Time-dependent Propensity Score Research Articles

Islet-after-kidney transplantation versus kidney alone in kidney transplant recipients with type 1 diabetes (KAIAK): a population-based target trial emulation in France.

Islet transplantation has been associated with better metabolic control and quality of life than insulin treatment alone, but direct evidence of its effect on hard clinical endpoints is scarce. We aimed to assess the effect of islet transplantation on patient-graft survival in kidney transplant recipients with type 1 diabetes. In this retrospective cohort study, we enrolled all patients with type 1 diabetes who received a kidney graft in France during the study period, identified from the CRISTAL nationwide registry. Non-inclusion criteria included recipients from transplant centres that never proposed islet transplantation during the study period, recipients with a functional pancreas throughout the follow-up duration, recipients with more than two kidney transplants, HLA-sensitised recipients, recipients with less than 1 year of follow-up after kidney transplantation, misclassified recipients with type 2 diabetes, recipients aged over 65 years, recipients of kidney grafts from Donation after Circulatory Death donors, recipient with HIV or hepatitis, recipients with cancer, and recipients of combined liver-kidney transplants. Patients who also received islet-after-kidney (IAK) transplantation were compared with controls who received kidney transplantation alone according to a 1:2 matching method based on time-dependent propensity scores, ensuring patients comparability at the time of islet transplantation. The primary outcome was patient-graft survival, a composite outcome defined by death, re-transplantation, or return to dialysis. Between Jan 1, 2000, and Dec 31, 2017, 2391 patients with type 1 diabetes were identified as having received a kidney transplant, 47 patients of whom also received an islet transplantation. 2002 patients were not eligible for islet transplantation and 62 were excluded due to missing data. 327 eligible recipients from 15 centres were included in the study dataset for the target trial emulation. 40 patients who received IAK transplantation were successfully matched to 80 patients who received kidney transplantation alone. 13 (33%) of 40 patients in the IAK transplantation group returned to dialysis or died, compared with 36 (45%) of 80 patients in the kidney transplantation alone group. We found a significant benefit of islet transplantation compared with kidney transplantation alone on patient-graft survival, with a hazard ratio (HR) of 0·44 (95% CI 0·23-0·88; p=0·022), mainly explained by a protective effect on the risk of death (HR 0·41, 0·13-0·91; p=0·042). There was no meaningful association between IAK and death-censored graft survival (0·73, 0·30-1·89; p=0·36). In kidney transplant recipients with type 1 diabetes, IAK transplantation was associated with a significantly better patient-graft survival compared with kidney transplantation alone, mainly due to a protective effect on the risk of death. These results potentially serve as compelling grounds for advocating wider access to islet transplantation in patients with type 1 diabetes undergoing kidney transplant, as reimbursement of islet transplantation is provided in few countries worldwide. Programme Hospitalier de la Recherche Clinique, Fondation pour la Recherche Medicale, and Fonds de Dotation Line Renaud-Loulou Gasté.

Survival After Intra-Arrest Transport vs On-Scene Cardiopulmonary Resuscitation in Children

For pediatric out-of-hospital cardiac arrest (OHCA), emergency medical services (EMS) may elect to transport to the hospital during active cardiopulmonary resuscitation (CPR) (ie, intra-arrest transport) or to continue on-scene CPR for the entirety of the resuscitative effort. The comparative effectiveness of these strategies is unclear. To evaluate the association between intra-arrest transport compared with continued on-scene CPR and survival after pediatric OHCA, and to determine whether this association differs based on the timing of intra-arrest transport. This cohort study included pediatric patients aged younger than 18 years with EMS-treated OHCA between December 1, 2005 and June 30, 2015. Data were collected from the Resuscitation Outcomes Consortium Epidemiologic Registry, a prospective 10-site OHCA registry in the US and Canada. Data analysis was performed from May 2022 to February 2024. Intra-arrest transport, defined as an initiation of transport prior to the return of spontaneous circulation, and the interval between EMS arrival and intra-arrest transport. The primary outcome was survival to hospital discharge. Patients who underwent intra-arrest transport at any given minute after EMS arrival were compared with patients who were at risk of undergoing intra-arrest transport within the same minute using time-dependent propensity scores calculated from patient demographics, arrest characteristics, and EMS interventions. We examined subgroups based on age (<1 year vs ≥1 year). Of 2854 eligible pediatric patients (median [IQR] age, 1 [0-9] years); 1691 males [59.3%]) who experienced OHCA between December 2005 and June 2015, 1892 children (66.3%) were treated with intra-arrest transport and 962 children (33.7%) received continued on-scene CPR. The median (IQR) time between EMS arrival and intra-arrest transport was 15 (9-22) minutes. In the propensity score-matched cohort (3680 matched cases), there was no significant difference in survival to hospital discharge between the intra-arrest transport group and the continued on-scene CPR group (87 of 1840 patients [4.7%] vs 95 of 1840 patients [5.2%]; risk ratio [RR], 0.81 [95% CI, 0.59-1.10]). Survival to hospital discharge was not modified by the timing of intra-arrest transport (P value for the interaction between intra-arrest transport and time to matching = .10). Among patients aged younger than 1 year, intra-arrest transport was associated with lower survival to hospital discharge (RR, 0.52; 95% CI, 0.33-0.83) but there was no association for children aged 1 year or older (RR, 1.22; 95% CI, 0.77-1.93). In this cohort study of a North American OHCA registry, intra-arrest transport compared with continued on-scene CPR was not associated with survival to hospital discharge among children with OHCA. However, intra-arrest transport was associated with a lower likelihood of survival to hospital discharge among children aged younger than 1 year.

