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Nevin Manimala Statistics

Causal inference in survival analysis using longitudinal observational data: Sequential trials and marginal structural models

Stat Med. 2023 Apr 22. doi: 10.1002/sim.9718. Online ahead of print.

ABSTRACT

Longitudinal observational data on patients can be used to investigate causal effects of time-varying treatments on time-to-event outcomes. Several methods have been developed for estimating such effects by controlling for the time-dependent confounding that typically occurs. The most commonly used is marginal structural models (MSM) estimated using inverse probability of treatment weights (IPTW) (MSM-IPTW). An alternative, the sequential trials approach, is increasingly popular, and involves creating a sequence of “trials” from new time origins and comparing treatment initiators and non-initiators. Individuals are censored when they deviate from their treatment assignment at the start of each “trial” (initiator or noninitiator), which is accounted for using inverse probability of censoring weights. The analysis uses data combined across trials. We show that the sequential trials approach can estimate the parameters of a particular MSM. The causal estimand that we focus on is the marginal risk difference between the sustained treatment strategies of “always treat” vs “never treat.” We compare how the sequential trials approach and MSM-IPTW estimate this estimand, and discuss their assumptions and how data are used differently. The performance of the two approaches is compared in a simulation study. The sequential trials approach, which tends to involve less extreme weights than MSM-IPTW, results in greater efficiency for estimating the marginal risk difference at most follow-up times, but this can, in certain scenarios, be reversed at later time points and relies on modelling assumptions. We apply the methods to longitudinal observational data from the UK Cystic Fibrosis Registry to estimate the effect of dornase alfa on survival.

PMID:37086186 | DOI:10.1002/sim.9718

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Nevin Manimala Statistics

Prognostic value of mitral regurgitation in patients undergoing left ventricular assist device deployment: A systematic review and meta-analysis

Artif Organs. 2023 Apr 22. doi: 10.1111/aor.14549. Online ahead of print.

ABSTRACT

BACKGROUND: Left ventricular assist devices (LVADs) represent an important therapeutic option for patients progressing to end-stage heart failure. LVAD has previously been shown to have a promising role in improving mitral regurgitation (MR). Nevertheless, the prognostic value of preoperative uncorrected MR in this population remains unclear.

METHODS: A systematic database search with meta-analysis was conducted of comparative original articles of patients with preoperative mild MR (Grade 0-I) versus moderate-severe MR (Grade II-III) undergoing LVAD implantation, in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to June 2022. Primary outcomes were overall and operative mortality. Secondary outcomes were neurological dysfunction, gastrointestinal bleeding, right heart failure, LVAD thrombosis, and driveline infection.

RESULTS: Our search yielded 2228 relevant studies. A total of 19 studies met the inclusion criteria with a total of 11 873 patients. LVAD caused a statistically significant decrease of 35.9% in the number of patients with moderate-severe MR (grade II-III) postoperatively. No significant difference was observed in terms of overall mortality, operative mortality, GI bleeding, LVAD thrombosis, and driveline infection rates between mild and moderate-severe MR. An increased rate of right heart failure was seen among patients with moderate-severe MR, while lower rates of neurological events were also observed.

CONCLUSION: LVAD improves the haemodynamics of the left ventricle, to promote resolution of MR. Nevertheless, the severity of preoperative mitral regurgitation in patients undergoing LVAD deployment does not seem to affect mortality.

PMID:37086154 | DOI:10.1111/aor.14549

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Nevin Manimala Statistics

Clinical utility of reproductive carrier screening for preconception and pregnant couples for multiple genetic conditions: a systematic review and meta-analysis

Expert Rev Mol Diagn. 2023 Apr 22. doi: 10.1080/14737159.2023.2206519. Online ahead of print.

ABSTRACT

INTRODUCTION: Many scientific societies have emphasized the importance of evaluating the clinical utility of reproductive carrier screening (RCS). This systematic review aims to assess the clinical utility of RCS and synthesize the outcomes in a meta-analysis.

AREAS COVERED: A total of eleven studies were included. The number of conditions screened in the studies varied from three to 176 and led to the identification of one to 24 high-risk couples (HRCs) per 1,000 screened individuals. Pooled estimations were as follows: the prenatal diagnosis (PND) rate among pregnant HRCs 0.644 (95% CI=0.364, 0.923), the termination rate among affected pregnancies 0.714 (95% CI=0.524, 0.904), and the rate of in-vitro fertilization (IVF) with preimplantation genetic testing (PGT) 0.631 (95% CI=0.538, 0.725). There is a statistically significant decrease in the rates of undertaking PND and termination as the number of screened conditions increases. Carriers of conditions classified as having a more severe impact were found to be more likely to choose termination or IVF with PGT.

