Category: Statistics

Wetlands (Wilmington). 2023;43(5):45. doi: 10.1007/s13157-023-01693-4. Epub 2023 May 3.

ABSTRACT

Salt marshes play a critical role in ecological functioning and have significant economic value. Hydrological elements are considered to be one of the major contributors to salt marsh degradation. However, how hydrological connectivity affects salt marshes remains poorly investigated at fine scales. This paper used spatial analysis and statistical methods to investigate the impact of hydrological connectivity on the spatial and temporal distribution characteristics of salt marsh vegetation in two natural succession areas of the Liao River Delta wetland in 2020 and 2021 by selecting vegetation area, NDVI, tidal creeks area, distance to tidal creeks, and the Index of Connectivity, using 1 m Gaofen-2 data and 0.2 m aerial topographic data. The study found that the area and growth status of vegetation and the overall connectivity in 2021 were better than that in 2020, while the west bank of the Liao River was better than that on the east bank. Phragmites australis showed a round island distribution pattern primarily at the end of tidal creeks. The differences between different hydrological connectivity and vegetation area were significant in 2021. The vegetation area was the largest under poor and moderate connectivity. We also found that within a distance range of 0-6 m from tidal creeks, the vegetation area increased with increasing distance, but beyond 6 m, the vegetation area decreased with increasing distance. Our results showed that poor and moderate connectivity conditions were more suitable for vegetation growth. The threshold value of 6 m can provide an important reference for wetland vegetation restoration in the Liao River Delta wetland.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13157-023-01693-4.

PMID:37193562 | PMC:PMC10154185 | DOI:10.1007/s13157-023-01693-4

Inform Med Unlocked. 2023;39:101269. doi: 10.1016/j.imu.2023.101269. Epub 2023 May 9.

ABSTRACT

BACKGROUND: The COVID-19 pandemic continues with new waves that could persist with the arrival of new SARS-CoV-2 variants. Therefore, the availability of validated and effective triage tools is the cornerstone for proper clinical management. Thus, this study aimed to assess the validity of the ISARIC-4C score as a triage tool for hospitalized COVID-19 patients in Saudi Arabia and to compare its performance with the CURB-65 score.

MATERIAL AND METHODS: This retrospective observational cohort study was conducted between March 2020 and May 2021 at KFHU, Saudi Arabia, using 542 confirmed COVID-19 patient data on the variables relevant to the application of the ISARIC-4C mortality score and the CURB-65 score. Chi-square and t-tests were employed to study the significance of the CURB-65 score and the ISARIC-4C score variables considering the ICU requirements and the mortality of COVID-19 hospitalized patients. In addition, logistic regression was used to predict the variables related to COVID-19 mortality. In addition, the diagnostic accuracy of both scores was validated by calculating sensitivities, specificities, positive predictive value, negative predictive value, and Youden’s J indices (YJI).

RESULTS: ROC analysis showed an AUC value of 0.834 [95% CI; 0.800-0.865]) for the CURB-65 score and 0.809 [95% CI; 0.773-0.841]) for the ISARIC-4C score. The sensitivity for CURB-65 and ISARIC-4C is 75% and 85.71%, respectively, while the specificity was 82.31% and 62.66%, respectively. The difference between AUCs was 0.025 (95% [CI; -0.0203-0.0704], p = 0.2795).

CONCLUSION: Study results support external validation of the ISARIC-4C score in predicting the mortality risk of hospitalized COVID-19 patients in Saudi Arabia. In addition, the CURB-65 and ISARIC-4C scores showed comparable performance with good consistent discrimination and are suitable for clinical utility as triage tools for hospitalized COVID-19 patients.

PMID:37193544 | PMC:PMC10167802 | DOI:10.1016/j.imu.2023.101269

Arthroplast Today. 2023 Apr 25;21:101127. doi: 10.1016/j.artd.2023.101127. eCollection 2023 Jun.

ABSTRACT

BACKGROUND: Total knee arthroplasty (TKA) is an effective treatment method for severe osteoarthritis of the knee. Poor alignment of a knee replacement has been associated with suboptimal clinical results. Traditionally, mechanical alignment (MA) has been considered the gold standard. In light of reports of decreased satisfaction with TKA, a new technique called kinematic alignment (KA) has been developed. The purpose of this study is to (1) review the results of KA and MA for TKA in randomized controlled trials based on the Western Ontario and McMaster Universities Arthritis Index score, the Oxford Knee Score, and the Knee Society Scores, (2) perform a meta-analyses of the randomized controlled trials with baseline and follow-up values of these parameters, and (3) discuss other shortcomings of this literature from the perspective of study design and execution.

