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Nevin Manimala Statistics

PROGNOSTIC VALUE OF CHARLSON COMORBIDITY INDEX IN ACUTE EMBOLIC LOWER LIMB ISCHAEMIA PATIENTS

Ann Vasc Surg. 2021 May 2:S0890-5096(21)00373-3. doi: 10.1016/j.avsg.2021.04.022. Online ahead of print.

ABSTRACT

INTRODUCTION: Charlson Comorbidity Index (CCI) is commonly used in outcome studies to adjust for patient comorbid conditions but has not been specifically validated for use in acute embolic lower limb ischaemia (AELLI).

OBJECTIVES: The aim of this study was to access whether a high CCI score unadjusted (CCIu) and adjusted (CCIa) by age relates to major amputation and mortality after a first episode of AELLI.

METHODS: The last 100 patients presenting with the first event of AELLI submitted to embolectomy at our Vascular Surgery Department were retrospectively evaluated. Patient characteristics, pre- and post-operative period variables were collected and CCIu and CCIa calculated. Survival predictors were analyzed using Cox regression. The area under the curve of the receiver operating characteristic curves was calculated to validate and determine the discriminating ability of CCIu and CCIa in predicting amputation rate and 30-day mortality. Youden index was used to determine the critical value. Survival analysis was performed with Kaplan-Meier method and differences between survival curves were tested with Log-Rank test. A p value of <.05 was considered statistically significant.

RESULTS: The mean age was 80.03±10.776 years and the mean follow-up 19.28±7.929 months. Amputation rate was 16%, 30-day mortality 21% and long-term mortality 42%. Patients with CCIu≥3 compared with patients with CCIu<3 had higher amputation rate (37.5% vs. 1.7%; OR:35.400), 30-day mortality (47.5% vs. 3.3%; OR:35.400) and global mortality (p=.00). Also, patients with CCIa≥6 compared with patients with CCIa<6 had higher amputation rate (34.1% vs. 1.8%; OR:28.488), 30-day mortality (47.7% vs. 0.0%) and global mortality (p=.00). Multivariate analysis showed that both CCIu and CCIa were independent predictors of amputation rate and 30-day mortality.

CONCLUSION: CCIu and CCIa have proven to be good predictors of amputation rate and survival, thus being a valuable prognostic factor in patients presenting with the first event of AELLI.

PMID:33951526 | DOI:10.1016/j.avsg.2021.04.022

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Nevin Manimala Statistics

Outcome of femoral-popliteal bypass procedures in different ethnic groups in England: A retrospective analysis of Hospital Episode Statistics

Ann Vasc Surg. 2021 May 2:S0890-5096(21)00369-1. doi: 10.1016/j.avsg.2021.04.018. Online ahead of print.

ABSTRACT

BACKGROUND: Previous studies, mainly from the United States, have reported worse outcomes from lower limb bypass procedures in ethnic minority populations. Limited nationwide data are available from ethnic minority populations from Europe. The aim of this study is to investigate outcomes from lower limb bypass procedures in ethnic minorities from England.

METHODS: We enquired the “Hospital Episode Statistics” database, using ICD-10 codes to identify all cases of femoral-popliteal bypass operations from English NHS Hospitals from 01/01/2006 to 31/12/2015. Every case was followed up for 2 years for subsequent events. The primary outcomes were mortality and major leg amputation. Patients were broadly categorised according to Black, Asian and White ethnicity. Chi-square test was used to the ethnic groups and odds ratios (OR) were calculated using White ethnic group with the largest numbers of participants as a reference category.

RESULTS: In the examined 10-year period, 20825 femoral-popliteal bypass procedures (250 of Black, 167 of Asian, and 20.408 of White ethnicity) were recorded. Thirty-day and 2-year mortality were 2.8% and 16.8% with no significant ethnic differences. Patients of Black ethnicity had higher risk of limb loss compared to Whites (23.2% vs 15.6%, OR =1.63, 95% confidence interval (CI) 1.21-2.19, p<0.01). There was no significant difference in amputation rates between Asians and Whites (16.2% vs 15.6%, p=0.94).

CONCLUSION: Patients of Black ethnicity are at higher risk of limb loss after a femoropopliteal bypass procedure. Further research is needed to identify the causes of this discrepancy.

PMID:33951529 | DOI:10.1016/j.avsg.2021.04.018

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Nevin Manimala Statistics

Aortic neck IFU violations during EVAR for ruptured infrarenal aortic aneurysms are associated with increased in-hospital mortality

Ann Vasc Surg. 2021 May 2:S0890-5096(21)00370-8. doi: 10.1016/j.avsg.2021.04.019. Online ahead of print.

