David B. Preen

Comorbidity and repeat admission to hospital for adverse drug reactions in older adults: retrospective cohort study

Objectives To identify factors that predict repeat admission to hospital for adverse drug reactions (ADRs) in older adults. Design Population based retrospective cohort study. Setting All public and private hospitals in Western Australia. Participants 28 548 patients aged ≥60 years with an admission for an ADR during 1980-2000 followed for three years using the Western Australian data linkage system. Results 5056 (17.7%) patients had a repeat admission for an ADR. Repeat ADRs were associated with sex (hazard ratio 1.08, 95% confidence interval 1.02 to 1.15, for men), first admission in 1995-9 (2.34, 2.00 to 2.73), length of hospital stay (1.11, 1.05 to 1.18, for stays ≥14 days), and Charlson comorbidity index (1.71, 1.46 to 1.99, for score ≥7); 60% of comorbidities were recorded and taken into account in analysis. In contrast, advancing age had no effect on repeat ADRs. Comorbid congestive cardiac failure (1.56, 1.43 to 1.71), peripheral vascular disease (1.27, 1.09 to 1.48), chronic pulmonary disease (1.61, 1.45 to 1.79), rheumatological disease (1.65, 1.41 to 1.92), mild liver disease (1.48, 1.05 to 2.07), moderate to severe liver disease (1.85, 1.18 to 2.92), moderate diabetes (1.18, 1.07 to 1.30), diabetes with chronic complications (1.91, 1.65 to 2.22), renal disease (1.93, 1.71 to 2.17), any malignancy including lymphoma and leukaemia (1.87, 1.68 to 2.09), and metastatic solid tumours (2.25, 1.92 to 2.64) were strong predictive factors. Comorbidities requiring continuing care predicted a reduced likelihood of repeat hospital admissions for ADRs (cerebrovascular disease 0.85, 0.73 to 0.98; dementia 0.62, 0.49 to 0.78; paraplegia 0.73, 0.59 to 0.89). Conclusions Comorbidity, but not advancing age, predicts repeat admission for ADRs in older adults, especially those with comorbidities often managed in the community. Awareness of these predictors can help clinicians to identify which older adults are at greater risk of admission for ADRs and, therefore, who might benefit from closer monitoring.

Muscle phosphocreatine repletion following single and repeated short sprint efforts

Phosphocreatine (PCr) repletion following either single (1x6 s, n=7) or repeated (5x6 s, departing every 30 s, n=8) maximal short sprint cycling efforts was measured in separate groups of trained subjects. Muscle biopsies (vastus lateralis) were taken pre‐exercise before warming up, and then at 10 s, 30 s and 3 min post‐exercise. After the 1 × 6 s sprint PCr concentration was respectively, 55% (10 s; P<0.01), 69% (30 s; P<0.01) and 90% (3 min; NS) of the pre‐exercise value (mean±SD) (81.1±7.4 mmol · kg−1 DM), whereas after the 5 × 6 s sprints, PCr concentration was, respectively, 27% (10 s; P<0.01), 45% (30 s; P<0.01) and 84% (3 min; P<0.01) of the pre‐exercise value (77.1±4.9 mmol · kg−1 DM). PCr concentration was correlated with muscle lactate at 30 s (r=−0.82; P<0.05) and 3 min of recovery (r=−0.94; P<0.01) for the 1 × 6 s sprint, but not for the 5 × 6 s sprints. The extent of PCr repletion was significantly greater after the 5 × 6 s sprints than the 1 × 6 s sprint between both 10 s and 30 s and 30 s and 3 min, despite lower PCr levels at 10 s, 30 s and 3 min following the 5 × 6 s sprints. Full repletion of PCr is likely to take longer after repeated sprints than single short sprints because of a greater degree of PCr depletion, such that replenishment must commence from lower PCr levels rather than because of slower rates of repletion.

The impact of co-payment increases on dispensings of government-subsidised medicines in Australia

Patient co‐payments for medicines subsidised under the Australian Pharmaceutical Benefits Scheme (PBS) increased by 24% in January 2005. We investigated whether this increase and two related co‐payment changes were associated with changes in dispensings of selected subsidised medicines in Australia.

Whole Population Trends in Complications of Cataract Surgery over 22 Years in Western Australia

