Category: Statistics

J Am Heart Assoc. 2022 May 10:e023010. doi: 10.1161/JAHA.121.023010. Online ahead of print.

ABSTRACT

Background Experiments measuring the contractile properties of human myocardium are important for translational research but complicated by the logistical difficulties of acquiring specimens. Accordingly, many groups perform contractile assays using samples that are acquired from patients at one institution and shipped to another institution for experiments. This necessitates freezing the samples and performing subsequent assays using chemically permeabilized preparations. It is unknown how prior freezing affects the contractile function of these preparations. Methods and Results To examine the effects of freezing we measured the contractile function of never-frozen and previously frozen myocardial samples. Samples of left ventricular tissue were obtained from 7 patients who were having a ventricular assist device implanted. Half of each sample was chemically permeabilized and used immediately for contractile assays. The other half of the sample was snap frozen in liquid nitrogen and maintained at -180 °C for at least 6 months before being thawed and tested in a second series of experiments. Maximum isometric force measured in pCa 4.5 solution, passive force measured in pCa 9.0 solution, and Hill coefficients were not influenced by prior freezing (P=0.07, P=0.14, and P=0.27 respectively). pCa₅₀ in never-frozen samples (6.11±0.04) was statistically greater (P<0.001) than that measured after prior freezing (5.99±0.04) but the magnitude of the effect was only ≈0.1 pCa units. Conclusions We conclude that prior freezing has minimal impact on the contractile properties that can be measured using chemically permeabilized human myocardium.

PMID:35535623 | DOI:10.1161/JAHA.121.023010

Hum Brain Mapp. 2022 May 10. doi: 10.1002/hbm.25898. Online ahead of print.

ABSTRACT

In recent neuroimaging studies, threshold-free cluster enhancement (TFCE) gained popularity as a sophisticated thresholding method for statistical inference. It was shown to feature higher sensitivity than the frequently used approach of controlling the cluster-level family-wise error (cFWE) and it does not require setting a cluster-forming threshold at voxel level. Here, we examined the applicability of TFCE to a widely used method for coordinate-based neuroimaging meta-analysis, Activation Likelihood Estimation (ALE), by means of large-scale simulations. We created over 200,000 artificial meta-analysis datasets by independently varying the total number of experiments included and the amount of spatial convergence across experiments. Next, we applied ALE to all datasets and compared the performance of TFCE to both voxel-level and cluster-level FWE correction approaches. All three multiple-comparison correction methods yielded valid results, with only about 5% of the significant clusters being based on spurious convergence, which corresponds to the nominal level the methods were controlling for. On average, TFCE’s sensitivity was comparable to that of cFWE correction, but it was slightly worse for a subset of parameter combinations, even after TFCE parameter optimization. cFWE yielded the largest significant clusters, closely followed by TFCE, while voxel-level FWE correction yielded substantially smaller clusters, showcasing its high spatial specificity. Given that TFCE does not outperform the standard cFWE correction but is computationally much more expensive, we conclude that employing TFCE for ALE cannot be recommended to the general user.

PMID:35535616 | DOI:10.1002/hbm.25898

Circulation. 2022 May 10. doi: 10.1161/CIRCULATIONAHA.122.059235. Online ahead of print.

ABSTRACT

BACKGROUND: There are good data to support using a single high-sensitivity cardiac troponin T (hs-cTnT) below the limit of detection (LoD) of 5 ng/L to exclude acute myocardial infarction. Per the United States (US) Food and Drug Administration (FDA), hs-cTnT can only report to the limit of quantitation (LoQ) of 6 ng/L, a threshold for which there is limited data. Our goal was to determine whether a single hs-cTnT below the LoQ of 6 ng/L is a safe strategy to identify patients at low-risk for acute myocardial injury and infarction.

