Hanh Ngo

Injectable and implantable sustained release naltrexone in the treatment of opioid addiction

Sustained release technologies for administering the opioid antagonist naltrexone (SRX) have the potential to assist opioid‐addicted patients in their efforts to maintain abstinence from heroin and other opioid agonists. Recently, reliable SRX formulations in intramuscular or implantable polymers that release naltrexone for 1–7 months have become available for clinical use and research. This qualitative review of the literature provides an overview of the technologies currently available for SRX and their effectiveness in reducing opioid use and other relevant outcomes. The majority of studies indicate that SRX is effective in reducing heroin use, and the most frequently studied SRX formulations have acceptable adverse events profiles. Registry data indicate a protective effect of SRX on mortality and morbidity. In some studies, SRX also seems to affect other outcomes, such as concomitant substance use, vocational training attendance, needle use, and risk behaviour for blood‐borne diseases such as hepatitis or human immunodeficiency virus. There is a general need for more controlled studies, in particular to compare SRX with agonist maintenance treatment, to study combinations of SRX with behavioural interventions, and to study at‐risk groups such as prison inmates or opioid‐addicted pregnant patients. The literature suggests that sustained release naltrexone is a feasible, safe and effective option for assisting abstinence efforts in opioid addiction.

Hospital psychiatric comorbidity and its role in heroin dependence treatment outcomes using naltrexone implant or methadone maintenance

Our objectives were to (i) estimate lifetime prevalence of psychiatric comorbidity in heroin users and (ii) evaluate psychiatric comorbidity as a predictor of drug-related hospitalization following either (a) methadone maintenance or (b) naltrexone implant treatment. Our method consisted of retrospective, longitudinal follow-up using prospectively collected, state-wide hospital data on two cohorts of heroin-dependent persons (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), first time treated with naltrexone implant (n = 317) or methadone (n = 521) between January 2001 and December 2002. Outcome measures were: (i) prevalence of comorbidity and (ii) changes in risk for drug-related hospitalization – categorized as ‘opioid drugs’, ‘non-opioid drugs’, and ‘any drug’ – to 3.5 years post-treatment. Nearly 32% had psychiatric comorbidity. In both cohorts, comorbid patients generally had significantly greater odds of drug-related hospitalization pre-treatment compared with non-comorbid counterparts. These differences generally reduced in magnitude post-treatment. Comorbid naltrexone-treated patients had less ‘opioid’ and ‘any drug’ related hospitalizations post-treatment. Similarly, comorbid methadone-treated patients had reduced hospitalization risk for ‘non-opioid’ and ‘any drug’ related hospitalization post-treatment. Treatment of persons without depression, anxiety, or personality disorder with naltrexone implant was associated with increased risk of ‘non-opioid’ drug-related hospitalization, while methadone treatment was associated with increased risk of ‘opioid’ drug-related hospitalization. Although comorbid heroin users entered treatment with significantly higher risk of drug-related hospitalization than non-comorbid users, substantial reductions in drug-related hospitalization were generally observed post-treatment. This challenges the view that comorbidity predicts poor drug treatment outcomes. Differences in research methodology were noted; recommendation for rigorous analytical methodology in future research on assessing treatment outcomes was accordingly offered.

Plasma cholesterol levels continue to decline despite the rising prevalence of obesity: population trends in Perth, Western Australia, 1980–1999

Background The rising prevalence of obesity and its putative impact on coronary risk factors threatens the sustained decline in the incidence of coronary heart disease. An understanding of the temporal relationship between obesity and other risk factors is required. Design Independent cross-sectional surveys. Methods We analysed standardized data from five population surveys of risk factors involving Perth men (n = 2767) and women (n = 2833) aged 35–64 years from 1980 to 1999. Trends in plasma cholesterol, BMI and waist-hip ratio were assessed. Results Striking annual increases were noted in BMI (and waist-hip ratio) of 0.075 kg/m2 in men and 0.083 kg/m2 in women (each P < 0.0001), approximating an 0.8% annual rise in the prevalence of overweight. In contrast, annual mean total cholesterol fell by 0.024 mmol/l in men and 0.030 mmol/l in women (both P < 0.0001), adjusted for confounders. Similarly, the prevalence of cholesterol ≥ 6.5 mmol/l declined an average of 0.6% per annum in men [odds ratio (OR) = 0.970, 95% confidence interval (CI) 0.954–0.985, P = 0.0002)] and by 0.9% in women (OR = 0.955, 95% CI 0.938–0.971, P < 0.0001). Decreases in cholesterol were associated with a downward population shift and increasing awareness and treatment of high cholesterol among the elderly. Conclusions Despite rapid increases in adult obesity, plasma mean cholesterol levels have fallen, due possibly to both dietary changes and greater awareness and treatment of high cholesterol in some individuals. This finding fails to confirm a positive association between trends in obesity and plasma cholesterol in the general population.

