Efficacy of Convalescent Plasma to Treat Mild to Moderate COVID-19 in Kidney Transplant Patients: A Propensity Score Matching Analysis.
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ABSTRACT:
SUBMITTER: Cristelli MP
PROVIDER: S-EPMC8667676 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundAn increased number of end-stage renal disease patients suffer psychosocial conditions and may experience delayed access to transplantation due to listing restrictions. However, it remains to be shown whether preexisting psychosocial conditions confer an independent risk factor of poor posttransplant outcomes.ObjectiveWe addressed this gap in knowledge by conducting a retrospective cohort study to investigate an independent association between the risk of death after transplant and having a diagnosis of psychosocial conditions 1 year prior to starting dialysis.MethodsAll cases of adult deceased-donor kidney transplantation performed in Ontario, Canada, between April 1, 2002, and March 31, 2013, were used. Propensity score matching was applied to adjust for potential endogenous bias of using predialysis psychosocial status to predict posttransplant mortality. Survival analysis techniques, including Kaplan-Meier curves and Cox proportional hazards modeling, were also used.ResultsOur results indicate a 49.4% (hazard ratio [HR] = 1.494 [95% confidence interval (CI) = 1.168-1.913]) increased relative risk of posttransplant death to be associated with predialysis psychosocial conditions, when other factors are held constant. The effect is significant (P = .001) and is independent of other known predictors of death including advanced age.ConclusionsFindings from this study offered strong support for the development of psychosocial evaluation to screen candidates prior to transplant listing and early interventions for transplant candidates with psychosocial concerns.
| S-EPMC6600500 | biostudies-literature
Project description: Not available
| S-EPMC8233547 | biostudies-literature
Project description:PurposeData for elucidating post-kidney transplantation (KT) acute pancreatitis (AP) risk are limited and no large-scale cohort study has investigated the impact of AP after KT.MethodData from Taiwan National Health Insurance (NHI) Research Database (NHIRD) were calculated through the method of propensity score matching to compare the pancreatitis risk in patients with and without KT.ResultsThe overall pancreatitis incidence rates were 1.71 and 0.61 per 1,000 person-years in the KT and non-KT groups, respectively and corresponding adjusted HR (aHR [95% CI]) for pancreatitis was 2.48 (1.51-4.09) in the KT group. In the multivariable model, AP risk was higher in transplant patients with alcohol-related illnesses (aHR: 3.78, 95% CI: 1.32-10.8), gall stone disease (aHR: 3.53, 95% CI: 1.48-8.44), or past history of pancreatitis (aHR: 10.3, 95% CI: 5.08-20.8). Of note, recurrent AP risk was significantly higher in the KT group (aHR: 8.19, 95% CI: 2.89-23.2). Patients with post-KT AP demonstrated shorter patient and allograft survival than did those without (both P < 0.001, respectively).ConclusionIn conclusion, KT recipients are very likely to be associated with AP. Moreover, their inferior outcomes are strongly associated with post-KT AP.
| S-EPMC6738600 | biostudies-literature
Project description:Cluster randomization trials with relatively few clusters have been widely used in recent years for evaluation of health-care strategies. On average, randomized treatment assignment achieves balance in both known and unknown confounding factors between treatment groups, however, in practice investigators can only introduce a small amount of stratification and cannot balance on all the important variables simultaneously. The limitation arises especially when there are many confounding variables in small studies. Such is the case in the INSTINCT trial designed to investigate the effectiveness of an education program in enhancing the tPA use in stroke patients. In this article, we introduce a new randomization design, the balance match weighted (BMW) design, which applies the optimal matching with constraints technique to a prospective randomized design and aims to minimize the mean squared error (MSE) of the treatment effect estimator. A simulation study shows that, under various confounding scenarios, the BMW design can yield substantial reductions in the MSE for the treatment effect estimator compared to a completely randomized or matched-pair design. The BMW design is also compared with a model-based approach adjusting for the estimated propensity score and Robins-Mark-Newey E-estimation procedure in terms of efficiency and robustness of the treatment effect estimator. These investigations suggest that the BMW design is more robust and usually, although not always, more efficient than either of the approaches. The design is also seen to be robust against heterogeneous error. We illustrate these methods in proposing a design for the INSTINCT trial.