METHODS: The efficacy (proportion identified as low-risk based on baseline hs-cTnT<6 ng/L) of identifying low-risk patients was examined in a multicenter (n=22 sites) US cohort study of emergency department patients undergoing at least one hs-cTnT (CV Data Mart Biomarker cohort). We then determined the performance of a single hs-cTnT<6 ng/L (biomarker alone) to exclude acute myocardial injury (subsequent hs-cTnT >99^th percentile in those with an initial hs-cTnT<6 ng/L). The clinically intended rule-out strategy combining a nonischemic electrocardiogram with a baseline hs-cTnT<6 ng/L was subsequently tested in an adjudicated cohort in which the diagnostic performance for ruling-out acute myocardial infarction and safety (myocardial infarction or death at 30-days) were evaluated.

RESULTS: A total of 85,610 patients were evaluated in the CV Data Mart Biomarker cohort, amongst which 24,646 (29%) had a baseline hs-cTnT<6 ng/L. Women were more likely than men to have hs-cTnT<6 ng/L (38% vs. 20%, p<0.0001). Among 11,962 patients with baseline hs-cTnT<6 ng/L and serial measurements, only 1.2% developed acute myocardial injury, resulting in a negative predictive value of 98.8% (95% CI 98.6, 99.0) and sensitivity of 99.6% (95% CI 99.5, 99.6). In the adjudicated cohort, a nonischemic electrocardiogram with hs-cTnT<6 ng/L identified 33% of patients (610 of 1849) as low-risk and resulted in a negative predictive value and sensitivity of 100% and a 30-day rate of 0.2% for 30-day myocardial infarction or death.

CONCLUSIONS: A single hs-cTnT below the LoQ of 6 ng/L is a safe and rapid method to identify a substantial number of patients at very low risk for acute myocardial injury and infarction.

PMID:35535607 | DOI:10.1161/CIRCULATIONAHA.122.059235

Phys Chem Chem Phys. 2022 May 10. doi: 10.1039/d2cp00490a. Online ahead of print.

ABSTRACT

We report measurements of the statistical vibrational autodetachment (VAD, also called thermionic emission) and radiative cooling rates of isolated para-benzoquinone (pBQ, C₆H₄O₂) radical anions using the cryogenic electrostatic ion storage ring facility DESIREE. The results are interpreted using master equation simulations with rate coefficients calculated using statistical detailed balance theory. The VAD rate is determined by measuring the time-dependent yield of neutral pBQ due to spontaneous electron emission from a highly-excited ensemble of anions formed in an electron-attachment ion source. Competition with radiative cooling quenches the VAD rate after a critical time of τ_c = 11.00(5) ms. Master equation simulations which reproduce the VAD yield provide an estimate of the initial effective vibrational temperature of the ions of 1100(20) K, and provide insight into the anion formation scenario. A second measurement of the radiative cooling rate of pBQ^– stored for up to 0.5 s was achieved using time-dependent photodetachment action spectroscopy across the ²A_u ← ²B_2g and ²B_2u ← ²B_2g transitions. The rate at which hot-band contributions fade from the action spectrum is quantified by non-negative matrix factorisation. This is found to be commensurate with the average vibrational energy extracted from the simulations, with 1/e lifetimes of 0.16(3) s and 0.1602(7) s, respectively. Implications for astrochemistry are discussed.

PMID:35535575 | DOI:10.1039/d2cp00490a

Popul Stud (Camb). 2022 May 10:1-19. doi: 10.1080/00324728.2022.2057576. Online ahead of print.

ABSTRACT

The study of the mortality differences between groups has traditionally focused on metrics that describe average levels of mortality, for example life expectancy and standardized mortality rates. Additional insights can be gained by using statistical distance metrics to examine differences in lifespan distributions between groups. Here, we use a distance metric, the non-overlap index, to capture the sociological concept of stratification, which emphasizes the emergence of unique, hierarchically layered social strata. We show an application using Finnish registration data that cover the entire population over the period from 1996 to 2017. The results indicate that lifespan stratification and life-expectancy differences between income groups both increased substantially from 1996 to 2008; subsequently, life-expectancy differences declined, whereas stratification stagnated for men and increased for women. We conclude that the non-overlap index uncovers a unique domain of inequalities in mortality and helps to capture important between-group differences that conventional approaches miss.