OBJECTIVE To examine the trends in major complications of cataract surgery in the Western Australian population over 22 years. DESIGN Population-based study. PARTICIPANTS We included 129 982 cataract/lens surgery patients across 46 health facilities. METHODS Using the Western Australian Data Linkage System, we identified all patients who underwent cataract/lens surgery in Western Australia between 1980 and 2001. Complications of interest were identified from those patients admitted to hospital or who underwent unplanned surgery after cataract surgery and were validated by medical record review. MAIN OUTCOME MEASURES Admission for retinal detachment, dropped nucleus, wound dehiscence, pseudophakic corneal edema, intraocular lens (IOL) dislocation, and postoperative endophthalmitis requiring surgery. RESULTS There were 129 982 cataract/lens procedures and 2087 (1.6%) complications. Complications fell almost 70% over the study period. Retinal detachment (n = 905; 0.70%) was most common, followed by IOL dislocation (n = 361; 0.28%), endophthalmitis (n = 228; 0.18%), wound dehiscence (n = 227; 0.17%), pseudophakic corneal edema (n = 207; 0.16%), and dropped nucleus (n = 159; 0.12%). The incidence of complications lessened over time, except for IOL dislocations, which has increased since 1995. Overall, the risk of complications after phacoemulsification halved since it was introduced in the late 1990s (incidence rate ratio, 0.52; 95% confidence interval, 0.37-0.74), whereas complications after extracapsular extraction (ECCE) have increased over recent years. CONCLUSIONS Cataract surgery remains an extremely safe procedure with comparatively few major complications. Changes in operative techniques have been accompanied by a significant decrease in complication rates over time, although the increase in IOL dislocations and complications after ECCE warrants further study. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Is Western Australia representative of other Australian States and Territories in terms of key socio-demographic and health economic indicators?

OBJECTIVE To evaluate the extent to which Western Australian (WA) represents the broader Australian population in terms of key socio-demographic and health economic indicators. METHODS We compared key demographic, social and health economic indicators across all Australian States and Territories from Australian government publications in the census years 1991-2006. Jurisdictional averages (JAs) were calculated as the mean (+/-s.d.) or median (+/-range). Observed jurisdiction indicators were compared with the JA and ranked according its representativeness of the JA. RESULTS WA was among the three closest jurisdictions to the national JA for all socio-demographic and health economic indicators examined, with the exception of uptake of private health insurance (ranked 6th) and per-capita health expenditure (ranked 5th). The Northern Territory and Australian Capital Territory were least representative for the majority of indicators. Excluding the proportions of people living in rural or remote areas (0-100%) and of indigenous origin (0.4-28.8%), variations in the indicators across the jurisdictions were relatively small. CONCLUSIONS Population differences between Australias States were small, whereas Australias Territories were least representative of the JA. WA was the most representative population of Australias eight jurisdictions and continues to be in a strong position to contribute to knowledge of the Australian health system that is applicable Australia-wide.

EFFECT OF CREATINE LOADING ON LONG-TERM SPRINT EXERCISE PERFORMANCE AND METABOLISM

PURPOSE This study examined whether creatine (Cr) supplementation could enhance long-term repeated-sprint exercise performance of approximately 80 min in duration. METHODS Fourteen active, but not well-trained, male subjects initially performed 10 sets of either 5 or 6 x 6 s maximal bike sprints, with varying recoveries (24, 54, or 84 s between sprints) over a period of 80 min. Work done (kJ) and peak power (W) were recorded for each sprint, and venous blood was collected preexercise and on four occasions during the exercise challenge. Muscle biopsies (vastus lateralis) were obtained preexercise as well as 0 min and 3 min postexercise. Subjects were then administered either 20 g.d-1 Cr.H2O (N = 7) or placebo (N = 7) for 5 d. Urine samples were collected for each 24 h of the supplementation period. Subjects were then retested using the same procedures as in test 1. RESULTS Total work done increased significantly (P < 0.05) from 251.7 +/- 18.4 kJ presupplementation to 266.9 +/- 19.3 kJ (6% increase) after Cr ingestion. No change was observed for the placebo group (254.0 +/- 10.4 kJ to 252.3 +/- 9.3 kJ). Work done also improved significantly (P < 0.05) during 6 x 6 s sets with 54-s and 84-s recoveries and approached significance (P = 0.052) in 5 x 6 s sets with 24-s recovery in the Cr condition. Peak power was significantly increased (P < 0.05) in all types of exercise sets after Cr loading. No differences were observed for any performance variables in the placebo group. Resting muscle Cr and PCr concentrations were significantly elevated (P < 0.05) after 5 d of Cr supplementation (Cr: 48.9%; PCr: 12.5%). Phosphocreatine levels were also significantly higher (P < 0.05) immediately and 3 min after the completion of exercise in the Cr condition. CONCLUSION The results of this study indicate that Cr ingestion (20 g.day-1 x 5 d) improved exercise performance during 80 min of repeated-sprint exercise, possibly due to an increased TCr store and improved PCr replenishment rate.

Age- and Sex-Specific Trends in the Incidence of Hospitalized Acute Coronary Syndromes in Western Australia

Background— The incidence of myocardial infarction has declined during the past 4 decades in many populations. However, there are limited population data measuring trends in acute coronary syndromes (ACS). We therefore examined temporal trends in the incidence of hospitalized ACS by age and sex in a population-based cohort. Methods and Results— The Western Australian Data Linkage System, a repository of linked administrative health data, was used to identify 29 421 incident ACS hospitalizations between 1996 and 2007. Poisson log-linear regression models were used to calculate incidence rate changes. Age-standardized incidence rates of ACS declined annually in men by 1.7% (95% confidence interval [CI], −2.1 to −1.3) and in women by 1.6% (95% CI, −2.1 to −1.0). These declining rates were underpinned by annual reductions in the incidence of unstable angina (men, −3.0%; 95% CI, −3.7 to −2.4; women, −2.5; 95% CI, −3.3 to −1.7), whereas annual changes in myocardial infarction incidence were less (men, −1.0%; 95% CI, −1.5 to −0.5; women, −0.8%; 95% CI, −1.6 to 0). However, the overall trends masked age group differences, with ACS incidence increasing annually in 35- to 54-year-old women (2.3%; 95% CI, 1.0 to 3.8), predominantly driven by increasing incidence of myocardial infarction. Conclusions— The age-standardized incidence of ACS decreased significantly in Western Australia from 1996 to 2007. However, an increase in ACS incidence in women ages 35 to 54 years is troubling and warrants further investigation.

