Sodium-glucose cotransporter-2 inhibitors and the risk of urinary tract infection among diabetic patients in Japan: Target trial emulation using a nationwide administrative claims database

Methodologies for the Emulation of Biomarker-Guided Trials Using Observational Data: A Systematic Review

Background: Target trial emulation involves the application of design principles from randomised controlled trials (RCTs) to observational data, and is particularly useful in situations where an RCT would be unfeasible. Biomarker-guided trials, which incorporate biomarkers within their design to either guide treatment and/or determine eligibility, are often unfeasible in practice due to sample size requirements or ethical concerns. Here, we undertake a systematic review of methodologies used in target trial emulations, comparing treatment effectiveness, critically appraising them, and considering their applicability to the emulation of biomarker-guided trials. Methods: A comprehensive search strategy was developed to identify studies reporting on methods for target trial emulation comparing the effectiveness of treatments using observational data, and applied to the following bibliographic databases: PubMed, Scopus, Web of Science, and Ovid MEDLINE. A narrative description of methods identified in the review was undertaken alongside a critique of their relative strengths and limitations. Results: We identified a total of 59 papers: 47 emulating a target trial ('application' studies), and 12 detailing methods to emulate a target trial ('methods' studies). A total of 25 papers were identified as emulating a biomarker-guided trial (42%). While all papers reported methods to adjust for baseline confounding, 40% of application papers did not specify methods to adjust for time-varying confounding. Conclusions: This systematic review has identified a range of methods used to control for baseline, time-varying, and residual/unmeasured confounding within target trial emulation and provides a guide for researchers interested in emulation of biomarker-guided trials.

Risk of Urinary Tract Infections with Sodium-Glucose Transport Protein-2 Inhibitors in Subpopulations with Abnormal Genitourinary Pathology

Key Points

Use of sodium-glucose transport protein-2 inhibitors (SGLT2i) compared with glucagon-like peptide-1 receptor agonists portends a greater risk of candida urinary tract infection (UTI), but no increased risk of noncandida UTI. Abnormal genitourinary pathology is a risk factor for noncandida UTI, but no additive risk was observed in those taking SGLT2i. SGLT2i initiation is associated with an additive larger risk of candida UTI in those with genitourinary tract abnormalities.

Background

Although sodium-glucose transport protein-2 inhibitors (SGLT2i) possess multiple beneficial effects, the drugs are associated with genitourinary (GU) infections. We sought to define the precise relationship between SGLT2i exposure, types of urinary tract infections (UTIs), and clinical risk factors.

Methods

We used an incident user design with active comparator analysis to derive SGLT2i and glucagon-like peptide-1 receptor agonist (GLP1ra) user cohorts from US nationwide insurance claim data. We used both covariate-adjusted Cox models and Cox models with inverse probability of treatment weighting to investigate the risk of noncandida UTI and candida UTI after drug exposure. We compared the risk between SGLT2i and GLP1ra exposure in the general population and subpopulations with GU abnormalities.

Results

SGLT2i exposure compared with GLP1ra exposure was associated with a greater risk of candida UTI (all hazard ratios [HRs] ≥2.42 and all P values < 0.001), but a lower risk of noncandida UTI (all HRs ≤0.91 and all P values < 0.001). Prior GU abnormalities such as prior UTI, prior genital infection, GU malignancy, indwelling Foley, or other GU pathology were associated with greater risk of noncandida and/or candida UTI (all adjusted HRs ≥1.26 and all P values ≤ 0.002). However, no difference in comparative risk of SGLT2i to GLP1ra exposure for noncandida UTI was observed in these subpopulations. By contrast, an additive effect between SGLT2i exposure and several GU abnormalities was observed for candida UTI (all adjusted HRs ≥2.37 and all P values < 0.001).

Conclusions

SGLT2i exposure was associated with greater risk of candida UTI, but not noncandida UTI. SGLT2i to GLP1ra comparative risk of noncandida UTI did not differ in individuals with abnormal GU pathology compared with those without.