PMID:35535591 | DOI:10.1080/00324728.2022.2057576

Future Oncol. 2022 May 10. doi: 10.2217/fon-2022-0093. Online ahead of print.

ABSTRACT

Standard-of-care for resectable gastric/gastroesophageal junction cancer includes surgery and neoadjuvant-adjuvant 5-fluorouracil-leucovorin-oxaliplatin-docetaxel (FLOT) chemotherapy. Early-phase clinical studies support further clinical development of the immune checkpoint inhibitor (ICI); durvalumab, an anti-PD-L1 antibody, in patients with gastric/gastroesophageal junction cancer. Accumulating evidence indicates that ICIs combined with FLOT chemotherapy improve clinical outcomes in patients with advanced or metastatic cancer. We describe the rationale for and the design of MATTERHORN, a randomized, double-blind, placebo-controlled, phase III study investigating the efficacy and safety of neoadjuvant-adjuvant durvalumab and FLOT chemotherapy followed by adjuvant durvalumab monotherapy in patients with resectable gastric/gastroesophageal junction cancer. The planned sample size is 900 patients, the primary end point is event-free survival, and safety and tolerability will be evaluated. Clinical trial registration: NCT04592913 (ClinicalTrials.gov).

PMID:35535555 | DOI:10.2217/fon-2022-0093

Zhongguo Gu Shang. 2022 May 25;35(5):484-90. doi: 10.12200/j.issn.1003-0034.2022.05.015.

ABSTRACT

OBJECTIVE: To systematically evaluate the hemostatic efficacy of tranexamic acid and ε-aminocaproic acid in total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS: Randomized controlled trials (RCT) and retrospective case-control studies about tranexamic acid and ε-aminocaproic acid for the comparison of THA or TKA were searched electronically in PubMed, EMbase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, VIP from the time of building databases to July 2020. Two investigators carried out literature screening and data extraction according to the inclusion and exclusion criteria respectively. The methodological quality of the included randomized controlled studies was evaluated through the Cochrane Handbook, and the methodological quality of the included retrospective case-control studies was evaluated through the NOS scale. Blood loss, the incidence of thrombosis complications, per capita input of hemoglobin were Meta-analyzed by Review Manager 5.3 software.

RESULTS: A total of 6 articles were included, including 4 RCTs and 2 retrospective case-control studies. A total of 3 174 patients, including 1 353 in the tranexamic acid group and 1 821 in the ε-aminocaproic acid group. Meta-analysis results showed that there were no difference statistical significance in blood loss [MD=-88.60, 95%CI(-260.30, 83.10), P=0.31], blood transfusion rate [OR=1.48, 95%CI(0.96, 2.27), P=0.08], thrombotic complications [OR=0.80, 95%CI(0.07, 8.83), P=0.85], per capita hemoglobin input [MD=0.04, 95%CI(-0.02, 0.10), P=0.18] between tranexamic acid group and ε-aminocaproic acid group during THA. While in TKA, the blood loss of the tranexamic acid group was less than that of the ε-aminocaproic acid group [MD=-147.13, 95%CI(-216.52, -77.74), P<0.0001], the difference was statistically significant. The blood transfusion rate [OR=1.30, 95%CI(0.74, 2.28), P=0.37], thrombotic complications [OR=0.95, 95%CI(0.38, 2.36), P=0.92], per capita hemoglobin input [MD=-0.00, 95%CI(-0.05, 0.06), P=0.48], tourniquet time [MD=1.54, 95%CI(-2.07, 5.14), P=0.40] were similar between two groups, the difference was not statistically significant.

CONCLUSION: In THA, tranexamic acid and ε-aminocaproic acid have similar hemostatic effects, while in TKA, tranexamic acid can effectively reduce the patient’s blood loss and has a better hemostatic effect. Tranexamic acid is recommended as one of the first choice hemostatic drugs for TKA.