ABSTRACT

OBJECTIVE: Vascular surgeons treating patients with ruptured abdominal aortic aneurysm (rAAA) must make rapid treatment decisions and sometimes lack immediate access to endovascular devices meeting the anatomic specifications of the patient at hand. We hypothesized that endovascular treatment of rAAA (rEVAR) outside manufacturer instructions-for-use (IFU) guidelines would have similar in-hospital mortality compared to patients treated on-IFU or with an infrarenal clamp during open repair (rOAR).

METHODS: Vascular Quality Initiative (VQI) datasets for endovascular and open aortic repair were queried for patients presenting with ruptured infrarenal AAA between 2013-2018. Graft-specific IFU criteria were correlated with case-specific proximal neck dimension data to classify rEVAR cases as on- or off-IFU. Univariate comparisons between the on- and off-IFU groups were performed for demographic, operative and in-hospital outcome variables. To investigate mortality differences between rEVAR and rOAR approaches, coarsened exact matching was used to match patients receiving off-IFU rEVAR with those receiving complex rEVAR (requiring at least one visceral stent or scallop) or rOAR with infrarenal, suprarenal or supraceliac clamps. A multivariable logistic regression was used to identify factors independently associated with in-hospital mortality.

RESULTS: 621 patients were treated with rEVAR, with 65% classified as on-IFU and 35% off-IFU. The off-IFU group was more frequently female (25% vs. 18%, p=0.05) and had larger aneurysms (76 vs. 72 mm, p=0.01) but otherwise was not statistically different from the on-IFU cohort. In-hospital mortality was significantly higher in patients treated off-IFU vs. on-IFU (22% vs 14%, p=0.02). Off-IFU rEVAR was associated with longer operative times (135 min vs 120 min, p=0.004) and increased intraoperative blood product utilization (2 units vs. 1 unit, p=0.002). When off-IFU patients were matched to complex rEVAR and rOAR patients, no baseline differences were found between the groups. Overall in-hospital complications associated with off-IFU were reduced compared to more complex strategies (43% vs. 60-81%, p<0.001) and in-hospital mortality was significantly lower for off-IFU rEVAR patients compared to the supraceliac clamp group (18% vs 38%, p=0.006). However, there was no significantly increased mortality associated with complex rEVAR, infrarenal rOAR or suprarenal rOAR compared to off-IFU rEVAR (all P>0.05). This finding persisted in a multivariate logistic regression.

CONCLUSIONS: Off-IFU rEVAR yields inferior in-hospital survival compared to on-IFU rEVAR but remains associated with reduced in-hospital complications when compared with more complex repair strategies. When compared with matched patients undergoing rOAR with an infrarenal or suprarenal clamp, survival was no different from off-IFU rEVAR. Taken together with the growing available evidence suggesting reduced long-term durability of off-IFU EVAR, these data suggest that a patient’s comorbidity burden should be key in making the decision to pursue off-IFU rEVAR over a more complex repair when proximal neck violations are anticipated preoperatively.

PMID:33951521 | DOI:10.1016/j.avsg.2021.04.019

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Nevin Manimala Statistics

Focus on Survival Analysis for Eye Research

Invest Ophthalmol Vis Sci. 2021 May 3;62(6):7. doi: 10.1167/iovs.62.6.7.

ABSTRACT

Analysis of time-to-event data, otherwise known as survival analysis, is a common investigative tool in ophthalmic research. For example, time-to-event data is useful when researchers are interested in investigating how long it takes for an ocular condition to worsen or whether treatment can delay the development of a potentially vision-threatening complication. Its implementation requires a different set of statistical tools compared to those required for analyses of other continuous and categorial outcomes. In this installment of the Focus on Data series, we present an overview of selected concepts relating to analysis of time-to-event data in eye research. We introduce censoring, model selection, consideration of model assumptions, and best practice for reporting. We also consider challenges that commonly arise when analyzing time-to-event data in ophthalmic research, including collection of data from two eyes per person and the presence of multiple outcomes of interest. The concepts are illustrated using data from the Laser Intervention in Early Stages of Age-Related Macular Degeneration study and statistical computing code for Stata is provided to demonstrate the application of the statistical methods to illustrative data.

PMID:33950248 | DOI:10.1167/iovs.62.6.7

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Relevance of gastrointestinal manifestations in a large Spanish cohort of patients with systemic lupus erythematosus: what do we know?