EXPERT OPINION: Our review suggests that the number and the severity of screened conditions can significantly impact HRCs’ reproductive decisions. Future work needs to investigate the definition of clinical utility and the design of screening panels.

PMID:37086152 | DOI:10.1080/14737159.2023.2206519

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Nevin Manimala Statistics

Sickness absence among migrant and non-migrant care workers in Finland: A register-based follow-up study

Scand J Public Health. 2023 Apr 22:14034948231168434. doi: 10.1177/14034948231168434. Online ahead of print.

ABSTRACT

AIMS: This study aimed to compare the sickness absence (SA; over 10 days) rates of migrant and non-migrant care workers in Finland.

METHODS: Two cohorts were randomly sampled from nationwide registers and analysed together in a three-year follow-up design (2011-2013, 2014-2016). The pooled data consisted of 78,476 care workers, of whom 5% had a migrant background. Statistical methods included cross-tabulations and Poisson regression modelling.

RESULTS: Thirty-five percent of the Finnish-born care workers had at least one SA during the follow-up. Care workers from the post-2004 EU countries (30%, at least one SA), Russia, the Former Soviet Union and the Balkan states (25%) and the Global South and East (21%) had fewer episodes of SA than the Finnish-born care workers. The two latter groups also had lower SA rates after we controlled for occupation, gender, age, income and region of residence. Care workers from Western Europe and the Global North (36%) had higher SA rates than the Finnish-born care workers.

CONCLUSIONS: The following explanations were discussed: population-level health differences – migrants from lower-income non-EU countries are generally healthier than the Finnish-born population (due to, e.g., the ‘healthy migrant effect’); discrimination in recruitment and employment – migrants from lower-income non-EU countries need to be healthier than Finnish-born jobseekers to gain employment (in the care sector or more broadly); and sickness presenteeism – migrants from lower-income non-EU countries underuse their right to sickness allowance (due to, e.g., job insecurity). It is likely that these mechanisms affect migrants differently depending on, for example, their countries of origin and social status in Finland.

PMID:37086115 | DOI:10.1177/14034948231168434

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Nevin Manimala Statistics

Mechanisms of enhanced renal and hepatic erythropoietin synthesis by sodium-glucose cotransporter 2 inhibitors

Eur Heart J. 2023 Apr 22:ehad235. doi: 10.1093/eurheartj/ehad235. Online ahead of print.

ABSTRACT

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of major heart failure events, an action that is statistically linked to enhanced erythropoiesis, suggesting that stimulation of erythropoietin and cardioprotection are related to a shared mechanism. Four hypotheses have been proposed to explain how these drugs increase erythropoietin production: (i) renal cortical reoxygenation with rejuvenation of erythropoietin-producing cells; (ii) counterregulatory distal sodium reabsorption leading to increased tubular workload and oxygen consumption, and thus, to localized hypoxia; (iii) increased iron mobilization as a stimulus of hypoxia-inducible factor-2α (HIF-2α)-mediated erythropoietin synthesis; and (iv) direct HIF-2α activation and enhanced erythropoietin gene transcription due to increased sirtuin-1 (SIRT1) signaling. The first two hypotheses assume that the source of increased erythropoietin is the interstitial fibroblast-like cells in the deep renal cortex. However, SGLT2 inhibitors do not alter regional tissue oxygen tension in the non-diabetic kidney, and renal erythropoietin synthesis is markedly impaired in patients with anemia due to chronic kidney disease, and yet, SGLT2 inhibitors produce an unattenuated erythrocytic response in these patients. This observation raises the possibility that the liver contributes to the production of erythropoietin during SGLT2 inhibition. Hypoxia-inducible factor-2α and erythropoietin are coexpressed not only in the kidney but also in hepatocytes; the liver is a major site of production when erythropoietin stimulation is maintained for prolonged periods. The ability of SGLT2 inhibitors to improve iron mobilization by derepressing hepcidin and ferritin would be expected to increase cytosolic ferrous iron, which might stimulate HIF-2α expression in both the kidney and liver through the action of iron regulatory protein 1. Alternatively, the established ability of SGLT2 inhibitors to enhance SIRT1 might be the mechanism of enhanced erythropoietin production with these drugs. In hepatic cell lines, SIRT1 can directly activate HIF-2α by deacetylation, and additionally, through an effect of SIRT in the liver, peroxisome proliferator-activated receptor-γ coactivator-1α binds to hepatic nuclear factor 4 to promote transcription of the erythropoietin gene and synthesis of erythropoietin. Since SIRT1 up-regulation exerts direct cytoprotective effects on the heart and stimulates erythropoietin, it is well-positioned to represent the shared mechanism that links erythropoiesis to cardioprotection during SGLT2 inhibition.

