Representativeness of Randomized Clinical Trial Cohorts in End-stage Kidney Disease: A Meta-analysis

Comparative effectiveness of an individualized model of hemodialysis vs conventional hemodialysis: a study protocol for a multicenter randomized controlled trial (the TwoPlus trial)

BACKGROUND

Most patients starting chronic in-center hemodialysis (HD) receive conventional hemodialysis (CHD) with three sessions per week targeting specific biochemical clearance. Observational studies suggest that patients with residual kidney function can safely be treated with incremental prescriptions of HD, starting with less frequent sessions and later adjusting to thrice-weekly HD. This trial aims to show objectively that clinically matched incremental HD (CMIHD) is non-inferior to CHD in eligible patients.

METHODS

An unblinded, parallel-group, randomized controlled trial will be conducted across diverse healthcare systems and dialysis organizations in the USA. Adult patients initiating chronic hemodialysis (HD) at participating centers will be screened. Eligibility criteria include receipt of fewer than 18 treatments of HD and residual kidney function defined as kidney urea clearance ≥3.5 mL/min/1.73 m2 and urine output ≥500 mL/24 h. The 1:1 randomization, stratified by site and dialysis vascular access type, assigns patients to either CMIHD (intervention group) or CHD (control group). The CMIHD group will be treated with twice-weekly HD and adjuvant pharmacologic therapy (i.e., oral loop diuretics, sodium bicarbonate, and potassium binders). The CHD group will receive thrice-weekly HD according to usual care. Throughout the study, patients undergo timed urine collection and fill out questionnaires. CMIHD will progress to thrice-weekly HD based on clinical manifestations or changes in residual kidney function. Caregivers of enrolled patients are invited to complete semi-annual questionnaires. The primary outcome is a composite of patients' all-cause death, hospitalizations, or emergency department visits at 2 years. Secondary outcomes include patient- and caregiver-reported outcomes. We aim to enroll 350 patients, which provides ≥85% power to detect an incidence rate ratio (IRR) of 0.9 between CMIHD and CHD with an IRR non-inferiority of 1.20 (α = 0.025, one-tailed test, 20% dropout rate, average of 2.06 years of HD per patient participant), and 150 caregiver participants (of enrolled patients).

DISCUSSION

Our proposal challenges the status quo of HD care delivery. Our overarching hypothesis posits that CMIHD is non-inferior to CHD. If successful, the results will positively impact one of the highest-burdened patient populations and their caregivers.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05828823. Registered on 25 April 2023.

Drug stewardship in chronic kidney disease to achieve effective and safe medication use

People living with chronic kidney disease (CKD) often experience multimorbidity and require polypharmacy. Kidney dysfunction can also alter the pharmacokinetics and pharmacodynamics of medications, which can modify their risks and benefits; the extent of these changes is not well understood for all situations or medications. The principle of drug stewardship is aimed at maximizing medication safety and effectiveness in a population of patients through a variety of processes including medication reconciliation, medication selection, dose adjustment, monitoring for effectiveness and safety, and discontinuation (deprescribing) when no longer necessary. This Review is aimed at serving as a resource for achieving optimal drug stewardship for patients with CKD. We describe special considerations for medication use during pregnancy and lactation, during acute illness and in patients with cancer, as well as guidance for the responsible use of over-the-counter drugs, herbal remedies, supplements and sick-day rules. We also highlight inequities in medication access worldwide and suggest policies to improve access to quality and essential medications for all persons with CKD. Further strategies to promote drug stewardship include patient education and engagement, the use of digital health tools, shared decision-making and collaboration within interdisciplinary teams. Throughout, we position the person with CKD at the centre of all drug stewardship efforts.

The Ottawa Statement implementation guidance document for cluster randomized trials in the hemodialysis setting

Research teams are increasingly interested in using cluster randomized trial (CRT) designs to generate practice-guiding evidence for in-center maintenance hemodialysis. However, CRTs raise complex ethical issues. The Ottawa Statement on the Ethical Design and Conduct of Cluster Randomized Trials, published in 2012, provides 15 recommendations to address ethical issues arising within 7 domains: justifying the CRT design, research ethics committee review, identifying research participants, obtaining informed consent, gatekeepers, assessing benefits and harms, and protecting vulnerable participants. But applying the Ottawa Statement recommendations to CRTs in the hemodialysis setting is complicated by the unique features of the setting and population. Here, with the help of content experts and patient partners, we co-developed this implementation guidance document to provide research teams, research ethics committees, and other stakeholders with detailed guidance on how to apply the Ottawa Statement recommendations to CRTs in the hemodialysis setting, the result of a 4-year research project. Thus, our work demonstrates how the voices of patients, caregivers, and all stakeholders may be included in the development of research ethics guidance.

Estimating a Minimal Important Difference for the EQ-5D-5L Utility Index in Dialysis Patients

OBJECTIVES

The EQ-5D-5L is a commonly used health-related quality of life instrument for evaluating interventions in patients receiving dialysis; however, the minimal important difference (MID) that constitutes a meaningful treatment effect for this population has not been established. This study aims to estimate the MID for the EQ-5D-5L utility index in dialysis patients.

METHODS

6-monthly EQ-5D-5L measurements were collected from adult dialysis patients between April 2017 and November 2020 at a renal network in Sydney, Australia. EQ-VAS and Integrated Palliative care Outcome Scale Renal symptom burden scores were collected simultaneously and used as anchors. MID estimates for the EQ-5D-5L utility index were derived using anchor-based and distribution-based methods.

RESULTS

A total of 352 patients with ≥1 EQ-5D-5L observation were included, constituting 1127 observations. Mean EQ-5D-5L utility index at baseline was 0.719 (SD ± 0.267), and mean EQ-5D-5L utility decreased over time by -0.017 per year (95% CI -0.029 to -0.006, P = .004). Using cross-sectional anchor-based methods, MID estimates ranged from 0.073 to 0.107. Using longitudinal anchor-based methods, MID for improvement and deterioration ranged from 0.046 to 0.079 and -0.111 to -0.048, respectively. Using receiver operating characteristic curves, MID for improvement and deterioration ranged from 0.037 to 0.122 and -0.074 to -0.063, respectively. MID estimates from distribution-based methods were consistent with anchor-based estimates.

CONCLUSIONS

Anchor-based and distribution-based approaches provided EQ-5D-5L utility index MID estimates ranging from 0.034 to 0.134. These estimates can inform the target difference or "effect size" for clinical trial design among dialysis populations.

Systematic Review of Women Leading and Participating in Nephrology Randomized Clinical Trials

Introduction

Women are underrepresented in the leadership of and participation in randomized controlled trials (RCTs). We conducted a bibliometric review of nephrology RCTs to examine trial leadership by women and participation of women in nephrology RCTs.

Methods

A bibliometric review of RCTs published in top medical, surgical, or nephrology journals was conducted using MEDLINE and EMBASE from January 2011 to December 2021. Leadership by women as corresponding authors, women trial participation, and trial characteristics were examined with duplicate independent data extraction. Logistic regression was used to examine associations between trial characteristics and women leadership and trial participation.

Results

A total of 1770 studies were screened and 395 RCTs met eligibility criteria. The number (%) of women in corresponding, first, and last authorship positions were as follows: 89 (22%), 109 (28%), and 74 (19%), respectively, without change over time (P = 0.94). The median percentage (interquartile range [IQR]) of women trial participants was 39.0% (13.5%) with no difference between women or men lead authors (P = 0.15). Men lead authors were statistically less likely to enroll women in RCTs. Women lead authors were less likely to be funded by industry (odds ratio [OR]: 0.30; 95% confidence interval [CI]: 0.14-0.63; P = 0.002) or lead international trials (OR: 0.11; 95% CI: 0.01-0.83; P = 0.03). Trials with sex-specific eligibility criteria were more likely to have women leaders (OR: 2.56; 95% CI: 1.19-5.49; P = 0.02) than those without.

Discussion

Gender inequalities in RCT leadership and RCT participation exist in nephrology and did not improve over time. Strategies to improve inequalities need to be implemented and evaluated.

Effect of Intradialytic Exercise on Cardiovascular Outcomes in Maintenance Hemodialysis: A Systematic Review and Meta-Analysis

Key Points

Individuals receiving hemodialysis have high rates of cardiovascular disease not explained by traditional cardiovascular risk factors. Intradialytic exercise improves cardiovascular outcomes, including arterial resistance, BP, and heart rate variability. Clinicians should consider including intradialytic aerobic exercise programs in hemodialysis care to supplement broader treatment plans.

Background

Cardiovascular disease is the leading cause of death among people with kidney failure on hemodialysis, for whom improving cardiovascular health is a research priority. Intradialytic myocardial stunning is common and associated with adverse cardiovascular events. Intradialytic exercise may mitigate intradialytic myocardial stunning and improve cardiovascular structure and function. This systematic review investigated the effect of intradialytic exercise on cardiovascular outcomes in adults undergoing maintenance hemodialysis (PROSPERO CRD42018103118).

Methods

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we systematically searched MEDLINE, Embase, Cochrane CENTRAL, SportDiscus, and PEDro databases from 1960 until June 2022, for randomized and nonrandomized studies investigating the effect of intradialytic exercise programs on objective cardiovascular outcomes, prespecified as primary or secondary outcomes. The primary outcome was arterial resistance.

