Hospital-level associations with 30-day patient mortality after cardiac surgery: a tutorial on the application and interpretation of marginal and multilevel logistic regression

Background: Marginal and multilevel logistic regression methods can estimate associations between hospital-level factors and patient-level 30-day mortality outcomes after cardiac surgery. However, it is not widely understood how the interpretation of hospital-level effects differs between these methods. Methods. The Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) registry provided data on 32,354 patients undergoing cardiac surgery in 18 hospitals from 2001 to 2009. The logistic regression methods related 30-day mortality after surgery to hospital characteristics with concurrent adjustment for patient characteristics. Results: Hospital-level mortality rates varied from 1.0% to 4.1% of patients. Ordinary, marginal and multilevel regression methods differed with regard to point estimates and conclusions on statistical significance for hospital-level risk factors; ordinary logistic regression giving inappropriately narrow confidence intervals. The median odds ratio, MOR, from the multilevel model was 1.2 whereas ORs for most patient-level characteristics were of greater magnitude suggesting that unexplained between-hospital variation was not as relevant as patient-level characteristics for understanding mortality rates. For hospital-level characteristics in the multilevel model, 80% interval ORs, IOR-80%, supplemented the usual ORs from the logistic regression. The IOR-80% was (0.8 to 1.8) for academic affiliation and (0.6 to 1.3) for the median annual number of cardiac surgery procedures. The width of these intervals reflected the unexplained variation between hospitals in mortality rates; the inclusion of one in each interval suggested an inability to add meaningfully to explaining variation in mortality rates. Conclusions: Marginal and multilevel models take different approaches to account for correlation between patients within hospitals and they lead to different interpretations for hospital-level odds ratios. © 2012 Sanagou et al; licensee BioMed Central Ltd

Investigation of hospital-level associations with adverse outcomes following cardiac surgery

While decreases in rates of mortality after cardiac surgery have been observed due to improvements in technology and health management, rates of adverse outcomes and complications following cardiac surgery are less clear in Australia and in particular how these rates relate to system factors. The aims of this thesis were to investigate the association of hospital-level characteristics with adverse outcomes after cardiac surgery after extending knowledge on the necessary first steps of patient-level prediction of these outcomes and the methodology of hierarchical modelling. This thesis aimed to find associations between hospital-level characteristics and patient outcome following cardiac surgery in Australia during 2001 – 2011. The patient-level information was provided from the Australian and New Zealand Society of Cardiac and Thoracic Surgeons registry and hospital-level information for 16 hospitals was provided by that registry and also the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation. In this thesis, in order to estimate the associations between hospital-level characteristics and adverse outcomes following cardiac surgery with the hierarchically structured data, patients within hospitals, marginal logistic regression using generalized estimating equations with an independent working correlation structure was used. The main findings of the studies carried out in this thesis were that hospital-level characteristics are not associated with renal failure and pneumonia following cardiac surgery in Australia in ways that we might expect. Of the available hospital factors measured, most did not exhibit an association with adverse outcomes. Of those that did, the risk of renal failure was higher among hospitals with the presence of nephrology expertise and the risk of pneumonia was higher among hospitals with more registered nurses per 100 ICU admissions and per ICU available bed. These findings were somewhat counter-intuitive and, in the context of the finding that no other measured markers of quality of care accounted for differences in renal failure or pneumonia incidence, suggesting that overall there is little evidence of hospital-level factors relating to adverse outcome risks in cardiac surgery in Australia

Investigation of hospital-level associations with adverse outcomes following cardiac surgery

While decreases in rates of mortality after cardiac surgery have been observed due to improvements in technology and health management, rates of adverse outcomes and complications following cardiac surgery are less clear in Australia and in particular how these rates relate to system factors. The aims of this thesis were to investigate the association of hospital-level characteristics with adverse outcomes after cardiac surgery after extending knowledge on the necessary first steps of patient-level prediction of these outcomes and the methodology of hierarchical modelling. This thesis aimed to find associations between hospital-level characteristics and patient outcome following cardiac surgery in Australia during 2001 – 2011. The patient-level information was provided from the Australian and New Zealand Society of Cardiac and Thoracic Surgeons registry and hospital-level information for 16 hospitals was provided by that registry and also the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation. In this thesis, in order to estimate the associations between hospital-level characteristics and adverse outcomes following cardiac surgery with the hierarchically structured data, patients within hospitals, marginal logistic regression using generalized estimating equations with an independent working correlation structure was used. The main findings of the studies carried out in this thesis were that hospital-level characteristics are not associated with renal failure and pneumonia following cardiac surgery in Australia in ways that we might expect. Of the available hospital factors measured, most did not exhibit an association with adverse outcomes. Of those that did, the risk of renal failure was higher among hospitals with the presence of nephrology expertise and the risk of pneumonia was higher among hospitals with more registered nurses per 100 ICU admissions and per ICU available bed. These findings were somewhat counter-intuitive and, in the context of the finding that no other measured markers of quality of care accounted for differences in renal failure or pneumonia incidence, suggesting that overall there is little evidence of hospital-level factors relating to adverse outcome risks in cardiac surgery in Australia

