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Nevin Manimala Statistics

Algorithms used in medical image segmentation for 3D printing and how to understand and quantify their performance

3D Print Med. 2022 Jun 24;8(1):18. doi: 10.1186/s41205-022-00145-9.

ABSTRACT

BACKGROUND: 3D printing (3DP) has enabled medical professionals to create patient-specific medical devices to assist in surgical planning. Anatomical models can be generated from patient scans using a wide array of software, but there are limited studies on the geometric variance that is introduced during the digital conversion of images to models. The final accuracy of the 3D printed model is a function of manufacturing hardware quality control and the variability introduced during the multiple digital steps that convert patient scans to a printable format. This study provides a brief summary of common algorithms used for segmentation and refinement. Parameters for each that can introduce geometric variability are also identified. Several metrics for measuring variability between models and validating processes are explored and assessed.

METHODS: Using a clinical maxillofacial CT scan of a patient with a tumor of the mandible, four segmentation and refinement workflows were processed using four software packages. Differences in segmentation were calculated using several techniques including volumetric, surface, linear, global, and local measurements.

RESULTS: Visual inspection of print-ready models showed distinct differences in the thickness of the medial wall of the mandible adjacent to the tumor. Volumetric intersections and heatmaps provided useful local metrics of mismatch or variance between models made by different workflows. They also allowed calculations of aggregate percentage agreement and disagreement which provided a global benchmark metric. For the relevant regions of interest (ROIs), statistically significant differences were found in the volume and surface area comparisons for the final mandible and tumor models, as well as between measurements of the nerve central path. As with all clinical use cases, statistically significant results must be weighed against the clinical significance of any deviations found.

CONCLUSIONS: Statistically significant geometric variations from differences in segmentation and refinement algorithms can be introduced into patient-specific models. No single metric was able to capture the true accuracy of the final models. However, a combination of global and local measurements provided an understanding of important geometric variations. The clinical implications of each geometric variation is different for each anatomical location and should be evaluated on a case-by-case basis by clinicians familiar with the process. Understanding the basic segmentation and refinement functions of software is essential for sites to create a baseline from which to evaluate their standard workflows, user training, and inter-user variability when using patient-specific models for clinical interventions or decisions.

PMID:35748984 | DOI:10.1186/s41205-022-00145-9

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Nevin Manimala Statistics

Occurrence and exposure risk assessment of organochlorine pesticides in two waterbird species from Honghu Lake Wetland, Central China

Environ Geochem Health. 2022 Jun 24. doi: 10.1007/s10653-022-01316-7. Online ahead of print.

ABSTRACT

Monitoring and evaluating bird exposure to hazardous pollutants in wetlands are receiving considerable attention. In this study, the occurrence of 18 organochlorine pesticides (OCPs) in the muscle of bean geese (Anser fabalis) and common teals (Anas crecca) collected from Honghu Lake Wetland (HLW), Central China was studied. Additionally, an exposure risk assessment model was applied to obtain risk levels of OCPs to these birds through three oral routes (food intake, water drinking and soil ingestion). The results suggested that the most abundant OCPs detected in the muscle of waterbirds were DDTs (7.68-602 ng/g lipid weight), followed by HCHs (1.39-89.8 ng/g lipid weight). A significant difference (p < 0.05) existed between two species, but most of OCPs exhibited no statistically relationship with age or gender (p > 0.05). The compositional patterns of OCPs combined with ratios of certain metabolites to their parent compounds indicated that all OCPs in the HLW were largely from historical usage except heptachlor. The exposure risk assessment revealed that common teals with lighter weight had greater exposure risks than bean geese. Of the OCPs analyzed, DDTs could probably cause harm to target birds studied here. Exposure via food intake was identified to be significant while soil ingestion and water drinking contributed least, but they should still be concerned.

PMID:35748971 | DOI:10.1007/s10653-022-01316-7

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Nevin Manimala Statistics

Linkage of multiple electronic health record datasets using a ‘spine linkage’ approach compared with all ‘pairwise linkages’

Int J Epidemiol. 2022 Jun 24:dyac130. doi: 10.1093/ije/dyac130. Online ahead of print.