Results

Of 10,837 references identified, 32 met eligibility criteria. These studies investigated the effect of intradialytic exercise on arterial resistance (eight studies), BP (20 studies), myocardial structure and function (seven studies), endothelial function (two studies), sympathetic overactivity (nine studies), biomarkers of cardiac injury (three studies), and cardiovascular hospitalization and mortality (two studies). Most studies used aerobic exercise as the intervention and usual care (no exercise) controls. Meta-analysis of intradialytic exercise versus usual care resulted in a statistically significant reduction in arterial resistance measured by pulse wave velocity with mean difference −1.63 m/s (95% confidence interval, −2.51 to −0.75). Meta-analyses for diastolic BP, left ventricular ejection fraction, and low-frequency/high-frequency ratio measure of heart rate variability also showed statistically significant improvements with exercise. There was no significant difference in change in systolic BP, augmentation index, and left ventricular mass index between groups.

Conclusions

Intradialytic exercise programming resulted in a clinically meaningful improvement to pulse wave velocity, a component of arterial resistance. Improvements in several physiologic measures of cardiovascular health, including diastolic BP, left ventricular ejection fraction, and heart rate variability measured by the low-frequency/high-frequency ratio were also observed. The effects of intradialytic exercise on major adverse cardiovascular events remains uncertain.

Can the General Public Be a Proxy for an "At-Risk" Group in a Patient Preference Study? A Disease Prevention Example in Rheumatoid Arthritis

BACKGROUND

When selecting samples for patient preference studies, it may be difficult or impractical to recruit participants who are eligible for a particular treatment decision. However, a general public sample may not be an appropriate proxy.

OBJECTIVE

This study compares preferences for rheumatoid arthritis (RA) preventive treatments between members of the general public and first-degree relatives (FDRs) of confirmed RA patients to assess whether a sample of the general public can be used as a proxy for FDRs.

METHODS

Participants were asked to imagine they were experiencing arthralgia and had screening tests indicating a 60% chance of developing RA within 2 yrs. Using a discrete choice experiment, participants were offered a series of choices between no treatment and 2 unlabeled hypothetical treatments to reduce the risk of RA. To assess data quality, time to complete survey sections and comprehension questions were assessed. A random parameter logit model was used to obtain attribute-level estimates, which were used to calculate relative importance, maximum acceptable risk (MAR), and market shares of hypothetical preventive treatments.

RESULTS

The FDR sample (n = 298) spent more time completing the survey and performed better on comprehension questions compared with the general public sample (n = 982). The relative importance ranking was similar between the general public and FDR participant samples; however, other relative preference measures involving weights including MARs and market share differed between groups, with FDRs having numerically higher MARs.

CONCLUSION

In the context of RA prevention, the general public (average risk) may be a reasonable proxy for a more at-risk sample (FDRs) for overall relative importance ranking but not weights. The rationale for a proxy sample should be clearly justified.

HIGHLIGHTS

Participants from the general public were compared to first-degree relatives on their preferences for rheumatoid arthritis (RA) preventive treatments using a discrete choice experiment.Preferences were similar between groups in terms of the most important and least important attributes of preventive treatments, with effectiveness being the most important attribute. However, relative weights differed.Attention to the survey and predicted market shares of hypothetical RA preventive treatments differed between the general public and first-degree relatives.The general public may be a reasonable proxy for an at-risk group for patient preferences ranks but not weights in the disease prevention context; however, care should be taken in sample selection for patient preference studies when choosing nonpatients.

Disparities between randomized clinical trial participants and sepsis patients in real-world

BACKGROUND

The external validity or "generalizability" of randomized controlled trials (RCTs) often needs be considered when making treatment decisions. We evaluate whether participants in large multicenter RCTs investigating sepsis were similar in age, disease severity, comorbidities, and mortality to the general population of sepsis patients.

METHODS

Using MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials, RCTs that enrolled 100 or more adult sepsis patients from two or more sites published from 01 January 2000 to 04 August 2019 were identified. The weighted mean age of trial participants was calculated as the main variable, and it was compared with the mean ages of the overall populations derived from the MIMIC database and the EICU database. Two researchers independently screened all abstracts and performed data extraction, then aggregated the data using a random effects model. Multiple linear regression was used to determine whether any factors were significantly associated with age disparities.

RESULTS

The mean age of the 60,577 participants in the 94 trials included in the analysis was significantly lower than those of the patients in the MIMIC and EICU databases (weighted mean age 62.28 years vs. 64.47 years for MIMIC and 65.20 years for EICU; both p < 0.001). Trial participants were less likely to have known comorbidities such as diabetes (13.96% vs. 30.64% for MIMIC and 35.75% for EICU; both p < 0.001). The weighted mortality rate in trial participants was higher than that in patients in the MIMIC and EICU databases (29.33% vs. 20.72% for MIMIC and 17.53% for EICU; both p < 0.001). Differences in age, severity score, and comorbidities remained statistically significant in sensitivity analyses. Multivariable regression suggested that commercially supported trials were more likely to include patients with higher severity scores (p = 0.002), but after adjustment for study region and sepsis diagnosis inclusion in such trials was not significantly associated with age.

CONCLUSIONS

On average, trial participants were younger than the general sepsis patient population. Commercial support influenced patient selection. Efforts to understand and address the above-described patient disparities are necessary to improve the generalizability of RCT results.

TRIAL REGISTRATION

PROSPERO CRD42019145692.

Kidney and Cardiovascular Effects of Canagliflozin According to Age and Sex: A Post Hoc Analysis of the CREDENCE Randomized Clinical Trial

RATIONALE & OBJECTIVE

It is unclear whether the effect of canagliflozin on adverse kidney and cardiovascular events in those with diabetic kidney disease varies by age and sex. We assessed the effects of canagliflozin among age group categories and between sexes in the Canagliflozin and Renal Endpoints in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) study.

STUDY DESIGN

Secondary analysis of a randomized controlled trial.

SETTING & PARTICIPANTS

Participants in the CREDENCE trial.

INTERVENTION

Participants were randomly assigned to receive canagliflozin 100mg/d or placebo.

OUTCOMES

Primary composite outcome of kidney failure, doubling of serum creatinine concentration, or death due to kidney or cardiovascular disease. Prespecified secondary and safety outcomes were also analyzed. Outcomes were evaluated by age at baseline (<60, 60-69, and≥70 years) and sex in the intention-to-treat population using Cox regression models.

RESULTS

The mean age of the cohort was 63.0±9.2 years, and 34% were female. Older age and female sex were independently associated with a lower risk of the composite of adverse kidney outcomes. There was no evidence that the effect of canagliflozin on the primary outcome (a composite of kidney failure, a doubling of serum creatinine concentration, or death from kidney or cardiovascular causes) differed between age groups (HRs, 0.67 [95% CI, 0.52-0.87], 0.63 [0.48-0.82], and 0.89 [0.61-1.29] for ages<60, 60-69, and≥70 years, respectively; P=0.3for interaction) or sexes (HRs, 0.71 [95% CI, 0.54-0.95] and 0.69 [0.56-0.84] in women and men, respectively; P=0.8for interaction). No differences in safety outcomes by age group or sex were observed.

LIMITATIONS

This was a post hoc analysis with multiple comparisons.

CONCLUSIONS

Canagliflozin consistently reduced the relative risk of kidney events in people with diabetic kidney disease in both sexes and across age subgroups. As a result of greater background risk, the absolute reduction in adverse kidney outcomes was greater in younger participants.

FUNDING

This post hoc analysis of the CREDENCE trial was not funded. The CREDENCE study was sponsored by Janssen Research and Development and was conducted collaboratively by the sponsor, an academic-led steering committee, and an academic research organization, George Clinical.

TRIAL REGISTRATION

The original CREDENCE trial was registered at ClinicalTrials.gov with study number NCT02065791.

Treatment decision-making and care among older adults with kidney failure: protocol for a multicentre, prospective observational cohort study with nested substudies and linked qualitative research (the Elderly Advanced CKD Programme)

INTRODUCTION

Shared treatment decision-making and planning of care are fundamental in advanced chronic kidney disease (CKD) management. There are limited data on several key outcomes for the elderly population including survival, quality of life, symptom burden, changes in physical functioning and experienced burden of healthcare. Patients, caregivers and clinicians consequently face significant uncertainty when making life-impacting treatment decisions. The Elderly Advanced CKD Programme includes quantitative and qualitative studies to better address challenges in treatment decision-making and planning of care among this increasingly prevalent elderly cohort.

METHODS AND ANALYSIS

The primary component is OUTcomes of Older patients with Kidney failure (OUTLOOK), a multicentre prospective observational cohort study that will enrol 800 patients ≥75 years with kidney failure (estimated glomerular filtration rate ≤15 mL/min/1.73 m²) across a minimum of six sites in Australia. Patients entered are in the decision-making phase or have recently made a decision on preferred treatment (dialysis, conservative kidney management or undecided). Patients will be prospectively followed until death or a maximum of 4 years, with the primary outcome being survival. Secondary outcomes are receipt of short-term acute dialysis, receipt of long-term maintenance dialysis, changes in biochemistry and end-of-life care characteristics. Data will be used to formulate a risk prediction tool applicable for use in the decision-making phase. The nested substudies Treatment modalities for the InfirM ElderLY with end stage kidney disease (TIMELY) and Caregivers of The InfirM ElderLY with end stage kidney disease (Co-TIMELY) will longitudinally assess quality of life, symptom burden and caregiver burden among 150 patients and 100 caregivers, respectively. CONsumer views of Treatment options for Elderly patieNts with kiDney failure (CONTEND) is an additional qualitative study that will enrol a minimum of 20 patients and 20 caregivers to explore experiences of treatment decision-making and care.

ETHICS AND DISSEMINATION

Ethics approval was obtained through Sydney Local Health District Human Research Ethics Committee (2019/ETH07718, 2020/ETH02226, 2021/ETH01020, 2019/ETH07783). OUTLOOK is approved to have waiver of individual patient consent. TIMELY, Co-TIMELY and CONTEND participants will provide written informed consent. Final results will be disseminated through peer-reviewed journals and presented at scientific meetings.

