The impact of post-operative sepsis on mortality after hospital discharge among elective surgical patients: a population-based cohort study

Our aim in the present study was to assess the mortality impact of hospital-acquired post-operative sepsis up to 1 year after hospital discharge among adult non-short-stay elective surgical patients.We conducted a population-based, retrospective cohort study of all elective surgical patients admitted to 82 public acute hospitals between 1 January 2007 and 31 December 2012 in New South Wales, Australia. All adult elective surgical admission patients who stayed in hospital for ≥4 days and survived to discharge after post-operative sepsis were identified using the Admitted Patient Data Collection records linked with the Registry of Births, Deaths, and Marriages. We assessed post-discharge mortality rates at 30 days, 60 days, 90 days and 1 year and compared them with those of patients without post-operative sepsis.We studied 144,503 survivors to discharge. Of these, 1857 (1.3%) had experienced post-operative sepsis. Their post-discharge mortality rates at 30 days, 60 days, 90 days and 1 year were 4.6%, 6.7%, 8.1% and 13.5% (vs 0.7%, 1.2%, 1.5% and 3.8% in the non-sepsis cohort), respectively (P < 0.0001 for all). After adjustment for patient and hospital characteristics, post-operative sepsis remained independently associated with a higher mortality risk (30-day mortality HR 2.75, 95% CI 2.14-3.53; 60-day mortality HR 2.45, 95% CI 1.94-3.10; 90-day mortality HR 2.31, 95% CI 1.85-2.87; 1-year mortality HR 1.71, 95% CI 1.46-2.00). Being older than 75 years of age (HR 3.50, 95% CI 1.56-7.87) and presence of severe/very severe co-morbidities as defined by Charlson co-morbidity index (severe vs normal HR 2.05, 95% CI 1.45-2.89; very severe vs normal HR 2.17, 95% CI 1.49-3.17) were the only other significant independent predictors of increased 1-year mortality.Among elective surgical patients, post-operative sepsis is independently associated with increased post-discharge mortality up to 1 year after hospital discharge. This risk is particularly high in the first month, in older age patients and in the presence of severe/very severe co-morbidities. This high-risk population can be targeted for interventions.Lixin Ou, Jack Chen, Ken Hillman, Arthas Flabouris, Michael Parr, Hassan Assareh and Rinaldo Bellom

Change Point Estimation in Monitoring Survival Time

Precise identification of the time when a change in a hospital outcome has occurred enables clinical experts to search for a potential special cause more effectively. In this paper, we develop change point estimation methods for survival time of a clinical procedure in the presence of patient mix in a Bayesian framework. We apply Bayesian hierarchical models to formulate the change point where there exists a step change in the mean survival time of patients who underwent cardiac surgery. The data are right censored since the monitoring is conducted over a limited follow-up period. We capture the effect of risk factors prior to the surgery using a Weibull accelerated failure time regression model. Markov Chain Monte Carlo is used to obtain posterior distributions of the change point parameters including location and magnitude of changes and also corresponding probabilistic intervals and inferences. The performance of the Bayesian estimator is investigated through simulations and the result shows that precise estimates can be obtained when they are used in conjunction with the risk-adjusted survival time CUSUM control charts for different magnitude scenarios. The proposed estimator shows a better performance where a longer follow-up period, censoring time, is applied. In comparison with the alternative built-in CUSUM estimator, more accurate and precise estimates are obtained by the Bayesian estimator. These superiorities are enhanced when probability quantification, flexibility and generalizability of the Bayesian change point detection model are also considered

Incidences and variations of hospital acquired venous thromboembolism in Australian hospitals: a population-based study.