Key design considerations using a cohort stepped-wedge cluster randomised trial in evaluating community-based interventions : lessons learnt from an Australian domiciliary aged care intervention evaluation

The ‘stepped-wedge cluster randomised trial’ (SW-CRT) harbours promise when for ethical or practical reasons the recruitment of a control group is not possible or when a staggered implementation of an intervention is required. Yet SW-CRT designs can create considerable challenges in terms of methodological integration, implementation, and analysis. While cross-sectional methods in participants recruitment of the SW-CRT have been discussed in the literature the cohort method is a novel feature that has not been considered yet. This paper provides a succinct overview of the methodological, analytical, and practical aspects of cohort SW-CRTs.We discuss five issues that are of special relevance to SW-CRTs. First, issues relating to the design, secondly size of clusters and sample size; thirdly, dealing with missing data in the fourth place analysis; and finally, the advantages and disadvantages of SW-CRTs are considered. An Australian study employing a cohort SW-CRT to evaluate a domiciliary aged care intervention is used as case study. The paper concludes that the main advantage of the cohort SW-CRT is that the intervention rolls out to all participants. There are concerns about missing a whole cluster, and difficulty of completing clusters in a given time frame due to involvement frail older people. Cohort SW-CRT designs can be successfully used within public health and health promotion context. However, careful planning is required to accommodate methodological, analytical, and practical challenges

Key Design Considerations Using a Cohort Stepped-Wedge Cluster Randomised Trial in Evaluating Community-Based Interventions: Lessons Learnt from an Australian Domiciliary Aged Care Intervention Evaluation

The "stepped-wedge cluster randomised trial" (SW-CRT) harbours promise when for ethical or practical reasons the recruitment of a control group is not possible or when a staggered implementation of an intervention is required. Yet SW-CRT designs can create considerable challenges in terms of methodological integration, implementation, and analysis. While cross-sectional methods in participants recruitment of the SW-CRT have been discussed in the literature the cohort method is a novel feature that has not been considered yet. This paper provides a succinct overview of the methodological, analytical, and practical aspects of cohort SW-CRTs. We discuss five issues that are of special relevance to SW-CRTs. First, issues relating to the design, secondly size of clusters and sample size; thirdly, dealing with missing data in the fourth place analysis; and finally, the advantages and disadvantages of SW-CRTs are considered. An Australian study employing a cohort SW-CRT to evaluate a domiciliary aged care intervention is used as case study. The paper concludes that the main advantage of the cohort SW-CRT is that the intervention rolls out to all participants. There are concerns about missing a whole cluster, and difficulty of completing clusters in a given time frame due to involvement frail older people. Cohort SW-CRT designs can be successfully used within public health and health promotion context. However, careful planning is required to accommodate methodological, analytical, and practical challenges

Mobile phone use and incidence of brain tumour histological types, grading or anatomical location: A populationbased ecological study

Objective Some studies have reported increasing trends in certain brain tumours and a possible link with mobile phone use has been suggested. We examined the incidence time trends of brain tumour in Australia for three distinct time periods to ascertain the influence of improved diagnostic technologies and increase in mobile phone use on the incidence of brain tumours. Design In a population-based ecological study, we examined trends of brain tumour over the periods 1982- 1992, 1993-2002 and 2003-2013. We further compared the observed incidence during the period of substantial mobile phone use (2003-2013) with predicted (modelled) incidence for the same period by applying various relative risks, latency periods and mobile phone use scenarios. Setting National Australian incidence registration data on primary cancers of the brain diagnosed between 1982 and 2013. Population 16 825 eligible brain cancer cases aged 20- 59 from all of Australia (10 083 males and 6742 females). Main outcome measures Annual percentage change (APC) in brain tumour incidence based on Poisson regression analysis. Results The overall brain tumour rates remained stable during all three periods. There was an increase in glioblastoma during 1993-2002 (APC 2.3, 95% CI 0.8 to 3.7) which was likely due to advances in the use of MRI during that period. There were no increases in any brain tumour types, including glioma (-0.6, -1.4 to 0.2) and glioblastoma (0.8, -0.4 to 2.0), during the period of substantial mobile phone use from 2003 to 2013. During that period, there was also no increase in glioma of the temporal lobe (0.5, -1.3 to 2.3), which is the location most exposed when using a mobile phone. Predicted incidence rates were higher than the observed rates for latency periods up to 15 years. Conclusions In Australia, there has been no increase in any brain tumour histological type or glioma location that can be attributed to mobile phones