Development and validation of a distributed representation model of Japanese high-dimensional administrative claims data for clinical epidemiology studies

BACKGROUND

Unmeasured confounders pose challenges when observational data are analysed in comparative effectiveness studies. Integrating high-dimensional administrative claims data may help adjust for unmeasured confounders. We determined whether distributed representations can compress high-dimensional administrative claims data to adjust for unmeasured confounders.

METHOD

Using the Japanese Diagnosis Procedure Combination (DPC) database from 1291 hospitals (between April 2018 and March 2020), we applied the word2vec algorithm to create distributed representations for all medical codes. We focused on patients with heart failure (HF) and simulated four risk-adjustment models: 1, no adjustment; 2, adjusting for previously reported confounders; 3, adjusting for the sum of distributed representation weights of administrative claims data on the day of hospitalisation (novel method); and 4, a combination of models 2 and 3. We re-evaluated a previous study on the effect of early rehabilitation in patients with HF and compared these risk-adjustment methods (models 1-4).

RESULTS

Distributed representations were generated from the data of 15 998 963 in-patients, and 319 581 HF patients were identified. In the simulation study, Model 3 reduced the impact of unmeasured confounders and achieved better covariate balances than Model 1. Model 4 showed no increase in bias compared with the true model (Model 2) and was used as a reference model in the real-world application. When applied to a previous study, models 3 and 4 showed similar results.

CONCLUSION

Distributed representation can compress detailed administrative claims data and adjust for unmeasured confounders in comparative effectiveness studies.

Comparison of Clinical Outcomes Between Two Types of Dipeptidyl Peptidase-4 Inhibitors in Posttransplant Diabetes Mellitus in Kidney Transplantation Recipients: A Nationwide Population-Based Cohort Study in Korea

BACKGROUND

Dipeptidyl peptidase-4 inhibitors (DPP-4i) are antidiabetic drugs known for their minimal side effects and limited drug interaction witih immunosuppressants, making them suitable for patients with diabetes and kidney transplant recipients. However, there is limited real-world information regarding the use of DPP-4 inhibitors in patients with post transplant diabetes mellitus (PTDM).

METHOD

We performed a retrospective observational cohort study of 13,828 kidney transplant recipients form Janary 1, 2002, through December 21, 2018, using the Korean National Health Information Database. We extracted PTDM patients, and divided the patients into 2 groups baased on whether they received DPP4-inhibitor which needs dose adjustement (group A) or not (Group B) according to estimaged glomerular filtration rate.

RESULTS

Out of 3154 patients who developed PTDM after transplantation, 738 patients prescribed DPP-4 inhibitors. Among these, 490 patients prescribed Group B DPP-4 inhibitors and 238 patients prescribed Group A DPP-4 inhibitors. Multivariate-adjusted Cox regression analysis showed that compared Group B, Group A DPP-4 inhibitors was associated with higher incidence rate of genital tract infection (hazard ratio (HR) 1.87, 95% Confidence Interval (CI) 1.18-2.99), and emergency department visit (HR 3.12, 95% CI 1.89-5.16). However, there was no significantly difference in death (any cause), admission, graft failure, infection, or hypoglycemia between the 2 groups.

CONCLUSIONS

In patients with PTDM, some kinds of DPP-4 inhibitors, which need dose adjustment according to renal function, were associated with an increased rate of emergency department visit and genital tract infection.

Using Trial and Observational Data to Assess Effectiveness: Trial Emulation, Transportability, Benchmarking, and Joint Analysis

Comparisons between randomized trial analyses and observational analyses that attempt to address similar research questions have generated many controversies in epidemiology and the social sciences. There has been little consensus on when such comparisons are reasonable, what their implications are for the validity of observational analyses, or whether trial and observational analyses can be integrated to address effectiveness questions. Here, we consider methods for using observational analyses to complement trial analyses when assessing treatment effectiveness. First, we review the framework for designing observational analyses that emulate target trials and present an evidence map of its recent applications. We then review approaches for estimating the average treatment effect in the target population underlying the emulation, using observational analyses of the emulation data alone and using transportability analyses to extend inferences from a trial to the target population. We explain how comparing treatment effect estimates from the emulation against those from the trial can provide evidence on whether observational analyses can be trusted to deliver valid estimates of effectiveness-a process we refer to as benchmarking-and, in some cases, allow the joint analysis of the trial and observational data. We illustrate different approaches using a simplified example of a pragmatic trial and its emulation in registry data. We conclude that synthesizing trial and observational data-in transportability, benchmarking, or joint analyses-can leverage their complementary strengths to enhance learning about comparative effectiveness, through a process combining quantitative methods and epidemiologic judgments.