Background: Data on hospital-acquired venous thromboembolism (HA-VTE) incidence, case fatality rate and variation amongst patient groups and health providers is lacking. We aim to explore HA-VTE incidences, associated mortality, trends and variations across all acute hospitals in New South Wales (NSW)-Australia. Methods: A population-based study using all admitted patients (aged 18–90 with a length of stay of at least two days and not transferred to another acute care facility) in 104 NSW acute public and private hospitals during 2002–2009. Poisson mixed models were used to derive adjusted rate ratios (IRR) in presence of patient and hospital characteristics. Results: Amongst, 3,331,677 patients, the incidence of HA-VTE was 11.45 per 1000 patients and one in ten who developed HA-VTE died in hospital. HA-VTE incidence, initially rose, but subsequently declined, whereas case fatality rate consistently declined by 22 % over the study period. Surgical patients were 128 % (IRR = 2.28, 95 % CI: 2.19–2.38) more likely to develop HA-VTE, but had similar case fatality rates compared to medical patients. Private hospitals, in comparison to public hospitals had a higher incidence of HA-VTE (IRR = 1.76; 95 % CI: 1.42–2.18) for medical patients. However, they had a similar incidence (IRR = 0.91; 95 % CI: 0.75–1.11), but a lower mortality (IRR = 0.59; 95 % CI: 0.47–0.75) amongst surgical patients. Smaller public hospitals had a lower HA-VTE incidence rate compared to larger hospitals (IRR 1.71). Hospitals with a lower reported HA-VTE incidence tended to have a higher HA-VTE case fatality rate. Conclusion: Despite the decline in HA-VTE incidence and case fatality, there were large variations in incidents between medical and surgical patients, public and private hospitals, and different hospital groups. The causes of such differences warrant further investigation and may provide potential for targeted interventions and quality improvement initiatives.Hassan Assareh, Jack Chen, Lixin Ou, Ken Hillman and Arthas Flabouri

Rate of venous thromboembolism among surgical patients in Australian hospitals: a multicentre retrospective cohort study

OBJECTIVES: Despite the burden of venous thromboembolism (VTE) among surgical patients on health systems in Australia, data on VTE incidence and its variation within Australia are lacking. We aim to explore VTE and subsequent mortality rates, trends and variations across Australian acute public hospitals. SETTING: A large retrospective cohort study using all elective surgical patients in 82 acute public hospitals during 2002-2009 in New South Wales, Australia. PARTICIPANTS: Patients underwent elective surgery within 2 days of admission, aged between 18 and 90 years, and who were not transferred to another acute care facility; 4 362 624 patients were included. OUTCOME MEASURES: VTE incidents were identified by secondary diagnostic codes. Poisson mixed models were used to derive adjusted incidence rates and rate ratios (IRR). RESULTS: 2/1000 patients developed postoperative VTE. VTE increased by 30% (IRR=1.30, CI 1.19 to 1.42) over the study period. Differences in the VTE rates, trends between hospital peer groups and between hospitals with the highest and those with the lowest rates were significant (between-hospital variation). Smaller hospitals, accommodated in two peer groups, had the lowest overall VTE rates (IRR=0.56:0.33 to 0.95; IRR=0.37:0.23 to 0.61) and exhibited a greater increase (64% and 237% vs 19%) overtime and greater between-hospital variations compared to larger hospitals (IRR=8.64:6.23 to 11.98; IRR=8.92:5.49 to 14.49 vs IRR=3.70:3.32 to 4.12). Mortality among patients with postoperative VTE was 8% and remained stable overtime. No differences in post-VTE death rates and trends were seen between hospital groups; however, larger hospitals exhibited less between-hospital variations (IRR=1.78:1.30 to 2.44) compared to small hospitals (IRR>23). Hospitals performed differently in prevention versus treatment of postoperative VTE. CONCLUSIONS: VTE incidence is increasing and there is large variation between-hospital and within-hospital peer groups suggesting a varied compliance with VTE preventative strategies and the potential for targeted interventions and quality improvement opportunities.Hassan Assareh, Jack Chen, Lixin Ou, Stephanie J Hollis, Kenneth Hillman, Arthas Flabouri

Geographic variation of Failure-to-Rescue in public acute hospitals in New South Wales, Australia