Mental illness related disparities in diabetes prevalence, quality of care and outcomes: a population-based longitudinal study

BackgroundHealth care disparity is a public health challenge. We compared the prevalence of diabetes, quality of care and outcomes between mental health clients (MHCs) and non-MHCs.MethodsThis was a population-based longitudinal study of 139,208 MHCs and 294,180 matched non-MHCs in Western Australia (WA) from 1990 to 2006, using linked data of mental health registry, electoral roll registrations, hospital admissions, emergency department attendances, deaths, and Medicare and pharmaceutical benefits claims. Diabetes was identified from hospital diagnoses, prescriptions and diabetes-specific primary care claims (17,045 MHCs, 26,626 non-MHCs). Both univariate and multivariate analyses adjusted for socio-demographic factors and case mix were performed to compare the outcome measures among MHCs, category of mental disorders and non-MHCs.ResultsThe prevalence of diabetes was significantly higher in MHCs than in non-MHCs (crude age-sex-standardised point-prevalence of diabetes on 30 June 2006 in those aged ≥20 years, 9.3% vs 6.1%, respectively, P < 0.001; adjusted odds ratio (OR) 1.40, 95% CI 1.36 to 1.43). Receipt of recommended pathology tests (HbA1c, microalbuminuria, blood lipids) was suboptimal in both groups, but was lower in MHCs (for all tests combined; adjusted OR 0.81, 95% CI 0.78 to 0.85, at one year; and adjusted rate ratio (RR) 0.86, 95% CI 0.84 to 0.88, during the study period). MHCs also had increased risks of hospitalisation for diabetes complications (adjusted RR 1.20, 95% CI 1.17 to 1.24), diabetes-related mortality (1.43, 1.35 to 1.52) and all-cause mortality (1.47, 1.42 to 1.53). The disparities were most marked for alcohol/drug disorders, schizophrenia, affective disorders, other psychoses and personality disorders.ConclusionsMHCs warrant special attention for primary and secondary prevention of diabetes, especially at the primary care level.

Determinants of self-reported medicine underuse due to cost: a comparison of seven countries

Objectives To compare the predictors of self-reported medicine underuse due to cost across countries with different pharmaceutical subsidy systems and co-payments. Methods We analysed data from a 2007 survey of adults in Australia, Canada, Germany, the Netherlands, New Zealand (NZ), the United Kingdom (UK) and the United States (US). The predictors of underuse were calculated separately for each country using multivariate poisson regression. Results Reports of underuse due to cost varied from 3% in the Netherlands to 20% in the US. In Australia, Canada, NZ, the UK and the US, cost-related underuse was predicted by high out-of-pocket costs (RR range 2.0-4.6), below average income (RR range 1.9-3.1), and younger age (RR range 3.9-16.4). In all countries except Australia and the UK, history of depression was associated with cost-related underuse (RR range 1.2- 4.1). In Australia, Canada, Germany, the UK and the US lack of patient involvement in treatment decisions was associated with cost-related underuse (RR range 1.2-1.4). In Australia, Canada and NZ, indigenous persons more commonly reported underuse due to cost (RR range 2.1-2.9). Conclusions Cost-related underuse of medicines was least commonly reported in countries with the lowest out-of-pocket costs, the Netherlands and the UK. Countries with reduced co-payments or cost ceilings for low income patients showed the least disparity in rates of underuse between income groups. Despite differences in health insurance systems in these countries, age, ethnicity, depression, and involvement with treatment decisions were consistently predictive of underuse. There are opportunities for policy makers and clinicians to support medicine use in vulnerable groups.

The evolving epidemiology of hepatocellular carcinoma: A global perspective

Primary liver cancer, the majority of which are hepatocellular carcinomas, is now the second leading cause of cancer death worldwide. Hepatocellular carcinoma is a unique cancer that typically arises in the setting of chronic liver disease at a rate dependent upon the complex interplay between the host, disease and environmental factors. Infection with chronic hepatitis B or C virus is currently the dominant risk factor worldwide. However, changing lifestyle and environmental factors in western countries plus rising neonatal hepatitis B vaccination rates and decreasing exposure to dietary aflatoxins in developing countries are driving an evolution of the epidemiology of this cancer. An understanding of this change is crucial in combating the rising incidence currently being seen in western regions and will underpin the efforts to reduce the mortality rates associated with this cancer.