Association between unstable diabetes mellitus and risk of pancreatic cancer.

BACKGROUND: Deterioration of glycaemic control in people with long-standing diabetes mellitus (diabetes) may be a possible indicator of pancreatic cancer. However, the magnitude of the association between diabetes deterioration and pancreatic cancer has received little attention. METHODS: We conducted a matched cohort study, nested within a population-based cohort of Australian women with diabetes. Women with unstable diabetes, defined as a change in medication after a 2-year period of stable medication use, were matched by birth year to those with stable diabetes, in a 1:4 ratio. We used flexible parametric survival models to estimate hazard ratios (HRs) and 95% confidence intervals (CI). RESULTS: We included 134,954 and 539,789 women in the unstable and stable diabetes cohorts, respectively (mean age 68 years). In total, 1,315 pancreatic cancers were diagnosed. Deterioration of stable diabetes was associated with a 2.5-fold increased risk of pancreatic cancer (HR 2.55; 95% CI 2.29-2.85). The risk was particularly high within the first year after diabetes deteriorated. HRs at 3 months, 6 months and 1 year were: 5.76 (95% CI 4.72-7.04); 4.56 (95% CI 3.81-5.46); and 3.33 (95% CI 2.86-3.89), respectively. The risk was no longer significantly different after 7 years. CONCLUSIONS: Deterioration in glycaemic control in people with previously stable diabetes may be an indicator of pancreatic cancer, suggesting investigations of the pancreas may be appropriate. The weaker longer-term (3-7 years) association between diabetes deterioration and pancreatic cancer may indicate that poor glycaemic control can be a risk factor for pancreatic cancer.

Association between antihypertensive medicine use and risk of ovarian cancer in women aged 50 years and older.

BACKGROUND: Epithelial ovarian cancer (EOC) has few modifiable risk factors. There is evidence that some antihypertensive medicines may have cancer preventive and/or therapeutic actions; therefore, we assessed the associations between use of different antihypertensive medicines and risk of specific EOC histotypes. METHODS: Our nested case-control study of linked administrative health data included 6070 Australian women aged over 50 years diagnosed with EOC from 2004 to 2013, and 30,337 matched controls. We used multivariable conditional logistic regression to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) for the association between ever use of each antihypertensive medicine group, including beta-adrenergic blockers, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, and alpha blockers, and the risk of EOC overall and separately for the serous, endometrioid, mucinous, clear cell and other histotypes. RESULTS: We found that most antihypertensive medicines were not associated with risk of EOC. However, women who used calcium channel blockers had a reduced risk of serous EOC (OR= 0.89, 95 % CI:0.81,0.98) and use of combination thiazide and potassium-sparing diuretics was associated with an increased risk of endometroid EOC (OR= 2.09, 95 % CI:1.15,3.82). CONCLUSION: Our results provide little support for a chemo-preventive role for most antihypertensives, however, the histotype-specific associations we found warrant further investigation.

Stressors, Barriers and Facilitators Faced by Australian Farmers When Transitioning to Retirement: A Scoping Review.

Farms in Australia are largely family owned and managed. Complex interactions between farming history, traditions, family, business, succession, identity and place can lead to difficulties in planning for retirement for farmers. Due to the significant implications of this for farmers' health and wellbeing, there is a clear need to determine how farmers may be best supported through the work-to-retirement transition. This scoping review summarises the literature on Australian farmers' retirement experiences and the stressors they face during this transition. Barriers and facilitators that may hinder or help farmers were also explored. The relevant peer-reviewed literature was identified through database searching and the grey literature was collected via a web-based search. Seven studies were included in the review. Poor health and diminishing capacity to work was identified as a key stressor related to retirement. Other drivers of stress (i.e., pressure to live up to farming ideals, perceiving retirement as a threat to self-identity and financial concerns) overlapped with barriers to retirement. Farmers identified gradual transition, strong social networks, variety in interests and activities and early financial and succession planning as key facilitators of retirement. Findings will help inform the development of interventions to assist Australian farmers through this challenging stage of their lives.