In-hospital extracorporeal cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest: an analysis by time-dependent propensity score matching using a nationwide database in Japan

BackgroundExtracorporeal cardiopulmonary resuscitation (ECPR) has been proposed as a rescue therapy for patients with refractory cardiac arrest. This study aimed to evaluate the association between ECPR and clinical outcomes among patients with out-of-hospital cardiac arrest (OHCA) using risk-set matching with a time-dependent propensity score.MethodsThis was a secondary analysis of the JAAM-OHCA registry data, a nationwide multicenter prospective study of patients with OHCA, from June 2014 and December 2019, that included adults (≥ 18 years) with OHCA. Initial cardiac rhythm was classified as shockable and non-shockable. Patients who received ECPR were sequentially matched with the control, within the same time (minutes) based on time-dependent propensity scores calculated from potential confounders. The odds ratios with 95% confidence intervals (CI) for 30-day survival and 30-day favorable neurological outcomes were estimated for ECPR cases using a conditional logistic model.ResultsOf 57,754 patients in the JAAM-OHCA registry, we selected 1826 patients with an initial shockable rhythm (treated with ECPR, n = 913 and control, n = 913) and a cohort of 740 patients with an initial non-shockable rhythm (treated with ECPR, n = 370 and control, n = 370). In these matched cohorts, the odds ratio for 30-day survival in the ECPR group was 1.76 [95%CI 1.38–2.25] for shockable rhythm and 5.37 [95%CI 2.53–11.43] for non-shockable rhythm, compared to controls. For favorable neurological outcomes, the odds ratio in the ECPR group was 1.11 [95%CI 0.82–1.49] for shockable rhythm and 4.25 [95%CI 1.43–12.63] for non-shockable rhythm, compared to controls.ConclusionECPR was associated with increased 30-day survival in patients with OHCA with initial shockable and even non-shockable rhythms. Further research is warranted to investigate the reproducibility of the results and who is the best candidate for ECPR.Graphical

331 The Time Limit of Resuscitation at the Scene of Out-of-Hospital Cardiac Arrest in Japan- A study using time-dependent propensity score matching

331 The Time Limit of Resuscitation at the Scene of Out-of-Hospital Cardiac Arrest in Japan- A study using time-dependent propensity score matching

Genetic matching for time-dependent treatments: a longitudinal extension and simulation study

BackgroundLongitudinal matching can mitigate confounding in observational, real-world studies of time-dependent treatments. To date, these methods have required iterative, manual re-specifications to achieve covariate balance. We propose a longitudinal extension of genetic matching, a machine learning approach that automates balancing of covariate histories. We examine performance by comparing the proposed extension against baseline propensity score matching and time-dependent propensity score matching.MethodsTo evaluate comparative performance, we developed a Monte Carlo simulation framework that reflects a static treatment assigned at multiple time points. Data generation considers a treatment assignment model, a continuous outcome model, and underlying covariates. In simulation, we generated 1,000 datasets, each consisting of 1,000 subjects, and applied: (1) nearest neighbour matching on time-invariant, baseline propensity scores; (2) sequential risk set matching on time-dependent propensity scores; and (3) longitudinal genetic matching on time-dependent covariates. To measure comparative performance, we estimated covariate balance, efficiency, bias, and root mean squared error (RMSE) of treatment effect estimates. In scenario analysis, we varied underlying assumptions for assumed covariate distributions, correlations, treatment assignment models, and outcome models.ResultsIn all scenarios, baseline propensity score matching resulted in biased effect estimation in the presence of time-dependent confounding, with mean bias ranging from 29.7% to 37.2%. In contrast, time-dependent propensity score matching and longitudinal genetic matching achieved stronger covariate balance and yielded less biased estimation, with mean bias ranging from 0.7% to 13.7%. Across scenarios, longitudinal genetic matching achieved similar or better performance than time-dependent propensity score matching without requiring manual re-specifications or normality of covariates.ConclusionsWhile the most appropriate longitudinal method will depend on research questions and underlying data patterns, our study can help guide these decisions. Simulation results demonstrate the validity of our longitudinal genetic matching approach for supporting future real-world assessments of treatments accessible at multiple time points.