PMID:37086098 | DOI:10.1093/eurheartj/ehad235

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Nevin Manimala Statistics

Predictive value of prostate calcification for future cancer occurrence: a retrospective long-term follow-up cohort study

Br J Radiol. 2023 Apr 22:20221110. doi: 10.1259/bjr.20221110. Online ahead of print.

ABSTRACT

OBJECTIVE: Although prostate calcification is often identified on pelvic CT images, calcification itself is usually not considered clinically significant. A recent histological study proposed an association between prostate calcification and prostate cancer occurrence. Our aim was to determine the predictive value of prostate calcifications for future prostate cancer occurrence.

METHODS: We retrospectively analysed male patients (≥50 years old) without prior prostate cancer history, who underwent unenhanced pelvic CT between April 2010 and March 2011, and followed-up until December 2021. Cox proportional hazards models were used to assess prostate cancer risk with prostate calcification (defined as a high-density area larger than 3 mm with CT attenuation values ≥ 130 HU), controlling for age, body mass index (BMI), hypertension and diabetes mellitus.

RESULTS: A total of 636 male patients (mean age, 68 years ± 9 [standard deviation]) were evaluated. At the end of follow-up, prostate cancer had been more frequently diagnosed in patients with prostate calcification than those without prostate calcification (6.5% vs 2.6%). Multivariate analysis revealed that prostate calcification on CT was a significant predictor of future prostate cancer occurrence (hazard ratio [HR], 2.7; 95% CI: 1.20, 5.91; p = 0.016). No statistical differences were observed in any other factors.

CONCLUSION: Prostate calcification may be a significant predictor of future prostate cancer occurrence, and may be used for risk stratification and to guide screening protocols.

ADVANCES IN KNOWLEDGE: Presence of prostate calcification on unenhanced CT scan was associated with increased incidence of prostate cancer occurrence on long term follow-up.

PMID:37086073 | DOI:10.1259/bjr.20221110

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Nevin Manimala Statistics

Junior surgeons are quicker to master the single-port thoracoscopic lobectomy: comprehensive analysis of the learning curve and oncological outcomes

World J Surg Oncol. 2023 Apr 22;21(1):134. doi: 10.1186/s12957-023-03017-6.

ABSTRACT

BACKGROUND: The learning curve of single-port thoracoscopic lobectomy (SPTL) in lung cancer has been widely studied. However, the efficiency of different experience levels of thoracic surgeons in mastering the learning curve is unknown. Hence, we discuss this issue in depth by using several perioperative parameters and oncological outcomes.

METHODS: A total of 120 consecutive cases of SPTL performed by a senior (STS group) and junior (JTS group) thoracic surgeons were retrospectively analyzed. Operation time, estimated blood loss, and duration of postoperative hospital stay were recorded for cumulative summation (CUSUM) learning curve analysis, while the 5-year survival rate was used for oncological evaluation.

RESULTS: The CUSUM learning curve of the STS group was y = 0.000106x3 – 0.019x2 + 0.852x – 0.036, with a high R-value of 0.9517. When the number of cases exceeded 33, the slope changed from positive to negative. The CUSUM learning curve of the JTS group was y = 0.000266x3 – 0.04x2 + 1.429 × -0.335, with a high R-value of 0.9644. When the number of cases exceeded 25, the slope changed from positive to negative. The learning curve was divided into two phases (phases 1 and 2). The slope of the JTS group in phase 1 was greater than that of the STS group in phase 1 (p < 0.001). Meanwhile, comparisons of various parameters between both groups in phase 2 showed no statistically significant difference (p > 0.05). In addition, the 5-year survival rate was not significantly different between the two groups (p = 0.72).

CONCLUSION: This is the first study to analyze the learning curve of thoracic surgeons with different experience levels in mastering SPTL. Moreover, it is also the first study to include multiple perioperative parameters and overall survival to study how quickly surgeons master the SPTL technique. The junior thoracic surgeon was found to have a shorter learning curve for SPTL.

PMID:37085810 | DOI:10.1186/s12957-023-03017-6

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Nevin Manimala Statistics

Application of data-driven models to predict the dimensions of flow separation zone

Environ Sci Pollut Res Int. 2023 Apr 22. doi: 10.1007/s11356-023-27024-y. Online ahead of print.