Associations Between Sodium-Glucose Co-transporter 2 Inhibitors and Urologic Diseases: Implications for Lower Urinary Tract Symptoms From a Multi-State Health System Analysis

OBJECTIVE

To analyze the frequency of new urologic visits and urologic diagnoses in patients prescribed sodium-glucose co-transporter-2 inhibitors (SGLT-2is).

MATERIAL AND METHODS

Records from a multi-state health system between 2014 and 2022 were reviewed to identify patients referred for outpatient urology evaluation within 2 years of diabetes medication prescription. Patients were stratified by the prescription of SGLT-2is or another diabetes medication. Frequency of urology visits within 1-year, urologic diagnoses, and prescriptions to treat lower urinary tract symptoms (LUTS) were compared. Patients were stratified by whether they had achieved HbA1c goal (≥7% or <7%) following treatment as well as by sex. Multivariable logistic regression was performed to determine if SGLT-2 use independently predicted outcomes of interest.

RESULTS

163,827 patients met inclusion criteria. Use of SGLT-2is was associated with a higher frequency of early urologic referral, balanitis/balanoposthitis, overactive bladder, urinary frequency, urgency, and need for LUTS medications in males with HbA1c ≥7%. Females on SGLT-2is with HbA1c ≥7% also had higher rates of urinary incontinence. In those with HbA1c <7%, only balanitis/balanoposthitis and urinary incontinence were higher in the SGLT-2i cohorts for males and females, respectively. Multivariable analysis found SGLT-2i use as predictive of early urology referral, balanitis/balanoposthitis, urinary urgency, frequency, overactive bladder, and need for LUTS medications in males. Multivariable analysis of females demonstrated similar results.

CONCLUSION

SGLT-2is may lead to worse urologic outcomes and increased utilization of urologic care relative to other diabetic medications. Future studies are necessary to identify which patients are at highest risk of adverse urologic outcomes.

Early Addition of Selexipag to Double Therapy for Pulmonary Arterial Hypertension

Importance

A subgroup analysis of a randomized clinical trial established the efficacy of selexipag plus background therapy (monotherapy or double oral therapy [DOT]) vs placebo plus background therapy and found that the addition of selexipag within 6 months had an added benefit. However, the timing of selexipag addition to DOT and the incremental benefit in clinical practice is not well studied.

Objective

To compare triple oral therapy (TOT) consisting of selexipag, endothelin receptor antagonist (ERA), and phosphodiesterase type 5 inhibitor (PDE5i) vs DOT consisting of ERA and PDE5i.

Design, Setting, and Participants

This comparative effectiveness study was conducted using data from the US Komodo claims database to emulate a randomized trial. Patients aged 18 years or older with pulmonary arterial hypertension (PAH) treated with ERA plus PDE5i with records from July 2015 through June 2022 were duplicated to TOT and DOT and artificially censored when observed treatment deviated from assigned treatment. Hypothetical randomization was emulated using inverse probability of treatment weighting, and the study accounted for censoring-induced selection bias using inverse probability of censoring weighting. A pooled logistic model estimated the per-protocol difference between treatment groups. Data were analyzed from November 2022 through July 2023.

Interventions

TOT (addition of selexipag within 3, 6, and 12 months of initiating DOT) vs DOT.

Main Outcomes and Measures

Adjusted risk of all-cause hospitalization, PAH-related hospitalization, and PAH-related disease progression over a 2-year follow-up.

