This study introduced the inverse probability weight and overlap weight by propensity score and how to test the balance and estimate the effect after weighting. Four R packages that can be used for propensity score weight analysis were introduced and compared.
Objective To compare the ability of three propensity score weighting methods to balance the covariates and the advantages and disadvantages to estimate the treatment effects when dealing with multiple treatment data under different sample sizes. Methods Monte Carlo simulation was used to generate data sets and the advantages and disadvantages of balancing covariates and estimating the treatment effects of three propensity score weighting methods, Logistic-IPTW, Logistic-OW and GBM-OW were compared. The evaluation index of covariate equilibrium level was the absolute standard mean difference. The evaluation indexes of effect estimation included the point estimate of treatment effect, root mean square error and confidence interval coverage. Results Compared with Logistic-IPTW and Logistic-OW, GBM-OW was better in effect estimation and had a smaller root mean square error in five scenarios where covariates were related to treatment factors and outcome variables with different varying degrees of complexity. In terms of covariate equilibrium, all three methods had good effects. GBM-OW method performed better when the overlap of propensity score distribution of multiple treatment data was relatively low and covariables had increasingly complex nonlinear relationships with treatment factors and outcome variables. Conclusion When dealing with multiple treatment data, GBM-OW method has advantages over the other two methods when there is nonlinearity and/or interaction between covariates and treatment factors and outcome variables. Using this method, the effect estimation is closer to the real value, which is a better choice.
Objective To analyze the effects of hyperuricemia (HUA) on the prevalence of dyslipidemia in the elderly. MethodsA total of 5 990 elderly people with complete and important variables from the China Health and Retirement Longitudinal Study (CHARLS) public database in 2015 were extracted. Their blood lipids, related physiological and biochemical indices, and basic demographic information were collected. The effects of HUA on the prevalence of dyslipidemia in the elderly were analyzed using the probit model, and empirical analysis was performed using the propensity score matching method (PSM). Results Among the 5 990 subjects, 13.6% of the elderly had HUA and the prevalence of dyslipidemia was 37.5%. After correcting the endogeneity among variables, the probability of dyslipidemia in elderly patients with HUA increased by 9.5%-11.7% (P<0.01), in which the probability of high triglyceridemia (TG), high total cholesterol (TC), high low-density lipoprotein cholesterol (LDL-C), and low high-density lipoprotein cholesterol (HDL-C) increased by 10.4%-11.5% (P<0.01), 2.7%-3.8% (P<0.01), 1.7%-2.3% (P<0.05), and 4.3%-4.9% (P<0.05), respectively. Conclusion HUA is associated with various types of dyslipidemia, among which its relationship with high TG and low HDL-C is strong. Targeted interventions should be taken for elderly HUA patients, aiming to reduce the rate of dyslipidemia and promote the goal of "healthy ageing" in China.
ObjectiveTo study the direct economic burden of hospitalization in patients with carbapenem-resistant Enterobacteriaceae (CRE) infection.MethodsPatients with CRE detected in Jianyang People’s Hospital between January 2017 and June 2019 were divided into infection group and colonization group, and multiple linear regression analysis was used to analyze the confounding factors, and then propensity score matching method was used to match the confounding factors of the two groups, finally the direct economic burden of hospitalization was compared between the two groups.ResultsA total of 2 013 patients were enrolled, including 507 CRE-infected patients and 1 506 CRE-colonized patients. Multiple linear regression results showed that factors affecting the direct economic burden of hospitalization included mechanical ventilation, intravenous catheterization, blood transfusion or use of blood products, urinary intubation, tracheotomy, gender, surgery, intensive care unit stay, main diagnosis, and the type of medical insurance, together with CRE infection (P<0.05). After propensity score matching, these confounding factors were well balanced between the infection group (n=249) and the colonization group (n=249), and the differences were not statistically significant (P>0.05). The median of total hospitalization cost of CRE-infected patients was 1.29 times (15 589.23 yuan more than) that of CRE-colonized patients and the difference between the two groups was statistically significant (Z=–3.116, P=0.002). The top two types of hospitalization cost with largest differences in the medians were the cost of Western medicine (4 850.21 yuan; Z=–3.460, P=0.001) and the cost of laboratory diagnosis (2 613.00 yuan; Z=–3.529, P<0.001), respectively. The cost of antimicrobial drugs differed significantly between the two groups (Z=–3.391, P=0.001), and it was 1.54 times in patients with CRE infection what it was in patients with CRE colonization.ConclusionsThere are many factors affecting the direct economic burden of inpatients, and it is necessary to avoid the influence of confounding factors as far as possible during analysis. The economic burden of patients with CRE infection is significantly greater than that of CRE-colonized patients, so active measures should be adopted to prevent and control CRE infection.