#5876 ISLET TRANSPLANTATION VERSUS INSULIN ALONE IN TYPE 1 DIABETIC KIDNEY TRANSPLANT RECIPIENTS: A FRENCH NATIONWIDE STUDY ON BEHALF OF THE TREPID GROUP

Abstract Background and Aims Islet transplantation is associated with a benefit on glycaemic control compared to optimized insulin therapy in recent clinical trials. However, there is a lack of evidence concerning the long-term impact of islet transplantation on type 1 diabetic kidney transplant recipients’ prognosis. Method Every type 1 diabetic recipient transplanted with a kidney in France between 2000 and 2017 was included. Patients transplanted with pancreatic islets were compared to controls treated with insulin alone according to a matching method based on time-dependent propensity scores (using the following variables : yera of transplantation, donor age, and recipient age, serum creatinine, HBA1c, BMI, cardiovascular background) which allow to ensure patients comparability at the time of islet transplantation. The primary outcome was graft failure, defined by death or return to dialysis. Results Among 2393 type 1 diabetic patients transplanted with a kidney during the study period, 381 were eligible to islet transplantation, including 47 that were actually transplanted with islets. Median time for islet transplantation was 34.8 months [21.8-48.4]. Probabilities of insulino-independence and islet graft survival at 1, 5 and 10 years were respectively 63.8% [51.5-79.2], 46.3% [33.9-63.2], 38.7% [25.9-57.8] and 89.4% [81.0-98.6], 87.2% [78.2-97.3], 78.2% [66.2-92.4]. After matching, we observed a significant benefit of islet transplantation compared to insulin alone on graft failure, with a HR of 0.48 [0.20-0.94], mainly explained by a protective effect on the risk of death (HR = 0.38 [0.11-0.95]). We finally estimated the life-expectancy for a 10-year follow-up and found 9.61 years [9.02-10.00] in the islet transplantation group versus 8.85 years [7.97-9.56], with a difference of 8.88 months [-2.16-20.44] Conclusion We observe a significant benefit of islet transplantation on the risk of graft failure and death in type 1 diabetic kidney transplant recipients. These results provide incentives to promote islet transplantation in this population.

The impact of time to amiodarone administration on survival from out-of-hospital cardiac arrest

AimTo examine the impact of time to amiodarone administration on survival from shock-refractory Ventricular Fibrillation/pulseless Ventricular Tachycardia (VF/pVT) following out-of-hospital cardiac arrest (OHCA). MethodsA retrospective cohort study of adult (≥16 years) OHCA patients in shock-refractory VF/pVT (after 3 consecutive defibrillation attempts) of medical aetiology who arrested between January 2010 and December 2019. Time-dependent propensity score matching was used to sequentially match patients who received amiodarone at any given minute of resuscitation with patients eligible to receive amiodarone during the same minute. Log-binomial regression models were used to assess the association between time of amiodarone administration (by quartiles of time-to-matching) and survival outcomes. ResultsA total of 2,026 patients were included, 1,393 (68.8%) of whom received amiodarone with a median (interquartile range) time to administration of 22.0 (18.0–27.0) minutes. Propensity score matching yielded 1,360 matched pairs. Amiodarone administration within 28 minutes of the emergency call was associated with a higher likelihood of return of spontaneous circulation (ROSC) (≤18minutes: RR = 1.03 (95%CI 1.02, 1.04); 19-22minutes: RR = 1.02 (95%CI 1.01, 1.03); 23-27minutes: RR = 1.01 (95%CI 1.00, 1.02)) and event survival (pulse on hospital arrival) (≤18 minutes: RR = 1.05 (95%CI 1.03, 1.07); 19–22 minutes: RR = 1.03 (95%CI 1.01, 1.05); 23–27 minutes: RR = 1.02 (95%CI 1.00, 1.03). Amiodarone administration within 23 minutes of the emergency call was associated with a higher likelihood of survival to hospital discharge (≤18minutes: RR = 1.17 (95%CI 1.09, 1.24; 19–22 minutes: RR = 1.10 (95%CI 1.04, 1.17). ConclusionAmiodarone administered within 23 minutes of the emergency call is associated with improved survival outcomes in shock-refractory VF/pVT, although prospective trials are required to confirm these findings.