Despite the wide acceptance of Failure-to-Rescue (FTR) as a patient safety indicator (defined as the deaths among surgical patients with treatable complications), no study has explored the geographic variation of FTR in a large health jurisdiction. Our study aimed to explore the spatiotemporal variations of FTR rates across New South Wales (NSW), Australia. We conducted a population-based study using all admitted surgical patients in public acute hospitals during 2002-2009 in NSW, Australia. We developed a spatiotemporal Poisson model using Integrated Nested Laplace Approximation (INLA) methods in a Bayesian framework to obtain area-specific adjusted relative risk. Local Government Area (LGA) was chosen as the areal unit. LGA-aggregated covariates included age, gender, socio-economic and remoteness index scores, distance between patient residential postcode and the treating hospital, and a quadratic time trend. We studied 4,285,494 elective surgical admissions in 82 acute public hospitals over eight years in NSW. Around 14% of patients who developed at least one of the six FTR-related complications (58,590) died during hospitalization. Of 153 LGAs, patients who lived in 31 LGAs, accommodating 48% of NSW patients at risk, were exposed to an excessive adjusted FTR risk (10% to 50%) compared to the state-average. They were mostly located in state's centre and western Sydney. Thirty LGAs with a lower adjusted FTR risk (10% to 30%), accommodating 8% of patients at risk, were mostly found in the southern parts of NSW and Sydney east and south. There were significant spatiotemporal variations of FTR rates across NSW over an eight-year span. Areas identified with significantly high and low FTR risks provide potential opportunities for policy-makers, clinicians and researchers to learn from the success or failure of adopting the best care for surgical patients and build a self-learning organisation and health system.Hassan Assareh, Lixin Ou, Jack Chen, Kenneth Hillman, Arthas Flabouris, Stephanie J. Holli

Comparison of Allelopathic Effect of Zataria Multiflora on the Germination and Growth Features of Cymbopogen Olivieri and Stipa Arabica Seedlings 1

Abstract: Application of native and genetically modified species is one of the main approaches to revival and modification of ranches. But in the mean time, it should be noted that those species that are compatible to each other should be used in vegetation expansion projects. Shiraz oregano (Zataria Multiflora) is from among those plants which could cause allelopathic effects due to their various chemical compositions. Hence, due to profusion of this plant throughout the Khalil Beig ranch of Arsanjan, and the considerable amount of Stipa Arabica and Cymbopogen Olivieri in the adjacent areas to this ranch that are consumed by the livestock, it was decided to study the possibility of applying the aforesaid species for expansion of vegetation throughout the Khalil Beig ranch. To this end, an investigation was conducted in the greenhouse environment using the soil taken from the habitat of Shiraz oregano. Underground and aerial parts of this plant were collected and extracts of 25, 50, 75 and 100 percent as well as 50 and 100 % densities were obtained from aerial and underground parts, respectively. Also, a bittern was considered as the prototype (distilled water). Seeds of Sarabica and C.olivieri were cultivated in flower pots containing the soils of oregano habitat and were irrigated using the abovementioned bitterns throughout the entire study. The investigations lasted for 5 weeks and the germination and growth rates of seedlings were recorded on a daily basis. In the end, characteristics of both species such as percentage of germination, length of stem, length of root, wet weight of stem, wet weight of root, dry weight of stem and dry weight of root affected by different density percentages of Shiraz oregano extract were analyzed through variance analysis. The Duncan test was applied for comparison of means. The results represented the preventive effect of compositions existing in Shiraz oregano on the studied features and the less vulnerability of S.arabica as compared with the C.olivieri

Trends and variations in the rates of hospital complications, failure-to-rescue and 30-day mortality in surgical patients in New South Wales, Australia, 2002-2009

