Clinical Validation of Novel Digital Measures: Statistical Methods for Reliability Evaluation

Background: Assessment of reliability is one of the key components of the validation process designed to demonstrate that a novel clinical measure assessed by a digital health technology tool is fit-for-purpose in clinical research, care, and decision-making. Reliability assessment contributes to characterization of the signal-to-noise ratio and measurement error and is the first indicator of potential usefulness of the proposed clinical measure. Summary: Methodologies for reliability analyses are scattered across literature on validation of PROs, wet biomarkers, etc., yet are equally useful for digital clinical measures. We review a general modeling framework and statistical metrics typically used for reliability assessments as part of the clinical validation. We also present methods for the assessment of agreement and measurement error, alongside modified approaches for categorical measures. We illustrate the discussed techniques using physical activity data from a wearable device with an accelerometer sensor collected in clinical trial participants. Key Messages: This paper provides statisticians and data scientists, involved in development and validation of novel digital clinical measures, an overview of the statistical methodologies and analytical tools for reliability assessment

Moxifloxacin in Pediatric Patients With Complicated Intra-abdominal Infections: Results of the MOXIPEDIA Randomized Controlled Study

Background: This study was designed to evaluate primarily the safety and also the efficacy of moxifloxacin (MXF) in children with complicated intraabdominal infections (cIAIs). Methods: In this multicenter, randomized, double-blind, controlled study, 451 pediatric patients aged 3 months to 17 years with cIAIs were treated with intravenous/oral MXF (N = 301) or comparator (COMP, intravenous ertapenem followed by oral amoxicillin/clavulanate; N = 150) for 5 to 14 days. Doses of MXF were selected based on the results of a Phase 1 study in pediatric patients (NCT01049022). The primary endpoint was safety, with particular focus on cardiac and musculoskeletal safety; clinical and bacteriologic efficacy at test of cure was also investigated. Results: The proportion of patients with adverse events (AEs) was comparable between the 2 treatment arms (MXF: 58.1% and COMP: 54.7%). The incidence of drug-related AEs was higher in the MXF arm than in the COMP arm (14.3% and 6.7%, respectively). No cases of QTc interval prolongation-related morbidity or mortality were observed. The proportion of patients with musculoskeletal AEs was comparable between treatment arms; no drug-related events were reported. Clinical cure rates were 84.6% and 95.5% in the MXF and COMP arms, respectively, in patients with confirmed pathogen(s) at baseline. Conclusions: MXF treatment was well tolerated in children with cIAIs. However, a lower clinical cure rate was observed with MXF treatment compared with COMP. This study does not support a recommendation of MXF for children with cIAIs when alternative more efficacious antibiotics with better safety profile are available

Development and Validation of a New Hierarchical Composite End Point for Clinical Trials of Kidney Disease Progression

BACKGROUND: The established composite kidney end point in clinical trials combines clinical events with sustained large changes in GFR. However, the statistical method does not weigh the relative clinical importance of the end point components. A HCE accounts for the clinical importance of the end point components and enables combining dichotomous outcomes with continuous measures. METHODS: We developed and validated a new HCE for kidney disease progression, performing post hoc analyses of seven major Phase 3 placebo-controlled trials that assessed the effects of canagliflozin, dapagliflozin, finerenone, atrasentan, losartan, irbesartan, and aliskiren in patients with CKD. We calculated the win odds (WOs) for treatment effects on a kidney HCE, defined as a hierarchical composite of all-cause mortality; kidney failure; sustained 57%, 50%, and 40% GFR declines from baseline; and GFR slope. The WO describes the odds of a more favorable outcome for receiving the active compared with the control. We compared the WO with the hazard ratio (HR) of the primary kidney outcome of the original trials. RESULTS: In all trials, treatment effects calculated with the WO reflected a similar direction and magnitude of the treatment effect compared with the HR. Clinical trials incorporating the HCE would achieve increased statistical power compared with the established composite end point at equivalent sample sizes. CONCLUSIONS: In seven major kidney clinical trials, the WO and HR provided similar direction of treatment effect estimates with smaller HRs associated with larger WOs. The prioritization of clinical outcomes and inclusion of broader composite end points makes the HCE an attractive alternative to the established kidney end point

The changing importance of key factors associated with anaemia in 6- to 59-month-old children in a sub-Saharan African setting where malaria is on the decline: analysis of the Rwanda Demographic and Health Survey 2010.