Implementation and outcomes of dolutegravir-based first-line antiretroviral therapy for people with HIV in South Africa: a retrospective cohort study

There are few data assessing the uptake of first-line dolutegravir among men and women living with HIV in low-income and middle-income countries, and subsequent clinical outcomes in non-trial settings. We aimed to determine dolutegravir uptake in women, and the effect of dolutegravir on clinical outcomes in routine care in South Africa. In this cohort study, we analysed deidentified data from adults receiving first-line antiretroviral therapy (ART) at 59 South African clinics from Dec 1, 2019, to Feb 28, 2022, using two distinct cohorts. In the initiator cohort, we used Poisson regression models to assess the outcome of initiation with dolutegravir-based ART by gender, and associations between dolutegravir use and the outcomes of 12-month retention in care and viral suppression at less than 50 copies per mL. In the transition cohort, comprising adults who received non-dolutegravir-based first-line ART in December, 2019, we used Cox proportional hazards models to assess the outcome of transition to first-line dolutegravir by gender. We then used time-dependent propensity score matching to compare the outcomes of subsequent 12-month retention in care and viral suppression between people who transitioned to dolutegravir and those who had not yet transitioned at the same timepoint. In both the initiation and transition cohort, the primary viral load analysis was an intention-to-treat analysis, with a secondary as-treated analysis that excluded people who changed their ART regimen after baseline. In the initiator cohort, between Dec 1, 2019, and Feb 28, 2022, 45 392 people were initiated on ART. 23 945 (52·8%) of 45 392 were non-pregnant women, 4780 (10·5%) were pregnant women, and 16 667 (36·7%) were men. The median participant age was 31·0 years (IQR 26·0-38·0) and 2401 (5·3%) were receiving tuberculosis treatment at time of ART initiation. 31 264 (68·9%) of 45 392 people were initiated on dolutegravir, 14 102 (31·1%) on efavirenz, and 26 (0·1%) on nevirapine. In a univariable Poisson regression model, pregnant women (risk ratio [RR] 0·57, 95% CI 0·49 to 0·66; risk difference -35·4%, 95% CI -42·3 to -28·5) and non-pregnant women (RR 0·78, 0·74 to 0·82; risk difference -18·4%, -21·6 to -15·2) were less likely to be initiated on dolutegravir than were men. In Poisson models adjusted for age, gender (including pregnancy), time, tuberculosis status, and initiation CD4 count, people initiated on dolutegravir were more likely to be retained in care at 12 months (adjusted RR 1·09, 95% CI 1·04 to 1·14; adjusted risk difference 5·2%, 2·2 to 8·4) and virally suppressed (adjusted RR 1·04, 95% CI 1·01 to 1·06; adjusted risk difference 3·1%, 1·2 to 5·1) compared with those initiated on non-dolutegravir-based regimens. For the transition cohort, on Dec 1, 2019, 180 956 people were receiving non-dolutegravir-based first-line ART at the study clinics, of whom 124 168 (68·6%) were women. The median age was 38 years (IQR 32-45), and the median time on ART was 3·9 years (2·0-6·4) years, with most people receiving efavirenz (178 624 [98·7%] people) and tenofovir (178 148 [98·4%]). By Feb 28, 2022, 121 174 (67·0%) of 180 956 people had transitioned to first-line dolutegravir at a median of 283 days (IQR 203-526). In a univariable Cox regression model the hazard of being transitioned to dolutegravir was lower in women than in men (hazard ratio 0·56, 95% CI 0·56 to 0·57). Among 92 318 propensity score matched people, the likelihood of retention in care was higher among the dolutegravir group compared with matched controls (adjusted RR 1·03, 95% CI 1·02 to 1·03; risk difference 2·5%, 95% CI 2·1 to 2·9). In the dolutegravir group, 33 423 (90·5%) of 36 920 people were suppressed at less than 50 copies per mL compared with 31 648 (89·7%) of 35 299 matched controls (adjusted RR 1·01, 95% CI 1·00 to 1·02; risk difference 0·8%, 95% CI 0·3 to 1·4). Women were less likely to receive dolutegravir than men. As dolutegravir was associated with improved outcomes, roll-out should continue, with a particular emphasis on inclusion of women. Wellcome Trust, Africa Oxford Initiative, International Association of Providers of AIDS Care, and Bill & Melinda Gates Foundation. For the isiZulu translation of the abstract see Supplementary Materials section.