ABSTRACT

BACKGROUND: Methods for linking records between two datasets are well established. However, guidance is needed for linking more than two datasets. Using all ‘pairwise linkages’-linking each dataset to every other dataset-is the most inclusive, but resource-intensive, approach. The ‘spine’ approach links each dataset to a designated ‘spine dataset’, reducing the number of linkages, but potentially reducing linkage quality.

METHODS: We compared the pairwise and spine linkage approaches using real-world data on patients undergoing emergency bowel cancer surgery between 31 October 2013 and 30 April 2018. We linked an administrative hospital dataset (Hospital Episode Statistics; HES) capturing patients admitted to hospitals in England, and two clinical datasets comprising patients diagnosed with bowel cancer and patients undergoing emergency bowel surgery.

RESULTS: The spine linkage approach, with HES as the spine dataset, created an analysis cohort of 15 826 patients, equating to 98.3% of the 16 100 patients identified using the pairwise linkage approach. There were no systematic differences in patient characteristics between these analysis cohorts. Associations of patient and tumour characteristics with mortality, complications and length of stay were not sensitive to the linkage approach. When eligibility criteria were applied before linkage, spine linkage included 14 509 patients (90.0% compared with pairwise linkage).

CONCLUSION: Spine linkage can be used as an efficient alternative to pairwise linkage if case ascertainment in the spine dataset and data quality of linkage variables are high. These aspects should be systematically evaluated in the nominated spine dataset before spine linkage is used to create the analysis cohort.

PMID:35748342 | DOI:10.1093/ije/dyac130

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Nevin Manimala Statistics

Impact of SARS-CoV-2 on incidence, treatment and outcome of very preterm born infants in Switzerland: a retrospective, population-based cohort study

Swiss Med Wkly. 2022 May 13;152:w30174. doi: 10.4414/smw.2022.w30174. eCollection 2022 May 9.

ABSTRACT

AIMS OF THE STUDY: To assess whether the COVID-19 pandemic caused by SARS-CoV-2 had an impact on incidence, treatment or major adverse short-term outcome of preterm-born infants in Switzerland.

METHODS: Retrospective cohort study of preterm infants born in 2020 based on two independent data sources from the Swiss Federal Statistics Office (FSO) and SwissNeoNet. Based on FSO data, we calculated the odds ratios for extremely preterm (22-27 weeks gestation), very preterm (28-31 weeks gestation), and late preterm (32-36 weeks gestation) births during the pandemic. Based on SwissNeoNet data of infants born between 22 and 31 weeks gestation, we compared infants born during the Swiss lockdown period in 2020 with infants born during the same period between 2015 and 2019, all infants of 2020 with all infants between 2015 and 2019 and infants born to mothers tested SARS-CoV-2 positive and negative. Possible associations with the pandemic were tested using logistic regression adjusted for case-mix. As a control, we compared births of 2019 with those of 2015-2018.

RESULTS: The FSO data revealed equivalent odds for extremely preterm births in 2020 (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.89-1.14), as well as somewhat lower odds ratios for very preterm (OR 0.9, 95% CI 0.82-1.00) and late preterm (OR 0.91, 95% CI 0.88-0.93) births in 2020. A comparison between 2019 and 2015-2018, however, revealed matching odds ratios rendering an association to the pandemic unlikely. In the SwissNeoNet data, 137 infants were born during lockdown in 2020 compared with 134 births per year during 2015-2019. When including all infants, 744 infants were compared to 845 births, respectively. The only difference observed in treatments and short term outcomes between 2020 and the reference years were a higher odds for respiratory distress syndrome (OR 1.6, 95% CI 1.08-2.37) and provision of continuous positive airway pressure (CPAP) (OR 1.39, 95% CI 1.05-1.84).

CONCLUSIONS: Our Swiss population-based analysis did not identify the elsewhere reported association between the COVID-19 pandemic and a reduced preterm birth rate. However, we can confirm a possible link between the COVID-19 pandemic and higher odds of respiratory distress syndrome, possibly coupled with CPAP requirements. Further observation of potential effects of the pandemic on health and health care provision to newborns may however be indicated based on the literature available so far and that our data only covers the first 9 months of the current pandemic.

