High-Dose vs. Standard-Dose Influenza Vaccine and Cardiopulmonary Hospitalization or Mortality: Emulating the INVESTED Trial Using Insurance Claims Data.

The INVESTED trial did not show benefits of high-dose (HD) vaccine vs. standard-dose (SD) for a primary composite outcome of cardiopulmonary hospitalization or all-cause mortality (hazard ratio (HR) = 1.05, 95% confidence interval (CI) = 0.96-1.15) and its components (all-cause mortality HR = 1.01, 95% CI = 0.84-1.21, cardiopulmonary hospitalization HR = 1.05, 95% CI = 0.96-1.16) during three influenza seasons (2016-2019) among participants with recent myocardial infarction or hospitalization for heart failure (HHF). We emulated INVESTED using Medicare claims data to assess whether the real-world evidence (RWE) study reached similar conclusions. We identified 1:1 propensity score (PS)-matched trial-eligible Medicare beneficiaries aged > 65 years and with prior HHF who received an HD or SD vaccine for the 2016-2019 seasons. We also re-analyzed the INVESTED trial data restricting to participants > 65 years with prior HHF to align eligibility criteria more closely with the RWE study. We compared HRs from the trial and RWE study for the main outcomes. Among 53,393 pairs of PS-matched Medicare beneficiaries, the HD vaccine group showed lower risk of the primary composite outcome (HR = 0.96, 95% CI = 0.95-0.98) and all-cause mortality (HR = 0.93, 95% CI = 0.91-0.95), and similar risk of cardiopulmonary hospitalization (HR = 0.98, 95% CI = 0.96-1.00), compared with SD. The RWE and trial results were closely concordant after the trial population was limited to participants > 65 years with prior HHF: trial-based results for the primary composite outcome (HR = 1.02, 95% CI = 0.89-1.17), all-cause mortality (HR = 0.92, 95% CI = 0.72-1.16), and cardiopulmonary hospitalization (HR = 1.02, 95% CI = 0.88-1.18). Although similar to the main trial results, the RWE was closer to the results from trial participants with aligned eligibility criteria. This study affirms the importance of considering different distributions of baseline patient characteristics when comparing trial findings to RWE.

Long-Term Efficacy and Safety of Eculizumab in Patients With Paroxysmal Nocturnal Hemoglobinuria and High Disease Burden: Real-World Data From Korea.

BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disorder characterized by uncontrolled terminal complement activation. Eculizumab, a monoclonal antibody C5 inhibitor was introduced in Korea in 2009 and has been the standard treatment option for PNH. METHODS: This study assessed the long-term efficacy/safety of eculizumab in PNH using real-world data from the Korean Health Insurance Review and Assessment Service. Eighty patients who initiated eculizumab from 2009-2020 were enrolled. RESULTS: At eculizumab initiation, the median age was 51.5 years, lactate dehydrogenase (LDH) 6.8 × upper limit of normal, and granulocyte clone size 93.0%. All patients had at least one PNH-related complication before eculizumab initiation, including renal failure (n = 36), smooth muscle spasm (n = 24), thromboembolism (n = 20), and pulmonary hypertension (n = 15). The median (range) duration of eculizumab treatment was 52.7 (1.0, 127.3) months (338.6 total treated patient-years). Despite high disease activity in the study population before treatment initiation, overall survival was 96.2% and LDH levels were stabilized in most patients during treatment. PNH-related complications at treatment initiation were resolved in 44.4% of patients with renal failure, 95.8% with smooth muscle spasm, 70.0% with thromboembolism, and 26.7% with pulmonary hypertension. Extravascular hemolysis occurred in 28.8% of patients (n = 23; 0.09 per patient-year) and breakthrough hemolysis in 18.8% (n = 15; 0.06 per patient-year). No treatment discontinuation cases related to eculizumab were observed. CONCLUSION: These data provided evidence for the long-term efficacy and safety of eculizumab in Korean PNH patients with high disease burdens.

Predicting Treatment Effects of a New-to-Market Drug in Clinical Practice Based on Phase III Randomized Trial Results.