METHODS: Two independent reviewers performed a systematic review of the English literature using the Embase, Scopus, and PubMed databases searching for randomized controlled trials of MA vs KA in TKA. Of the initial 481 published reports, 6 studies were included in the final review for meta-analysis. The individual studies were then analyzed to evaluate for risks of bias and inconsistencies of methodology.

RESULTS: A majority of studies demonstrated low risk of bias. All studies had fundamental technical issues by utilizing different techniques to achieve KA vs MA. There was no significant difference between KA and MA in these studies.

CONCLUSIONS: There is no significant difference in any outcomes measured between KA and MA in TKA. Both statistical and methodological factors diminish the value of these conclusions.

PMID:37193540 | PMC:PMC10182176 | DOI:10.1016/j.artd.2023.101127

Arthroplast Today. 2023 Apr 25;21:101134. doi: 10.1016/j.artd.2023.101134. eCollection 2023 Jun.

ABSTRACT

BACKGROUND: Instability is a common indication for revision after total knee arthroplasty. Replacement of multiple components is the current standard, but isolated polyethylene liner exchange (IPE) may present a less-morbid alternative. This study aims to determine (1) whether IPE results in similar rerevision frequency to component revision in select patients with symptomatic instability and (2) the effect of increasing constraint on the outcome.

METHODS: We retrospectively reviewed 117 patients revised for symptomatic total knee arthroplasty instability from January 2016 to December 2017. The component revision (60 patients) or IPE (57 patients) cohorts were further stratified based on whether constraint was increased or not. The primary objective was to compare rerevision rates 2 years after component revision vs IPE. The secondary objectives consisted of evaluating reasons for rerevision, preoperative and postoperative patient-reported outcome measures, and range of motion.

RESULTS: The rerevision rate was 18%, with no statistical difference between component and IPE cohorts. Cases where level of constraint increased due to revision, a significantly lower rate of rerevision was detected (9 of 77) (12%) than in cases where constraint did not increase (12 of 39) (31%) (P=0.012). This association was also noted in the component revision cohort but not in the IPE cohort (P=0.011).

CONCLUSIONS: Rerevision occurred at similar frequencies 2 years after IPE or component revision for total knee arthroplasty instability. For component revision, increased constraint was associated with significantly fewer rerevisions.

PMID:37193537 | PMC:PMC10182170 | DOI:10.1016/j.artd.2023.101134

Med J Armed Forces India. 2023 May-Jun;79(3):280-285. doi: 10.1016/j.mjafi.2021.05.017. Epub 2021 Aug 13.

ABSTRACT

BACKGROUND: Obstetrics as a speciality has a very long association with the transfusion services and poses its own set of immunohematological (IHL) challenges. A study was carried out to evaluate the spectrum of IHL issues in obstetrics in our setup and to suggest a way forward.

METHODS: This study was carried out in a transfusion services setup catering to antenatal care (ANC) clientele in two tertiary-level health care setups. Samples were collected from all ANC patients requiring transfusion and patients reporting for Indirect Coombs Test (ICT). Data included ICT positive cases with implicated alloantibodies, those requiring specialised procedures and the foetal outcome. The results were described using descriptive statistics by frequencies and percentages.

RESULTS: A total of 4683 eligible samples were included in the study, out of 21,893 antenatal patients visiting our setup during study period. One hundred thirty-six ANC patient samples were found to be ICT positive. The most common single alloantibody was anti-D (n = 77, 57.5%). Double antibody positivity was found in 28 patients. Multiple alloantibodies were found in 1 patient. Up to 48% of these allo-anti D cases necessitated specialised procedures.

CONCLUSION: The IHL issues of obstetrics faced in our setup are no less than that in Indian population. We have much higher frequency of double alloantibody in our ANC population. The authors propose that all multiparous ANC patients, especially with a history of transfusion, irrespective of Rh D status should be screened for irregular alloantibodies to circumvent these issues and the last-minute rush for provision of compatible units.