Evaluation of Use of Epinephrine and Time to First Dose and Outcomes in Pediatric Patients With Out-of-Hospital Cardiac Arrest

While epinephrine has been widely used in prehospital resuscitation for pediatric patients with out-of-hospital cardiac arrest (OHCA), the benefit and optimal timing of epinephrine administration have not been fully investigated. To evaluate the association between epinephrine administration and patient outcomes and to ascertain whether the timing of epinephrine administration was associated with patient outcomes after pediatric OHCA. This cohort study included pediatric patients (<18 years) with OHCA treated by emergency medical services (EMS) from April 2011 to June 2015. Eligible patients were identified from the Resuscitation Outcomes Consortium Epidemiologic Registry, a prospective OHCA registry at 10 sites in the US and Canada. Data analysis was performed from May 2021 to January 2023. The main exposures were prehospital intravenous or intraosseous epinephrine administration and the interval between arrival of an advanced life support (ALS)-capable EMS clinician (ALS arrival) and the first administration of epinephrine. The primary outcome was survival to hospital discharge. Patients who received epinephrine at any given minute after ALS arrival were matched with patients who were at risk of receiving epinephrine within the same minute using time-dependent propensity scores calculated from patient demographics, arrest characteristics, and EMS interventions. Of 1032 eligible individuals (median [IQR] age, 1 [0-10] years), 625 (60.6%) were male. 765 patients (74.1%) received epinephrine and 267 (25.9%) did not. The median (IQR) time interval between ALS arrival and epinephrine administration was 9 (6.2-12.1) minutes. In the propensity score-matched cohort (1432 patients), survival to hospital discharge was higher in the epinephrine group compared with the at-risk group (epinephrine: 45 of 716 [6.3%] vs at-risk: 29 of 716 [4.1%]; risk ratio, 2.09; 95% CI, 1.29-3.40). The timing of epinephrine administration was also not associated with survival to hospital discharge after ALS arrival (P for the interaction between epinephrine administration and time to matching = .34). In this study of pediatric patients with OHCA in the US and Canada, epinephrine administration was associated with survival to hospital discharge, while timing of the administration was not associated with survival.

Secondary invasive fungal infection in hospitalised patients with COVID-19 in the United States.

Invasive fungal infections (IFIs) have been identified as a complication in patients with Coronavirus disease 2019 (COVID-19). To date, there are few US studies examining the excess humanistic and economic burden of IFIs on hospitalised COVID-19 patients. This study investigated the incidence, risk factors, clinical and economic burden of IFIs in patients hospitalised with COVID-19 in the United States. Data from adult patients hospitalised with COVID-19 during 01 April 2020-31 March 2021 were extracted retrospectively from the Premier Healthcare Database. IFI was defined either by diagnosis or microbiology findings plus systemic antifungal use. Disease burden attributable to IFI was estimated using time-dependent propensity score matching. Overall, 515,391 COVID-19 patients were included (male 51.7%, median age: 66 years); IFI incidence was 0.35/1000 patient-days. Most patients did not have traditional host factors for IFI such as hematologic malignancies; COVID-19 treatments including mechanical ventilation and systemic corticosteroid use were identified as risk factors. Excess mortality attributable to IFI was estimated at 18.4%, and attributable excess hospital costs were $16,100. Invasive fungal infection incidence was lower than previously reported, possibly due to a conservative definition of IFI. Typical COVID-19 treatments were among the risk factors identified. Furthermore, diagnosis of IFIs in COVID-19 patients may be complicated because of the several non-specific shared symptoms, leading to underestimation of the true incidence rate. The healthcare burden of IFIs was significant among COVID-19 patients, including higher mortality and greater cost.