OBJECTIVE: To estimate the relative contribution of malaria and other potential determinants to current anaemia prevalence in Rwanda. METHODS: The database for this study was the Rwanda Demographic and Health Survey 2010. Haemoglobin and malaria test results, and additional exposures ascertained through mothers' interviews, were analysed for all eligible children age 6-59 months (n = 4068), in addition to diet data available for the youngest under 5-year-old per household. We examined anaemia-exposure associations through forward logistic regression, first for the overall population (n = 3685), and second, for the subpopulation with diet data (n = 1934). RESULTS: In the overall study population, malaria was strongly associated with anaemia (OR = 6.83, 95% CI: 2.90-16.05), but population impact was modest (population-attributable fraction = 2.5%). Factors associated with lower odds of anaemia were recent de-worming medication (six months; OR = 0.60, 95% CI: 0.49-0.74), female sex (OR = 0.76, 95% CI: 0.66-0.87), increasing age, residence in North Province and educated mother. Being underweight and recent fever (two weeks) were associated with higher odds. In the subpopulation with diet data, odds were lower with consumption of vitamin A-rich foods (OR = 0.66, 95% CI: 0.50-0.88); and higher in households with many young children. CONCLUSIONS: Malaria remains a strong determinant of anaemia for the individual child: transmission control efforts must be maintained. At population level, to further reduce anaemia prevalence, promoting regular vitamin A intake from natural sources and reducing intestinal helminths burden appear the most promising strategies to explore; exploring potential hitherto unidentified sex-linked factors is warranted

Validity and Utility of a Hierarchical Composite End Point for Clinical Trials of Kidney Disease Progression:A Review

Clinical trials in nephrology often use composite end points comprising clinical events, such as onset of ESKD and initiation of kidney function replacement therapy, along with a sustained large (e.g., $50$50%. By contrast, hierarchical composite end points (HCEs) combine multiple outcomes and prioritize each patient’s most clinically relevant outcome for inclusion in analysis. In this review, we consider the use of HCEs in clinical trials of CKD progression, emphasizing the potential to combine dichotomous clinical events such as those typically used in CKD progression trials, with the continuous variable of GFR over time, while ranking all components according to clinical significance. We consider maraca plots to visualize overall treatment effects and the contributions of individual components, discuss the application of win odds in kidney HCE trials, and review general design considerations for clinical trials for CKD progression with kidney HCE as an efficacy end point.</p

Development and Validation of a New Hierarchical Composite End Point for Clinical Trials of Kidney Disease Progression

Background The established composite kidney end point in clinical trials combines clinical events with sustained large changes in GFR. However, the statistical method does not weigh the relative clinical importance of the end point components. A HCE accounts for the clinical importance of the end point components and enables combining dichotomous outcomes with continuous measures. Methods We developed and validated a new HCE for kidney disease progression, performing post hoc analyses of seven major Phase 3 placebo-controlled trials that assessed the effects of canagliflozin, dapagliflozin, finerenone, atrasentan, losartan, irbesartan, and aliskiren in patients with CKD. We calculated the win odds (WOs) for treatment effects on a kidney HCE, defined as a hierarchical composite of all-cause mortality; kidney failure; sustained 57%, 50%, and 40% GFR declines from baseline; and GFR slope. The WO describes the odds of a more favorable outcome for receiving the active compared with the control. We compared the WO with the hazard ratio (HR) of the primary kidney outcome of the original trials. Results In all trials, treatment effects calculated with the WO reflected a similar direction and magnitude of the treatment effect compared with the HR. Clinical trials incorporating the HCE would achieve increased statistical power compared with the established composite end point at equivalent sample sizes. Conclusions In seven major kidney clinical trials, the WO and HR provided similar direction of treatment effect estimates with smaller HRs associated with larger WOs. The prioritization of clinical outcomes and inclusion of broader composite end points makes the HCE an attractive alternative to the established kidney end point.</p

Digital health and artificial intelligence in kidney research: a report from the 2020 Kidney Disease Clinical Trialists (KDCT) meeting.