Perioperative Beta-Blocker Supply and Survival in Women With Epithelial Ovarian Cancer and a History of Cardiovascular Conditions.

PURPOSE: Surgery for epithelial ovarian cancer (EOC) may activate stress-inflammatory responses that stimulate tumor growth and increase metastatic growth. Animal and in vitro studies have shown that inhibition of the catecholamine-induced inflammatory response via beta-adrenergic receptor blockade has antitumor potential in EOC. However, observational studies have reported mixed results. We assessed whether beta-blocker (BB) use at the time of primary ovarian cancer surgery was associated with improved survival in a large population-based study. MATERIALS AND METHODS: Using linked administrative data, a population-based cohort of 3,844 Australian women age 50 years or older with a history of cardiovascular conditions who underwent surgery for EOC was followed for survival outcomes. The average treatment effect of selective BB (SBB) and nonselective BB (NSBB) supply at the time of surgery on survival was estimated from a causal inference perspective using covariate-balanced inverse probability of treatment weights with flexible parametric survival models that allowed for time-varying survival effects. RESULTS: Around the time of surgery, 560 (14.5%) women were supplied a SBB and 67 (1.7%) were supplied a NSBB. At 2 years postsurgery, the survival proportion was 80% (95% CI, 68 to 88) for women dispensed NSBBs at surgery compared with 69% (95% CI, 67 to 70) for women not supplied NSBBs. The survival advantage appeared to extend to at least 8 years postsurgery. No association was observed for women dispensed a SBB around the time of surgery. CONCLUSION: Perioperative supply of NSBBs appeared to confer a survival advantage for women age over 50 years with a history of cardiovascular conditions. Long-term clinical trials are required to confirm these findings.

The association between diabetes mellitus of different durations and risk of pancreatic cancer: an Australian national data-linkage study in women.

AIMS: The bidirectional association between diabetes mellitus (DM) and pancreatic cancer (PC) is established; however, the strength of association between duration of DM and risk of PC needs further investigation. METHODS: We conducted a case-control study nested within a population-based cohort of Australian women established using record linkage. Women diagnosed with PC from July 2007 to December 2013, were matched to five controls based on age and state of residence. DM was defined according to prescription of anti-diabetic medication from administrative prescription data. We used conditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI), adjusted for area-level socioeconomic status, rurality of residence, weighted comorbidity score, and predicted probability of obesity. RESULTS: The analyses included 7,267 cases and 35,978 controls. The mean age at the time of DM diagnosis was 71 years whereas the mean age at the time of diagnosis of PC was 76 years. A history of DM of any duration was associated with a 2-fold increase in risk of PC (OR=2.12; 95%CI:1.96-2.29) compared to having no history of DM. The risk decreased with increasing duration of DM. The highest risk was in those who had recent-onset DM (OR=8.08; 95%CI:6.88-9.50 for <12 months of DM), but the risk remained elevated with ≥5 years of DM (OR=1.40; 95%CI:1.27-1.55). CONCLUSION: The markedly increased risk of PC in those with recent-onset DM emphasises the need for further research to distinguish patients for whom new-onset DM is a manifestation of PC from those with type-2 DM. The elevated risk associated with long-standing DM suggests that preventing DM may contribute to a reduction in the incidence of PC.

Nitrogen-based Bisphosphonate Use and Ovarian Cancer Risk in Women Aged 50 Years and Older.