PMID:35748336 | DOI:10.4414/smw.2022.w30174

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Nevin Manimala Statistics

Benchmarking various types of partial atomic charges for classical all-atom simulations of metal-organic frameworks

Nanoscale. 2022 Jun 24. doi: 10.1039/d2nr00354f. Online ahead of print.

ABSTRACT

The density derived electrostatic and chemical (DDEC) approach for calculating the charges of atoms in a metal-organic framework (MOF) is considered to be the most accurate (yet computationally costly) one among many charge-assignment methods. Here, we conducted a comparative study on five different types of atomic partial charges (namely CM5, Mulliken, Qeq, EQeq and PACMOF) prepared for a subset of MOFs with affordable computational costs and benchmarked them with respect to the DDEC charges, which is particularly relevant because currently most databases lack MOFs with pre-calculated DDEC charges. To find a suitable charge type alternative to the DDEC approach, we statistically ranked the five charge types based on two metrics, the relative standard deviation of charges and relative dipole moment difference, based on which we provide general guidance as well as suggestions for specific MOFs according to bond polarity analyses. Finally, we recommend a possible and more accurate parametrization scheme for future studies.

PMID:35748335 | DOI:10.1039/d2nr00354f

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Nevin Manimala Statistics

Diagnostic Value of Quantitative Contrast-Enhanced Ultrasound in Comparison to Endoscopy in Children with Crohn’s Disease

J Ultrasound Med. 2022 Jun 24. doi: 10.1002/jum.16044. Online ahead of print.

ABSTRACT

OBJECTIVE: Quantitative contrast-enhanced US (CEUS) provides objective evaluation of bowel wall perfusion and has been reported as a useful method for evaluating Crohn’s disease (CD) activity in children. We tested its’ diagnostic accuracy in comparison to endoscopy and evaluated its’ usefulness in comparison to Pediatric Crohn’s Disease Activity Index (PCDAI) and fecal Calprotectin (FC).

MATERIALS AND METHODS: Children with CD and thickened bowel wall on abdominal US were prospectively enrolled. Disease activity was evaluated with quantitative CEUS, PCDAI and FC and compared to a simple endoscopic score for Crohn’s disease (SES-CD). Spearman’s correlation and Cohen’s kappa statistic between the SES-CD and other disease activity measures were performed and diagnostic accuracies calculated.

RESULTS: 36 children 3.5-18 years old (mean age 14 years) were included. The quantitative CEUS had 78.57% sensitivity (95%CI 0.59-0.92), 100% specificity (95%CI 0.63-1.0) and 83.33% diagnostic accuracy (95% CI 0.67-0.94). The concordance remission agreement with endoscopy was substantial for quantitative CEUS and PCDAI (quantitative CEUS: κ = 0.62; 95% CI 0.363-0.877; PCDAI: κ = 0.615; 95% CI 0.311-0.920), but only fair for FC (κ = 0.389; 95% CI 0.006-0.783). Correlation between all measures and endoscopy was moderate and statistically significant (quantitative CEUS: rs = 0.535, PCDAI: rs = 0.543, FC: rs = 0.497).

CONCLUSIONS: Quantitative CEUS has a potential of becoming a complementary method for evaluation of CD activity in children due to its’ high specificity in comparison to endoscopy. Lower sensitivity makes it deficient as a single measure and further management should be guided by PCDAI and FC results as well.

PMID:35748308 | DOI:10.1002/jum.16044

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Nevin Manimala Statistics

Association between the COVID-19 pandemic and pertussis derived from multiple nationwide data sources, France, 2013 to 2020

Euro Surveill. 2022 Jun;27(25). doi: 10.2807/1560-7917.ES.2022.27.25.2100933.

