Analyzing intent-to-treat and per-protocol effects on safety outcomes using a medical information database: an application to the risk assessment of antibiotic-induced liver injury

Reporting of Observational Studies Explicitly Aiming to Emulate Randomized Trials: A Systematic Review

Importance

Observational (nonexperimental) studies that aim to emulate a randomized trial (ie, the target trial) are increasingly informing medical and policy decision-making, but it is unclear how these studies are reported in the literature. Consistent reporting is essential for quality appraisal, evidence synthesis, and translation of evidence to policy and practice.

Objective

To assess the reporting of observational studies that explicitly aimed to emulate a target trial.

Evidence Review

We searched Medline, Embase, PsycINFO, and Web of Science for observational studies published between March 2012 and October 2022 that explicitly aimed to emulate a target trial of a health or medical intervention. Two reviewers double-screened and -extracted data on study characteristics, key predefined components of the target trial protocol and its emulation (eligibility criteria, treatment strategies, treatment assignment, outcome[s], follow-up, causal contrast[s], and analysis plan), and other items related to the target trial emulation.

Findings

A total of 200 studies that explicitly aimed to emulate a target trial were included. These studies included 26 subfields of medicine, and 168 (84%) were published from January 2020 to October 2022. The aim to emulate a target trial was explicit in 70 study titles (35%). Forty-three studies (22%) reported use of a published reporting guideline (eg, Strengthening the Reporting of Observational Studies in Epidemiology). Eighty-five studies (43%) did not describe all key items of how the target trial was emulated and 113 (57%) did not describe the protocol of the target trial and its emulation.

Conclusion and Relevance

In this systematic review of 200 studies that explicitly aimed to emulate a target trial, reporting of how the target trial was emulated was inconsistent. A reporting guideline for studies explicitly aiming to emulate a target trial may improve the reporting of the target trial protocols and other aspects of these emulation attempts.

Carfilzomib's Real-World Safety Outcomes in Korea: Target Trial Emulation Study Using Electronic Health Records

Carfilzomib is a promising anticancer drug for relapsed/refractory multiple myeloma (RRMM). However, real-world evidence has only investigated the cardiovascular safety of carfilzomib, and there is a high demand for thorough safety evaluations. We aimed to comprehensively evaluate the risk of adverse events associated with carfilzomib in Korean patients with RRMM. We followed up with 138 matched patients with RRMM (69 KRd (carfilzomib, lenalidomide, and dexamethasone) and 69 Rd (lenalidomide and dexamethasone) users). A total of 12 adverse events were evaluated. More than 75% of adverse events occurred during the early cycle (1-6 cycles), and the incidence rate showed a tendency to decrease in the later cycle (7-12 and 13-18 cycles). Severities of most adverse events were evaluated as grade 1-2. The KRd regimen were related with significantly increased risks of dyspnea (adjusted HR (aHR) 2.27, 95% confidence interval (CI) 1.24-4.16), muscle spasm (aHR 5.12, 95% CI 1.05-24.9) and thrombocytopenia (aHR 1.84, 95% CI 1.10-3.06). Although the severities were low, carfilzomib has many side effects in treating RRMM; hence, findings on the patterns of its adverse events could lead to both effective and safe use of KRd therapy in real-world settings.

Actual impact of angiotensin II receptor blocker or calcium channel blocker monotherapy on renal function in real-world patients

OBJECTIVE

This observational retrospective cohort study investigates the effect of antihypertensive therapy with angiotensin II receptor blockers (ARBs) or dihydropyridine calcium channel blockers (dCCBs) monotherapy on renal function using longitudinal real-world health data of a drug-naive, hypertensive population without kidney disease.

METHODS

Using propensity score matching, we selected untreated hypertensive participants (n = 10 151) and dCCB (n = 5078) or ARB (n = 5073) new-users based on annual health check-ups and claims between 2008 and 2020. Participants were divided by the first prescribed drug.