ABSTRACT

In this research, the effect of a submerged multiple-vane system on the dimensions of flow separation zone (DFSZ) is assessed via 192 measured datasets. The vanes’ shape comprised two segments, curved and flat plates which are located in the connection of main channel to the lateral intake channel with an angle of 55°. In this direction, a butterfly’s array for the vanes’ arrangement along with different main controlling factors such as distances of vanes along the flow (δl), degree of curvature (β), and angles of attack to the local primary flow direction (θ) is utilized. Through capturing photos and utilizing AutoCAD and SURFER software, maximum relative length and width are calculated. Based on the experimental measurements, maximum percentage reduction of DFSZ, in comparison with the controlled test (without submerged vanes), is obtained with θ = 30°, β = 34°, and δl = 10 cm with value of 78 and 76%, respectively. Moreover, several data-driven models, namely, gene expression programming (GEP), support vector regression (SVR), and a robust hybrid SVR with an ant colony optimization algorithm (ACO) (i.e., hybrid SVR-ACO model), are developed in order to predict DFSZ via the operative dimensionless variables realized by Spearman’s rho and Pearson’s coefficient processes. In accordance with the statistical metrics, model grading process, scatter plot, and the hybrid SVR(RBF)-ACO model are preferred as the best and most precise model to predict maximum relative length and width with a total grade (TG) of 6.75 and 5.8, respectively. The generated algebraic formula for DFSZ under the optimal scenario of GEP is equated with the corresponding measured ones and the results are within 0-10%.

PMID:37085682 | DOI:10.1007/s11356-023-27024-y

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Nevin Manimala Statistics

Mentor training for junior faculty: a brief evaluation report from the Georgia Clinical and Translational Science Alliance

J Investig Med. 2023 Apr 21:10815589231168601. doi: 10.1177/10815589231168601. Online ahead of print.

ABSTRACT

To provide a foundation for mentoring, junior faculty participated in a mentor training workshop informed by the Mentoring Clinical and Translational Researchers curriculum. The goal was to develop skills and behaviors that engender more rewarding and inclusive mentoring practices. Attendees responded to baseline and follow-up surveys assessing perceived mentoring skills. Follow-up surveys included closed- and open-ended questions about the value and satisfaction of the training, and intended behavior changes. Junior faculty respondents (n = 39) reported significantly higher overall mentoring skills after the training (t = -2.6, p = 0.012) with a medium effect size (Cohen’s D = 0.59). Domains with statistically significant improvement from baseline to follow-up included aligning mentor-mentee expectations and assessing understanding. Thirty-eighty (97%) found the training valuable, and 32 (82%) indicated they would change mentoring-related behaviors because of the training. Intended behavior changes described in open-ended responses aligned with mentoring skills assessed (e.g., aligning expectations). An additional competency domain of evaluating mentoring relationships was also described. A mentor training workshop for junior faculty appeared to contribute to changes in mentoring skills and intended behaviors. Mentor training has the potential to enhance mentorship, which is critical to strengthening a diverse pipeline of clinical and translational science researchers.

PMID:37085987 | DOI:10.1177/10815589231168601

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Nevin Manimala Statistics

Cognitive Behavioral Group Therapy for Anger Management in Juvenile Delinquents: Effectiveness Study in a Turkey Child Prison

Int J Offender Ther Comp Criminol. 2023 Apr 21:306624X231165418. doi: 10.1177/0306624X231165418. Online ahead of print.

ABSTRACT

The purpose of this study was to evaluate the effectiveness of cognitive-behavioral group therapy (CBGT) for anger management in Juvenile Delinquents. The therapy program consisted of eight sessions including relaxation, self-instruction, cognitive restructuring, and assertiveness training techniques. The therapy program has been conducted for juvenile delinquents in one of the juvenile prisons in Turkey. Sixty juvenile delinquents, aged between 14 and 18, who met the inclusion criteria (treatment = 30, control = 30), were included at the beginning of the study. To evaluate the effectiveness of the program, State Trait Anger and Expression Inventory (STAXI), and Brief Symptom Inventory (BSI) were administered as pre-test. At the end of the therapy program, final analysis was conducted on 35 participants (20 therapy group, 15 control group) due to participants dropout. Mixed ANOVA was conducted to examine the time (pre-test and post-test) and group effects (therapy and control group). Results showed that the participants in the therapy group showed a significant decrease in trait anger and anger expression scores, both subscales of STAXI and in the hostility subscale of BSI; a statistically significant increase in the anger control scores of the subscale of STAXI when compared to the control group. In conclusion, this culturally attuned CBGT for anger management may be applicable for Juvenile Delinquents in Turkey.

PMID:37085985 | DOI:10.1177/0306624X231165418