Extracorporeal cardiopulmonary resuscitation for adult out-of-hospital cardiac arrest patients: time-dependent propensity score-sequential matching analysis from a nationwide population-based registry

BackgroundThere is inconclusive evidence regarding the effectiveness of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) patients. We aimed to evaluate the association between ECPR and neurologic recovery in OHCA patients using time-dependent propensity score matching analysis.MethodsUsing a nationwide OHCA registry, adult medical OHCA patients who underwent CPR at the emergency department between 2013 and 2020 were included. The primary outcome was a good neurological recovery at discharge. Time-dependent propensity score matching was used to match patients who received ECPR to those at risk for ECPR within the same time interval. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated, and stratified analysis by the timing of ECPR was also performed.ResultsAmong 118,391 eligible patients, 484 received ECPR. After 1:4 time-dependent propensity score matching, 458 patients in the ECPR group and 1832 patients in the no ECPR group were included in the matched cohort. In the matched cohort, ECPR was not associated with good neurological recovery (10.3% in ECPR and 6.9% in no ECPR; RR [95% CI] 1.28 [0.85–1.93]). In the stratified analyses according to the timing of matching, ECPR with a pump-on within 45 min after emergency department arrival was associated with favourable neurological outcomes (RR [95% CI] 2.51 [1.33–4.75] in 1–30 min, 1.81 [1.11–2.93] in 31–45 min, 1.07 (0.56–2.04) in 46–60 min, and 0.45 (0.11–1.91) in over 60 min).ConclusionsECPR itself was not associated with good neurological recovery, but early ECPR was positively associated with good neurological recovery. Research on how to perform ECPR at an early stage and clinical trials to evaluate the effect of ECPR is warranted.

Improving the decision to switch from first- to second-line therapy in multiple sclerosis: A dynamic scoring system

Background: In relapsing-remitting multiple sclerosis (RRMS), early identification of suboptimal responders can prevent disability progression. Objective: We aimed to develop and validate a dynamic score to guide the early decision to switch from first- to second-line therapy. Methods: Using time-dependent propensity scores (PS) from a French cohort of 12,823 patients with RRMS, we constructed one training and two validation PS-matched cohorts to compare the switched patients to second-line treatment and the maintained patients. We used a frailty Cox model for predicting individual hazard ratios (iHRs). Results: From the validation PS-matched cohort of 348 independent patients with iHR ⩽ 0.69, we reported the 5-year relapse-free survival at 0.14 (95% confidence interval (CI) 0.09–0.22) for the waiting group and 0.40 (95% CI 0.32–0.51) for the switched group. From the validation PS-matched cohort of 518 independent patients with iHR > 0.69, these values were 0.37 (95% CI 0.30–0.46) and 0.44 (95% CI 0.37–0.52), respectively. Conclusions: By using the proposed dynamic score, we estimated that at least one-third of patients could benefit from an earlier switch to prevent relapse.

Effect Modification on Death by Age and Sex in Elderly Hip Fracture.

This study compared the effects of hip fractures on mortality according to sex and age in a nationwide cohort of elderly patients with hip fractures and controls. Patients with hip fractures and matched controls were selected from the National Health Insurance Service-Senior cohort. Time-dependent propensity score matching was estimated from a Cox proportional hazards model with January 1, 2005, as the baseline and hip fracture as an event. Patients were matched by age and sex to participants at risk of developing a hip fracture at time zero. The effect size is presented as hazard ratio (HR) using a Cox proportional hazards model with a robust variance estimator that accounts for clustering within the matched pairs. Altogether, 14,283 patients with incident hip fractures and 28,566 matched controls were identified. The HR of male sex in hip fractures was 1.31 (95% confidence interval [CI], 1.22-1.40; Pinteraction<0.01). Moreover, the HR of age group in hip fractures was 0.73 (95% CI, 0.66-0.80; Pinteraction<0.01) between the 65 to 74 and 75 to 84 years groups, 0.76 (95% CI, 0.71-0.81; Pinteraction<0.01) between the 75 to 84 and ≥85 years groups, and 0.55 (95% CI, 0.50-0.61; Pinteraction<0.01) between the 65 to 74 and ≥85 years groups. Male sex increases the risk of death in elderly patients with hip fractures versus matched controls, but the increased risk of death with age in hip fractures was decreased compared to that in matched controls.