Baseline representativeness of patients in clinics enrolled in the PRimary care Opioid Use Disorders treatment (PROUD) trial: comparison of trial and non-trial clinics in the same health systems

BACKGROUND

Pragmatic primary care trials aim to test interventions in "real world" health care settings, but clinics willing and able to participate in trials may not be representative of typical clinics. This analysis compared patients in participating and non-participating clinics from the same health systems at baseline in the PRimary care Opioid Use Disorders treatment (PROUD) trial.

METHODS

This observational analysis relied on secondary electronic health record and administrative claims data in 5 of 6 health systems in the PROUD trial. The sample included patients 16-90 years at an eligible primary care visit in the 3 years before randomization. Each system contributed 2 randomized PROUD trial clinics and 4 similarly sized non-trial clinics. We summarized patient characteristics in trial and non-trial clinics in the 2 years before randomization ("baseline"). Using mixed-effect regression models, we compared trial and non-trial clinics on a baseline measure of the primary trial outcome (clinic-level patient-years of opioid use disorder (OUD) treatment, scaled per 10,000 primary care patients seen) and a baseline measure of the secondary trial outcome (patient-level days of acute care utilization among patients with OUD).

RESULTS

Patients were generally similar between the 10 trial clinics (n = 248,436) and 20 non-trial clinics (n = 341,130), although trial clinics' patients were slightly younger, more likely to be Hispanic/Latinx, less likely to be white, more likely to have Medicaid/subsidized insurance, and lived in less wealthy neighborhoods. Baseline outcomes did not differ between trial and non-trial clinics: trial clinics had 1.0 more patient-year of OUD treatment per 10,000 patients (95% CI: - 2.9, 5.0) and a 4% higher rate of days of acute care utilization than non-trial clinics (rate ratio: 1.04; 95% CI: 0.76, 1.42).

CONCLUSIONS

trial clinics and non-trial clinics were similar regarding most measured patient characteristics, and no differences were observed in baseline measures of trial primary and secondary outcomes. These findings suggest trial clinics were representative of comparably sized clinics within the same health systems. Although results do not reflect generalizability more broadly, this study illustrates an approach to assess representativeness of clinics in future pragmatic primary care trials.

Findings of Sodium-Glucose Cotransporter-2 Inhibitor Kidney Outcome Trials Applied to a Canadian Chronic Kidney Disease Population: A Retrospective Cohort Study

Background

The canagliflozin and renal endpoints in diabetes with established nephropathy clinical evaluation (CREDENCE) and dapagliflozin and prevention of adverse outcomes in chronic kidney disease (DAPA-CKD) trials have demonstrated significant kidney benefits with sodium-glucose cotransporter-2 (SGLT2) inhibitors. SGLT2 inhibitors are now standard of care for patients with diabetic kidney disease and have also been shown to be effective in those with albuminuric CKD with or without diabetes.

Objective

We sought to determine how many patients in nephrology care in British Columbia, Canada, would have been eligible for those trials, to compare rates of outcomes, and to estimate cost avoidance arising from widespread use of SGLT2 inhibitors in this cohort.

Study design

Retrospective cohort study.

Setting

British Columbia, Canada.

Participants

CKD patients followed in the Kidney Care Clinics in British Columbia.

Measurements

We compared the outcomes of kidney failure, sustained estimated glomerular filtration rate (eGFR) <15 mL/min/1.73 m², dialysis, transplant, death from any cause, and doubling of serum creatinine. We also compared the composite outcome of kidney failure and doubling of serum creatinine.

Methods

The cohort was derived using a provincial database by combining the inclusion criteria of CREDENCE and DAPA-CKD trials. We included adult patients aged ≥18 years, urine albumin to creatinine ratio (UACR) ≥20 mg/mmol, and eGFR between 25 and 90 mL/min/1.73 m², between April 1, 2014 and March 31, 2017. The primary outcome was compared with the outcomes experienced in the placebo arms of CREDENCE and DAPA-CKD. The composite outcome stratified by eGFR categories were compared in the British Columbia cohort and the CREDENCE trial. Cost avoidance was estimated based on the number needed to treat to prevent one instance of kidney failure.

Results

A total of 17.5% (3138/17 963) of patients were eligible, resulting in a cohort with a mean age of 69.7 years and 38% women. The eGFR slope of the British Columbia cohort was -4.21 ± 0.47 mL/min. The mean eGFR was 37.0 mL/min/1.73 m², median UACR was 55.3 mg/mmol, and use of renin-angiotensin-aldosterone system inhibitors was 56.6%. The British Columbia cohort experienced nearly double the outcomes of kidney failure, death from any cause, and doubling of serum creatinine than the placebo arms of CREDENCE and DAPA-CKD. When stratified by eGFR, the British Columbia cohort and the CREDENCE placebo arm had similar event rates for those with an eGFR <45 mL/min but there were still higher rates of outcome in the greater than 45 mL/min eGFR groups in the British Columbia cohort. Treating the British Columbia cohort with canagliflozin could lead to net cost avoidance of $2.31 million over 2.6 years.

Limitations

The database only captures those referred to the Kidney Care Clinics by nephrologists, which may lead to selection bias of higher risk patients in the British Columbia cohort. The cost avoidance analysis was a limited high-level analysis.

Conclusions

The British Columbia cohort represents a high-risk group in whom implementation of the use of SGLT2 inhibitors may well improve outcomes and reduce health care system costs.

Sex and Gender in Randomized Controlled Trials of Adults Receiving Maintenance Dialysis: A Meta-epidemiologic Study

RATIONALE & OBJECTIVE

How sex and gender concepts are incorporated into randomized controlled trials (RCTs) in adults with kidney failure receiving maintenance dialysis is largely unknown. We describe these practices in published journal articles as well as investigate the proportion of women and female participants in these studies.

STUDY DESIGN

Meta-epidemiologic study.

SETTING & STUDY POPULATIONS

RCTs in maintenance dialysis.

SELECTION CRITERIA FOR STUDIES

Trials published in high-impact journals in 2000-2020.

DATA EXTRACTION

Implemented in duplicate with conflicts resolved by a third reviewer.

ANALYTICAL APPROACH

Meta-regression was performed to identify trial characteristics independently associated with the proportion of women and female participants.

RESULTS

Among 561 included RCTs, 69.7% were parallel and 28.0% were crossover in design; 80.6% were conducted in the hemodialysis population; and 25% of trials compared the treatment of interest with a placebo arm, 25% with a usual care treatment arm, and 50% with an active alternative therapy arm. Of the RCTS, 37.6% were masked. The median size was 60 (IQR, 26-151) participants, and the median follow-up period was 154 (IQR, 42-365) days. The mean proportion of women or female participants was 0.40±0.13 (SD): 39.0% of trials reported sex, and 26.6% reported the gender of the participants. Also, 56.2% referred to participants as females, 25.3% referred to participants as women, and 15.5% referred to both females and women. No trial characteristic other than region (β of 0.062 [95% CI, 0.007-0.117] for Asia) was associated with the proportion of women or female participants. Considering trial design and conduct, 2.7% of trials used sex and/or gender as an inclusion criterion, 26.6% as an exclusion criterion, 4.5% for randomization, 4.8% for subgroup analyses, and 15.7% for covariate adjustment.

LIMITATIONS

Only high-impact journal articles were studied; and the included studies lacked pediatric trials, those addressing chronic kidney disease or kidney transplantation, any trials from Africa and underrepresentation of other regions, and missing data.

CONCLUSIONS

RCTs in dialysis are representative of the general dialysis population with regard to sex and gender but they uncommonly report both and often do not include either in their reporting or analysis.

Personalised cooler dialysate for patients receiving maintenance haemodialysis (MyTEMP): a pragmatic, cluster-randomised trial

BACKGROUND

Haemodialysis centres have conventionally provided maintenance haemodialysis using a standard dialysate temperature (eg, 36·5°C) for all patients. Many centres now use cooler dialysate (eg, 36·0°C or lower) for potential cardiovascular benefits. We aimed to assess whether personalised cooler dialysate, implemented as centre-wide policy, reduced the risk of cardiovascular-related death or hospital admission compared with standard temperature dialysate.

METHODS

MyTEMP was a pragmatic, two-arm, parallel-group, registry-based, open-label, cluster-randomised, superiority trial done at haemodialysis centres in Ontario, Canada. Eligible centres provided maintenance haemodialysis to at least 15 patients a week, and the medical director of each centre had to confirm that their centre would deliver the assigned intervention. Using covariate-constrained randomisation, we allocated 84 centres (1:1) to use either personalised cooler dialysate (nurses set the dialysate temperature 0·5-0·9°C below each patient's measured pre-dialysis body temperature, with a lowest recommended dialysate temperature of 35·5°C), or standard temperature dialysate (36·5°C for all patients and treatments). Patients and health-care providers were not masked to the group assignment; however, the primary outcome was recorded in provincial databases by medical coders who were unaware of the trial or the centres' group assignment. The primary composite outcome was cardiovascular-related death or hospital admission with myocardial infarction, ischaemic stroke, or congestive heart failure during the 4-year trial period. Analysis was by intention to treat. The study is registered at ClinicalTrials.gov, NCT02628366.