ABSTRACT

BackgroundInterventions to mitigate the COVID-19 pandemic may impact other respiratory diseases.AimsWe aimed to study the course of pertussis in France over an 8-year period including the beginning of the COVID-19 pandemic and its association with COVID-19 mitigation strategies, using multiple nationwide data sources and regression models.MethodsWe analysed the number of French pertussis cases between 2013 and 2020, using PCR test results from nationwide outpatient laboratories (Source 1) and a network of the paediatric wards from 41 hospitals (Source 2). We also used reports of a national primary care paediatric network (Source 3). We conducted a quasi-experimental interrupted time series analysis, relying on negative binomial regression models. The models accounted for seasonality, long-term cycles and secular trend, and included a binary variable for the first national lockdown (start 16 March 2020).ResultsWe identified 19,039 pertussis cases from these data sources. Pertussis cases decreased significantly following the implementation of mitigation measures, with adjusted incidence rate ratios of 0.10 (95% CI: 0.04-0.26) and 0.22 (95% CI: 0.07-0.66) for Source 1 and Source 2, respectively. The association was confirmed in Source 3 with a median of, respectively, one (IQR: 0-2) and 0 cases (IQR: 0-0) per month before and after lockdown (p = 0.0048).ConclusionsThe strong reduction in outpatient and hospitalised pertussis cases suggests an impact of COVID-19 mitigation measures on pertussis epidemiology. Pertussis vaccination recommendations should be followed carefully, and disease monitoring should be continued to detect any resurgence after relaxation of mitigation measures.

PMID:35748301 | DOI:10.2807/1560-7917.ES.2022.27.25.2100933

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Nevin Manimala Statistics

Comparison of Computed Tomography Perfusion and Multiphase Computed Tomography Angiogram in Predicting Clinical Outcomes in Endovascular Thrombectomy

Stroke. 2022 Jun 24:101161STROKEAHA122038576. doi: 10.1161/STROKEAHA.122.038576. Online ahead of print.

ABSTRACT

BACKGROUND: In patients with acute stroke who undergo endovascular thrombectomy, the relative prognostic power of computed tomography perfusion (CTP) parameters compared with multiphase CT angiogram (mCTA) is unknown. We aimed to compare the predictive accuracy of mCTA and CTP parameters on clinical outcomes.

METHODS: We included patients with acute ischemic stroke who had anterior circulation large vessel occlusion within 24 hours of onset in Melbourne Brain Centre at the Royal Melbourne Hospital. All patients underwent CTP for endovascular thrombectomy, and the mCTA collateral score was determined using CTP-reconstructed mCTA images. The primary outcome was 90-day functional outcomes defined by modified Rankin Scale. Multivariable logistic regression models analyzed associations between mCTA and CTP parameters and 90-day functional outcomes. The ability to discriminate 90 days-functional outcomes was compared between mCTA collateral score and CTP parameters using receiver operating curve analysis and C statistics.

RESULTS: One hundred and twenty patients were included. The median age was 69 years (interquartile range, 60-79), the median baseline National Institutes of Health Stroke Scale score was 14 (interquartile range, 9-19). The baseline ischemic core volume, defined by CTP-based relative cerebral blood flow <30%, was associated with excellent functional outcome (modified Rankin Scale score 0-1; odds ratio, 0.942 [-0.897 to -0.989]; P=0.015) and poor functional outcome (modified Rankin Scale score 5-6; odds ratio, 1.032 [1.007-1.056]; P=0.010) at 90 days in the analysis of multivariable regression. There was no significant association between the mCTA score and excellent functional outcome (P=0.58) or poor functional outcome (P=0.155). The relative cerebral blood flow <30%-based regression model best fit the data for the 90-day poor functional outcome (C statistic, 0.834).

CONCLUSIONS: The CTP-based ischemic core volume may provide better discrimination for 90-day functional outcomes for patients with acute stroke undergoing endovascular thrombectomy than the mCTA collateral score.

PMID:35748291 | DOI:10.1161/STROKEAHA.122.038576

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Nevin Manimala Statistics

Physical Therapy and Nusinersen Impact on Spinal Muscular Atrophy Rehabilitative Outcome

Front Biosci (Landmark Ed). 2022 Jun 6;27(6):179. doi: 10.31083/j.fbl2706179.