Abstract 282: Extracorporeal Resuscitation For Out-of-Hospital Cardiac Arrest Patients: Analysis By Time-Dependent Propensity Score Matching Using Nationwide Database In Japan

Background: Extracorporeal cardiopulmonary resuscitation (ECPR) has been focused as a rescue therapy for the refractory cardiac arrest patients; however, little is known about the effect of ECPR on survival. The aim of this study is to evaluate the association between ECPR and the survival among the out-of-hospital cardiac arrest patients. Method: This was the secondary analysis of JAAM-OHCA registry which is a nationwide multicenter prospective study collecting the data of out-of-hospital cardiac arrest patients from July 2012 to December 2019. The study participant were adult (≥18 years) cardiac arrest patients due to internal medical cause. Initial cardiac rhythm was stratified as initial shockable and non-shockable rhythm. Patients received ECPR were sequentially matched with the patients who had not yet received within the same minutes (control) based on the time-dependent propensity scores calculated from the patient characteristics to eliminate the resuscitation time bias. Odds ratio with 95% confidence interval (CI) of ECPR for the 30-day survival were calculated by conditional logistic model. Results: Of 57,754 patients in the JAAM-OHCA registry, 1,826 matched cohort with initial shockable rhythm (913 treated with ECPR and 913 control) and 740 matched cohort with initial non-shockable rhythm (370 treated with ECPR and 370 control) were eligible for analysis. Their characteristics between with ECPR and control were well balanced. In the matched cohort with initial shockable rhythm, 30-day survival was 24.6% (225/913) in the patients with ECPR and 16.3% (149/913) in the control. In the matched cohort with initial non-shockable rhythm, 30-day survival was 11.9% (44/370) in the patients with ECPR and 2.4% (9/370) in the control. Odds ratio of with ECPR for 30-day survival was 1.76 [95%CI: 1.38-2.25] in shockable rhythm and 5.37 [95%CI: 2.53- 11.43] in non-shockable rhythm, referred to the control. Conclusion: This time-dependent propensity score sequential matching analysis suggested that ECPR was associated with the 30-day survival outcomes among the out-of-hospital cardiac arrest patients with both initial shockable and non-shockable rhythms.

Time-varying risk of death after SARS-CoV-2 infection in Swedish long-term care facility residents: a matched cohort study

ObjectivesTo evaluate whether SARS-CoV-2 infection in residents of long-term care (LTC) facilities is associated with higher mortality after the acute phase of infection, and to estimate survival in uninfected residents.DesignExtended...

Increased risk of all-cause, Alzheimer’s, and vascular dementia in adults with migraine in Korea: a population-based cohort study

BackgroundStudies investigating the association between migraine and dementia have reported inconsistent findings. This study aimed to evaluate whether patients with migraine have an increased risk of dementia compared to individuals without migraine.MethodsWe obtained data from the 2002–2019 Korean National Health Insurance Health Screening Cohort. Non-migraine controls were selected using a 1:1 risk-set matching with a time-dependent propensity score. The main outcome was the development of all-cause dementia, and the secondary outcome was the development of each cause of dementia (Alzheimer’s, vascular, mixed or other specified, and unspecified dementia). The incidence rate of dementia was calculated using Poisson regression, and the association between migraine and dementia was evaluated using Cox proportional hazards regression.ResultsAmong 88,390 participants, 66.1% were female, and the mean baseline age was 55.3 ± 9.4 years. During the study period, dementia cases were identified in 4,800 of the 44,195 patients with migraine and 3,757 of the 44,915 matched controls. The incidence rate of dementia was 139.6 (95% confidence interval [CI], 135.7–143.5) and 107.7 (95% CI, 104.3–111.1) cases per 10,000 person-years in patients with migraine and matched controls, respectively. Patients with migraine had a 1.30 (hazard ratio [HR], 1.30; 95% CI, 1.25–1.35), 1.29 (HR, 1.29; 95% CI, 1.23–1.35), 1.35 (HR, 1.35; 95% CI, 1.19–1.54), 1.36 (HR, 1.36; 95% CI, 1.00–1.83), and 1.30 (HR, 1.30; 95% CI, 1.17–1.45) times higher risk of developing all-cause dementia, Alzheimer’s dementia, vascular dementia, mixed or other specified dementias, and unspecified dementia than their matched controls, respectively.ConclusionOur results suggest that migraine is associated with an increased risk of subsequent dementia. Further research is warranted to confirm these findings and to reveal the underlying mechanisms.

P154 The Time Limit of Resuscitation at the Scene of Out-of-Hospital Cardiac Arrest in Japan -A study using time-dependent propensity score matching-

P154 The Time Limit of Resuscitation at the Scene of Out-of-Hospital Cardiac Arrest in Japan -A study using time-dependent propensity score matching-

Trends in Sexual Behavior and Sexually Transmitted Infections After Initiating Human Immunodeficiency Virus Pre-Exposure Prophylaxis in Men Who Have Sex with Men from Amsterdam, the Netherlands: A Longitudinal Exposure-Matched Study.