Biodegradability of naltrexone-poly(DL) lactide implants in vivo assessed under ultrasound in humans.

Ultrasound was used to assess the in vivo biodegradability of a sustained release poly(DL)lactide naltrexone implant in 71 persons previously treated for heroin dependence. We assessed 139 implant sites ranging from 2 to 1808 days post implant. Ultrasound assessment showed that implant tablets were initially well demarcated from each other and from the surrounding tissues. Biodegradation resulted in less demarcated tablets followed by clumping into a single mass‐like structure. This mass subsequently dispersed by approximately 1201 days post implant with no implant material visualized by ultrasound. The biodegradation was also assessed by visual clinical examination and palpation of the implant site as well as patient self‐report. These measures were generally well correlated with ultrasound results. Clinical assessment of the biodegradation process concluded that the implant changed from ‘firm’ to ‘less firm’ and from ‘initial square edge’ to ‘rounded edge’ tablets. Collectively, these data provide direct evidence of the in vivo absorption of the Go Medical implant over time, and its biodegradability in humans.

Impact of the Four-Hour Rule in Western Australian hospitals: Trend analysis of a large record linkage study 2002-2013

Background In 2009, the Western Australian (WA) Government introduced the Four-Hour Rule (FHR) program. The policy stated that most patients presenting to Emergency Departments (EDs) were to be seen and either admitted, transferred, or discharged within 4 hours. This study utilised de-identified data from five participating hospitals, before and after FHR implementation, to assess the impact of the FHR on several areas of ED functioning. Methods A state (WA) population-based intervention study design, using longitudinal data obtained from administrative health databases via record linkage methodology, and interrupted time series analysis technique. Findings There were 3,214,802 ED presentations, corresponding to 1,203,513 ED patients. After the FHR implementation, access block for patients admitted through ED for all five sites showed a significant reduction of up to 13.2% (Rate Ratio 0.868, 95%CI 0.814, 0.925) per quarter. Rate of ED attendances for most hospitals continued to rise throughout the entire study period and were unaffected by the FHR, except for one hospital. Pattern of change in ED re-attendance rate post-FHR was similar to pre-FHR, but the trend reduced for two hospitals. ED occupancy was reduced by 6.2% per quarter post-FHR for the most ‘crowded’ ED. ED length of stay and ED efficiency improved in four hospitals and deteriorated in one hospital. Time to being seen by ED clinician and Did-Not-Wait rate improved for some hospitals. Admission rates in post-FHR increased, by up to 1% per quarter, for two hospitals where the pre-FHR trend was decreasing. Conclusions The FHR had a consistent effect on ‘flow’ measures: significantly reducing ED overcrowding and access block and enhancing ED efficiency. Time-based outcome measures mostly improved with the FHR. There is some evidence of increased ED attendance, but no evidence of increased ED re-attendance. Effects on patient disposition status were mixed. Overall, this reflects the value of investing resources into the ED/hospital system to improve efficiency and patient experience. Further research is required to illuminate the exact mechanisms of the effects of FHR on the ED and hospital functioning across Australia.

Opting for rural practice: the influence of medical student origin, intention and immersion experience

Objective: To compare the influence of rural background, rural intent at medical school entry, and Rural Clinical School (RCS) participation on the likelihood of later participation in rural practice.