| S-EPMC3407414 | biostudies-literature
Project description:The propensity score is defined as the probability of each individual study subject being assigned to a group of interest for comparison purposes. Propensity score adjustment is a method of ensuring an even distribution of confounders between groups, thereby increasing between group comparability. Propensity score analysis is therefore an increasingly applied statistical method in observational studies. The purpose of this article was to provide a step-by-step nonmathematical conceptual guide to propensity score analysis with particular emphasis on propensity score matching. A software program code used for propensity score matching was also presented.
| S-EPMC4347264 | biostudies-literature
Project description:Recent work has demonstrated that propensity score matching may lead to increased covariate imbalance, even with the corresponding decrease in propensity score distance between matched units. The extent to which this paradoxical phenomenon might harm causal inference in real epidemiologic studies has not been explored. We evaluated the effect of this phenomenon using insurance claims data from the Pharmaceutical Assistance Contract for the Elderly (1999-2002) and Medicaid Analytic eXtract (2000-2007) databases in the United States. For each data set, we created several 1:1 propensity-score-matched data sets by manipulating the size of the covariate set used to generate propensity scores, the index exposure prevalence in the prematched data set, and the matching algorithm. We matched all index units, then progressively pruned matched sets in order of decreasing propensity score distance, calculating covariate imbalance after each pruning. Although covariate imbalance sometimes increased after progressive pruning of matched sets, the application of commonly used propensity score calipers for defining an acceptable match stopped pruning near the lowest region of the imbalance trend and resulted in an improvement over the imbalance in the prematched data set. Thus, propensity score matching does not appear to induce increased covariate imbalance when standard propensity score calipers are applied in these types of pharmacoepidemiologic studies.
| S-EPMC6118075 | biostudies-literature
Project description:BACKGROUND:Malnutrition with hypoalbuminemia (albumin < 35 g/L) is an important factor in predicting risks associated with colorectal cancer surgery. However, there is limited data about the effects of mild hypoalbuminemia with small decreases in albumin on postoperative complications. METHODS:This is a retrospective study using the multi-institutional, nationally validated database of the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) to investigate mild hypoalbuminemia and its association with postoperative mortality and morbidity by using a propensity score matching method. RESULTS:In a group of 30,676 colorectal cancer patients who received surgery, 5230 had mild hypoalbuminemia (< 35 and > =30 g/L) and 21,310 had normal albumin levels (> = 35 g/L). Significant differences were noted in 21 clinical characteristics between the two groups. After 1:2 propensity score matching postoperative mortality was significantly associated with mild hypoalbuminemia (OR = 1.74; p < 0.001). There were significant associations between mild hypoalbuminemia and 11 postoperative morbidities including deep vein thrombosis, pulmonary embolism, superficial and deep surgical site infection, pneumonia, septic shock, ventilator> 48 h, blood transfusion, return to operating room, stroke and re-intubation. Mild hypoalbuminemia was also associated with overall complication (B = 0.064, p < 0.001) and length of total hospital stay (B = 2.236, p < 0.001). CONCLUSIONS:In colorectal cancer, this is the first propensity score matching study of malnutrition with mild hypoalbuminemia which demonstrates that a mild decrease in serum albumin contributes significantly to poor postoperative outcome.
| S-EPMC6598281 | biostudies-literature
Project description:Many studies have found a statistical association between breastfeeding and childhood adiposity. This paper investigates whether breastfeeding has an effect on subsequent childhood body mass index (BMI) using propensity scores to account for confounding.We use data from the Millennium Cohort Study, a nationally representative UK cohort survey, which contains detailed information on infant feeding and childhood BMI. Propensity score matching is used to investigate the mean BMI in children breastfed exclusively and partially for different durations of time.We find statistically significant influences of breastfeeding on childhood BMI, particularly in older children, when breastfeeding is prolonged and exclusive. At 7 years, children who were exclusively breastfed for 16 weeks had a BMI 0.28 kg/m2 (95% confidence interval 0.07 to 0.49) lower than those who were never breastfed, a 2% reduction from the mean BMI of 16.6 kg/m2.For this young cohort, even small effects of breastfeeding on BMI could be important. In order to reduce BMI, breastfeeding should be encouraged as part of wider lifestyle intervention. This evidence could help to inform public health bodies when creating public health guidelines and recommendations.