Men who have sex with men (MSM) initiating human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) may increase condomless anal sex (CAS) and number of partners, and, consequently, more often acquire sexually transmitted infections (STIs). Using data from the Amsterdam Cohort Studies, we compared sexual behavior and STI among MSM after PrEP-initiation with controls not initiating PrEP. The MSM reported on sexual behavior and were tested for HIV, chlamydia, gonorrhea, and syphilis semi-annually. We matched MSM who initiated PrEP between January 1, 2015 and December 31, 2019 1:1 to MSM who did not use time-dependent propensity scores based on age, sexual behavior, and STI. Primary end-points were number of casual partners, and proportion with CAS and receptive CAS (rCAS) with casual partners, sexualized drug use (SDU), any STI, and anal STI. We modeled end-points during the 4 years before and 2 years after PrEP-initiation or matched PrEP-initiation timepoint by using logistic regression (dichotomous end-points) or negative binomial regression (count end-point), adjusted for calendar year. Two hundred twenty-eight out of the 858 (26.6%) MSM initiated PrEP. We matched 198 out of 228 (86.8%) to a control. Before PrEP-initiation, end-points increased over time in both groups, with no statistically significant difference. The odds of CAS, rCAS, and anal STI were on average higher after than before PrEP-initiation in PrEP initiators, whereas after versus before differences were not observed in controls. After PrEP-initiation, PrEP initiators had statistically significantly more casual partners, and higher odds of CAS, rCAS, SDU, any STI, and anal STI than controls. These findings support frequent STI screening and counseling in MSM using PrEP.

Intra-cardiac arrest transport and survival from out-of-hospital cardiac arrest: A nationwide observational study

AimTo assess whether intra-cardiac arrest transport as compared to continued on-scene resuscitation was associated with improved clinical outcomes among out-of-hospital cardiac arrest patients in Denmark. MethodsThis was an observational study using data from population-based registries in Denmark. Adults (aged ≥ 18 to ≤ 65 years) with an out-of-hospital cardiac arrest attended by Emergency Medical Services (EMS) between 2016 and 2018 were included. The primary outcome was survival to 30 days. Time-dependent propensity score matching was used to match patients transported to the hospital within 20 minutes of EMS arrival to patients with assumed on-scene resuscitation (with or without subsequent intra-cardiac arrest transport) at risk of being transported within the same minute. ResultsThe full cohort included 2,873 cardiac arrests. The median age was 56 (quartiles: 48 to 62) years, 1987 (69%) were male, and 104 (4%) were transported within 20 minutes. A total of 87 transported patients were matched to 87 patients at risk of being transported based on the propensity score. Although not reaching statistical significance, in comparison with on-scene resuscitation, intra-cardiac arrest transport was associated with increased survival to 30 days (risk ratio, 1.55; 95%CI, 0.99–2.44; P = 0.06). Similar associations were observed for return of spontaneous circulation and survival to one year. ConclusionsAmong patients aged 18–65 years, intra-cardiac arrest transport was associated with a non-significant increase in survival within 20 minutes of EMS on-scene arrival. However, the results did not eliminate the potential for bias and the results should be interpreted carefully.

Impact of kidney transplantation in obese candidates: a time-dependent propensity score matching study

ABSTRACT Background Although kidney transplantation (KT) is considered the best treatment for end-stage renal disease (ESRD), there are concerns about its benefit in the obese population because of the increased incidence of post-transplant adverse events. We compared patients who underwent KT versus patients awaiting KT on dialysis. Methods We estimated the life expectancy [restricted mean survival time (RMST)] for a 10-year follow-up by matching on time-dependent propensity scores. The primary outcome was time to death. Results In patients with a body mass index (BMI) ≥30 kg/m2 (n = 2155 patients per arm), the RMST was 8.23 years [95% confidence interval (CI) 8.05–8.40] in the KT group versus 8.00 years (95% CI 7.82–8.18) in the awaiting KT group, a difference of 2.71 months (95% CI −0.19–5.63). In patients with a BMI ≥35 kg/m2 (n = 212 patients per arm), we reported no significant difference [8.56 years (95% CI 7.96–9.08) versus 8.66 (95% CI 8.10–9.17)]. Hence we deduced that KT in patients with a BMI between 30 and 35 kg/m2 was beneficial in terms of life expectancy. Conclusion Regarding the organ shortage, KT may be questionable for those with a BMI ≥35 kg/m2. These results do not mean that a BMI ≥35 kg/m2 should be a barrier to KT, but it should be accounted for in allocation systems to better assign grafts and maximize the overall life expectancy of ESRD patients.