FINDINGS

We assessed all of Ontario's 97 centres for inclusion into the study. Nine centres had less than 15 patients and one director requested that four of their seven centres not participate. 84 centres were recruited and on Feb 1, 2017, these centres were randomly assigned to administer personalised cooler dialysate (42 centres) or standard temperature dialysate (42 centres). The intervention period was from April 3, 2017, to March 31, 2021, and during this time the trial centres provided outpatient maintenance haemodialysis to 15 413 patients (about 4·3 million haemodialysis treatments). The mean dialysate temperature was 35·8°C in the cooler dialysate group and 36·4°C in the standard temperature group. The primary outcome occurred in 1711 (21·4%) of 8000 patients in the cooler dialysate group versus 1658 (22·4%) of 7413 patients in the standard temperature group (adjusted hazard ratio 1·00, 96% CI 0·89 to 1·11; p=0·93). The mean drop in intradialytic systolic blood pressure was 26·6 mm Hg in the cooler dialysate group and 27·1 mm Hg in the standard temperature group (mean difference -0·5 mm Hg, 99% CI -1·4 to 0·4; p=0·14).

INTERPRETATION

Centre-wide delivery of personalised cooler dialysate did not significantly reduce the risk of major cardiovascular events compared with standard temperature dialysate. The rising popularity of cooler dialysate is called into question by this study, and the risks and benefits of cooler dialysate in some patient populations should be clarified in future trials.

FUNDING

Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Ontario Renal Network, Ontario Strategy for Patient-Oriented Research Support Unit, Dialysis Clinic, Inc., ICES (formerly known as the Institute for Clinical Evaluative Sciences), Lawson Health Research Institute, and Western University.

Real-world comparison of fidaxomicin versus vancomycin or metronidazole in the treatment of Clostridium difficile infection: a systematic review and meta-analysis

PURPOSE

There is a lack of real-world evidence of the comparative effectiveness of fidaxomicin versus vancomycin or metronidazole for treating patients with Clostridium difficile (CDI) infection. No systematic evidence comparing these treatment regimens using real-world observational studies was published up to date. The goal of this study is to compare the fidaxomicin and vancomycin/metronidazole regimens in terms of treatment outcomes in CDI patients.

METHODS

Systematic and comprehensive search was carried out in the following databases and search engines: EMBASE, Cochrane, MEDLINE, ScienceDirect, and Google Scholar from 1954 until January 2022. Newcastle-Ottawa (NO) scale was used to assess the risk of bias. Meta-analysis was carried out using random effects model, and pooled odds ratios (OR) with 95% confidence interval (CI) were reported.

RESULTS

A total of 10 studies satisfied the inclusion criteria, most of them were with poorer quality. The pooled OR was 0.40 (95% CI: 0.09-1.68; I² = 82.4%) for clinical cure and 2.02 (95% CI: 0.36-11.39; I² = 88.4%) for sustained cure. We reported pooled OR of 0.69 (95% CI: 0.40-1.20; I² = 65.7%) for the recurrence rate, 2.81 (95% CI: 1.08-7.29; I² = 70.6%) for the treatment failure, and 0.73 (95% CI: 0.50-1.07; I² = 0%) for all-cause mortality between patients that received fidaxomicin and vancomycin. The pooled OR was 0.71 (95% CI: 0.05-9.47; I² = 69.6%) in terms of recurrence between patients receiving fidaxomicin and metronidazole.

CONCLUSION

Fidaxomicin and vancomycin/metronidazole regimens did not have significant difference in terms of treatment outcomes, such as clinical cure, sustained cure, recurrence, and all-cause mortality. However, there was significantly higher risk of treatment failure in CDI patients taking fidaxomicin.

Quality and variation of care for chronic kidney disease in Swiss general practice: A retrospective database study

Background

Chronic kidney disease (CKD) is a common condition in general practice. Data about quality and physician-level variation of CKD care provided by general practitioners is scarce. In this study, we evaluated determinants and variation of achievement of 14 quality indicators for CKD care using electronic medical records data from Swiss general practice during 2013–2019.

Methods

We defined two patient cohorts from 483 general practitioners, one to address renal function assessment in patients with predisposing conditions (n = 47,201, median age 68 years, 48.7% female) and one to address care of patients with laboratory-confirmed CKD (n = 14,654, median age 80 years, 57.5% female). We investigated quality indicator achievement with mixed-effect logistic regression and expressed physician-level variation as intraclass correlation coefficients (ICCs) and range odds ratios (rORs).

Results

We observed the highest quality indicator achievement rate for withholding non-steroidal anti-inflammatory drug prescription in patients with CKD staged G2–3b within 12 months of follow-up (82.6%), the lowest for albuminuria assessment within 18 months of follow-up (18.1%). Highest physician-level variation was found for renal function assessment during 18 months of follow-up in patients with predisposing conditions (diabetes: ICC 0.31, rOR 26.5; cardiovascular disease: ICC 0.28, rOR 17.4; hypertension: ICC 0.24, rOR 17.2).

Conclusion

This study suggests potentially unwarranted variation in general practice concerning RF assessment in patients affected by conditions predisposing for CKD. We further identified potential gaps in quality of CKD monitoring as well as lower quality of CKD care for female patients and patients not affected by comorbidities.

Identification of tools used to assess the external validity of randomized controlled trials in reviews: a systematic review of measurement properties

Background

Internal and external validity are the most relevant components when critically appraising randomized controlled trials (RCTs) for systematic reviews. However, there is no gold standard to assess external validity. This might be related to the heterogeneity of the terminology as well as to unclear evidence of the measurement properties of available tools. The aim of this review was to identify tools to assess the external validity of RCTs. It was further, to evaluate the quality of identified tools and to recommend the use of individual tools to assess the external validity of RCTs in future systematic reviews.

Methods

A two-phase systematic literature search was performed in four databases: PubMed, Scopus, PsycINFO via OVID, and CINAHL via EBSCO. First, tools to assess the external validity of RCTs were identified. Second, studies investigating the measurement properties of these tools were selected. The measurement properties of each included tool were appraised using an adapted version of the COnsensus based Standards for the selection of health Measurement INstruments (COSMIN) guidelines.

Results

38 publications reporting on the development or validation of 28 included tools were included. For 61% (17/28) of the included tools, there was no evidence for measurement properties. For the remaining tools, reliability was the most frequently assessed property. Reliability was judged as “sufficient” for three tools (very low certainty of evidence). Content validity was rated as “sufficient” for one tool (moderate certainty of evidence).

Conclusions

Based on these results, no available tool can be fully recommended to assess the external validity of RCTs in systematic reviews. Several steps are required to overcome the identified difficulties to either adapt and validate available tools or to develop a better suitable tool.

Trial registration

Prospective registration at Open Science Framework (OSF): 10.17605/OSF.IO/PTG4D.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01561-5.

Evaluation of the design, conduct and reporting of randomised controlled trials in the haemodialysis population: a scoping review and interview study

BACKGROUND

Fewer trials are conducted in nephrology than any other specialty, often failing to recruit to target, resulting in unclear evidence affecting translation to clinical practice. This mixed-methods study aims to provide guidance for designing and reporting future randomised controlled trials (RCTs) in the haemodialysis population.

METHOD

A scoping review was conducted. Five databases (MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov) were searched for RCTs published between 2013 and 2019 involving prevalent adult haemodialysis patients. Reporting of sample size, recruitment, retention and statistical significance of primary outcome were assessed. Face-to-face semistructured interviews were conducted with individuals from a single centre during dialysis sessions. Interviews were analysed thematically.

RESULTS

Of 786 RCTs identified, 636 (80.9%) were parallel-group, 139 (17.7%) were crossover and 11 (1.4%) were cluster (including one stepped-wedge) design. Sample size justification was reported in 73.1%, 53.8% and 45.5% of parallel-group, crossover and cluster trials, respectively.Target recruitment was achieved by 45.5% of cluster, 53.8% of crossover and 57.7% of parallel-group trials with patient retention at 75.6%, 83.1% and 87.8%, respectively. Primary outcome reached statistical significance in 81.8% of cluster trials, 69.2% of parallel-group and 38.5% of crossover trials.Themes identified from individual interviews: perceptions of the convenience of trial participation; group allocation; perceptions of the benefits and adverse effects of taking part in clinical trials.

CONCLUSION

The recruitment and reporting of RCTs involving people on haemodialysis could be improved. Involvement of all stakeholders and especially participants in the trial design process may address issues around participant burden and ultimately improve the evidence base for clinical practice.

Chronic Kidney Disease in the Transgender, Nonbinary, or Gender Diverse Person

Nephrologists are increasingly providing care to transgender, nonbinary, and gender diverse (TNBGD) individuals with chronic kidney disease. This narrative review discusses the care of TNBGD individuals from a nephrology perspective. TNBGD individuals are under-represented in the nephrology literature. TNBGD individuals are at an increased risk of adverse outcomes compared with the cisgender population including mental health, cardiovascular disease, malignancy, sexually transmitted infections, and mortality. Gender-affirming hormone therapy (GAHT) with estradiol in transfeminine individuals potentially increases the risk of venous thromboembolism and cardiovascular disease. GAHT with testosterone in transmasculine individuals potentially increases the risk of erythrocytosis and requires careful monitoring. GAHT modifies body composition and lean muscle mass, which in turn influence creatinine generation and excretion, which may impact the performance of estimated glomerular filtration rate (GFR) equations and the estimation of 24-hour urine values from spot urine albumin/protein to creatinine ratios. There are limited studies regarding TNBGD individuals with chronic kidney disease. Additional research is needed to evaluate the effects of GAHT on GFR and biomarkers of kidney function and the performance of the estimated GFR equation in TNBGD populations.

Comparing survival outcomes for kidney transplant recipients with pre-existing diabetes versus those who develop post-transplantation diabetes

INTRODUCTION

The aim of this study was to compare the management strategy and clinical outcomes for kidney transplant recipients with pre-transplant versus post-transplantation diabetes (PTDM) in a contemporary cohort.