Results

A total of 2966 patients with PAH (mean [SD] age, 54.3 [14.0] years; 2125 female [71.6%]) met eligibility criteria. Adding selexipag within 6 months of ongoing DOT was associated with a reduction in risk for all-cause hospitalization (adjusted hazard ratio [aHR], 0.82; 95% CI, 0.72-0.94), PAH-related hospitalization (aHR, 0.81; 95% CI, 0.70-0.95), and PAH-related progression (aHR, 0.82; 95% CI, 0.70-0.95) vs DOT alone. There were no associations if selexipag was initiated within 12 months for all-cause hospitalization, PAH-related hospitalization, or PAH-related disease progression. The association remained with a greater decrease in risk for disease progression vs DOT for selexipag initiation within 3 months (aHR, 0.74; 95% CI, 0.61-0.90).

Conclusions and Relevance

This study found that early selexipag addition to ERA plus PDE5i was associated with a reduction in risk of hospitalization and disease progression. These findings suggest that delays in selexipag initiation likely contribute to suboptimal patient and health system outcomes.

Target trial emulation of carfilzomib safety among patients with relapsed/refractory multiple myeloma using a nationwide observational data in Korea

PURPOSE

Carfilzomib, commonly used for relapsed/refractory multiple myeloma (RRMM), has been associated with various adverse events in randomized controlled trials (RCTs). However, real-world safety data for a more diverse population are needed, as carfilzomib received expedited approval. This study aimed to evaluate carfilzomib's safety in Korea by comparing new users of KRd (carfilzomib, lenalidomide, and dexamethasone) to Rd (lenalidomide and dexamethasone) using a nationwide administrative claims database.

METHODS

The retrospective cohort study utilized target trial emulation, focusing on adverse events in various organ systems similar to the ASPIRE trial.

RESULTS

This study included 4,580 RRMM patients between 2007 and 2020, and the KRd group showed significantly higher risks of hematologic adverse events (anemia, neutropenia, thrombocytopenia) and some non-hematologic adverse events (cough, hypokalemia, constipation, hypertension, heart failure) compared to the Rd group. Among non-hematologic adverse events, cardiovascular events (heart failure [HR 2.04; 95% CI 1.24-3.35], hypertension [HR 1.58; 95% CI 1.15-2.17]) had the highest risk in the KRd group.

CONCLUSION

The safety profile of carfilzomib in Korean patients was similar to previous RCTs. Therefore, caution should be exercised when using carfilzomib in Asian individuals with RRMM due to the increased risk of cardiovascular adverse events.

Incident infection risks depending on oral antidiabetic exposure in insulin-treated type 2 diabetes patients

Dipeptidyl peptidase-4 inhibitors (DPP4is) and sodium glucose cotransporter-2 inhibitors (SGLT2is) have been speculated to have a potential to increase infection risks in type 2 diabetes mellitus (T2DM) patients. We performed a cohort study using the Korean health insurance data to investigate infection risks with each drug class relative to metformin in insulin-treated T2DM patients. After propensity score matching, we included 1,498 and 749 patients in DPP4i + insulin vs metformin + insulin and 300 and 549 patients in SGLT2i + insulin vs metformin + insulin, respectively. In stratified analyses per patient factor, none of the odds ratios (ORs) were associated with a statistical significance across respiratory, genital, and urinary tract infections (UTIs), except that of the male stratum for respiratory infections (OR 0.77, p = 0.04). With regard to SGLT2is, a higher risk of genital infections was analyzed with their use than with metformin therapy (OR 1.76, p = 0.03). In stratified analyses, the OR for genital infections remained significant in the baseline cardiovascular disease stratum (OR 2.29, p = 0.01). No increased UTI risk was detected with SGLT2is compared against metformin. In this study on insulin-receiving T2DM patients, DPP4is were not associated with increased infection risks, whereas SGLT2is led to a higher risk for genital infections, but not for UTIs, relative to metformin.

Implementation of the trial emulation approach in medical research: a scoping review

BACKGROUND

When conducting randomised controlled trials is impractical, an alternative is to carry out an observational study. However, making valid causal inferences from observational data is challenging because of the risk of several statistical biases. In 2016 Hernán and Robins put forward the 'target trial framework' as a guide to best design and analyse observational studies whilst preventing the most common biases. This framework consists of (1) clearly defining a causal question about an intervention, (2) specifying the protocol of the hypothetical trial, and (3) explaining how the observational data will be used to emulate it.