PMID:35535540 | DOI:10.12200/j.issn.1003-0034.2022.05.015

Zhongguo Gu Shang. 2022 May 25;35(5):429-34. doi: 10.12200/j.issn.1003-0034.2022.05.005.

ABSTRACT

OBJECTIVE: To compare the efficacy between vesselplasty and percutanous kyphoplasty (PKP) in the treatment of Kümmell disease.

METHODS: The clinical data of patients with Kümmell disease from July 2018 to December 2019 were retrospectively analyzed. According to the different therapeutic methods, the patients were divided into vesselplasty group and PKP group. There were 20 patients in vesselplasty group, including 2 males and 18 females, aged from 54 to 83 years with an average of (67.40±7.44)years, 1 case of T₁₀ fracture, 3 cases of T₁₂ fracture, 9 cases of L₁ fractures, 5 cases of L₂ fractures and 2 cases of L₃ fractures. There were 20 patients in PKP group, including 3 males and 17 females, aged from 56 to 81 with an average of(67.20±7.01) years, 2 cases of T₁₀ fracture, 1 case of T₁₁ fracture, 6 cases of T₁₂ fracture, 10 cases of L₁ fracture and 1 case of L₃ fracture. Visual analogue scale(VAS), Cobb angle, anterior vertebral height were recorded before operation, 1 day after operation and 1 year after operation. Oswestry Disability Index(ODI) was recorded before operation, 1 month after operation and 1 year after operation. And bone cement leakage rate was compared between two groups after operation.

RESULTS: All the patient were followed up for more than 1 year. In vesselplasty group, VAS score was 1.20±0.41, ODI was(13.50±3.10)%, Cobb angle was(17.20±3.12)° and anterior vertebral height was(20.20±1.35) mm at 1 year after operation. In PKP group, VAS score was 1.15±0.40, ODI was (13.20±3.00)%, Cobb angle was (17.10±3.19)° and anterior vertebral height was (20.10±1.37) mm at 1 year after operation. These index was significantly better than pre-operation through intra-group comparison(P<0.05), and there was no statistically difference between the two groups(P>0.05). There were 20 cases (20 vertebrae) in vesselplasty group, of which 1 case had bone cement leakage at the upper endplate, with a leakage rate of 5%(1/20). In PKP group, there were 20 cases (20 vertebrae), 3 cases of upward endplate leakage(3/7), 1 case of downward endplate leakage(1/7), 1 case of leakage to the front of the vertebral body(1/7), 2 cases of leakage to the side of the vertebral body(2/7), with a leakage rate of 35% (7/20). The difference between two groups was statistically significant(P<0.05).

CONCLUSION: Vesselplasty in the treatment of Kümmell disease can better reduce leakage rate of bone cement and reduce complications.

PMID:35535530 | DOI:10.12200/j.issn.1003-0034.2022.05.005

Zhongguo Gu Shang. 2022 May 25;35(5):448-53. doi: 10.12200/j.issn.1003-0034.2022.05.008.

ABSTRACT

OBJECTIVE: To explore the clinical effect of percutaneous endoscopic lumbar discectomy in the treatment of adjacent segment lumbar disc herniation after lumbar fusion.

METHODS: From February 2010 to June 2018, 64 patients with adjacent segment lumbar disc herniation after lumbar fusion were retrospectively analyzed and divided into observation group and control group. In observation group, there were 23 males and 10 females performed with percutaneous endoscopic lumbar discectomy, including 27 cases of single segment fusion and 6 cases of double segment fusion, aged from 55 to 83 years old with an average of (65.7±7.4) years old. In control group, there were 22 males and 9 females performed with traditional open fusion revision, including 25 cases of single-segment fusion and 6 cases of double segment fusion, aged from 51 to 78 years old with an average of(64.8±7.8) years old. The operative time, intraoperative blood loss, fluoroscopy times, postoperative ambulation time and length of postoperative hospital stay were recorded. The clinical efficacy was evaluated by visual analogue scale(VAS) and Oswestry Disability Index(ODI). The complications between two groups were observed.