ObjectiveTo evaluate the safety, efficacy, and cost-effectiveness of different uses of oxidized regenerated cellulose (ORC) in video-assisted thoracoscopic surgery (VATS) for lung cancer resection to provide a reference for the selection, clinical use, and rational utilization of absorbable hemostatic materials. MethodsA retrospective analysis of relevant data from inpatients who underwent VATS for lung cancer resection at a tertiary hospital from July 2019 to January 2020 and from July 2020 to December 2020 was conducted. Patients were divided into two groups based on the use of ORC: 1) combined use group (ORC and collagen sponge) and 2) sole-use group (ORC). Safety, efficacy, and economic outcome indicators were compared between the two groups. ResultsThe main analysis included a total of 904 patients, with 466 in the combined use group and 438 in the sole-use group. Compared to the combined use group, the sole-use group had a significantly longer hospital stay, used fewer hemostatic drugs, had a lower average cost of hemostatic materials, and a lower median total hospitalization cost (P<0.05). No statistically significant difference was found between the two groups in terms of intraoperative blood loss volume, massive blood loss rate, perioperative transfusion rate, reoperation rate, postoperative 48-hour drainage volume, bloody drainage fluid rate, or postoperative laboratory test indicators. ConclusionThere was no significant difference in the safety or efficacy of VATS for lung cancer resection between the sole use of ORC and the combined use of ORC, but the sole use of ORC was associated with a lower cost of hemostatic materials and a lower total hospitalization cost. The sole use of hemostatic gauze in VATS for lung cancer resection may be a more cost-effective choice.
With the continuous progress of national medical insurance strategic purchasing and value-based healthcare, pharmacoeconomic evaluation, serving as a technical tool for assessing the cost-effectiveness of healthcare interventions, has played an important role in policy decision support. Comparative efficacy evidence is the core data source for pharmacoeconomic evaluation, and also the foundation for conducting pharmacoeconomic research. In recent years, the number of innovative drugs approved based on single-arm trial has been increasing. Most existing randomized controlled clinical trials are also placebo-controlled or compared with traditional treatments, unable to directly meet the need for efficacy evidence of comparisons with conventional or standard treatments in pharmacoeconomic evaluations. In the absence of direct comparative efficacy evidence, exploring indirect comparison methods for efficacy has become a cutting-edge direction in pharmacoeconomic evaluation. Through a comprehensive literature review and systematic analysis, this study focuses on five indirect comparison methods based on individual patient data for population adjustment, including match adjusted indirect comparison (MAIC), simulated treatment comparison (STC), propensity score matching (PSM), inverse probability of treatment weighting (IPTW) and network meta regression (NMR), and discussing their basic concepts, advantages and disadvantages and application comparisons. Finally, it provides methodological suggestions on how to choose an indirect comparison method for efficacy, with the aim of promoting the generation of higher-quality indirect comparison evidence for efficacy and advancing pharmacoeconomic evaluation to provide high-quality evidence references for healthcare policy decision-making.
Diabetic retinopathy (DR), which is a common complication of diabetic and the main cause of blindness, brings not only a heavy economic burden to society, but also seriously threatens to the patients’ quality of life. Clinical researches on the therapies of DR are active at present, but how to perform a good clinical research with scientific design should be considered with high priority. The randomized controlled trial (RCT) is considered to be the gold standard for evidence-based medicine, but RCT is not always perfect. Limitations still exist in certain circumstance and the conclusions from RCTs also need to be interpreted by an objective point of view before clinical practice. Real world study (RWS) bridges the gap between RCT and clinical practice, in which the data can be easily collected without much cost, and results might be obtained within a short period. However, RWS is also faced with the challenge of not having standardized data and being susceptible to confounding bias. The standardized single disease database for DR and propensity score matching method can provide a wide range of data sources and avoid of bias for RWS in DR.