BACKGROUND: There are few readily modifiable risk factors for epithelial ovarian cancer; preclinical studies suggest bisphosphonates could have chemopreventive actions. Our study aimed to assess the association between use of nitrogen-based bisphosphonate medicine and risk of epithelial ovarian cancer, overall and by histotype. METHODS: We conducted a case-control study nested within a large, linked administrative dataset including all Australian women enrolled for Medicare, Australia's universal health insurance scheme, between July 2002 and December 2013. We included all women with epithelial ovarian cancer diagnosed at age 50 years and older between July 1, 2004, and December 31, 2013 (n = 9367) and randomly selected up to 5 controls per case, individually matched to cases by age, state of residence, area-level socioeconomic status, and remoteness of residence category (n = 46 830). We used prescription records to ascertain use of nitrogen-based bisphosphonates (ever use and duration of use), raloxifene, and other osteoporosis medicines (no nitrogen-based bisphosphonates, strontium and denosumab). We calculated adjusted odds ratios (OR) and 95% confidence intervals (CI) using conditional logistic regression. RESULTS: Ever use of nitrogen-based bisphosphonates was associated with a reduced risk of epithelial ovarian cancer compared with no use (OR = 0.81, 95% CI = 0.75 to 0.88). There was a reduced risk of endometrioid (OR = 0.51, 95% CI = 0.33 to 0.79) and serous histotypes (OR = 0.84, 95% CI = 0.75 to 0.93) but no association with the mucinous or clear cell histotypes. CONCLUSION: Use of nitrogen-based bisphosphonates was associated with a reduced risk of endometrioid and serous ovarian cancer. This suggests the potential for use for prevention, although validation of our findings is required.

Hysterectomy and Risk of Breast, Colorectal, Thyroid, and Kidney Cancer - an Australian Data Linkage Study.

BACKGROUND: This study aimed to investigate the associations between hysterectomy for benign indications and risk of breast, colorectal, kidney, and thyroid cancer, and to explore whether these associations are modified by removal of ovaries at the time of surgery or by age at surgery. METHODS: We conducted a retrospective cohort study of the female population of Western Australia (n = 839,332) linking data from electoral, hospital, births, deaths, and cancer records. We used Cox regression to estimate HRs and 95% confidence intervals (CI) for the associations between hysterectomy and diagnosis of breast, colorectal, kidney, and thyroid cancers. RESULTS: Compared with no surgery, hysterectomy without oophorectomy (hysterectomy) and hysterectomy with bilateral salpingo-oophorectomy (hysterectomy-BSO) were associated with higher risk of kidney cancer (HR, 1.32; 95% CI, 1.11-1.56 and HR, 1.29; 95% CI, 0.96-1.73, respectively). Hysterectomy, but not hysterectomy-BSO, was related to higher risk of thyroid cancer (HR, 1.38; 95% CI, 1.19-1.60). In contrast, hysterectomy (HR, 0.94; 95% CI, 0.90-0.98) and hysterectomy-BSO (HR, 0.92; 95% CI, 0.85-1.00) were associated with lower risk of breast cancer. We found no association between hysterectomy status and colorectal cancer. CONCLUSIONS: The associations between hysterectomy and cancer varied by cancer type with increased risks for thyroid and kidney cancer, decreased risk for breast cancer, and no association for colorectal cancer. IMPACT: As breast, colorectal, and gynecologic cancers comprise a sizeable proportion of all cancers in women, our results suggest that hysterectomy is unlikely to increase overall cancer risk; however, further research to understand the higher risk of thyroid and kidney cancer is warranted.

Hysterectomy with and without oophorectomy and all-cause and cause-specific mortality.