Rheumatology (Oxford). 2021 May 5:keab401. doi: 10.1093/rheumatology/keab401. Online ahead of print.

ABSTRACT

BACKGROUND: Systemic lupus erythematosus (SLE) can affect any part of the gastrointestinal (GI) tract. GI symptoms are reported to occur in more than 50% of SLE patients.

AIMS: To describe the GI manifestations of SLE in the RELESSER (Registry of Systemic Lupus Erythematosus Patients of the Spanish Society of Rheumatology) cohort and to determine if these are associated with a more severe disease, damage accrual and a worse prognosis.

METHODS: We conducted a nationwide, retrospective, multicenter, cross-sectional cohort study of 3658 SLE patients who fulfill ≥ 4 ACR-97 criteria. Data on demographics, disease characteristics, activity (SLEDAI-2K or BILAG), damage (SLICC/ACR/DI) and therapies were collected. Demographic and clinical characteristics were compared between lupus patients with and without GI damage to establish whether GI damage is associated with a more severe disease.

RESULTS: From 3654 lupus patients, 3.7% developed GI damage. Patients in this group (group 1) were older, they had longer disease duration, and were more likely to have vasculitis, renal disease and serositis than patients without GI damage (group 2). Hospitalizations and mortality were significantly higher in group 1. Patients in group 1 had higher modified SDI. The presence of oral ulcers reduced risk of developing damage in 33% of patients.

CONCLUSIONS: Having GI damage is associated with a worse prognosis. Patients on high dose of glucocorticoids are at higher risk of developing GI damage which reinforces the strategy of minimizing glucocorticoids. Oral ulcers appear to decrease the risk of GI damage.

PMID:33950249 | DOI:10.1093/rheumatology/keab401

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Nevin Manimala Statistics

Motor and cognitive outcomes of cerebello-spinal stimulation in neurodegenerative ataxia

Brain. 2021 May 5:awab157. doi: 10.1093/brain/awab157. Online ahead of print.

ABSTRACT

Cerebellar ataxias represent a heterogeneous group of disabling disorders characterized by motor and cognitive disturbances, for which no effective treatment is currently available. In this randomized, double-blind, sham-controlled trial, followed by an open-label phase, we investigated whether treatment with cerebello-spinal transcranial direct current stimulation (tDCS) could improve both motor and cognitive symptoms in patients with neurodegenerative ataxia at short and long-term. Sixty-one patients were randomized in two groups for the first controlled phase. At baseline (T0), Group 1 received placebo stimulation (sham tDCS) while Group 2 received anodal cerebellar tDCS and cathodal spinal tDCS (real tDCS) for 5 days/week for two weeks (T1), with a 12-week (T2) follow-up (randomized, double-blind, sham controlled phase). At the 12-week follow-up (T2), all patients (Group 1 and Group 2) received a second treatment of anodal cerebellar tDCS and cathodal spinal tDCS (real tDCS) for 5 days/week for two weeks, with a 14-week (T3), 24-week (T4), 36-week (T5) and 52-week follow-up (T6) (open-label phase). At each time point, a clinical, neuropsychological and neurophysiological evaluation was performed. Cerebellar-motor cortex connectivity was evaluated using transcranial magnetic stimulation (TMS). We observed a significant improvement in all motor scores (scale for the assessment and rating of ataxia, international cooperative ataxia rating scale), in cognition (evaluated with the cerebellar cognitive affective syndrome scale), in quality-of-life scores, in motor cortex excitability and in cerebellar inhibition after real tDCS compared to sham stimulation and compared to baseline (T0), both at short and long-term. We observed an addon-effect after two repeated treatments with real tDCS compared to a single treatment with real tDCS. The improvement at motor and cognitive scores correlated with the restoration of cerebellar inhibition evaluated with TMS. Cerebello-spinal tDCS represents a promising therapeutic approach for both motor and cognitive symptoms in patients with neurodegenerative ataxia, a still orphan disorder of any pharmacological intervention.

PMID:33950222 | DOI:10.1093/brain/awab157

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Fundamental gene network rewiring at the second order within and across mammalian systems

Bioinformatics. 2021 May 5:btab240. doi: 10.1093/bioinformatics/btab240. Online ahead of print.

ABSTRACT

MOTIVATION: Genetic or epigenetic events can rewire molecular networks to induce extraordinary phenotypical divergences. Among the many network rewiring approaches, no model-free statistical methods can differentiate gene-gene pattern changes not attributed to marginal changes. This may obscure fundamental rewiring from superficial changes.