METHODS

The aim of this scoping review was to identify and review all explicit attempts of trial emulation studies across all medical fields. Embase, Medline and Web of Science were searched for trial emulation studies published in English from database inception to February 25, 2021. The following information was extracted from studies that were deemed eligible for review: the subject area, the type of observational data that they leveraged, and the statistical methods they used to address the following biases: (A) confounding bias, (B) immortal time bias, and (C) selection bias.

RESULTS

The search resulted in 617 studies, 38 of which we deemed eligible for review. Of those 38 studies, most focused on cardiology, infectious diseases or oncology and the majority used electronic health records/electronic medical records data and cohort studies data. Different statistical methods were used to address confounding at baseline and selection bias, predominantly conditioning on the confounders (N = 18/49, 37%) and inverse probability of censoring weighting (N = 7/20, 35%) respectively. Different approaches were used to address immortal time bias, assigning individuals to treatment strategies at start of follow-up based on their data available at that specific time (N = 21, 55%), using the sequential trial emulations approach (N = 11, 29%) or the cloning approach (N = 6, 16%).

CONCLUSION

Different methods can be leveraged to address (A) confounding bias, (B) immortal time bias, and (C) selection bias. When working with observational data, and if possible, the 'target trial' framework should be used as it provides a structured conceptual approach to observational research.

Strategies to Address Current Challenges in Real-World Evidence Generation in Japan

The generation of real-world evidence (RWE), which describes patient characteristics or treatment patterns using real-world data (RWD), is rapidly growing more popular as a tool for decision-making in Japan. The aim of this review was to summarize challenges to RWE generation in Japan related to pharmacoepidemiology, and to propose strategies to address some of these challenges. We first focused on data-related issues, including the lack of transparency of RWD sources, linkage across different care settings, definitions of clinical outcomes, and the overall assessment framework of RWD when used for research purposes. Next the study reviewed methodology-related challenges. As lack of design transparency impairs study reproducibility, transparent reporting of study design is critical for stakeholders. For this review, we considered different sources of biases and time-varying confounding, along with potential study design and methodological solutions. Additionally, the implementation of robust assessment of definition uncertainty, misclassification, and unmeasured confounders would enhance RWE credibility in light of RWD source-related limitations, and is being strongly considered by task forces in Japan. Overall, the development of guidance for best practices on data source selection, design transparency, and analytical methods to address different sources of biases and robustness in the process of RWE generation will enhance credibility for stakeholders and local decision-makers.

Cost-Effectiveness of Dapagliflozin for Chronic Kidney Disease in Japan

BACKGROUND

The cost-effectiveness of sodium-glucose cotransporter 2 (SGLT2) inhibitors for chronic kidney disease (CKD) has not been evaluated in Japan, so we analyzed the cost-effectiveness of dapagliflozin, an SGLT2 inhibitor, for CKD stages 3a and 3b.

METHODS AND RESULTS

We used the Markov model for CKD to assess the costs and benefits associated with and without dapagliflozin from a health system perspective. We estimated the incremental cost-effectiveness ratio (ICER), expressed as per quality-adjusted life-years (QALYs). An ICER <5 million Japanese yen (JPY)/QALY was judged to be cost-effective. The effect of dapagliflozin on renal and cardiovascular events was based on published clinical trials. In patients with CKD stage 3a, the ICER of dapagliflozin over standard treatment was 4.03 million JPY/QALY gained. With a cost-effectiveness threshold of 5 million JPY/QALY gained, the cost-effectiveness probability of dapagliflozin over standard treatment was 52.6%. In patients with CKD stage 3b, the ICER of dapagliflozin over standard treatment was 0.12 million JPY/QALY gained. The cost-effectiveness probability of dapagliflozin over standard treatment was 75.2%.

CONCLUSIONS

The results seemed to show acceptable cost-effectiveness when dapagliflozin was used for CKD stage 3b. On the other hand, cost-effectiveness of dapagliflozin for CKD stage 3a was ambiguous, and further validation is needed.

Real-world data: a brief review of the methods, applications, challenges and opportunities

Background

The increased adoption of the internet, social media, wearable devices, e-health services, and other technology-driven services in medicine and healthcare has led to the rapid generation of various types of digital data, providing a valuable data source beyond the confines of traditional clinical trials, epidemiological studies, and lab-based experiments.