| S-EPMC5939873 | biostudies-other
Project description:BackgroundRegdanvimab (CT-P59) is a neutralizing antibody authorized in Republic of Korea for the treatment of adult patients with moderate or mild-COVID-19 who are not on supplemental oxygen and have high risk of progressing to severe disease (age ≥ 50 years or comorbidities). This study evaluated the clinical efficacy, safety and medical utilization/costs associated with real-world regdanvimab therapy.MethodsThis non-interventional, retrospective cohort study included adult patients with confirmed mild-to-moderate SARS-CoV-2 infection. Patients treated with regdanvimab were compared with controls who had received other therapies. The primary endpoint was the proportion of patients progressing to severe/critical COVID-19 or death due to SARS-CoV-2 infection up to Day 28. Propensity score matching was applied to efficacy analyses.ResultsOverall, 552 patients were included in the Safety and Efficacy Sets (regdanvimab, n = 156; control, n = 396) and 274 patients in the propensity score-matched (PSM) Efficacy Set (regdanvimab, n = 113; control, n = 161). In the PSM Set, the risk of severe/critical COVID-19 or death was significantly lower in the regdanvimab group (7.1% vs 16.1%, P = 0.0263); supplemental oxygen was required by 8.0% and 18.6% of patients in the regdanvimab and control groups, respectively (P = 0.0128). There were no unexpected safety findings in the regdanvimab group. Medical utilization analysis showed an overall cost reduction with regdanvimab compared with control treatments.ConclusionsRegdanvimab significantly reduced the proportion of patients progressing to severe/critical disease or dying of SARS-CoV-2 infection. This study shows the potential benefits of regdanvimab in reducing disease severity and improving medical utility in patients with COVID-19.
| S-EPMC8813598 | biostudies-literature
Project description:BackgroundThe diagnostic process is a key element of medicine but it is complex and prone to errors. Infectious diseases are one of the three categories of diseases in which diagnostic errors can be most harmful to patients. In this study we aimed to estimate the effect of initial misdiagnosis of the source of infection in patients with bacteraemia on 14 day mortality using propensity score methods to adjust for confounding.MethodsData from a previously described longitudinal cohort of patients diagnosed with monobacterial bloodstream infection (BSI) at the Leiden University Medical Centre (LUMC) between 2013 and 2015 were used. Propensity score matching and inversed probability of treatment weighting (IPTW) were applied to correct for confounding. The average treatment effect on the treated (ATT), which in this study was the average effect of initial misdiagnosis on the misdiagnosed (AEMM), was estimated. Methodological issues that were encountered when applying propensity score methods were addressed by performing additional sensitivity analyses. Sensitivity analyses consisted of varying caliper in propensity score matching and using different truncated weights in inversed probability of treatment weighting.ResultsData of 887 patients were included in the study. Propensity scores ranged between 0.015 and 0.999 and 80 patients (9.9%) had a propensity score > 0.95. In the matched analyses, 35 of the 171 misdiagnosed patients died within 14 days (20.5%), versus 10 of the 171 correctly diagnosed patients (5.8%), yielding a difference of 14.6% (7.6%; 21.6%). In the total group of patients, the observed percentage of patients with an incorrect initial diagnosis that died within 14 days was 19.8% while propensity score reweighting estimated that their probability of dying would have been 6.5%, if they had been correctly diagnosed (difference 13.3% (95% CI 6.9%;19.6%)). After adjustment for all variables that showed disbalance in the propensity score a difference of 13.7% (7.4%; 19.9%) was estimated. Sensitivity analyses yielded similar results. However, performing weighted analyses without truncation yielded unstable results.ConclusionThus, we observed a substantial increase of 14 day mortality in initially misdiagnosed patients. Furthermore, several patients received propensity scores extremely close to one and were almost sure to be initially misdiagnosed.
| S-EPMC11007998 | biostudies-literature