Disaster risk education of final year high school students requires a partnership with families and charity organizations: an international cross-sectional survey

UNLABELLED Introduction The aim of disaster reduction education (DRE) is to achieve behavioral change. Over the past two decades, many efforts have been directed towards this goal, but educational activities have been developed based on unverified assumptions. Further, the literature has not identified any significant change towards disaster preparedness at the individual level. In addition, previous research suggests that change is dependent on multiple independent predictors. It is difficult to determine what specific actions DRE might result in; therefore, the preamble of such an action, which is to have discussions about it, has been chosen as the surrogate outcome measure for DRE success. This study describes the relationship of the perceived entity responsible for disaster education, disaster education per se, sex, and country-specific characteristics, with students discussing disasters with friends and family as a measure of proactive behavioral change in disaster preparedness. METHODS A total of 3,829 final year high school students participated in an international, multi-center prospective, cross-sectional study using a validated questionnaire. Nine countries with different levels of disaster exposure risk and economic development were surveyed. Regression analyses examined the relationship between the likelihood of discussing disasters with friends and family (dependent variable) and a series of independent variables. RESULTS There was no statistically significant relationship between a single entity responsible for disaster education and discussions about potential hazards and risks with friends and/or family. While several independent predictors showed a significant main effect, DRE through school lessons in interaction with Family & Charity Organizations had the highest predictive value. CONCLUSIONS Disaster reduction education might require different delivery channels and methods and should engage with the entities with which the teenagers are more likely to collaborate. Codreanu TA , Celenza A , Ngo H . Disaster risk education of final year high school students requires a partnership with families and charity organizations: an international cross-sectional survey. Prehosp Disaster Med. 2016;31(3):242-254.

Assessing the usefulness of health data linkage in obtaining adverse event data in a randomised controlled trial of oral and implant naltrexone in the treatment of heroin dependence

Background The completeness of self-reported serious adverse events (SAEs) in clinical trials can be reduced by inaccuracies in subject reporting and lost to follow-up. Purpose This study assesses the usefulness of a health data linkage system in obtaining SAE data in a randomised controlled study of oral and implant naltrexone. Methods SAEs were collected from 68 heroin-dependent subjects during a randomised controlled trial of oral and implant naltrexone with follow-up to 26 weeks. Patient self-report data were cross-matched against hospital and emergency department (ED) attendances for the same period using a health data linkage system. Results A total of 29 hospital admissions and 74 ED attendances were identified using health data linkage. Of these, 12 (41.4%) hospital admissions and 50 (67.7%) of ED attendances had not been reported as SAE in the randomised controlled trial. In subjects participating in the trial at the time of the event, there was a 1.25-fold increase in the number of hospital admissions and a 2.25-fold increase in the number of ED attendances recorded using data linkage. Overall (including withdrawn subjects or those lost to follow-up), there was a 1.71-fold increase in hospital admission and a 3.09-fold increase in ED attendance recorded. Limitations The use of data linkage should not be used as a replacement for thorough follow-up, as the datasets can take substantial periods to update, making them a poor substitute for real-time follow-up. Additionally, some SAEs such as life-threatening events that do not involve ED or hospital attendance may be overlooked as would SAEs that occurred outside the dataset’s range, for example, interstate or overseas. Conclusions Health data linkage can be used to effectively reduce the extent of missing health data in a clinical trial.

Reasons for Removal of Emergency Department–Inserted Peripheral Intravenous Cannulae in Admitted Patients: A Retrospective Medical Chart Audit in Australia

It has been reported that the peripheral intravenous cannula (PIVC) is the first choice of vascular access device for patient treatment in the emergency department (ED). The number of PIVC insertions in our Australian ED is more than 35,000 per year. Concern arises when ED-inserted PIVCs are used exclusively for blood sampling because this may lead to unused PIVCs being left in situ after patients are transferred to the ward, increasing risk of infection. The rate of unused or idle PIVCs inserted in the ED has been reported at 45%-50%. PIVC insertions in the ED have been identified as a cause for phlebitis and bacteremia, leading to their premature failure. Analysis of 5 years of prospective data from 2 hospitals in Australia found a high incidence of catheter-related Staphylococcus aureus bloodstream infections with 39.6% of such infections associated with PIVCs inserted in the ED. As a result, routine PIVC replacement should be considered after 24 hours for PIVCs inserted under emergent conditions 6 and after 96 hours for those inserted under nonemergent conditions. These worrying statistics prompted the design of the current study that was performed to investigate how and why PIVCs are used in the ED, and during the subsequent hospital admission, as well as the documented rationale for removal of ED-inserted PIVCs by ward staff. To our knowledge, there is no prior study investigating this phenomenon.

Impact of the National Emergency Access Target policy on emergency departments’ performance: A time-trend analysis for New South Wales, Australian Capital Territory and Queensland: IMPACT OF FOUR HOUR NEAT POLICY ON ED PERFORMANCE

To evaluate the impact of the Australian National Emergency Access Target (NEAT) policy introduced in 2012 on ED performance.