusion risk. One hundred thirteen women (1.6%) with a progressively decreasing trajectory also had higher risk of transfusion. Women with high haemoglobin across the antenatal period had higher than expected risk of preterm birth, small for gestational age and infants transferred to higher care. CONCLUSIONS: Haemoglobin trajectories across pregnancy can predict women at higher risk of requiring transfusion around birth. Women who maintain high haemoglobins across the pregnancy are worthy of increased surveillance as they carry increased risks of newborn morbidity.

Mortality and hospital readmissions in the first year of life after intra-uterine and neonatal blood product transfusions: A population data linkage study.

AIM: Blood product transfusions are a potentially life-saving therapy for fetal and neonatal anaemia, but there is limited population-based research on outcomes. We aimed to describe mortality, readmission and average hospital stay in the first year of life for infants with or without intra-uterine or neonatal blood product transfusions. METHODS: Linked birth, hospital and deaths data from New South Wales, Australia (January 2002-June 2014) were used to identify singleton infants (≥23 weeks' gestation, surviving to 29 days; n = 1 089 750) with intra-uterine or neonatal transfusion or no transfusion. Rates of mortality and readmission in the first year (29-365 days) and days in hospital were calculated. RESULTS: Overall, 68 (0.06/1000) infants had experienced intra-uterine transfusion and 4332 (3.98/1000) neonatal transfusion. Transfusion was more common among those born at earlier gestational ages requiring invasive ventilation. Mortality, readmissions and average days in hospital were higher among transfused than non-transfused infants. Over half of infants with intra-uterine and neonatal transfusion had ≥1 readmission in the first 29-365 days (55.9 and 51.8%, respectively), and around a quarter had ≥2 (20.6 and 28.5%, respectively) compared with 15.3% with ≥1 and 3.5% with ≥2 in the non-transfused group. CONCLUSION: Infants with a history of blood product transfusion, particularly those needing a neonatal transfusion, had higher mortality and more frequent contact with the hospital system in the first year of life than those infants with no history of transfusion.

Outcomes of subsequent pregnancy following obstetric transfusion in a first birth.

BACKGROUND: Increasing rates of postpartum haemorrhage and obstetric transfusion mean that more women are entering subsequent pregnancies with a history of blood transfusion. This study investigates subsequent pregnancy outcomes of women with a prior obstetric red cell transfusion, compared to women without a transfusion. METHODS: All women with a first pregnancy resulting in a liveborn singleton infant of at least 20 weeks gestation delivering in hospitals in New South Wales, Australia, between 2003 and 2012 were included in the study, with followup for second births until June 2015. Linked hospital and births data were used to identify women with a transfusion and/or postpartum haemorrhage in their first birth, time to second pregnancy and adverse birth outcomes (including transfusion, postpartum haemorrhage and severe morbidity) in their subsequent birth. RESULTS: There were 358,384 singleton births to primiparous women, with 1.4% receiving an obstetric blood transfusion. Sixty-three percent of women had at least one subsequent birth. The relative risk (RR) of requiring a transfusion in a second birth was 4.9 (95% CI 4.1,6.1) for women with a previous transfusion compared with women without. The risk (RR) of severe morbidity in a second birth was 4.1 times higher (95% CI 2.2,7.4) for those receiving a transfusion without haemorrhage in their first birth compared with women with neither haemorrhage nor transfusion. CONCLUSION: It is important to consider a woman's history of transfusion and/or haemorrhage as part of her obstetric history to ensure management in a manner that minimises risk in subsequent pregnancies.

Multimorbidity among Aboriginal people in New South Wales contributes significantly to their higher mortality.