BACKGROUND: Hysterectomy is one of the most commonly performed gynecologic surgeries, with an estimated 30% of women in Australia undergoing the procedure by age of 70 years. In the United States, about 45% of women undergo hysterectomy in their lifetime. Some studies have suggested that this procedure increases the risk of premature mortality. With many women making the decision to undergo hysterectomy for a benign indication each year, additional research is needed to clarify whether there are long-term health consequences of hysterectomy. OBJECTIVE: This study aimed to examine the association between hysterectomy for benign indications, with or without removal of the ovaries, and cause-specific and all-cause mortality. STUDY DESIGN: Our cohort of 666,588 women comprised the female population of Western Australia with linked hospital and health records from 1970 to 2015. Cox regression models were used to assess the association between hysterectomy and all-cause, cardiovascular disease, cancer, and other mortality by oophorectomy type (categorized as none, unilateral, and bilateral), with no hysterectomy or oophorectomy as the reference group. We repeated these analyses using hysterectomy without oophorectomy as the reference group. We also investigated whether associations varied by age at the time of surgery, although small sample size precluded this analysis in women who underwent hysterectomy with unilateral salpingo-oophorectomy. In our main analysis, women who underwent hysterectomy or oophorectomy as part of cancer treatment were retained in the analysis and considered unexposed to that surgery. For a sensitivity analysis, we censored procedures performed for cancer. RESULTS: Compared with no surgery, hysterectomy without oophorectomy before 35 years was associated with an increase in all-cause mortality (hazard ratio, 1.29; 95% confidence interval, 1.19-1.40); for surgery after 35 years of age, there was an inverse association (35-44 years: hazard ratio, 0.93; 95% confidence interval, 0.89-0.97). Similarly, hysterectomy with bilateral salpingo-oophorectomy before 45 years of age was associated with increased all-cause mortality (35-44 years: hazard ratio, 1.15; 95% confidence interval, 1.04-1.27), but decreased mortality rates after 45 years of age. In our sensitivity analysis, censoring gynecologic surgeries for cancer resulted in many cancer-related deaths being excluded for women who did not have surgery for benign indications and thus increased the hazard ratios for the associations between both hysterectomy without oophorectomy and hysterectomy with bilateral salpingo-oophorectomy and risk of all-cause and cancer-specific mortality. The sensitivity analysis therefore potentially biased the results in favor of no surgery. CONCLUSION: Among women having surgery for benign indications, hysterectomy without oophorectomy performed before 35 years of age and hysterectomy with bilateral salpingo-oophorectomy performed before 45 years of age were associated with an increase in all-cause mortality. These procedures are not associated with poorer long-term survival when performed at older ages.

The Association Between Hysterectomy and Ovarian Cancer Risk: A Population-Based Record-Linkage Study.

BACKGROUND: Recent studies have called into question the long-held belief that hysterectomy without oophorectomy protects against ovarian cancer. This population-based longitudinal record-linkage study aimed to explore this relationship, overall and by age at hysterectomy, time period, surgery type, and indication for hysterectomy. METHODS: We followed the female adult Western Australian population (837 942 women) across a 27-year period using linked electoral, hospital, births, deaths, and cancer records. Surgery dates were determined from hospital records, and ovarian cancer diagnoses (n = 1640) were ascertained from cancer registry records. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between hysterectomy and ovarian cancer incidence. RESULTS: Hysterectomy without oophorectomy (n = 78 594) was not associated with risk of invasive ovarian cancer overall (HR = 0.98, 95% CI = 0.85 to 1.11) or with the most common serous subtype (HR = 1.05, 95% CI = 0.89 to 1.23). Estimates did not vary statistically significantly by age at procedure, time period, or surgical approach. However, among women with endometriosis (5.8%) or with fibroids (5.7%), hysterectomy was associated with substantially decreased ovarian cancer risk overall (HR = 0.17, 95% CI = 0.12 to 0.24, and HR = 0.27, 95% CI = 0.20 to 0.36, respectively) and across all subtypes. CONCLUSIONS: Our results suggest that for most women, having a hysterectomy with ovarian conservation is not likely to substantially alter their risk of developing ovarian cancer. However, our results, if confirmed, suggest that ovarian cancer risk reduction could be considered as a possible benefit of hysterectomy when making decisions about surgical management of endometriosis or fibroids.

Risk of high-grade serous ovarian cancer associated with pelvic inflammatory disease, parity and breast cancer.