METHODS

This is a single-centre, retrospective. observational study of kidney transplant recipients between 2007 and 2018 with follow-up to 31 December 2020. Data were extracted from hospital electronic patient records, with clinical outcomes linked to national data sets. PTDM was diagnosed by international consensus guidelines. Unadjusted and adjusted survival outcomes were assessed with Kaplan-Meier curves and Cox regression models, respectively, with PTDM handled as a time-varying covariate.

RESULTS

Data were analysed for 1,757 kidney transplant recipients, of whom 11.8% (n = 207) had pre-transplant diabetes, and 13.8% (n = 243) developed PTDM with median time to onset 108 days (IQR 46-549 days). Median follow-up was 1,839 days (IQR 928-2985 days). Disparate management strategies were observed, although insulin was the commonest glucose-lowering therapy for all patients with diabetes. In adjusted models, PTDM was associated with lower mortality (HR 0.663, 95% CI 0.543-0.810) and pre-diabetes with higher mortality (HR 1.675, 95% CI 1.396-2.011). However, if analyses are restricted to those with at least 5-year follow-up, then PTDM has no association with mortality (HR 0.771, 95% CI 0.419-1.096), but pre-transplant diabetes remains associated with higher mortality (HR 2.029, 95% CI 1.367-3.012).

CONCLUSIONS

Pre-transplant diabetes remains associated with increased mortality risk after kidney transplantation, but PTDM effects are time dependent. Development of PTDM should be encouraged as a mandated registry return to study the long-term impact on survival outcomes.

Clinical Outcomes With Medium Cut-Off Versus High-Flux Hemodialysis Membranes: A Systematic Review and Meta-Analysis

BACKGROUND

A novel medium cut-off (MCO) dialyzer (Theranova, Baxter Healthcare, Deerfield, IL, USA) enhances large middle molecule clearance while retaining selectivity for molecules >45 000 Da.

OBJECTIVE

We undertook a systematic review and meta-analysis evaluating clinical outcomes with MCO vs high-flux membranes.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Cochrane Library, and Web of Science through July 2020, and gray literature sources from 2017. We included randomized (RS) and nonrandomized studies (NRS) comparing MCO and high-flux membranes in adults receiving maintenance hemodialysis. Pairs of reviewers performed study selection, data extraction, and risk of bias assessment in duplicate. We conducted random-effects pairwise meta-analyses to pool results across studies and used the Grading of Recommendations Assessment, Development and Evaluation approach to assess evidence certainty.

RESULTS

We identified 22 eligible studies (6 RS, 16 NRS; N = 1811 patients; patient-years = 1546). The MCO dialyzer improved (estimate; 95% confidence interval [CI]; certainty rating) quality of life (mean difference [MD] = 16.7/100 points; 6.9 to 26.4; moderate), Kidney Disease Quality of Life Instrument (KDQOL) subscales-burden (MD = 4.0; 1.1 to 6.9; moderate) and effects (MD = 5.4; 3.2 to 7.6; moderate), pruritus (MD = -4.4; -7.1 to -1.7; moderate), recovery time (MD = -420 minutes; -541 to -299; high), and restless legs syndrome (odds ratio = 0.39; 0.29 to 0.53; moderate). There was little to no difference in all-cause mortality (risk difference = -0.4%; -2.8 to 2.1; moderate) and serious adverse events (rate ratio = 0.63; 0.38 to 1.04; low). MCO dialysis reduced hospitalization (rate ratio = 0.48; 0.27 to 0.84; low), infection (rate ratio = 0.38; 0.17 to 0.85; moderate), hospitalization days (MD = -1.5 days; 95% CI, -2.22 to -0.78; moderate), erythropoiesis resistance index (MD = -2.92 U/kg/week/g/L; 95% CI, -4.25 to -1.6; moderate) and cumulative iron use over 12 weeks (MD = -293 mg; 95% CI, -368 to -218; moderate). We found with low certainty that MCO dialysis had little to no effect on KDQOL symptoms/problem list, pain, and physical health and moderate certainty that MCO dialysis likely has no effect on the KDQOL mental health composite.

CONCLUSIONS

We found with predominantly moderate certainty that the MCO dialyzer improves several patient-important outcomes with no apparent risks or harms. More definitive studies are needed to better quantify the effects of MCO membranes on mortality, hospitalization, and other rare events.

Pragmatic Clinical Studies: An Emerging Clinical Research Discipline for Improving Evidence-Based Practice of Cardiovascular Diseases in Asia

Pragmatic clinical studies, as an emerging clinical research discipline, include a wide range of studies that are largely embedded with routine clinical practice aiming to evaluate comparative effectiveness and safety of different clinical intervention strategies. In this review, we described the evolution of the conceptual framework of pragmatic clinical studies, shared perspectives on the importance of pragmatic clinical studies for cardiovascular diseases as a complement to conventional randomized controlled trials, as well as highlighted the specific importance of pragmatic clinical research in improving evidence-based practice for cardiovascular disease managements in Asia.

Pragmatic clinical studies, an emerging clinical research discipline, include a wide range of studies that are largely embedded with routine clinical practice and aim to evaluate the comparative effectiveness and safety of different clinical intervention strategies. Increased availability and quality of electronic medical/health records drives the development of pragmatic clinical studies. In this review, we describe evolution of the conceptual framework of pragmatic clinical studies and share perspectives on the importance of pragmatic clinical studies in evidence-based practice for cardiovascular diseases, as a complement to conventional randomized controlled trials. We also highlight specific needs of pragmatic clinical studies in improving evidence-based practice for cardiovascular disease in Asian countries. The main challenges of pragmatic clinical studies are discussed briefly in this review.

External validity of randomized clinical trial studying preventing depressive symptoms following acute coronary syndrome

OBJECTIVE

The objective of the current study was to quantitatively explore aspects of external validity, both researcher's choices (eligibility) and patient's choices (consent), of a recently conducted clinical trial.

METHODS

A cohesive comparison between the MEDACIS trial (NCT02451293) database and a national quality and research database was conducted. Comparisons between both participants and nonconsenting patients (patient consent) and participants and noneligible patients (researcher selection) were performed. Comparisons of outcomes were depressive and anxiety symptoms, demographics, and somatic or psychiatric comorbidity.

RESULTS

Noneligible patients had significantly higher levels of depressive symptoms and anxiety and were older and more likely to suffer from unstable angina pectoris. Furthermore, noneligible patients were less likely to be married, had a lower educational level, used more medication, and had a higher frequency of comorbidity. Nonconsenting patients had significantly higher levels of depressive symptoms and anxiety and were older and more likely to be females compared to participants.

CONCLUSION

Significant differences were present between noneligible patients and participants; however, more troublingly significant differences were shown between nonconsenting patients and participants. The presence of depressive symptoms and anxiety has a significant impact on patients' willingness to give informed consent in clinical trials in cardiology with a focus on psychological outcomes.

Effect of the FDA Safety and Innovation Act on racial and gender diversity in neurosurgical device trials

OBJECTIVE

The US FDA uses evidence from clinical trials in its determination of safety and utility. However, these trials have often suffered from limited external validity and generalizability due to unrepresentative study populations with respect to clinical patient demographics. Section 907 of the FDA Safety and Innovation Act (FDASIA) of 2012 attempted to address this issue by mandating the reporting of certain study demographics in new device applications. However, no study has been performed on its effectiveness in the participant diversity of neurosurgical device trials.

METHODS

The FDA premarket approval (PMA) online database was queried for all original neurosurgical device submissions from January 1, 2006, to December 31, 2019. Endpoints of the study included racial and gender demographics of reported effectiveness trials, which were summated for each submission. Chi-square tests were performed on both endpoints for before and after years of FDASIA passage and implementation.

RESULTS

A total of 33 device approvals were analyzed, with 14 occurring before SIA implementation and 19 after. Most trials (96.97%) reported gender to the FDA, while 66.67% reported race and 63.64% reported ethnicity. Gender breakdown did not change significantly post-SIA (53.30% female, p = 0.884). Racial breakdown was significantly different from the 2010 US Census for all races (p < 0.001) both pre- and post-SIA. Only Native American race was significantly different in terms of representation post-SIA, increasing from 0% to 0.63% (p = 0.0187). There was no significant change in ethnicity.

CONCLUSIONS

The FDASIA, as currently written, does not appear to have had a significant impact on the racial or gender diversity of neurosurgical device clinical trial populations. This may be due to the noncompulsory nature of its guidance, or a lack of more stringent regulation on the composition of clinical trials themselves.

Clinical comparison between trial participants and potentially eligible patients using electronic health record data: A generalizability assessment method

OBJECTIVE

To present a generalizability assessment method that compares baseline clinical characteristics of trial participants (TP) to potentially eligible (PE) patients as presented in their electronic health record (EHR) data while controlling for clinical setting and recruitment period.

METHODS

For each clinical trial, a clinical event was defined to identify patients of interest using available EHR data from one clinical setting during the trial's recruitment timeframe. The trial's eligibility criteria were then applied and patients were separated into two mutually exclusive groups: (1) TP, which were patients that participated in the trial per trial enrollment data; (2) PE, the remaining patients. The primary outcome was standardized differences in clinical characteristics between TP and PE per trial. A standardized difference was considered prominent if its absolute value was greater than or equal to 0.1. The secondary outcome was the difference in mean propensity scores (PS) between TP and PE per trial, in which the PS represented prediction for a patient to be in the trial. Three diverse trials were selected for illustration: one focused on hepatitis C virus (HCV) patients receiving a liver transplantation; one focused on leukemia patients and lymphoma patients; and one focused on appendicitis patients.