ObjectiveTo explore the clinical efficacy of fascial manipulation (FM) treatment in patients with chronic ankle instability (CAI).MethodsThe clinical data of CAI patients who received rehabilitation treatment in the Department of Rehabilitation Medicine of the Second Hospital of Jilin University from October 2018 to December 2020 were retrospectively collected. According to different treatment methods, patients were divided into balance training (BT) group and FM group. The BT group received BT for 4 weeks, while the FM group received BT for 4 weeks after FM treatment. Propensity score matching (PSM) was used for 1∶1 matching to compare the effects of different treatment options on the dysfunction of CAI patients. Foot and Ankle Ability Measure (FAAM) [including FAAM-activity of daily living (FAAM-ADL), activity of daily living (ADL) self-scoring, FAAM-sports (FAAM-S), and sports self-scoring], center of pressure (COP), foot lift test (FLT) were used to evaluate the changes in balance function and symptoms pre-treatment and post-treatment.ResultsA total of 52 patients were included, including 24 cases in FM group and 28 cases in BT group. Finally, after PSM method, 34 patients were included, 17 cases in each group. Before intervention, there was no significant difference in FAAM, COP and FLT between the two groups (P>0.05). After the intervention, FAAM-ADL, ADL self score, COP and FLT in the FM group were better than those in the BT group (P<0.05); there was no significant difference between FAAM-S and exercise self score (P>0.05). Before and after the intervention, FAAM, COP and FLT were improved in both groups (P<0.05). The improvement of FAAM ADL, ADL self-score and the decrease of COP in FM group were higher than that of the BT group (P<0.05). Comparison of FAAM-S, exercise self score and FLT before and after intervention, there was no significant difference between the two groups (P>0.05).ConclusionBT can improve the function of patients with CAI, and the combination of FM is more effective in improving the ability of daily living and static balance.
Objective To compare surgical outcomes of Stanford type A acute aortic dissection between operations at midnight and daytime. Methods From January 2004 to March 2013，195 patients with Stanford type A acute aortic dissection received surgical treatment in Nanjing Hospital Affiliated to Nanjing Medical University （Nanjing Cardiovascular Disease Hospital）. Patients with identical or similar propensity scores were matched from 127 patients who underwent emergency operation at daytime and 68 patients who underwent emergency operation at midnight. A total of 58 pairs of matched patients which had the same or similar propensity score were selected in daytime surgery group （n=58，43 males and 15 females，47.7±14.6 years） and midnight surgery group （n=58，45 males and 13 females，48.3±14.6 years）. Operation time，postoperative chest drainage，mechanical ventilation time，postoperative incidence of dialysis and tracheostomy，length of ICU stay and in-hospital mortality were compared between the daytime group and midnight group. Results A total of 58 pair of patients were matched in this study. There was no statistical difference in postoperative incidence of tracheostomy ［19.0% （11/58） vs. 6.9% （4/58），P=0.053］ or in-hospital mortality ［8.6% （5/58） vs. 6.9%（4/58），P=0.729］ between the midnight group and daytime group. Operation time （485.7±93.5 minutes vs. 428.5±123.3 minutes，P=0.048），postoperative chest drainage （979.5±235.7 ml vs. 756.6±185.9 ml，P=0.031），mechanical ventilation time （67.9±13.8 hours vs. 55.7±11.9 hours，P=0.025），postoperative incidence of dialysis ［17.2% （10/58） vs. 5.2%（3/58），P=0.039］ and length of ICU stay （89.4±16.2 hours vs. 74.8±12.5 hours，P=0.023） of the midnight group weresignificantly longer or higher than those of the daytime group. A total of 107 patients were followed up for 4-6 months after discharge. During follow-up，there was no late death. Among the 13 patients who required postoperative dialysis，12 patientsno longer needed regular dialysis. Conclusion Emergency operation at midnight does not increase in-hospital mortalitybut increase some postoperative morbidity in patients with Stanford type A acute aortic dissection. Whether at midnight or daytime，better preoperative preparation and surgeons’ vigor are needed for timely surgical treatment for patients with Stanford type A acute aortic dissection.
ObjectivesTo compare the survival outcomes between hepatocellular carcinoma and hepatic angiosarcoma, and to develop and validate a nomogram predicting the outcome of hepatic angiosarcoma.MethodsThe Surveillance, Epidemiology and End Results (SEER) database was electronically searched to collect the data of hepatic angiosarcoma patients and hepatocellular carcinoma patients from 2004 to 2016. Propensity score matching (PSM) was used to match the two groups by the ratio of 1:3. Cox regression analysis was used to compare the survival outcomes between hepatic angiosarcoma and HCC. In the angiosarcoma group, population was divided into training set and validation set by 6:4. Nomograms were built for the prediction of half- and one- year survival, and validated by concordance index (C-index) and calibration plots.ResultsA total of 210 histologically confirmed hepatic angiosarcoma patients and 630 hepatocellular carcinoma patients were included. The overall survival of HCC was significantly longer than angiosarcoma (3-year survival: 18.4% vs. 6.7%, median survival: 5 months vs. 1 month, P<0.001), and the nomogram achieved good accuracy with an internal C-index of 0.751 and an external C-index of 0.737.ConclusionsThe overall survival of HCC is significantly longer than angiosarcoma. The proposed nomograms can assist to predict survival probability in patients with hepatic angiosarcoma. Due to limitation of the data of included patients, more high-quality studies are required to verify above conclusions.