BACKGROUND: Ovarian carcinoma is not a single disease, but rather a collection of subtypes with differing molecular properties and risk profiles. The most common of these, and the subject of this work, is high-grade serous ovarian carcinoma (HGSC). METHODS: In this population-based study we identified a cohort of 441,382 women resident in Western Australia who had ever been admitted to hospital in the State. Of these, 454 were diagnosed with HGSC. We used Cox regression to derive hazard ratios (HRs) comparing the risk of disease in women who had each of a range of medical diagnoses and surgical procedures with women who did not. RESULTS: We found an increased risk of HGSC associated with a diagnosis of pelvic inflammatory disease (PID) (HR 1.47, 95% CI 1.04-2.07) but not with a diagnosis of infertility or endometriosis with HRs of 1.12 (95% CI 0.73-1.71) and 0.82 (95% CI 0.55-1.22) respectively. A personal history of breast cancer was associated with a three-fold increase in the rate of HGSC. Increased parity was associated with a reduced risk of HGSC in women without a personal history of breast cancer (HR 0.57; 95% CI 0.44-0.73), but not in women with a personal history of breast cancer (HR 1.48; 95% CI 0.74-2.95). CONCLUSIONS: Our finding of an increased risk of HGSC associated with PID lends support to the hypothesis that inflammatory processes may be involved in the etiology of HGSC.

Risk of Pelvic Inflammatory Disease in Relation to Chlamydia and Gonorrhea Testing, Repeat Testing, and Positivity: A Population-Based Cohort Study.

Background: There is uncertainty around whether the risks of pelvic inflammatory disease (PID) differ following Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) infection. We quantified the risk of PID associated with chlamydia and gonorrhea infection and subsequent repeat infections in a whole-population cohort. Methods: A cohort of 315123 Western Australian women, born during 1974-1995, was probabilistically linked to chlamydia and gonorrhea testing records and to hospitalizations and emergency department presentations for PID from 2002 to 2013. Time-updated survival analysis was used to investigate the association between chlamydia and gonorrhea testing, and positivity, and risk of PID. Results: Over 3199135 person-years, 120748 women had pathology test records for both chlamydia and gonorrhea, 10745 chlamydia only, and 653 gonorrhea only. Among those tested, 16778 (12.8%) had ≥1 positive chlamydia test, 3195 (2.6%) ≥1 positive gonorrhea test, and 1874 (1.6%) were positive for both. There were 4819 PID presentations (2222 hospitalizations, 2597 emergency presentations). Adjusting for age, Aboriginality, year of follow-up, health area, and socioeconomic status, compared to women negative for chlamydia and gonorrhea, the relative risk (adjusted incidence rate ratio) of PID was 4.29 (95% confidence interval [CI], 3.66-5.03) in women who were both chlamydia and gonorrhea positive; 4.54 (95% CI, 3.87-5.33) in those only gonorrhea positive; and 1.77 (95% CI, 1.61-1.94) in those only chlamydia positive. Conclusions: Gonorrhea infection conferred a substantially higher risk than chlamydia of hospitalization or emergency department presentation for PID. The emergence of gonorrhea antimicrobial resistance may have a serious impact on rates of PID and its associated reproductive health sequelae.

Declining rates of sterilisation reversal procedures in western Australian women from 1990 to 2008: the relationship with age, hospital type and government policy changes.

BACKGROUND: Female sterilisation is usually performed on an elective basis at perceived family completion, however, around 1-3% of women who have undergone sterilisation elect to undergo sterilisation reversal (SR) at a later stage. The trends in SR rates in Western Australia (WA), proportions of SR procedures between hospital types (public and private), and the effects of Federal Government policies on these trends are unknown. METHODS: Using records from statutory state-wide data collections of hospital separations and births, we conducted a retrospective descriptive study of all women aged 15-49 years who underwent a SR procedure during the period 1st January 1990 to 31st December 2008 (n = 1868 procedures). RESULTS: From 1991 to 2007 the annual incidence rate of SR procedures per 10,000 women declined from 47.0 to 3.6. Logistic regression modelling showed that from 1997 to 2001 the odds of women undergoing SR in a private hospital as opposed to all other hospitals were 1.39 times higher (95% CI 1.07-1.81) and 7.51 times higher (95% CI 5.46-10.31) from 2002 to 2008. There were significant decreases in SR rates overall and among different age groups after the Federal Government interventions. CONCLUSION: Rates of SR procedures in WA have declined from 1990 to 2008, particularly following policy changes such as the introduction of private health insurance (PHI) policies. This suggests decisions to undergo SR may be influenced by Federal Government interventions.