Adoption of respiratory motion management in radiation therapy

Background and Purpose: A survey on the patterns of practice of respiratory motion management (MM) was distributed to 111 radiation therapy facilities to inform the development of an end-to-end dosimetry audit including respiratory motion. Materials and methods: The survey (distributed via REDCap) asked facilities to provide information specific to the combinations of MM techniques (breath-hold gating – BHG, internal target volume – ITV, free-breathing gating – FBG, mid-ventilation – MidV, tumour tracking – TT), sites treated (thorax, upper abdomen, lower abdomen), and fractionation regimes (conventional, stereotactic ablative body radiation therapy – SABR) used in their clinic. Results: The survey was completed by 78% of facilities, with 98% of respondents indicating that they used at least one form of MM. The ITV approach was common to all MM-users, used for thoracic treatments by 89% of respondents, and upper and lower abdominal treatments by 38%. BHG was the next most prevalent (41% of MM users), with applications in upper abdominal and thoracic treatment sites (28% vs 25% respectively), but minimal use in the lower abdomen (9%). FBG and TT were utilised sparingly (17%, 7% respectively), and MidV was not selected at all. Conclusions: Two distinct treatment workflows (including use of motion limitation, imaging used for motion assessment, dose calculation, and image guidance procedures) were identified for the ITV and BHG MM techniques, to form the basis of the initial audit. Thoracic SABR with the ITV approach was common to nearly all respondents, while upper abdominal SABR using BHG stood out as more technically challenging. Other MM techniques were sparsely used, but may be considered for future audit development

Measuring professionalism in residency training programs in Iran

Background and aim: To assess the Farsi (Persian) translated and modified version of the questionnaire of the American Board of Internal Medicine (ABIM) for measuring professionalism, and also, measuring the professional attitudes and behaviors associated with the medical residency training environment in Iran

Bolus administration of intravenous lidocaine reduces pain after an elective caesarean section: Findings from a randomised, double-blind, placebo-controlled trial

We conducted a randomised double-blind, placebo-controlled trial to assess whether a bolus dose of lidocaine during the induction of general anaesthesia would reduce postoperative pain over 24 h. Level of satisfaction with pain control at 48 h after surgery and Apgar score were also examined. A total of 100 women aged 20–35 years, who were candidates for elective caesarean section (CS) were randomised to receive either 1.5 mg/kg lidocaine or placebo during the induction of general anaesthesia. Results showed that lidocaine decreased pain intensity over 24 h after surgery (p < .001), and decreased postoperative morphine consumption from median (range) of 3.79 (0–9) mg in the placebo group to 0 (0–12) mg and in the lidocaine group (p <.001). Lidocaine was not associated with postoperative nausea and vomiting or any side effects in women and newborn babies. We conclude that a small bolus dose of lidocaine attenuates postoperative pain, thus reducing the requirement for opioid consumption in the postoperative period.Impact statement • With its anti-inflammatory, anti-hyperalgesic and analgesic properties, intravenous perioperative lidocaine infusion (IVLI) has been used for optimal postoperative care in different surgeries. Limited evidence suggests that IVLI may be a useful adjuvant during general anaesthesia. There is a report of a positive effect on several outcomes after surgery including postoperative pain over 24 h after laparoscopic abdominal surgery or open abdominal surgery. However, there was a paucity of information regarding the efficacy of a bolus dose of lidocaine in patients undergoing caesarean section (CS). In this randomized, placebo-controlled trial the use of a bolus dose of 1.5 mg/kg lidocaine 2%, compared with placebo, during the induction of general anaesthesia for elective CS resulted in a significant decrease in postoperative pain score as well as decreased postoperative morphine consumption over 24 h. Lidocaine use was not associated with any side effect in participants and newborns. • This study provides the first evidence that a bolus dose of lidocaine may be a safe and simple alternative therapeutic intervention for enhanced postoperative recovery in terms of pain and postoperative opioid consumption. Future studies are needed to examine pain reducing effect of perioperative bolus dose of lidocaine after CS under spinal or epidural anesthesia