BACKGROUND: Despite the increased acceptance of failure-to-rescue (FTR) as an important patient safety indicator (defined as the percentage of deaths among surgical patients with treatable complications), there has not been any large epidemiological study reporting FTR in an Australian setting nor any evaluation on its suitability as a performance indicator. METHODS: We conducted a population-based study on elective surgical patients from 82 public acute hospitals in New South Wales, Australia between 2002 and 2009, exploring the trends and variations in rates of hospital complications, FTR and 30-day mortality. We used Poisson regression models to derive relative risk ratios (RRs) after adjusting for a range of patient and hospital characteristics. RESULTS: The average rates of complications, FTR and 30-day mortality were 13.8 per 1000 admissions, 14.1% and 6.1 per 1000 admission, respectively. The rates of complications and 30-day mortality were stable throughout the study period however there was a significant decrease in FTR rate after 2006, coinciding with the establishment of national and state-level peak patient safety agencies. There were marked variations in the three rates within the top 20% of hospitals (best) and bottom 20% of hospitals (worst) for each of the four peer-hospital groups. The group comprising the largest volume hospitals (principal referral/teaching hospitals) had a significantly higher rate of FTR in comparison to the other three groups of smaller-sized peer hospital groups (RR = 0.78, 0.57, and 0.61, respectively). Adjusted rates of complications, FTR and 30-day mortality varied widely for individual surgical procedures between the best and worst quintile hospitals within the principal referral hospital group. CONCLUSIONS: The decrease in FTR rate over the study period appears to be associated with a wide range of patient safety programs. The marked variations in the three rates between- and within- peer hospital groups highlight the potential for further quality improvement intervention opportunities.Lixin Ou, Jack Chen, Hassan Assareh, Stephanie J. Hollis, Ken Hillman, Arthas Flabouri

Meta-review of the effectiveness of computerised CBT in treating depression

<p>Abstract</p> <p>Background</p> <p>Several computerised cognitive behaviour therapy (cCBT) packages are now available to treat mild to moderate depression with or without anxiety. These have been usually been reviewed alongside cCBT for a wide range of psychological problems. Here, we single out the results of these reviews for the most common mental disorder, mild to moderate depression. The aim of this paper is to evaluate the quality of existing reviews and to enable reliable comparisons of alternative computer packages for the same patient group.</p> <p>Methods</p> <p>A thorough search and analysis of reviews of efficacy of cCBT published between 1999 and February 2011.</p> <p>Results</p> <p>The search yielded twelve systematic reviews from ten studies covering depression. Their methodology is appraised and selected findings are presented here.</p> <p>Conclusions</p> <p>The meta-review supports the efficacy of cCBT for treatment of depression; however there is limited information on different approaches, whose relative cost-effectiveness remains to be demonstrated. Suggestions are made for future studies in the field.</p

Risk-adjusted CUSUM control charts for shared frailty survival models with application to hip replacement outcomes: a study using the NJR dataset

Background:  Continuous monitoring of surgical outcomes after joint replacement is needed to detect which brands’ components have a higher than expected failure rate and are therefore no longer recommended to be used in surgical practice. We developed a monitoring method based on cumulative sum (CUSUM) chart specifically for this application.  Methods:  Our method entails the use of the competing risks model with the Weibull and the Gompertz hazard functions adjusted for observed covariates to approximate the baseline time-to-revision and time-to-death distributions, respectively. The correlated shared frailty terms for competing risks, corresponding to the operating unit, are also included in the model. A bootstrap-based boundary adjustment is then required for risk-adjusted CUSUM charts to guarantee a given probability of the false alarm rates. We propose a method to evaluate the CUSUM scores and the adjusted boundary for a survival model with the shared frailty terms. We also introduce a unit performance quality score based on the posterior frailty distribution. This method is illustrated using the 2003-2012 hip replacement data from the UK National Joint Registry (NJR). Results:  We found that the best model included the shared frailty for revision but not for death. This means that the competing risks of revision and death are independent in NJR data. Our method was superior to the standard NJR methodology. For one of the two monitored components, it produced alarms four years before the increased failure rate came to the attention of the UK regulatory authorities. The hazard ratios of revision across the units varied from 0.38 to 2.28. Conclusions:  An earlier detection of failure signal by our method in comparison to the standard method used by the NJR may be explained by proper risk-adjustment and the ability to accommodate time-dependent hazards. The continuous monitoring of hip replacement outcomes should include risk adjustment at both the individual and unit level