RESULTS

The mean age was 51 years, 79% were men and the mean estimated glomerular filtration rate (eGFR) was 78 ml/min per 1.73 m2. Blood pressure rapidly decreased by approximately 10% in both treatment groups. At the 1-year visit, eGFR levels decreased in the ARB group by nearly 2% but increased in the dCCB group by less than 1%. However, no significant difference was apparent in the annual eGFR change after the 1-year visit. The risk for composite kidney outcome (new-onset proteinuria or eGFR decline ≥30%) was lowest in the ARB group owing to their robust effect on preventing proteinuria: hazard ratio (95% confidence interval) for proteinuria was 0.90 (0.78-1.05) for the dCCB group and 0.54 (0.44-0.65) for the ARB group, compared with that for the untreated group after ending follow-up at the last visit before changing antihypertensive treatment.

CONCLUSION

From the present findings based on the real-world data, ARBs can be recommended for kidney protection even in a primary care setting. Meanwhile, dCCB treatment initially increases eGFR with no adverse effects on proteinuria.

Systemic quinolones and risk of acute liver failure III: A nested case-control study using a US electronic health records database

BACKGROUND AND AIM

Quinolones are globally popular antibiotics with proven potency, broad coverage, and reasonable safety. However, some concerns were raised as to their possible association with acute liver failure (ALF). The aim of this study is to assess ALF risk within 30 days of receiving a systemically administered quinolone antibiotic, in individuals with no history of liver/diseases.

METHODS

We conducted a nested case-control study using electronic health records from the Cerner Health Facts. The initial cohort (n = 35 349 943) included all patients who were admitted between 2000 and 2016, with no history of liver diseases, and had a minimum medical history of one year. Eligible cases were inpatients who were first diagnosed with ALF between 2010 and 2015. Using incidence density sampling, each case was matched with up to five unique controls by sex, race, age at index encounter, and period-at-risk. We used conditional logistic regression to calculate the odds ratio and 95% confidence interval for ALF risk, upon adjusting for exposure to other medications, and major confounders (diabetes mellitus and alcohol abuse). We used the STROBE Statement for reporting on our study.

RESULTS

We identified 3151 cases and 15 657 controls. Our primary analysis did not reveal an association between quinolones and ALF risk. However, some risk was identified among those with no or few comorbidities, those ≤ 60 years of age, women, men, African Americans, and Caucasians.

CONCLUSION

Although our study does not suggest an overall association between quinolones and ALF, elevated risks seen in some subgroups warrant further investigation.

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

AIM

To assess the risk of urinary tract infection (UTI) occurrence associated with sodium-glucose cotransporter-2 (SGLT2) inhibitor use relative to biguanide use in diabetes in a population-based cohort study using a target trial emulation framework.

METHODS

Using a Japanese nationwide administrative claims database, we constructed a cohort of patients aged ≥40 years who were dispensed SGLT2 inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors or biguanides between April 2014 and March 2015. For computational ease, we randomly sampled 100% of SGLT2 inhibitor users, 3% of DPP-4 inhibitor users, and 20% of biguanide users; new antidiabetic drug initiators were analysed. We estimated the intention-to-treat (ITT) hazard ratios (HRs) of UTI with inverse probability of treatment (IPT)-weighted Cox's proportional hazards models that ignored subsequent treatment changes. Treatment weights were computed using patient sex, age, medications, medical history and hospitalization history. We also estimated per-protocol (PP) HRs using IPT- and inverse probability of censoring-weighted Cox's models that adjusted for nonrandom treatment changes.

RESULTS

We analysed 11 364 SGLT2 inhibitor initiators, 9035 DPP-4 inhibitor initiators, and 10 359 biguanide initiators. When compared with biguanide initiators, SGLT2 inhibitor initiators had a crude HR of 1.14 (95% confidence interval [CI] 1.05-1.24), an ITT HR of 0.94 (95% CI 0.86-1.03), and a PP HR of 0.90 (95% CI 0.78-1.03); and DPP-4 inhibitor initiators had a crude HR of 1.13 (95% CI 1.04-1.23), an ITT HR of 0.85 (95% CI 0.77-0.94), and a PP HR of 0.83 (95% CI 0.71-0.95).

CONCLUSION

Use of SGLT2 inhibitors or DPP-4 inhibitors did not increase the risk of UTI compared with biguanide use. Accounting for treatment changes did not substantially influence the estimated effects.