Trial results may not be generalizable to target populations treated in clinical practice with different distributions of baseline characteristics that modify the treatment effect. We used outcome models developed with trial data to predict treatment effects in Medicare populations. We used data from the Randomized Evaluation of Long-Term Anticoagulation Therapy trial (RE-LY), which investigated the effect of dabigatran vs. warfarin on stroke or systemic embolism (stroke/SE) among patients with atrial fibrillation. We developed outcome models by fitting proportional hazards models in trial data. Target populations were trial-eligible Medicare beneficiaries who initiated dabigatran or warfarin in 2010-2011 ("early") and 2010-2017 ("extended"). We predicted 2-year risk ratios (RRs) and risk differences (RDs) for stroke/SE, major bleeding, and all-cause death in the Medicare populations using the observed baseline characteristics. The trial and early target populations had similar mean (SD) CHADS2 scores (2.15 (SD 1.13) vs. 2.15 (SD 0.91)) but different mean ages (71 vs. 79 years). Compared with RE-LY, the early Medicare population had similar predicted benefit of dabigatran vs. warfarin for stroke/SE (trial RR = 0.63, 95% confidence interval (CI) = 0.50 to 0.76 and RD = -1.37%, -1.96% to -0.77%, Medicare RR = 0.73, 0.65 to 0.82 and RD = -0.92%, -1.26% to -0.59%) and risks for major bleeding and all-cause death. The time-extended target population showed similar results. Outcome model-based prediction facilitates estimating the average treatment effects of a drug in different target populations when treatment and outcome data are unreliable or unavailable. The predicted effects may inform payers' coverage decisions for patients, especially shortly after a drug's launch when observational data are scarce.

Cardiovascular Outcomes in Patients Initiating First-Line Treatment of Type 2 Diabetes With Sodium-Glucose Cotransporter-2 Inhibitors Versus Metformin : A Cohort Study.

BACKGROUND: Evidence on the risk for cardiovascular events associated with use of first-line sodium-glucose cotransporter-2 inhibitors (SGLT-2i) compared with metformin is limited. OBJECTIVE: To assess cardiovascular outcomes among adults with type 2 diabetes (T2D) who initiated first-line treatment with SGLT-2i versus metformin. DESIGN: Population-based cohort study. SETTING: Claims data from 2 large U.S. commercial and Medicare databases (April 2013 to March 2020). PARTICIPANTS: Patients with T2D aged 18 years and older (>65 years in Medicare) initiating treatment with SGLT-2i or metformin during April 2013 to March 2020, without any use of antidiabetic medications before cohort entry, were identified. After 1:2 propensity score matching in each database, pooled hazard ratios (HRs) and 95% CIs were reported. INTERVENTION: First-line SGLT-2i (canagliflozin, empagliflozin, or dapagliflozin) or metformin. MEASUREMENTS: Primary outcomes were a composite of hospitalization for myocardial infarction (MI), hospitalization for ischemic or hemorrhagic stroke or all-cause mortality (MI/stroke/mortality), and a composite of hospitalization for heart failure (HHF) or all-cause mortality (HHF/mortality). Safety outcomes including genital infections were assessed. RESULTS: Among 8613 first-line SGLT-2i initiators matched to 17 226 metformin initiators, SGLT-2i initiators had a similar risk for MI/stroke/mortality (HR, 0.96; 95% CI, 0.77 to 1.19) and a lower risk for HHF/mortality (HR, 0.80; CI, 0.66 to 0.97) during a mean follow-up of 12 months. Initiators receiving SGLT-2i showed a lower risk for HHF (HR, 0.78; CI, 0.63 to 0.97), a numerically lower risk for MI (HR, 0.70; CI, 0.48 to 1.00), and similar risk for stroke, mortality, and MI/stroke/HHF/mortality compared with metformin. Initiators receiving SGLT-2i had a higher risk for genital infections (HR, 2.19; CI, 1.91 to 2.51) and otherwise similar safety as those receiving metformin. LIMITATION: Treatment selection was not randomized. CONCLUSION: As first-line T2D treatment, initiators receiving SGLT-2i showed a similar risk for MI/stroke/mortality, lower risk for HHF/mortality and HHF, and a similar safety profile except for an increased risk for genital infections compared with those receiving metformin. PRIMARY FUNDING SOURCE: Brigham and Women's Hospital and Harvard Medical School.

Evolving channeling in prescribing SGLT-2 inhibitors as first-line treatment for type 2 diabetes.

PURPOSE: Sodium-glucose cotransporter-2 inhibitors (SGLT-2i) are increasingly being considered as first-line treatment for type 2 diabetes (T2D). The benefits of SGLT-2i from cardiovascular outcome trials may lead to preferential prescribing of SGLT-2i to patients at high cardiovascular risk, possibly causing confounding in non-randomized studies of SGLT-2i as first-line treatment. We assessed evolving imbalances in characteristics of patients starting SGLT-2i versus metformin as first-line monotherapy. METHODS: Using claims data from two US commercial health insurance and Medicare, we identified patients with T2D aged ≥18 years (>65 years in Medicare) initiating first-line SGLT-2i or metformin from 2013 through 2019. Standardized differences (SDs) for patient characteristics were assessed during four consecutive calendar time blocks (T1:4/2013-12/2014; T2:1/2015-6/2016; T3:7/2016-12/2017; and T4:1/2018-12/2019). We also estimated the propensity score of receiving SGLT-2i versus metformin within each time block and evaluated time trends in model discrimination with c-statistics. RESULTS: We identified 9113 initiators of first-line SGLT-2i and 810 348 initiators of first-line metformin. During T1, SGLT-2i initiators were younger (SD = -0.24) and less likely to have seen cardiologists (-0.07) with a similar prevalence of CVD (0.04) compared with metformin. During T4, patients were more balanced for age (-0.01). Cardiologist visits (0.08) and CVD (0.25) became more prevalent among SGLT-2i initiators. CONCLUSIONS: When comparing initiators of first-line SGLT-2i versus metformin, imbalances in patient characteristics evolved from 2013 through 2019, particularly channeling SGLT-2i to individuals at high cardiovascular risk. Evolving channeling in prescribing first-line SGLT-2i should be expected and accounted for in non-randomized comparative effectiveness research.