The exponential growth in digital technology coupled with the global COVID-19 pandemic is driving a profound change in the delivery of medical care and research conduct. The growing availability of electronic monitoring, electronic health records, smartphones and other devices, and access to ever greater computational power, provides new opportunities, but also new challenges. Artificial intelligence (AI) exemplifies the potential of this digital revolution, which also includes other tools such as mobile health (mHealth) services and wearables. Despite digital technology becoming commonplace, its use in medicine and medical research is still in its infancy, with many clinicians and researchers having limited experience with such tools in their usual practice. This paper, derived from the 'Digital Health and Artificial Intelligence' session of the Kidney Disease Clinical Trialists virtual workshop held in September 2020, aims to illustrate the breadth of applications to which digital tools and AI can be applied in clinical medicine and research. It highlights several innovative projects incorporating digital technology that range from streamlining medical care of those with acute kidney injury to the use of AI to navigate the vast genomic and proteomic data gathered in kidney disease. Important considerations relating to any new digital health project are presented, with a view to encouraging the further evolution and refinement of these new tools in a manner that fosters collaboration and the generation of robust evidence

Vericiguat and NT‐proBNP in patients with heart failure with reduced ejection fraction: analyses from the VICTORIA trial

International audienceAims Treatment response to vericiguat, based on baseline N-terminal pro-brain natriuretic peptide (NT-proBNP) subgroups specified in the protocol, was evaluated in the heart failure (HF) VICTORIA trial population by post hoc analysis of combined lower three quartiles [Q1-Q3] vs. the upper quartile [Q4]. Methods and results VICTORIA participants with available baseline NT-proBNP levels (n = 4805; 95.1% of total) were included. Compared with patients in Q1-Q3 (NT-proBNP: Q1, ≤1556 pg/mL; Q2, >1556-2816 pg/mL; and Q3, >2816-5314 pg/mL), patients in Q4 (NT-proBNP: >5314 pg/mL) were older (69.2 ± 12.0 vs. 66.6 ± 12.1 years), had lower mean ejection fraction (27.2 ± 8.3% vs. 29.5 ± 8.2%; P < 0.0001), and were more likely to be in New York Heart Association (NYHA) Class III (51.8 vs. 35.6%) or IV (2.4 vs. 1.0%). Compared with Q1-Q3, patients in Q4 had higher mean Meta-Analysis Global Group in Chronic Heart Failure risk score (27.3 ± 6.6 vs. 23.5 ± 6.4; P < 0.0001), had lower mean estimated glomerular filtration rate (eGFR; 51.5 ± 25.5 vs. 65.0 ± 26.8 mL/min/1.73 m 2 ; P < 0.0001) and haemoglobin (12.8 ± 2.0 vs. 13.6 ± 1.9 g/dL; P < 0.0001), and more had atrial fibrillation (48.7% vs. 43.1%; P = 0.0007) and were randomized while hospitalized for HF (14.8 vs. 9.9%; P < 0.0001). Target dose was achieved in 72.3 and 63.7% of patients in Q1-Q3 and Q4, respectively (P < 0.0001). Primary outcome (composite of time to cardiovascular death or first HF hospitalization) rates were 24.5 and 31.7 per 100 patient-years for vericiguat and placebo in Q1-Q3 [hazard ratio (HR) 0.78; 95% confidence interval (CI) 0.69-0.88, P < 0.001] and 73.6 and 63.6 in Q4 (HR 1.15; 95% CI 0.99-1.34, P = 0.070). Serious adverse events were more frequent in NT-proBNP Q4 (total population) compared with Q1-Q3 (38.3 vs. 32.3%; P = 0.0001), driven mainly by the placebo group. Adverse events leading to death were more frequent in Q4 than Q1-Q3 (5.8 vs. 2.4%; P < 0.0001). Conclusions Plasma NT-proBNP may help identify patients with worsening HF with reduced ejection fraction, in whom the beneficial effects of vericiguat may be highest. Patients with highest NT-proBNP values are probably too far advanced, suffering more co-morbidities, or still clinically unstable after decompensation to derive benefit from vericiguat