RESULTS

For the HCV trial, 43 TP and 83 PE were found, with 61 characteristics evaluated. Prominent differences were found among 69% of characteristics, with a mean PS difference of 0.13. For the leukemia/lymphoma trial, 23 TP and 23 PE were found, with 39 characteristics evaluated. Prominent differences were found among 82% of characteristics, with a mean PS difference of 0.76. For the appendicitis trial, 123 TP and 242 PE were found, with 52 characteristics evaluated. Prominent differences were found among 52% of characteristics, with a mean PS difference of 0.15.

CONCLUSIONS

Differences in clinical characteristics were observed between TP and PE among all three trials. In two of the three trials, not all of the differences necessarily compromised trial generalizability and subsets of PE could be considered similar to their corresponding TP. In the remaining trial, lack of generalizability appeared present, but may be a result of other factors such as small sample size or site recruitment strategy. These inconsistent findings suggest eligibility criteria alone are sometimes insufficient in defining a target group to generalize to. With caveats in limited scalability, EHR data quality, and lack of patient perspective on trial participation, this generalizability assessment method that incorporates control for temporality and clinical setting promise to better pinpoint clinical patterns and trial considerations.

Real-world comparison of direct-acting oral anticoagulants and vitamin K antagonists in chronic kidney disease: a systematic review and meta-analysis

Background: No clear clinical guidelines exist on anticoagulant use for chronic kidney disease (CKD) patients. We compared the efficacy and safety of direct-acting oral anticoagulants (DOACs) vs. vitamin K antagonists (VKA) in patients with CKD by pooling data from real-world observational studies.Research design & methods: This systematic review searched PubMed, Embase, and CENTRAL databases and pooled multivariable-adjusted hazard ratios (HR) of outcomes.Results: Fifteen studies were included. Our results indicated a small but significant reduction in the risk of all-cause mortality (p = 0.01), stroke or systemic embolism (p = 0.03), and major bleeding (p = 0.01) with DOAC as compared to VKA. In subgroup analysis based on the severity of CKD, no difference in the risk of stroke or systemic embolism was noted in any subgroups. The risk of mortality was reduced only in patients with moderate-severe or severe CKD and the risk of major bleeding was reduced only in patients with moderate-severe or moderate CKD.Conclusion: DOACs are associated with only a modest reduction in stroke or systemic embolism, major bleeding, and mortality when compared to VKA in CKD patients. Reduction in mortality and major bleeding with DOAC may only be seen in moderate-to-severe CKD patients.

Randomized clinical trials and real life studies: Comparison of baseline characteristics of patients in oral target therapies for renal cell carcinoma

INTRODUCTION

Pivotal Randomized Controlled Trials (RCTs) constitute scientific evidence in support of therapeutic choices when a drug is authorized in the market. In RCTs, patients are selected in a rigorous manner, in order to avoid bias that may influence efficacy assessments. Therefore, patients who take the drug in Real Life Studies (RLSs) are not the same as those participating in RCTs, which, in turn, leads to low data transferability from RCTs to RLS. The objective of this study was to evaluate the differences between RCTs and RLS, in terms of patient baseline characteristics.

MATERIALS AND METHODS

Our study includes all oral target therapies for RCC (Renal Cell Carcinoma) marketed in Europe before March 31, 2019. For each treatment, we considered both RCTs and RLSs, the former gathered from Summary of Product Characteristics published on the European Medicine Agency (EMA) website, and the latter yielded by our search in relevant literature. For each drug considered, we then compared the baseline characteristics of patients included in the RCT samples with those of the samples included in the RLSs using the Chi-squared and Mann-Whitney tests.

RESULTS

We considered six medicines, for a total of 9 pivotal RCTs and 31 RLSs. RCTs reported the same type of patient baseline characteristics, whereas RLSs are more varied in reporting. Some patient baseline characteristics (metastases, previous treatments, etc.) were significantly different between RCTs and RLs. Other characteristics, such as ECOG Performance Status, brain metastases, and comorbidities, liver and kidney failure, are comprised in exclusion criteria of RCTs, though are included in RLS.Discussion and Conclusion: While evaluating equal treatments for the same indications, RCTs and RLSs do not always assess patients with the same characteristics. It would be necessary to produce evidence from RLSs so as to have an idea of treatment effectiveness in patients groups that are not eligible or underrepresented in RCTs.

Comparison of Clinical Characteristics Between Clinical Trial Participants and Nonparticipants Using Electronic Health Record Data

IMPORTANCE

Assessing generalizability of clinical trials is important to ensure appropriate application of interventions, but most assessments provide minimal granularity on comparisons of clinical characteristics.

OBJECTIVE

To assess the extent of underlying clinical differences between clinical trial participants and nonparticipants by using a combination of electronic health record and trial enrollment data.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used data obtained from a single academic medical center between September 1996 and January 2019 to identify 1645 clinical trial participants from a diverse set of 202 available trials conducted at the center. Using an aggregated resampling procedure, nonparticipants were matched to participants 1:1 based on trial conditions, number of recent visits to a health care professional, and calendar time.

EXPOSURES

Clinical trial enrollment vs no enrollment.

MAIN OUTCOMES AND MEASURES

The primary outcome was standardized differences in clinical characteristics between participants and nonparticipants in clinical trials stratified into the 4 most common disease domains.

RESULTS

This cross-sectional study included 1645 participants from 202 trials (929 [56.5%] male; mean [SD] age, 54.65 [21.38] years) and an aggregated set of 1645 nonparticipants (855 [52.0%] male; mean [SD] age, 57.24 [21.91] years). The most common disease domains for the selected trials were neoplastic disease (86 trials; 737 participants), disorders of the digestive system (31 trials; 321 participants), inflammatory disorders (28 trials; 276 participants), and disorders of the cardiovascular system (27 trials; 319 participants); trials could qualify for multiple disease domains. Among 31 conditions, the percentage of conditions for which the prevalence was lower among participants than among nonparticipants per standardized differences was 64.5% (20 conditions) for neoplastic disease trials, 61.3% (19) for digestive system trials, 58.1% (18) for inflammatory disorder trials, and 38.7% (12) for cardiovascular system trials. Among 17 medications, the percentage of medications for which use was less among participants than among nonparticipants per standardized differences was 64.7% (11) for neoplastic disease trials, 58.8% (10) for digestive system trials, 88.2% (15) for inflammatory disorder trials, and 52.9% (9) for cardiovascular system trials.

CONCLUSIONS AND RELEVANCE

Using a combination of electronic health record and trial enrollment data, this study found that clinical trial participants had fewer comorbidities and less use of medication than nonparticipants across a variety of disease domains. Combining trial enrollment data with electronic health record data may be useful for better understanding of the generalizability of trial results.

Comparison of the outcomes of the prolonged antianginal therapy use in stable coronary artery disease patients according to the data of randomized and observational studies

Objective

To compare the results of treatment with antianginal drug nicorandil in patients with stable coronary artery disease according to the results of the observational study (OS) «NIKEA» and randomized controlled trial (RCT) «IONA».

Methods

«NIKEA » observational program included 590 patients with stable angina pectoris. Subgroups in the OS were formed based on the adherence to nicorandil use. Adherence was assessed during follow-up direct questioning. «IONA » RCT included 5126 patients with stable angina pectoris.

Results

Follow-up period and mean age of patients were equal in OS and RCT. In OS the group of adherent to nicorandil use patients had fewer males, life-saving drugs were administered significantly more often than in RCT, comorbidities (arterial hypertension, peripheral atherosclerosis and diabetes mellitus) were more pronounced. Angina pectoris class III was diagnosed in 32% of the OS patients vs 11% of the RCT patients, and class I – in 4.4% and 26%, respectively (р<0.001). Both in RCT and OS, there were significantly fewer cases of all cardiovascular events in the groups of nicorandil and adherent to nicorandil use patients in comparison with the groups of placebo and nonadherent patients. Both in RCT and OS the use of nicorandil led to significant decrease in the risk of all cardiovascular events.

Conclusion

Results of the efficacy and effectiveness studies complement each other and give the opportunity to assess the realisation of the RCT results in real clinical practice.

Assessment of a Clinical Trial-Derived Survival Model in Patients With Metastatic Castration-Resistant Prostate Cancer

IMPORTANCE

Randomized clinical trials (RCTs) are considered the criterion standard for clinical evidence. Despite their many benefits, RCTs have limitations, such as costliness, that may reduce the generalizability of their findings among diverse populations and routine care settings.

OBJECTIVE

To assess the performance of an RCT-derived prognostic model that predicts survival among patients with metastatic castration-resistant prostate cancer (CRPC) when the model is applied to real-world data from electronic health records (EHRs).

DESIGN, SETTING, AND PARTICIPANTS

The RCT-trained model and patient data from the RCTs were obtained from the Dialogue for Reverse Engineering Assessments and Methods (DREAM) challenge for prostate cancer, which occurred from March 16 to July 27, 2015. This challenge included 4 phase 3 clinical trials of patients with metastatic CRPC. Real-world data were obtained from the EHRs of a tertiary care academic medical center that includes a comprehensive cancer center. In this study, the DREAM challenge RCT-trained model was applied to real-world data from January 1, 2008, to December 31, 2019; the model was then retrained using EHR data with optimized feature selection. Patients with metastatic CRPC were divided into RCT and EHR cohorts based on data source. Data were analyzed from March 23, 2018, to October 22, 2020.

EXPOSURES

Patients who received treatment for metastatic CRPC.

MAIN OUTCOMES AND MEASURES

The primary outcome was the performance of an RCT-derived prognostic model that predicts survival among patients with metastatic CRPC when the model is applied to real-world data. Model performance was compared using 10-fold cross-validation according to time-dependent integrated area under the curve (iAUC) statistics.