PMID:37193527 | PMC:PMC10182281 | DOI:10.1016/j.mjafi.2021.05.017

Med J Armed Forces India. 2023 May-Jun;79(3):292-299. doi: 10.1016/j.mjafi.2021.06.027. Epub 2021 Sep 7.

ABSTRACT

BACKGROUND: Coma is one of the frequently encountered clinical conditions in any intensive care unit (ICU), which is responsible for considerable morbidity and mortality. Therefore, this study was designed to look at the clinical and EEG profile of Nonconvulsive Status Epilepticus (NCSE) in comatose ICU patients using portable electroencephalography (EEG).

METHODS: In all 102 patients of unresponsive coma (GCS ≤ 8), who remained in poor sensorium despite 48 h of optimum treatment in ICU, were included in the study. All patients underwent 1 h of electroencephalography (EEG) monitoring with a portable EEG machine. All EEGs were screened according to Salzburg Consensus Criteria (SCC) for Nonconvulsive Status Epilepticus (NCSE). Patients with evidence of NCSE were administered parenteral Antiepileptic Drugs (AED). A repeat EEG was done after 24 h of baseline to ascertain the effect of AED. The primary outcome was the recognition of patients with NCSE on the basis of established EEG criteria. The secondary outcome measure was the Glasgow outcome scale (GOS) at the time of discharge.

RESULTS: Out of 102 cases enrolled, 12 (11.8%) cases were detected to have NCSE on portable EEG. The mean age of patients with NCSE was 52.2 years. In terms of gender distribution, 2/12 (17%) were female, and 10/12 (83%) were male (M: F = 5:1). Median GCS was 6 (range 3-8). Looking at CNS infections, 4/12 (33.3%) had evidence of some form of CNS infection in the NCSE group, compared to 16/90 (18%) in the group without NCSE. This difference was statistically significant (P-value < 0.05). The EEG recordings of patients with NCSE showed dynamicity with fluctuating rhythms and ictal-EEG patterns associated with spatiotemporal evolution. All twelve cases showed reversal of EEG changes with AED administration. In 5 out of 12, transient improvement in GCS (>2 points) after administration of AED’ was noted with good clinical outcomes (GOS 5). In five of these 12 cases, death was the final outcome (GOS 1).

CONCLUSIONS: NSCE should be considered in the differential diagnosis of all unresponsive comatose ICU patients. In resource-limited settings, where continuous EEG monitoring may not be feasible, bedside portable EEG testing can be used to diagnose patients with NCSE. Treating NCSE reverses epileptiform EEG changes and improves clinical outcomes in a subset of comatose ICU patients.

PMID:37193513 | PMC:PMC10182287 | DOI:10.1016/j.mjafi.2021.06.027

J Am Stat Assoc. 2023;118(541):257-271. doi: 10.1080/01621459.2021.1924178. Epub 2021 Jun 22.

ABSTRACT

Graphical modeling of multivariate functional data is becoming increasingly important in a wide variety of applications. The changes of graph structure can often be attributed to external variables, such as the diagnosis status or time, the latter of which gives rise to the problem of dynamic graphical modeling. Most existing methods focus on estimating the graph by aggregating samples, but largely ignore the subject-level heterogeneity due to the external variables. In this article, we introduce a conditional graphical model for multivariate random functions, where we treat the external variables as conditioning set, and allow the graph structure to vary with the external variables. Our method is built on two new linear operators, the conditional precision operator and the conditional partial correlation operator, which extend the precision matrix and the partial correlation matrix to both the conditional and functional settings. We show that their nonzero elements can be used to characterize the conditional graphs, and develop the corresponding estimators. We establish the uniform convergence of the proposed estimators and the consistency of the estimated graph, while allowing the graph size to grow with the sample size, and accommodating both completely and partially observed data. We demonstrate the efficacy of the method through both simulations and a study of brain functional connectivity network.

PMID:37193511 | PMC:PMC10181795 | DOI:10.1080/01621459.2021.1924178

J Am Stat Assoc. 2023;118(541):29-42. doi: 10.1080/01621459.2022.2105703. Epub 2022 Sep 20.