Methods

We provide a brief overview on the type and sources of real-world data and the common models and approaches to utilize and analyze real-world data. We discuss the challenges and opportunities of using real-world data for evidence-based decision making This review does not aim to be comprehensive or cover all aspects of the intriguing topic on RWD (from both the research and practical perspectives) but serves as a primer and provides useful sources for readers who interested in this topic.

Results and Conclusions

Real-world hold great potential for generating real-world evidence for designing and conducting confirmatory trials and answering questions that may not be addressed otherwise. The voluminosity and complexity of real-world data also call for development of more appropriate, sophisticated, and innovative data processing and analysis techniques while maintaining scientific rigor in research findings, and attentions to data ethics to harness the power of real-world data.

Systematic Review of Literature Examining Bacterial Urinary Tract Infections in Diabetes

This systematic review addresses the central research question, "what is known from the published, peer-reviewed literature about the impact of diabetes on the risk of bacterial urinary tract infections (UTI)?" We examine the results from laboratory studies where researchers have successfully adapted mouse models of diabetes to study the pathophysiology of ascending UTI. These studies have identified molecular and cellular effectors shaping immune defenses against infection of the diabetic urinary tract. In addition, we present evidence from clinical studies that in addition to diabetes, female gender, increased age, and diabetes-associated hyperglycemia, glycosuria, and immune impairment are important risk factors which further increase the risk of UTI in diabetic individuals. Clinical studies also show that the uropathogenic genera causing UTI are largely similar between diabetic and nondiabetic individuals, although diabetes significantly increases risk of UTI by drug-resistant uropathogenic bacteria.

Comparison of New Oral Hypoglycemic Agents on Risk of Urinary Tract and Genital Infections in Type 2 Diabetes: A Network Meta-analysis

INTRODUCTION

Dipeptidyl peptidase 4 (DPP4) inhibitors and sodium-glucose co-transporter 2 (SGLT2) inhibitors have often been used for patients with T2DM because of the reduced risk of hypoglycemia. However, DPP4 inhibitors and SGLT2 inhibitors may increase the risk of infectious diseases. This network meta-analysis (NMA) was performed to investigate the risk of urinary tract and genital infections associated with the use of two new glucose-lowering drug classes in patients with type 2 diabetes.

METHODS

PubMed, Web of Science, Embase, and the Cochrane Library were comprehensively searched for articles from the date of database inception until September 8, 2020. Placebo-controlled or head-to-head trials of the two new drug classes used for treatment of adults with type 2 diabetes were included. The primary outcome was the incidence of any confirmed urinary tract infection; genital infection was also used as an important outcome indicator.

RESULTS

Fifty-five studies were identified, covering 29,574 participants. Regarding urinary tract infections, SGLT2 inhibitors were not associated with increased risk, and among all drugs, sitagliptin, ipragliflozin, and linagliptin were the safest according to probability ranking. Regarding genital infections, saxagliptin was associated with significantly reduced risk in pairwise comparisons with placebo (RR 0.12, 95% CI 0.00-0.78), linagliptin (RR 0.09, 95% CI 0.00-0.78), canagliflozin (RR 0.04, 95% CI 0.00-0.31), dapagliflozin (RR 0.04, 95% CI 0.00-0.26), empagliflozin (RR 0.03, 95% CI 0.00-0.25), and ertugliflozin (RR 0.03, 95% CI 0.00-0.24). Among all drugs, saxagliptin, sitagliptin, and ipragliflozin were the safest according to probability ranking. Considering both urinary tract and genital infection risks, DPP4 inhibitors showed greater reductions than SGLT2 inhibitors and placebo. Saxagliptin was the safest drug according to probability ranking for both infection risks.

CONCLUSIONS

This NMA showed that, to reduce genital infection risk, current evidence favors DPP4 inhibitors over SGLT2 inhibitors. Most SGLT2 inhibitors may not be associated with the risk of urinary tract infections. Considering both infection risks, saxagliptin may be the safest drug. Finally, mechanistic studies are needed to better understand the physiological basis for these effects.