OBJECTIVES: To compare the prevalence of multimorbidity and its impact on mortality among Aboriginal and non-Aboriginal Australians who had been hospitalised in New South Wales in the previous 10 years. DESIGN, SETTING AND PARTICIPANTS: Cohort study analysis of linked NSW hospital (Admitted Patient Data Collection) and mortality data for 5 437 018 New South Wales residents with an admission to a NSW hospital between 1 March 2003 and 1 March 2013, and alive at 1 March 2013. MAIN OUTCOME MEASURES: Admissions for 30 morbidities during the 10-year study period were identified. The primary outcome was the presence or absence of multimorbidity during the 10-year lookback period; the secondary outcome was mortality in the 12 months from 1 March 2013 to 1 March 2014. RESULTS: 31.5% of Aboriginal patients had at least one morbidity and 16.1% had two or more, compared with 25.0% and 12.1% of non-Aboriginal patients. After adjusting for age, sex, and socio-economic status, the prevalence of multimorbidity among Aboriginal people was 2.59 times that for non-Aboriginal people (95% CI, 2.55-2.62). The prevalence of multimorbidity was higher among Aboriginal people in all age groups, in younger age groups because of the higher prevalence of mental morbidities, and from age 60 because of physical morbidities. The age-, sex- and socio-economic status-adjusted hazard of one-year mortality (Aboriginal v non-Aboriginal Australians) was 2.43 (95% CI, 2.24-2.62), and 1.51 (95% CI, 1.39-1.63) after also adjusting for morbidity count. CONCLUSIONS: The prevalence of multimorbidity was higher among Aboriginal than non-Aboriginal patients, and this difference accounted for much of the difference in mortality between the two groups. Evidence-based interventions for reducing multimorbidity among Aboriginal and Torres Strait Islander Australians must be a priority.

The impact of blood-borne viruses on cause-specific mortality among opioid dependent people: An Australian population-based cohort study.

BACKGROUND: Blood-borne viruses (BBV) are prevalent among people with opioid dependence but their association with cause-specific mortality has not been examined at the population-level. METHODS: We formed a population-based cohort of 29,571 opioid substitution therapy (OST) registrants in New South Wales, Australia, 1993-2007. We ascertained notifications of infection and death by record linkage between the Pharmaceutical Drugs of Addiction System (OST data), registers of hepatitis C (HCV), hepatitis B (HBV) and human immunodeficiency virus (HIV) diagnoses, and the National Death Index. We used competing risks regression to quantify associations between notification for BBV infection and causes of death. BBV status, age, year, OST status, and OST episodes were modelled as time-dependent covariates; sex was a fixed covariate. RESULTS: OST registrants notified with HCV infection were more likely to die from accidental overdose (subdistribution hazard ratio, 95% Confidence Interval: 1.7, 1.5-2.0), cancer (2.0, 1.3-3.2) and unintentional injury (1.4, 1.0-2.0). HBV notification was associated with a higher hazard of mortality due to unintentional injury (2.1, 1.1-3.9), cancer (2.8, 1.5-5.5), and liver disease (2.1, 1.0-4.3). Liver-related mortality was higher among those notified with HIV only (11, 2.5-50), HCV only (5.9, 3.2-11) and both HIV and HCV (15, 3.2-66). Registrants with an HIV notification had a higher hazard of cardiovascular-related mortality (4.0, 1.6-9.9). CONCLUSIONS: Among OST registrants, BBVs are a direct cause of death and also a marker of behaviours that can result in unintended death. Ongoing and enhanced BBV prevention strategies and treatment, together with targeted education strategies to reduce risk, are justified.

Variation in the recording of common health conditions in routine hospital data: study using linked survey and administrative data in New South Wales, Australia.

OBJECTIVES: To investigate the nature and potential implications of under-reporting of morbidity information in administrative hospital data. SETTING AND PARTICIPANTS: Retrospective analysis of linked self-report and administrative hospital data for 32,832 participants in the large-scale cohort study (45 and Up Study), who joined the study from 2006 to 2009 and who were admitted to 313 hospitals in New South Wales, Australia, for at least an overnight stay, up to a year prior to study entry. OUTCOME MEASURES: Agreement between self-report and recording of six morbidities in administrative hospital data, and between-hospital variation and predictors of positive agreement between the two data sources. RESULTS: Agreement between data sources was good for diabetes (κ=0.79); moderate for smoking (κ=0.59); fair for heart disease, stroke and hypertension (κ=0.40, κ=0.30 and κ =0.24, respectively); and poor for obesity (κ=0.09), indicating that a large number of individuals with self-reported morbidities did not have a corresponding diagnosis coded in their hospital records. Significant between-hospital variation was found (ranging from 8% of unexplained variation for diabetes to 22% for heart disease), with higher agreement in public and large hospitals, and hospitals with greater depth of coding. CONCLUSIONS: The recording of six common health conditions in administrative hospital data is highly variable, and for some conditions, very poor. To support more valid performance comparisons, it is important to stratify or control for factors that predict the completeness of recording, including hospital depth of coding and hospital type (public/private), and to increase efforts to standardise recording across hospitals. Studies using these conditions for risk adjustment should also be cautious of their use in smaller hospitals.