ABSTRACT

Cancer is a heterogeneous disease, and rapid progress in sequencing and -omics technologies has enabled researchers to characterize tumors comprehensively. This has stimulated an intensive interest in studying how risk factors are associated with various tumor heterogeneous features. The Cancer Prevention Study-II (CPS-II) cohort is one of the largest prospective studies, particularly valuable for elucidating associations between cancer and risk factors. In this paper, we investigate the association of smoking with novel colorectal tumor markers obtained from targeted sequencing. However, due to cost and logistic difficulties, only a limited number of tumors can be assayed, which limits our capability for studying these associations. Meanwhile, there are extensive studies for assessing the association of smoking with overall cancer risk and established colorectal tumor markers. Importantly, such summary information is readily available from the literature. By linking this summary information to parameters of interest with proper constraints, we develop a generalized integration approach for polytomous logistic regression model with outcome characterized by tumor features. The proposed approach gains the efficiency through maximizing the joint likelihood of individual-level tumor data and external summary information under the constraints that narrow the parameter searching space. We apply the proposed method to the CPS-II data and identify the association of smoking with colorectal cancer risk differing by the mutational status of APC and RNF43 genes, neither of which is identified by the conventional analysis of CPS-II individual data only. These results help better understand the role of smoking in the etiology of colorectal cancer.

PMID:37193510 | PMC:PMC10168026 | DOI:10.1080/01621459.2022.2105703

J Parasit Dis. 2023 Jun;47(2):319-328. doi: 10.1007/s12639-023-01573-y. Epub 2023 Mar 18.

ABSTRACT

Cerebral toxoplasmosis is an opportunistic infection, occurring mostly in immunosuppressed patients due to the reactivation of latent Toxoplasma cysts. The cerebral comorbidity in diabetic patients tends to intensify the burden of pathogenic infection within the brain. The aim of this work was to study the effect of cerebral toxoplasmosis in experimentally infected hyperglycemic mice, on histopathology and glial fibrillary acidic protein (GFAP) expression, compared to normoglycemic mice at different time intervals. Vasculopathy was exclusively observed in diabetic groups, with features of increased severity during Toxoplasma infection. Gliosis was observed in diabetic groups, while hyperactive astroglial activity was detected in normoglycemic groups, especially at 6 weeks of infection. GFAP expression showed significant up-regulation in normoglycemic mice at 6 weeks of infection (40.03 ± 1.41) afterwards, it decreased to 22.22 ± 3.14 at 12 weeks which was statistically insignificant to the normal level, possibly indicating the successful Toxoplasma stage transformation (to bradyzoite), thereby limiting the infection within the brain. In hyperglycemic infected groups, GFAP was significantly down-regulated, in both acute and chronic phases of infection, most likely indicating failure of stage transformation and infection limitation. This may expose those vulnerable groups to the risk of dissemination, resulting in life-threatening diffuse encephalitis. The current study emphasized the importance of rapid diagnosis of Toxoplasma infection in diabetic subjects, and highlighted the value of using GFAP as a neurological indicator of disease progression in those comorbid cases.

PMID:37193484 | PMC:PMC10182235 | DOI:10.1007/s12639-023-01573-y

Cureus. 2023 Apr 12;15(4):e37512. doi: 10.7759/cureus.37512. eCollection 2023 Apr.

ABSTRACT

Background In this study, we aimed to evaluate the knowledge and awareness about cervical cancer, human papillomavirus (HPV) and its vaccine among women living in the western region of Saudi Arabia. Methodology Using a cross-sectional online survey, this study assesses the knowledge and awareness level of HPV and the risk factors of cervical cancer among women living in the western region of Saudi Arabia. The design of the questionnaire is based on several earlier studies in different populations. Results The total completed responses include a sample of 624 that was subjected to statistical analysis; the analysis showed that only 34.6% were aware of HPV. Participants who belonged to the 21-30 and 31-40-year-old groups had comparatively more awareness than other age groups (p<0.001). Most (83.8%) believed that it would cause cervical cancer. Less than half (45.8%) knew that there is a vaccine against HPV infection. When we assessed the willingness to receive the vaccine, it was found that 75.8% were willing to take it. Conclusions The study found that women in the western region of Saudi Arabia have limited knowledge of cervical cancer and HPV and its vaccine. There is a need to educate and promote awareness of HPV and its complications for women in the western region of Saudi Arabia.

PMID:37193479 | PMC:PMC10182381 | DOI:10.7759/cureus.37512