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.
ObjectiveTo explore the difference between minimally invasive direct and conventional thoracotomy off-pump coronary artery bypass surgery (CABG). MethodsWe selected 276 patients underwent off-pump CABG surgery in our hospital from June 2005 through June 2014. There were 55 patients with minimally invasive off-pump CABG surgery and 221 patients conventional thoracotomy surgery. By using the method of peopensity score matching, we selected 55 conventional thoracotomy patients as a control group in our study. There were 41 males and 14 females at age of 60.8±10.5 years with minimally invasive off-pump CABG surgery, 44 males and 11 females at age of 60.6±12.5 years with conventional thoracotomy. ResultsThere was no statistical difference in surgery time, stay in the intensive care unit (ICU) time between conventional thoracotomy surgery and minimally invasive off-pump CABG. Compared with conventional thoracotomy surgery, minimally invasive off-pump CABG patients had statistical improvement in post-operative hospital stay time (7.3±3.1 d vs. 8.8±3.9 d, P=0.01), postoperative drainage (684(0-2 790)ml vs. 739(50-4 460)ml, P=0.03), perioperative blood transfusion (1.91(0-20)U vs. 6.62(0-20)U, P=0.00), surgery incision length (5.6±1.1 cm vs. 26.3±4.5 cm, P=0.00). ConclusionOverlooking the learning curve, minimally invasive direct off-pump CABG surgery has more advantages than conventional thoracotomy surgery. It is a safe and effective procedure.
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.
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.
ObjectivesTo explore the value of neural networks (NN) in estimating propensity score, and to compare the performance of propensity score methods based on both logistic regression (LR) and NN.MethodsData sets including ten binary or continuous covariates, binary treatment variable and continuous outcome variable were simulated by SAS 9.2 software, and 5 scenarios differing by non-linear and/or non-additive associations between treatment assignment and covariates were set up. The sample sizes 500, 1000, 2000, 5000 and 10000 were considered. Propensity scores were estimated using either LR or NN model using only partial covariates associated with the outcome (methods LR1, NN1), or all covariates associated with either outcome or treatment (methods LR2, NN2). The average treatment effect (ATE) estimates, standard error (SE), bias, and mean square error (MSE) of ATE among the different models were compared.ResultsThe 95% confidence intervals of the average treatment effect were narrower in NN than that in LR models. SE, bias and MSE increased with the increasing complexity of non-linear and/or non-additive associations between the treatment and covariates, and smaller SE, bias, and MSE were observed in LR1 than LR2, and in NN1 than NN2. NN generally produced less bias than LR under most scenarios when variables associated with the outcome were introduced. SE and MSE decreased with the increasing sample size for both LR and NN models.ConclusionsNN for estimating propensity scores may be less biased and produce more precise estimates for ATE than LR in a meaningful manner when the complex association between treatment and covariates exists.
Propensity score methods belong to an analytical approach by incorporating the measured covariates and mimicking randomization to enhance the comparability between groups, hence reducing the impact of potential confounding in observational studies. Propensity score methods have been increasingly used in observational studies. This paper illustrates the principle and the methods based on the propensity score, in combination with its application in observational studies. It also compares results from propensity score methods with those from multivariable regression and randomized controlled trials. It was found that currently there has been a lack of recommendations for the selection of propensity score methods. Differences may exist when comparing results from propensity score methods with findings from typical regression analyses and randomized controlled trials.
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 compare the outcomes of kidney transplantation (KT) between Tibetan and Han recipients.MethodsPatients greater than 18 years old, who had received the first ABO-compatible KT between April 2006 and March 2017, were retrospectively included. A propensity score matching (PSM) of Tibetans to Hans was performed by 1∶3 ratio. Survival, renal function and adverse events of the two groups were compared.ResultsOf the 1 820 patients who fit the screening criteria, 123 Tibetans and 357 Hans were included after PSM. The median follow-up time was 48 months. There was no statistically significant difference in death-censored grafts survival (P=0.061) or patients survival (P=0.440) between the two groups. The serum creatinine was higher in Tibetans than that in Hans within one year after KT (P<0.05), and the estimated glomerular filtration rate was lower in Tibetans than that in Hans within 5 years after KT (P<0.05), but no difference thereafter (P>0.05). The incidence of delayed graft function in Tibetan patients after operation was higher than that in Han patients (4.9% vs. 1.4%, P=0.037), but there was no significant difference in the incidence of acute rejection, infection, reoperation, or cancer between the two groups (P>0.05).ConclusionTibetans receiving KT achieve excellent and comparable long-term graft and patient survival to Hans, with similar long-term graft function.
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.
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.