RESULTS: Here we introduce a model-free Sharma-Song test to determine if patterns differ in the second order, meaning that the deviation of the joint distribution from the product of marginal distributions is unequal across conditions. We prove an asymptotic chi-squared null distribution for the test statistic. Simulation studies demonstrate its advantage over alternative methods in detecting second-order differential patterns. Applying the test on three independent mammalian developmental transcriptome datasets, we report a lower frequency of co-expression network rewiring between human and mouse for the same tissue group than the frequency of rewiring between tissue groups within the same species. We also find secondorder differential patterns between microRNA promoters and genes contrasting cerebellum and liver development in mice. These patterns are enriched in the spliceosome pathway regulating tissue specificity. Complementary to previous mammalian comparative studies mostly driven by first-order effects, our findings contribute an understanding of system-wide second-order gene network rewiring within and across mammalian systems. Second-order differential patterns constitute evidence for fundamentally rewired biological circuitry due to evolution, environment, or disease.

AVAILABILITY: The generic Sharma-Song test is available from the R package ‘DiffXTables’ at https://cran.rproject.org/package=DiffXTables. Other code and data are described in Methods.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

PMID:33950233 | DOI:10.1093/bioinformatics/btab240

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Nevin Manimala Statistics

Diversification of Academic Surgery, Its Leadership, and the Importance of Intersectionality

JAMA Surg. 2021 May 5. doi: 10.1001/jamasurg.2021.1546. Online ahead of print.

ABSTRACT

IMPORTANCE: Diversity in academic surgery is lacking, particularly among positions of leadership.

OBJECTIVE: To evaluate trends among racial/ethnical minority groups stratified by gender along the surgical pipeline, as well as in surgical leadership.

DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional and longitudinal analysis assessed US surgical faculty census data obtained from the Association of American Medical Colleges faculty roster in the Faculty Administrative Management Online User System database. Surgical faculty members captured in census data from December 31, 2013, to December 31, 2019, were included in the analysis. Faculty were identified from the surgery category of the faculty roster, which includes general surgeons and subspecialists, neurosurgeons, and urologists.

MAIN OUTCOMES AND MEASURES: Gender and race/ethnicity were obtained for surgical faculty stratified by rank. Descriptive statistics with annual percentage of change in representation are reported based on faculty rank.

RESULTS: A total of 15 653 US surgical faculty, including 3876 women (24.8%), were included in the data set for 2019. Female faculty from racial/ethnic minority groups experienced an increase in representation at instructor and assistant and associate professorship appointments, with a more favorable trajectory than male faculty from racial/ethnic minority groups across nearly all ranks. White faculty maintain most leadership positions as full professors (3105 of 3997 [77.7%]) and chairs (294 of 380 [77.4%]). The greatest magnitude of underrepresentation along the surgical pipeline has been among Black (106 of 3997 [2.7%]) and Hispanic/Latinx (176 of 3997 [4.4%]) full professors. Among full professors, although Black and Hispanic/Latinx male representation increased modestly (annual change, 0.07% and 0.10%, respectively), Black female representation remained constant (annual change, 0.00004%) and Hispanic/Latinx female representation decreased (annual change, -0.16%). Overall Hispanic/Latinx (20 of 380 [5.3%]) and Black (13 of 380 [3.4%]) representation as chairs has not changed, with only 1 Black and 1 Hispanic/Latinx woman ascending to chair from 2013 to 2019.

CONCLUSIONS AND RELEVANCE: A disproportionately small number of faculty from minority groups obtain leadership positions in academic surgery. Intersectionality may leave female members of racial/ethnic minority groups more disadvantaged than their male colleagues in achieving leadership positions. These findings highlight the urgency to diversify surgical leadership.

PMID:33950242 | DOI:10.1001/jamasurg.2021.1546

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Nevin Manimala Statistics

Comparison of long-term skeletal stability following maxillary advancement using rigid external distraction in growing and non-growing patients with cleft lip and palate: a systematic review and meta-analysis

Eur J Orthod. 2021 May 5:cjab017. doi: 10.1093/ejo/cjab017. Online ahead of print.

ABSTRACT

OBJECTIVES: To compare the long-term skeletal stability following maxillary advancement using Rigid External Distraction (RED) in growing and non-growing patients with Cleft Lip and Palate (CLP).