Value of Pathology Review in a Population-based Series of Ovarian Tumors.

Ovarian neoplasia comprises a heterogenous group of tumors with distinct clinicopathologic and molecular features and therefore assessment of potential risk factors should be tumor subtype specific. As part of ongoing epidemiological investigations of ovarian neoplasia in Western Australia, we performed an initial review of original pathology reports followed, in selected cases, by reassessment of histology material to optimize accurate diagnosis. Additional immunohistochemistry, often using antibodies unavailable at the time of initial assessment, was also performed as required. From an initial cohort of 1660 cases identified through the Western Australia Cancer Registry, benign, nonepithelial, nonovarian, miscellaneous, and indeterminate cases were excluded. Also excluded were 33 cases that were reclassified as ovarian metastases rather than primary ovarian tumors. Following exclusions there remained 1321 borderline and malignant epithelial neoplasms. The diagnosis was considered accurate in 1186 cases (89.8%) based upon information in the initial pathology reports and clinical follow-up data but uncertain in 135 cases (10.2%). Histologic review was possible in 92 of the latter tumors leading to an amended diagnosis in 63 cases (68.5%). The most common types of diagnostic amendment were the reclassification of high-grade carcinomas of undifferentiated, endometrioid, or transitional appearance as high-grade serous carcinoma, and the reclassification of most carcinomas of mixed epithelial type as "pure" carcinomas. This review illustrated specific pitfalls in the diagnosis of ovarian epithelial neoplasia and helped to maintain the accuracy of the Western Australia Cancer Registry. Accurate diagnosis will optimize further epidemiological studies assessing risk factors in specific subtypes of ovarian neoplasia.

Declining rates of sterilization procedures in Western Australian women from 1990 to 2008: the relationship with age, hospital type, and government policy changes.

OBJECTIVE: To describe trends in age-specific incidence rates of female sterilization (FS) procedures in Western Australia and to evaluate the effects of the introduction of government-subsidized contraceptive methods and the implementation of the Australian government's baby bonus policy on FS rates. DESIGN: Population-based retrospective descriptive study. SETTING: Not applicable. PATIENT(S): All women ages 15-49 undergoing an FS procedure during the period January 1, 1990, to December 31, 2008 (n = 47,360 procedures). INTERVENTION(S): Records from statutory statewide data collections of hospitals separations and births were extracted and linked. MAIN OUTCOME MEASURE(S): Trends in FS procedures and the influence on these trends of the introduction of government policies: subsidization of long-acting reversible contraceptives (Implanon and Mirena) and the Australian baby bonus initiative. RESULT(S): The annual incidence rate of FS procedures declined from 756.9 per 100,000 women in 1990 to 155.2 per 100,000 women in 2008. Compared with the period 1990-1994, women ages 30-39 years were 47% less likely (rate ratio [RR] = 0.53; 95% confidence interval [CI], 0.39-0.72) to undergo sterilization during the period 2005-2008. Adjusting for overall trend, there were significant decreases in FS rates after government subsidization of Implanon (RR = 0.89; 95% CI, 0.82-0.97) and Mirena (RR = 0.81; 95% CI, 0.73-0.91) and the introduction of the baby bonus (RR = 0.70; 95% CI, 0.61-0.81). CONCLUSION(S): Rates of female sterilization procedures in Western Australia have declined substantially across all age groups in the last two decades. Women's decisions to undergo sterilization procedures may be influenced by government interventions that increase access to long-term reversible contraceptives or encourage childbirth.

Live delivery outcome after tubal sterilization reversal: a population-based study.