RESULTS

Among 2113 participants with metastatic CRPC, 1600 participants were included in the RCT cohort, and 513 participants were included in the EHR cohort. The RCT cohort comprised a larger proportion of White participants (1390 patients [86.9%] vs 337 patients [65.7%]) and a smaller proportion of Hispanic participants (14 patients [0.9%] vs 42 patients [8.2%]), Asian participants (41 patients [2.6%] vs 88 patients [17.2%]), and participants older than 75 years (388 patients [24.3%] vs 191 patients [37.2%]) compared with the EHR cohort. Participants in the RCT cohort also had fewer comorbidities (mean [SD], 1.6 [1.8] comorbidities vs 2.5 [2.6] comorbidities, respectively) compared with those in the EHR cohort. Of the 101 variables used in the RCT-derived model, 10 were not available in the EHR data set, 3 of which were among the top 10 features in the DREAM challenge RCT model. The best-performing EHR-trained model included only 25 of the 101 variables included in the RCT-trained model. The performance of the RCT-trained and EHR-trained models was adequate in the EHR cohort (mean [SD] iAUC, 0.722 [0.118] and 0.762 [0.106], respectively); model optimization was associated with improved performance of the best-performing EHR model (mean [SD] iAUC, 0.792 [0.097]). The EHR-trained model classified 256 patients as having a high risk of mortality and 256 patients as having a low risk of mortality (hazard ratio, 2.7; 95% CI, 2.0-3.7; log-rank P < .001).

CONCLUSIONS AND RELEVANCE

In this study, although the RCT-trained models did not perform well when applied to real-world EHR data, retraining the models using real-world EHR data and optimizing variable selection was beneficial for model performance. As clinical evidence evolves to include more real-world data, both industry and academia will likely search for ways to balance model optimization with generalizability. This study provides a pragmatic approach to applying RCT-trained models to real-world data.

Statins and atherosclerotic cardiovascular outcomes in patients on incident dialysis and with atherosclerotic heart disease

Statins failed to reduce cardiovascular (CV) events in trials of patients on dialysis. However, trial populations used criteria that often excluded those with atherosclerotic heart disease (ASHD), in whom statins have the greatest benefit, and included outcome composites with high rates of nonatherosclerotic CV events that may not be modified by statins. Here, we study whether statin use associates with lower atherosclerotic CV risk among patients with known ASHD on dialysis, including in those likely to receive a kidney transplant, a group excluded within trials but with lower competing mortality risks.

METHODS

Using data from the United States Renal Data System including Medicare claims, we identified adults initiating dialysis with ASHD. We matched statin users 1:1 to statin nonusers with propensity scores incorporating hard matches for age and kidney transplant listing status. Using Cox models, we evaluated associations of statin use with the primary composite of fatal/nonfatal myocardial infarction and stroke (including within prespecified subgroups of younger age [<50 years] and waitlisting status); secondary outcomes included all-cause mortality and the composite of all-cause mortality, nonfatal myocardial infarction, or stroke.

RESULTS

Of 197,716 patients with ASHD, 47,562 (24%) were consistent statin users from which we created 46,186 matched pairs. Over a median 662 days, statin users had similar risk of fatal/nonfatal myocardial infarction or stroke overall (hazard ratio [HR] 1.00, 95% CI 0.97-1.02), or in subgroups (age< 50 years [HR = 1.05, 95% CI 0.95-1.17]; waitlisted for kidney transplant [HR 0.99, 95% CI 0.97-1.02]). Statin use was modestly associated with lower all-cause mortality (HR 0.96, 95% CI 0.94-0.98; E value = 1.21) and, similarly, a modest lower composite risk of all-cause mortality, nonfatal myocardial infarction, or stroke over the first 2 years (HR 0.90, 95% CI 0.88-0.91) but attenuated thereafter (HR 0.98, 95% CI 0.96-1.01).

CONCLUSIONS

Our large observational analyses are consistent with trials in more selected populations and suggest that statins may not meaningfully reduce atherosclerotic CV events even among incident dialysis patients with established ASHD and those likely to receive kidney transplants.

Pharmacoepidemiology for nephrologists (part 1): concept, applications and considerations for study design

Randomized controlled trials on drug safety and effectiveness are the foundation of medical evidence, but they may have limited generalizability and be unpowered to detect rare and long-term kidney outcomes. Observational studies in routine care data can complement and expand trial evidence on the use, safety and effectiveness of medications and aid with clinical decisions in areas where evidence is lacking. Access to routinely collected large healthcare data has resulted in the proliferation of studies addressing the effect of medications in patients with kidney diseases and this review provides an introduction to the science of pharmacoepidemiology to critically appraise them. In this first review we discuss the concept and applications of pharmacoepidemiology, describing methods for drug-utilization research and discussing the strengths and caveats of the most commonly used study designs to evaluate comparative drug safety and effectiveness.

Real-world Evidence to Estimate Prostate Cancer Costs for First-line Treatment or Active Surveillance

Background

Prostate cancer is the most common cancer in men and second leading cause of cancer-related deaths. Changes in screening guidelines, adoption of active surveillance (AS), and implementation of high-cost technologies have changed treatment costs. Traditional cost-effectiveness studies rely on clinical trial protocols unlikely to capture actual practice behavior, and existing studies use data predating new technologies. Real-world evidence reflecting these changes is lacking.

Objective

To assess real-world costs of first-line prostate cancer management.

Design setting and participants

We used clinical electronic health records for 2008-2018 linked with the California Cancer Registry and the Medicare Fee Schedule to assess costs over 24 or 60 mo following diagnosis. We identified surgery or radiation treatments with structured methods, while we used both structured data and natural language processing to identify AS.

Outcome measurements and statistical analysis

Our results are risk-stratified calculated cost per day (CCPD) for first-line management, which are independent of treatment duration. We used the Kruskal-Wallis test to compare unadjusted CCPD while analysis of covariance log-linear models adjusted estimates for age and Charlson comorbidity.

Results and limitations

In 3433 patients, surgery (54.6%) was more common than radiation (22.3%) or AS (23.0%). Two years following diagnosis, AS ($2.97/d) was cheaper than surgery ($5.67/d) or radiation ($9.34/d) in favorable disease, while surgery ($7.17/d) was cheaper than radiation ($16.34/d) for unfavorable disease. At 5 yr, AS ($2.71/d) remained slightly cheaper than surgery ($2.87/d) and radiation ($4.36/d) in favorable disease, while for unfavorable disease surgery ($4.15/d) remained cheaper than radiation ($10.32/d). Study limitations include information derived from a single healthcare system and costs based on benchmark Medicare estimates rather than actual payment exchanges.

Patient summary

Active surveillance was cheaper than surgery (-47.6%) and radiation (-68.2%) at 2 yr for favorable-risk disease, which decreased by 5 yr (-5.6% and -37.8%, respectively). Surgery was less costly than radiation for unfavorable risk for both intervals (-56.1% and -59.8%, respectively).

Ethical Issues in the Design and Conduct of Pragmatic Cluster Randomized Trials in Hemodialysis Care: An Interview Study With Key Stakeholders

BACKGROUND

Pragmatic cluster randomized trials (CRTs) offer an opportunity to improve health care by answering important questions about the comparative effectiveness of treatments using a trial design that can be embedded in routine care. There is a lack of empirical research that addresses ethical issues generated by pragmatic CRTs in hemodialysis.

OBJECTIVE

To identify stakeholder perceptions of ethical issues in pragmatic CRTs conducted in hemodialysis.

DESIGN

Qualitative study using semi-structured interviews.

SETTING

In-person or telephone interviews with an international group of stakeholders.

PARTICIPANTS

Stakeholders (clinical investigators, methodologists, ethicists and research ethics committee members, and other knowledge users) who had been involved in the design or conduct of a pragmatic individual patient or cluster randomized trial in hemodialysis, or their role would require them to review and evaluate pragmatic CRTs in hemodialysis.

METHODS

Interviews were conducted in-person or over the telephone and were audio-recorded with consent. Recorded interviews were transcribed verbatim prior to analysis. Transcripts and field notes were analyzed using a thematic analysis approach.

RESULTS

Sixteen interviews were conducted with 19 individuals. Interviewees were largely drawn from North America (84%) and were predominantly clinical investigators (42%). Six themes were identified in which pragmatic CRTs in hemodialysis raise ethical issues: (1) patients treated with hemodialysis as a vulnerable population, (2) appropriate approaches to informed consent, (3) research burdens, (4) roles and responsibilities of gatekeepers, (5) inequities in access to research, and (6) advocacy for patient-centered research and outcomes.

LIMITATIONS

Participants were largely from North America and did not include research staff, who may have differing perspectives.

CONCLUSIONS

The six themes reflect concerns relating to individual rights, but also the need to consider population-level issues. To date, concerns regarding inequity of access to research and the need for patient-centered research have received less coverage than other, well-known, issues such as consent. Pragmatic CRTs offer a potential approach to address equity concerns and we suggest future ethical analyses and guidance for pragmatic CRTs in hemodialysis embed equity considerations within them. We further note the potential for the co-creation of health data infrastructure with patients which would aid care but also facilitate patient-centered research. These present results will inform planned future guidance in relation to the ethical design and conduct of pragmatic CRTs in hemodialysis.

TRIAL REGISTRATION

Registration is not applicable as this is a qualitative study.