ABSTRACT

INTRODUCTION: Spinal muscular atrophy (SMA) is a progressive neurological disease with autosomal recessive transmission that affects motor neurons, causing their loss and resulting in muscle waste and motor deficiency. Nusinersen, the first SMN2 pre-mRNA targeted therapy approved by the Food and Drug Administration and the European Medicines Agency, has demonstrated high efficacy in improving motor function, as well as respiratory and nutritional statuses.

MATERIALS AND METHODS: We observed 55 patients (children/adolescents) diagnosed with spinal muscular atrophy (SMA), who received nusinersen therapy. To investigate the benefits of physical therapy on rehabilitation outcomes, we compared the motor evolution of patients who received nusinersen and performed daily physical therapy (study group) to those of the control group, who received only nusinersen therapy.

RESULTS: Motor skill improvements were statistically significantly (p < 0.001) higher in the study group, being almost four times better (12.66%), effect size, in comparison to the control group (3.18%).

CONCLUSIONS: Physical therapy has provided superior results for those who receive it on a regular basis. These results include the correction of posture, reduction in stiffness, expansion of the range of motion and strengthening of muscles, thus allowing patients to do more movements and boosting their ability to perform everyday tasks.

PMID:35748255 | DOI:10.31083/j.fbl2706179

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Nevin Manimala Statistics

Socioeconomic Deprivation: An Important, Largely Unrecognized Risk Factor in Primary Prevention of Cardiovascular Disease

Circulation. 2022 Jun 24:101161CIRCULATIONAHA122060042. doi: 10.1161/CIRCULATIONAHA.122.060042. Online ahead of print.

ABSTRACT

BACKGROUND: Socioeconomic deprivation is associated with higher cardiovascular morbidity and mortality. Whether deprivation status should be incorporated in more cardiovascular risk estimation scores remains unclear. This study evaluates how socioeconomic deprivation status affects the performance of 3 primary prevention cardiovascular risk scores.

METHODS: The Generation Scotland Scottish Family Health Study was used to evaluate the performance of 3 cardiovascular risk scores with (ASSIGN [Assessing Cardiovascular Risk Using SIGN]) and without (SCORE2 [Systematic Coronary Risk Evaluation 2 Algorithm], pooled cohort equations) socioeconomic deprivation as a covariate in the risk prediction model. Deprivation was defined by Scottish Index of Multiple Deprivation score. The predicted 10-year risk was evaluated against the observed event rate for the cardiovascular outcome of each risk score. The comparison was made across 3 groups defined by the deprivation index score consisting of group 1 defined as most deprived, group 3 defined as least deprived, and group 2, which consisted of individuals in the middle deprivation categories.

RESULTS: The study population consisted of 15 506 individuals (60.0% female, median age of 51). Across the population, 1808 (12%) individuals were assigned to group 1 (most deprived), 8119 (52%) to group 2, and 4708 (30%) to group 3 (least deprived), and 871 individuals (6%) had a missing deprivation score. Risk scores based on models that did not include deprivation status significantly under predicted risk in the most deprived (6.43% observed versus 4.63% predicted for SCORE2 [P=0.001] and 6.69% observed versus 4.66% predicted for pooled cohort equations [P<0.001]). Both risk scores also significantly overpredicted the risk in the least deprived group (3.97% observed versus 4.72% predicted for SCORE2 [P=0.007] and 4.22% observed versus 4.85% predicted for pooled cohort equations [P=0.028]). In contrast, no significant difference was demonstrated in the observed versus predicted risk when using the ASSIGN risk score, which included socioeconomic deprivation status in the risk model.

CONCLUSIONS: Socioeconomic status is a largely unrecognized risk factor in primary prevention of cardiovascular disease. Risk scores that exclude socioeconomic deprivation as a covariate under- and overestimate the risk in the most and least deprived individuals, respectively. This study highlights the importance of incorporating socioeconomic deprivation status in risk estimation systems to ultimately reduce inequalities in health care provision for cardiovascular disease.

PMID:35748241 | DOI:10.1161/CIRCULATIONAHA.122.060042