Meta-analysis for individual participant data with a continuous exposure: A case study

OBJECTIVE: Methods for meta-analysis of studies with individual participant data and continuous exposure variables are well described in the statistical literature but are not widely used in clinical and epidemiological research. The purpose of this case study is to make the methods more accessible. STUDY DESIGN AND SETTING: A two-stage process is demonstrated. Response curves are estimated separately for each study using fractional polynomials. The study-specific curves are then averaged pointwise over all studies at each value of the exposure. The averaging can be implemented using fixed effects or random effects methods. RESULTS: The methodology is illustrated using samples of real data with continuous outcome and exposure data and several covariates. The sample data set, segments of Stata and R code, and outputs are provided to enable replication of the results. CONCLUSION: These methods and tools can be adapted to other situations, including for time-to-event or categorical outcomes, different ways of modelling exposure-outcome curves, and different strategies for covariate adjustment

Measures of kidney function by minimally invasive techniques correlate with histological glomerular damage in SCID mice with adriamycin-induced nephropathy

Maximising the use of preclinical murine models of progressive kidney disease as test beds for therapies ideally requires kidney function to be measured repeatedly in a safe, minimally invasive manner. To date, most studies of murine nephropathy depend on unreliable markers of renal physiological function, exemplified by measuring blood levels of creatinine and urea, and on various end points necessitating sacrifice of experimental animals to assess histological damage, thus counteracting the principles of Replacement, Refinement and Reduction. Here, we applied two novel minimally invasive techniques to measure kidney function in SCID mice with adriamycin-induced nephropathy. We employed i) a transcutaneous device that measures the half-life of intravenously administered FITC-sinistrin, a molecule cleared by glomerular filtration; and ii) multispectral optoacoustic tomography, a photoacoustic imaging device that directly visualises the clearance of the near infrared dye, IRDye 800CW carboxylate. Measurements with either technique showed a significant impairment of renal function in experimental animals versus controls, with significant correlations with the proportion of scarred glomeruli five weeks after induction of injury. These technologies provide clinically relevant functional data and should be widely adopted for testing the efficacies of novel therapies. Moreover, their use will also lead to a reduction in experimental animal numbers

A comparison of characteristics of patients seen in a tertiary hospital diabetes telehealth service versus specialist face-to-face outpatients

This study aimed to describe patient-related characteristics of those attending the diabetes telehealth service delivered from a tertiary hospital and compare these with the characteristics of patients attending face-to-face visits at the same hospital's diabetes outpatient service. This analysis could inform diabetes telehealth service improvements. To our knowledge, there has been no prior evaluation of a diabetes telehealth service in Australia. A cross-sectional survey was conducted as part of the Australian National Diabetes Audit in May 2016 for all patients attending the diabetes telehealth service and diabetes outpatient service. The diabetes telehealth service was serving a greater proportion of females, indigenous people and patients with a longer mean duration of type 2 diabetes mellitus. Type 2 diabetes mellitus patients in the diabetes telehealth service group had a higher average glycated haemoglobin of 9.1% (76 mmol/mol) vs 8.1% (65 mmol/mol) in the diabetes outpatient service group. The diabetes telehealth service had more people with initial visits; had higher self-reported smoking rates in type 2 diabetes mellitus patients; and had adequate access to allied health supports as recommended for diabetes management. Diabetes telehealth service patients had more complex diabetes as evidenced by a higher proportion of indigenous clients, higher glycated haemoglobin and longer mean duration of diabetes

Microrheology of sodium polystyrene sulfonate (NaPSS) solutions with different polymer concentrations and molecular weights studied by diffusing wave spectroscopy

Conference on Holography, diffractive optics, and applications IV, vol. 7848, 201

Monitoring a polycycloaddition by the combination of dynamic rheology and FTIR spectroscopy

International audienceA rheometer coupled with a FTIR spectrometer under controlled atmosphere was successfully used to monitor in situ the synthesis of a preceramic polycarbosilane starting from two suitable monomers. This original hyper-branched polymer was obtained using the azide-alkyne cycloaddition activated by temperature. The device allowed for the following of the polymerization reaction by monitoring the intensity of several characteristic vibrational bands corresponding to the reagents (e.g. eN 3 , CeH alkyne) and the products (e.g. CeH triazole). The impact of the surrounding atmosphere and the kinetic aspects of the reaction were investigated for the three studied temperatures, and an apparent activation energy of 73.3 kJ mol À1 was calculated for the 1,3-dipolar polycycloaddition

Measures of kidney function by minimally invasive techniques correlate with histological glomerular damage in SCID mice with adriamycin-induced nephropathy

Maximising the use of preclinical murine models of progressive kidney disease as test beds for therapies ideally requires kidney function to be measured repeatedly in a safe, minimally invasive manner. To date, most studies of murine nephropathy depend on unreliable markers of renal physiological function, exemplified by measuring blood levels of creatinine and urea, and on various end points necessitating sacrifice of experimental animals to assess histological damage, thus counteracting the principles of Replacement, Refinement and Reduction. Here, we applied two novel minimally invasive techniques to measure kidney function in SCID mice with adriamycin-induced nephropathy. We employed i) a transcutaneous device that measures the half-life of intravenously administered FITC-sinistrin, a molecule cleared by glomerular filtration; and ii) multispectral optoacoustic tomography, a photoacoustic imaging device that directly visualises the clearance of the near infrared dye, IRDye 800CW carboxylate. Measurements with either technique showed a significant impairment of renal function in experimental animals versus controls, with significant correlations with the proportion of scarred glomeruli five weeks after induction of injury. These technologies provide clinically relevant functional data and should be widely adopted for testing the efficacies of novel therapies. Moreover, their use will also lead to a reduction in experimental animal numbers

Early peritonitis and its outcome in incident peritoneal dialysis patients

Early-onset peritonitis is a serious complication of peritoneal dialysis (PD) and is associated with heightened risks of technique failure and death. The risk factors for early peritonitis and its outcomes are unknown.This registry study examined all incident Australian PD patients between 2003 and 2014. The primary outcome was early peritonitis, defined as onset within 12 months of starting therapy. Secondary outcomes were medical cure, relapse/recurrence, catheter removal, peritonitis-associated technique failure, and peritonitis-associated death.Of 9,845 patients, 2,615 experienced 3,827 early-peritonitis episodes (0.50 episodes per patient-year). Early peritonitis was more common in patients who were male, obese, had a history of cigarette smoking or cerebrovascular disease, used continuous ambulatory PD, and had received prior renal replacement therapy for > 90 days. Remoteness was a risk modifier for the association between race and early peritonitis; remote Aboriginal, Torres Strait Islander, Maori and Pacific Islander patients had the highest risk. Obese patients were more likely to achieve medical cure. Older patients were less likely to achieve cure and more likely to experience peritonitis-associated death.In summary, several factors predicted early peritonitis in incident PD patients. Modified approaches to patient selection, training techniques, and prevention strategies should be considered in high-risk individuals