RESULTS: All patients were followed up for at least 2 years. The observation group patients were followed up with an average of (2.4±0.5) years. The control group patients were followed up with an average of(2.6±0.7) years. Compared with control group, operation time, intraoperative blood loss, postoperative ambulation time and length of postoperative hospital stay of the observation group were significantly reduced (P<0.05), and the fluoroscopy times of observation group were significantly increased compared with control group(P<0.05). The VAS of low back and lower limb, and ODI at the latest follow-up between two groups were all significantly improved compared to those of pre-operation (P<0.05). The VAS of low back at each point and ODI at 1, 3 months after operation in observation group was significantly reduced compared with control group(P<0.05), however there was no significant difference in VAS for lower limb between two groups (P>0.05). The difference of complications between two groups was statistically significant (P<0.05).

CONCLUSION: Compared with traditional open fusion revision surgery, percutaneous endoscopic lumbar discectomy for the treatment of adjacent segment lumbar disc herniation after lumbar fusion has the advantages of reducing operation time and intra-operative blood loss, shortening ambulation time and the length of postoperative hospital stay, and promoting pain and functional improvement, and decrease incidence of complications. However, long-term clinical efficacy needs further study.

PMID:35535533 | DOI:10.12200/j.issn.1003-0034.2022.05.008

Zhongguo Gu Shang. 2022 May 25;35(5):418-22. doi: 10.12200/j.issn.1003-0034.2022.05.003.

ABSTRACT

OBJECTIVE: To analyze the efficacy of percutaneous vertebroplasty for osteoporotic vertebral compression fractures with spinal origin abdominal pain as the main symptom.

METHODS: A retrospective analysis was performed on 37 patients with osteoporotic vertebral compression fractures treated from January 2015 to January 2021, all of whom had spin-derived abdominal pain as the main symptom, and were divided into surgery group(21 cases) and conservative group (16 cases) according to different treatment methods. Patients in the surgery group were treated with percutaneous vertebroplasty, including 7 males and 14 females, with an average age of (75.95±6.84) years old and an average course of disease of (5.26±3.79) days. The conservative group received non-surgical treatment, including 5 males and 11 females, with an average age of (75.50±8.07) years old and an average course of disease of (4.28±3.42) days. Two groups of patients with preoperative mainly characterized by abdominal pain, abdominal distension and constipation, have no obvious chest waist back pain symptoms, the thoracolumbar MRI diagnosed as fresh osteoporotic vertebral compression fractures, record its postoperative abdominal pain visual analogue scale (VAS), medical outcomes study short form-36 (SF-36) score, defecation interval after treatment, etc.

RESULTS: Thirty-seven patients were followed up for (14.90±14.11) months in surgery group and( 21.42±17.53) months in conservative group. Compared with before treatment, the VAS of surgery group at each time period after treatment, VAS of conservative group at 1 month after treatment and SF-36 score between two groups at 3 months after treatment were all improved(P<0.05), while VAS of conservative group at 3 days after treatment showed no statistically significant difference(P>0.05). Compared between two groups, there were no significant differences in VAS and SF-36 scores at 1 day before treatment(P>0.05), but VAS at 3 days after treatment in surgery group, life vitality and social function score at 3 months after treatment, and defecation time after treatment in surgery group were better than those in conservative group(P<0.05). There were no significant differences in other indexes(P>0.05). The incision healing of patients in surgery group was good, and no serious complications occurred in both groups.

CONCLUSION: Percutaneous vertebroplasty is an effective method for the treatment of osteoporotic vertebral compression fractures with spinal origin abdominal pain as the main symptom. Compared with conservative treatment, percutaneous vertebroplasty has more advantages in early relief of abdominal pain and constipation, recovery of vitality and social function.

PMID:35535528 | DOI:10.12200/j.issn.1003-0034.2022.05.003