Trends in First-Line Glucose-Lowering Drug Use in Adults With Type 2 Diabetes in Light of Emerging Evidence for SGLT-2i and GLP-1RA.

OBJECTIVE: We evaluated recent use trends and predictors of first-line antidiabetes treatment in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Using two large U.S. health insurance databases (Clinformatics and Medicare), we identified adult patients with type 2 diabetes who initiated antidiabetes treatment from 2013 through 2019. Quarterly trends in use of first-line antidiabetes treatment were plotted overall and stratified by cardiovascular disease (CVD). Multinomial logistic regressions were fit to estimate predictors of first-line antidiabetes treatment, using metformin, the recommended first-line treatment for type 2 diabetes, as the common referent. RESULTS: Metformin was the most frequently initiated medication, used by 80.6% of Medicare beneficiaries and 83.1% of commercially insured patients. Sulfonylureas were used by 8.7% (Medicare) and 4.7% (commercial). Both populations had low use of sodium-glucose cotransporter 2 inhibitors (SGLT-2i, 0.8% [Medicare] and 1.7% [commercial]) and glucagon-like peptide 1 receptor agonists (GLP-1Ra; 1.0% [Medicare] and 3.5% [commercial]), with increasing trends over time (P < 0.01). Initiators of antidiabetes drugs with established cardiovascular benefits (SGLT-2i and GLP-1RA) were more likely to be younger and had prevalent CVD or higher socioeconomic status compared with initiators of metformin. CONCLUSIONS: Among adult patients with type 2 diabetes, metformin was by far the most frequent first-line treatment. While the use of SGLT-2i and GLP-1RA was low from 2013 through 2019, it increased among patients with CVD.

Preliminary Assessment of Muscle Activity and Muscle Characteristics during Training with Powered Robotic Exoskeleton: A Repeated-Measures Study.

A variety of robotic exoskeletons have been developed for patients with spinal cord injuries. However, the optimal training method and period for using a robotic exoskeleton have been uncertain until now. The purpose of this study is to determine the minimum training period for using a robotic exoskeleton with minimal muscle activity by investigating the changes in muscle activity and muscle characteristics of healthy adults during robotic exoskeleton training. A total of 16 people participated in the study. The robotic exoskeleton locomotion training consisted of three 50-min sessions a week for 7 weeks. The assessment consisted of sitting, standing, wide standing, sit-to-stand, and stand-to-sit where muscle activity and muscle characteristics were measured during each motion. All measurements were performed in the first session and every five sessions. Participants showed decreased muscle activity up to 10 sessions of training in the standing position, and 15 sessions in sit-to-stand and stand-to-sit motions. Upper extremity muscles showed decreased muscle activity, tone, stiffness, and logarithmic decrement up to the 15th session. The study results show that at least 15 training sessions are required to use the robotic exoskeleton with minimal load on the musculoskeletal system, and longer training is required for patients with spinal cord injury.

A review of the performance of different methods for propensity score matched subgroup analyses and a summary of their application in peer-reviewed research studies.

PURPOSE: When evaluating safety signals, there is often interest in understanding safety in all patients for whom compared treatments are reasonable alternatives, as well as in specific subgroups of interest. There are numerous ways that propensity score (PS) matching can be implemented for subgroup analyses. METHODS: We conducted a systematic literature review of methods papers that compared the performance of alternative methods to implement PS matched subgroup analyses and examined how frequently different PS matching methods have been used for subgroup analyses in applied studies. RESULTS: We identified 5 methods papers reporting small improvements in covariate balance and bias with use of a subgroup-specific PS instead of a mis-specified overall PS within subgroups. Applied research papers frequently used PS for subgroups in ways not evaluated in methods papers. Thirty three percent used PS to match in the overall cohort and broke the matched sets for subgroup analysis without further adjustment. CONCLUSIONS: While the performance of several alternative ways to use PS matching in subgroup analyses has been evaluated in methods literature, these evaluations do not include the most commonly used methods to implement PS matched subgroup analyses in applied studies. There is a need to better understand the relative performance of commonly used methods for PS matching in subgroup analyses, particularly within settings encountered during active surveillance, where there may be low exposure, infrequent outcomes, and multiple subgroups of interest.