OBJECTIVE: To determine the cumulative incidence of live delivery in women who underwent reversal of tubal sterilization. DESIGN: Population-based retrospective cohort study. SETTING: Hospitals in Western Australia. PATIENT(S): All women aged 20-44 years, with a history of hospital admission for tubal sterilization, who subsequently underwent reversal of sterilization during the period 1985 to 2009 in Western Australia (n = 1,898). INTERVENTION(S): Data regarding reversal of sterilization and prior tubal sterilization were extracted from routinely collected administrative hospital separation records, until commencement of IVF treatment. MAIN OUTCOME MEASURE(S): First live-delivery rates. RESULT(S): There were 969 first live deliveries observed during the study period. The overall cumulative live-delivery rate was 20% (95% confidence interval [CI] 18-23) within the first year after reversal, 40% (95% CI 38-42) at 2 years, 51% (95% CI 48-53) at 5 years, and 52% (95% CI 50-55) at 10 years. The 5-year cumulative live-delivery rate was significantly lower in women who were aged 40-44 years (26%) compared with younger women (aged 20-29, 30-34, and 35-39 years) (50%, 56%, and 51%, respectively). CONCLUSION(S): Women undergoing reversal of sterilization before they reach age 40 years have at least a 50% chance of delivering a live baby within the next 5 years. Up to that age, there is no significant difference in live deliveries. The live-delivery rate halves after the age of 40 years.

A comparison of multivariate and univariate time series approaches to modelling and forecasting emergency department demand in Western Australia.

OBJECTIVE: To develop multivariate vector-ARMA (VARMA) forecast models for predicting emergency department (ED) demand in Western Australia (WA) and compare them to the benchmark univariate autoregressive moving average (ARMA) and Winters' models. METHODS: Seven-year monthly WA state-wide public hospital ED presentation data from 2006/07 to 2012/13 were modelled. Graphical and VARMA modelling methods were used for descriptive analysis and model fitting. The VARMA models were compared to the benchmark univariate ARMA and Winters' models to determine their accuracy to predict ED demand. The best models were evaluated by using error correction methods for accuracy. RESULTS: Descriptive analysis of all the dependent variables showed an increasing pattern of ED use with seasonal trends over time. The VARMA models provided a more precise and accurate forecast with smaller confidence intervals and better measures of accuracy in predicting ED demand in WA than the ARMA and Winters' method. CONCLUSION: VARMA models are a reliable forecasting method to predict ED demand for strategic planning and resource allocation. While the ARMA models are a closely competing alternative, they under-estimated future ED demand.

Influence of offence type and prior imprisonment on risk of death following release from prison: a whole-population linked data study.

PURPOSE: The purpose of this paper is to examine the influence of offence type, prior imprisonment and various socio-demographic characteristics on mortality at 28 and 365 days following prison release. DESIGN/METHODOLOGY/APPROACH: Using whole-population linked, routinely collected administrative state-based imprisonment and mortality data, the authors conducted a retrospective study of 12,677 offenders released from Western Australian prisons in the period 1994-2003. Cox proportional hazards regression was used to examine the association between mortality at 28 and 365 days post-release and offence type, prior imprisonment, and a range of socio-demographic characteristics (age, gender, social disadvantage and Indigenous status). FINDINGS: Overall, 135 (1.1 per cent) died during the 365 days follow-up period, of these, 17.8 per cent (n=24) died within the first 28 days (four weeks) of their index release. Ex-prisoners who had committed drug-related offences had significantly higher risk of 28-day post-release mortality (HR=28.4; 95 per cent CI: 1.3-615.3, p=0.033), than those who had committed violent (non-sexual) offences. A significant association was also found between the number of previous incarcerations and post-release mortality at 28 days post-release, with three prior prison terms carrying the highest mortality risk (HR=73.8; 95 per cent CI: 1.8-3,092.5, p=0.024). No association between mortality and either offence type or prior imprisonment was seen at 365 days post-release. ORIGINALITY/VALUE: Post-release mortality at 28 days was significantly associated with offence type (with drug-related offences carrying the greatest risk) and with prior imprisonment, but associations did not persist to 365 days after release. Targeting of short-term transitional programmes to reduce preventable deaths after return to the community could be tailored to these high-risk ex-prisoners.