METHODS: Data sources: A systematic literature search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines from database inception till August 2020 in MEDLINE-PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Science Direct, Google Scholar and a manual search in the institutional library. Study eligibility criteria, participants and intervention: All available literature published in English, with a minimum of six human subjects with well-defined age range either 7-14.9 years or 15-30 years, follow up period of a minimum of 12 months assessing the skeletal stability as horizontal change at Point A (Subspinale) following maxillary advancement using a RED device, without the use of rigid internal fixation or bone grafts were included in the study. Study appraisal and synthesis method: The quality assessment of selected articles was done using the Newcastle-Ottawa scale. The meta-analysis was carried out with Q statistic method, I-squared statistics, fixed-effect model to estimate pooled mean and Begg-Mazumdar bias indicator.

RESULTS: Selected nine articles that were qualitatively assessed for relapse rate following maxillary advancement using a RED device, showed consistent and stable results. The meta-analysis found no significant difference in long-term skeletal stability of maxillary advancement by RED device in growing and non-growing patients with CLP [(growing group: Pooled proportion = 0.2927; 95% CI = 0.1534 to 0.4319) (non-growing group: Pooled proportion = 0.23077; 95% CI = 0.09854 to 0.36300)].

LIMITATIONS: No study, as revealed by the search, was available that compared the two groups as defined by the inclusion criteria. Data for the two groups were retrieved from different studies and meta-analysed.

CONCLUSION: RED is an effective modality for correction of maxillary hypoplasia secondary to CLP, requiring large maxillary advancement. The technique can be used in young and adult patients with similar long-term results.

PROSPERO REGISTRATION NUMBER: CRD42020205513.

PMID:33950171 | DOI:10.1093/ejo/cjab017

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Survival After Breast Conservation vs Mastectomy Adjusted for Comorbidity and Socioeconomic Status: A Swedish National 6-Year Follow-up of 48 986 Women

JAMA Surg. 2021 May 5. doi: 10.1001/jamasurg.2021.1438. Online ahead of print.

ABSTRACT

IMPORTANCE: Cohort studies show better survival after breast-conserving surgery (BCS) with postoperative radiotherapy (RT) than after mastectomy (Mx) without RT. It remains unclear whether this is an independent effect or a consequence of selection bias.

OBJECTIVE: To determine whether the reported survival benefit of breast conservation is eliminated by adjustment for 2 pivotal confounders, comorbidity and socioeconomic status.

DESIGN, SETTING, AND PARTICIPANTS: Cohort study using prospectively collected national data. Swedish public health care; nationwide clinical data from the National Breast Cancer Quality Register, comorbidity data from Patient Registers at the National Board of Health and Welfare, and individual-level education and income data from Statistics Sweden. The cohort included all women diagnosed as having primary invasive T1-2 N0-2 breast cancer and undergoing breast surgery in Sweden from 2008 to 2017. Data were analyzed between August 19, 2020, and November 12, 2020.

EXPOSURES: Locoregional treatment comparing 3 groups: breast-conserving surgery with radiotherapy (BCS+RT), mastectomy without radiotherapy (Mx-RT), and mastectomy with radiotherapy (Mx+RT).

MAIN OUTCOMES AND MEASURES: Overall survival (OS) and breast cancer-specific survival (BCSS). Main outcomes were determined before initiation of data retrieval.

RESULTS: Among 48 986 women, 29 367 (59.9%) had BCS+RT, 12413 (25.3%) had Mx-RT, and 7206 (14.7%) had Mx+RT. Median follow-up was 6.28 years (range, 0.01-11.70). All-cause death occurred in 6573 cases, with death caused by breast cancer in 2313 cases; 5-year OS was 91.1% (95% CI, 90.8-91.3) and BCSS was 96.3% (95% CI, 96.1-96.4). Apart from expected differences in clinical parameters, women receiving Mx-RT were older, had a lower level of education, and lower income. Both Mx groups had a higher comorbidity burden irrespective of RT. After stepwise adjustment for all covariates, OS and BCSS were significantly worse after Mx-RT (hazard ratio [HR], 1.79; 95% CI, 1.66-1.92 and HR, 1.66; 95% CI, 1.45-1.90, respectively) and Mx+RT (HR, 1.24; 95% CI, 1.13-1.37 and HR, 1.26; 95% CI, 1.08-1.46, respectively) than after BCS+RT.

CONCLUSIONS AND RELEVANCE: Despite adjustment for previously unmeasured confounders, BCS+RT yielded better survival than Mx irrespective of RT. If both interventions are valid options, mastectomy should not be regarded as equal to breast conservation.

PMID:33950173 | DOI:10.1001/jamasurg.2021.1438