Total Flavones of Abelmoschus manihot Remodels Gut Microbiota and Inhibits Microinflammation in Chronic Renal Failure Progression by Targeting Autophagy-Mediated Macrophage Polarization

Background

Recently, progression of chronic renal failure (CRF) has been closely associated with gut microbiota dysbiosis and intestinal metabolite-derived microinflammation. In China, total flavones of Abelmoschus manihot (TFA), a component of Abelmoschus manihot, has been widely used to delay CRF progression in clinics for the past two decades. However, the overall therapeutic mechanisms remain obscure. In this study, we designed experiments to investigate the renoprotective effects of TFA in CRF progression and its underlying mechanisms involved in gut microbiota and microinflammation, compared with febuxostat (FEB), a potent non-purine selective inhibitor of xanthine oxidase.

Methods

In vivo, the CRF rat models were induced by uninephrectomy, potassium oxonate, and proinflammatory diet, and received either TFA suspension, FEB, or vehicle after modeling for 28 days. In vitro, the RAW 264.7 cells were exposed to lipopolysaccharide (LPS) with or without TFA or FEB. Changes in parameters related to renal injury, gut microbiota dysbiosis, gut-derived metabolites, and microinflammation were analyzed in vivo. Changes in macrophage polarization and autophagy and its related signaling were analyzed both in vivo and in vitro.

Results

For the modified CRF model rats, the administration of TFA and FEB improved renal injury, including renal dysfunction and renal tubulointerstitial lesions; remodeled gut microbiota dysbiosis, including decreased Bacteroidales and Lactobacillales and increased Erysipelotrichales; regulated gut-derived metabolites, including d-amino acid oxidase, serine racemase, d-serine, and l-serine; inhibited microinflammation, including interleukin 1β (IL1β), tumor necrosis factor-α, and nuclear factor-κB; and modulated macrophage polarization, including markers of M1/M2 macrophages. More importantly, TFA and FEB reversed the expression of beclin1 (BECN1) and phosphorylation of p62 protein and light chain 3 (LC3) conversion in the kidneys by activating the adenosine monophosphate-activated protein kinase-sirtuin 1 (AMPK-SIRT1) signaling. Further, TFA and FEB have similar effects on macrophage polarization and autophagy and its related signaling in vitro.

Conclusion

In this study, we demonstrated that TFA, similar to FEB, exerts its renoprotective effects partially by therapeutically remodeling gut microbiota dysbiosis and inhibiting intestinal metabolite-derived microinflammation. This is achieved by adjusting autophagy-mediated macrophage polarization through AMPK-SIRT1 signaling. These findings provide more accurate information on the role of TFA in delaying CRF progression.

Improving Sexual Function in People With Chronic Kidney Disease: A Narrative Review of an Unmet Need in Nephrology Research

Purpose of review:

Sexual dysfunction occurs commonly in people with chronic kidney disease (CKD) and has been recognized as a research priority. We sought to evaluate the current state of the literature addressing sexual dysfunction in people with CKD and identify barriers and strategies to improve our management of this important symptom.

Sources of information:

OVID Medline and Google Scholar were searched for English, peer-reviewed studies using keywords and terms related to “Chronic Kidney Disease,” “sexuality,” and “sexual dysfunction OR function.”

Methods:

In this narrative review, we describe definitions of sexual dysfunction and contributors exacerbated by CKD, barriers to researching sexual dysfunction in people with CKD, and possible avenues for future research.

Key findings:

Sexual dysfunction is common in people with CKD and results from a combination of kidney disease itself, as well as its associated physical (ie, comorbidities) and nonphysical factors. Barriers to the study of sexual dysfunction in CKD include inconsistent disease definitions, stigma, variable efficacy and safety of established therapies, and evolving gender roles in sexual function. Potential avenues for future research to improve the sexual function in people with CKD may include evaluating the safety and efficacy of established therapies in people with CKD using a variety of observational and interventional study designs, engaging people with CKD and multidisciplinary team members in research, and using implementation science methods to translate what is known about sexual function into clinical practice. Concerted efforts are required to break down barriers and improve sexual function in people with CKD. Patients have identified this as an important research priority, and national networks need to direct efforts to reduce symptom burden.

Limitations:

This narrative review was limited by a paucity of high-quality studies examining sexual dysfunction specifically in people with kidney disease.

Temporal changes in dialysate [Na+] prescription from 1996 to 2018 and their clinical significance as judged from a meta-regression of clinical trials

Over the last two decades, the clinical care of dialysis patients has refocused sharply on fluid volume control. Dialysate [Na⁺] is a key, albeit under-investigated, clinical tool for manipulation of fluid volume on dialysis. In the article, we firstly use data from the Dialysis Outcomes and Practice Patterns Study to document the global decrease in dialysate [Na⁺] that has occurred from 1996 to 2018, and demonstrate the virtual disappearance of [Na⁺] profiling from routine dialysis practice over the same period. Second, we used data from previously synthesized randomized clinical trial evidence combined with that of a more recently published trail to assess the clinical significance of these changes, estimating the effects of different levels of low dialysate [Na⁺] on key clinical outcomes. Our analyses suggest that current levels of dialysate [Na⁺] in some health jurisdictions are possibly causing harm to many patients, especially given that real world populations are significantly less robust and more vulnerable than clinical trial ones. To quote a recent editorial, "more evidence needed before lower dialysate sodium concentrations can be recommended." That evidence is coming, and no further changes should be made to default customary practice until it is available.

Associations between multimorbidity and adverse clinical outcomes in patients with chronic kidney disease: a systematic review and meta-analysis

OBJECTIVE

To systematically review the literature exploring the associations between multimorbidity (the presence of two or more long-term conditions (LTCs)) and adverse clinical outcomes in patients with chronic kidney disease (CKD).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Cochrane Library and SCOPUS (1946-2019). The main search terms were 'Chronic Kidney Failure' and 'Multimorbid*'.

ELIGIBILITY CRITERIA

Observational studies of adults over the age of 18 with CKD stages 3-5, that is, estimated glomerular filtration rate less than 60 mL/min/1.73 m2. The exposure was multimorbidity quantified by measures and the outcomes were all-cause mortality, renal progression, hospitalisation and cardiovascular events. We did not consider CKD as a comorbid LTC.

DATA EXTRACTION AND SYNTHESIS

Newcastle-Ottawa Scale for quality appraisal and risk of bias assessment and fixed effects meta-analysis for data synthesis.

RESULTS

Of 1852 papers identified, 26 met the inclusion criteria. 21 papers involved patients with advanced CKD and no studies were from low or middle-income countries. All-cause mortality was an outcome in all studies. Patients with multimorbidity were at higher risk of mortality compared with patients without multimorbidity (total risk ratio 2.28 (95% CI 1.81 to 2.88)). The risk of mortality was higher with increasing multimorbidity (total HR 1.31 (95% CI 1.27 to 1.36)) and both concordant and discordant LTCs were associated with heightened risk. Multimorbidity was associated with renal progression in four studies, hospitalisation in five studies and cardiovascular events in two studies.

LIMITATIONS

Meta-analysis could only include 10 of 26 papers as the methodologies of studies were heterogeneous.

CONCLUSIONS

There are associations between multimorbidity and adverse clinical outcomes in patients with CKD. However, most data relate to mortality risk in patients with advanced CKD. There is limited evidence regarding patients with mild to moderate CKD, outcomes such as cardiovascular events, types of LTCs and regarding patients from low or middle-income countries.

PROSPERO REGISTRATION NUMBER

CRD42019147424.

Cultivating Innovative Pragmatic Cluster-Randomized Registry Trials Embedded in Hemodialysis Care: Workshop Proceedings From 2018

Hemodialysis is a life-sustaining treatment for persons with kidney failure. However, those on hemodialysis still face a poor quality of life and a short life expectancy. High-quality research evidence from large randomized controlled trials is needed to identify interventions that improve the experiences, outcomes, and health care of persons receiving hemodialysis. With the support of the Canadian Institutes of Health Research and its Strategy for Patient-Oriented Research, the Innovative Clinical Trials in Hemodialysis Centers initiative brought together Canadian and international kidney researchers, patients, health care providers, and health administrators to participate in a workshop held in Toronto, Canada, on June 2 and 3, 2018. The workshop served to increase knowledge and awareness about the conduct of innovative, pragmatic, cluster-randomized registry trials embedded into routine hemodialysis care and provided an opportunity to discuss and build support for new trial ideas. The workshop content included structured presentations, facilitated group discussions, and expert panel feedback. Partnerships and promising trial ideas borne out of the workshop will continue to be developed to support the implementation of future large-scale trials.

Inequities in the global representation of sites participating in large, multicentre dialysis trials: a systematic review

Background

The number of dialysis recipients is growing worldwide, making it important that the full range of patient populations are represented in randomised trials. As trial recruitment has not previously been examined at a global level, we compared the location of trial sites recruiting to large multicentre randomised controlled trials (RCTs) in dialysis to the global distribution of dialysis recipients.

Methods

A systematic review (2007–2016) was conducted to identify RCTs enrolling ≥100 dialysis patients from ≥2 sites. The number and location of sites were extracted from manuscripts and trial registration. The proportion of sites from each International Society of Nephrology global region was divided by the proportion of the global dialysis population in that region to determine a ‘representation index’ (RI), where 1.0 indicated that the number of sites was proportionate to the number of dialysis recipients in that region.

Results

We identified 180 RCTs, recruiting from 6172 sites in 54 countries. Eastern and Central Europe had the highest RI at 2.45. Other well-represented regions were Western Europe (2.20), North America (2.06), and Russia and newly independent states (1.36). Africa had the lowest RI at 0.05, followed by South Asia (0.08), Latin America (0.15), Middle East (0.27), North-East Asia (0.41), and South-East Asia and Oceania (0.62).

Conclusions

Regions of the world with growing numbers of dialysis patients are poorly represented in large, multicentre RCTs. Efforts to boost trial participation in these regions are required to ensure that generalisable and relevant information is available to local healthcare providers.