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Nevin Manimala Statistics

Conditional bias adjusted estimator of treatment effect in 2-in-1 adaptive design

J Biopharm Stat. 2024 Jun 6:1-20. doi: 10.1080/10543406.2024.2359147. Online ahead of print.

ABSTRACT

For implementation of adaptive design, the adjustment of bias in treatment effect estimation becomes an increasingly important topic in recent years. While adaptive design literature traditionally focuses on the control of type I error rate and the adjustment of overall unconditional bias, the research on adjusting conditional bias has been limited. This paper proposes a conditional bias adjustment estimator of treatment effect under the context of 2-in-1 adaptive design and aims to provide a comprehensive investigation on their statistical properties including bias, mean squared error and coverage probability of confidence intervals. It demonstrated that conditional bias adjusted estimators greatly reduce the conditional bias and have similarly negligible unconditional bias compared with mean and median (unconditional) unbiased estimators. In addition, the test statistics is constructed based on the conditional bias adjustment estimators and compared with the naive unadjusted test.

PMID:38841980 | DOI:10.1080/10543406.2024.2359147

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Nevin Manimala Statistics

Evaluation of nail fold capillaroscopy changes in patients with diabetic retinopathy and healthy controls, and its correlation with disease duration, HbA1c levels and severity of diabetic retinopathy: An observational study

Indian J Dermatol Venereol Leprol. 2024 Apr 29:1-7. doi: 10.25259/IJDVL_232_2023. Online ahead of print.

ABSTRACT

Background Diabetic retinopathy (DR) is an important microvascular complication of long-term type 2 diabetes mellitus (T2DM) leading to blindness if not properly diagnosed and managed. It can develop as early as 7 years before the diagnosis of diabetes. Nail fold capillaroscopy (NFC) is a non-invasive technique for observing capillary microvasculature and there are few studies which have explored the use of NFC in diabetes mellitus patients. Objective To study the nail fold capillaroscopic alterations in patients with T2DM having diabetic retinopathy and compare them to healthy controls. The secondary objective was to correlate the NFC findings with the duration of diabetes, haemoglobin A1c (HbA1c) levels and the severity of DR. Materials and methods This cross-sectional observational study enrolled 200 patients – 100 cases with T2DM having diabetic retinopathy (as per the American Diabetes Association criteria and Diabetic Retinopathy Disease Severity Scale) and 100 healthy age and sex-matched controls. All patients were subjected to NFC and ophthalmological assessment. Results NFC revealed that patients with DR showed significantly higher frequencies of tortuous, dilated, bushy, meandering, angulated capillaries, avascular areas and micro-haemorrhages as compared to healthy controls (p < 0.05). In proliferative DR (PDR), the frequency of tortuous, bushy capillaries, and avascular areas was statistically high and the capillary density was reduced as compared to non-proliferative DR. The DR patients with longer disease duration (>20) years had a significantly higher frequency of tortuous capillaries, avascular areas, meandering, angulated and dilated capillaries. The frequency of tortuosity, avascular areas, and bushy areas was significantly higher in patients with poor glycaemic control (HbA1c >11). Limitations A larger sample size study with different demographic populations could have provided a broader picture of NFC changes in T2DM patients with DR. Discussion NFC may act as a surrogate marker of retinal involvement in patients with DM and should be performed at regular intervals. Conclusion NFC is a quick, simple, safe, and non-invasive method to assess the capillaroscopic alterations in diabetic patients which inturn can help in assessing the severity of DR.

PMID:38841954 | DOI:10.25259/IJDVL_232_2023

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Nevin Manimala Statistics

Serum levels of tumour necrosis factor (TNF-α) and interleukin-17 (IL-17) in patients with nail psoriasis: A cross-sectional study

Indian J Dermatol Venereol Leprol. 2024 May 4:1-5. doi: 10.25259/IJDVL_367_2023. Online ahead of print.

ABSTRACT

Background Psoriasis is a common chronic inflammatory disorder affecting all aspects of a patient’s life. Nail involvement is frequent, but little is known about its associated inflammatory biomarker profile, including similarities or differences from cutaneous disease. Aims We conducted this cross-sectional study to evaluate serum levels of inflammatory cytokines [tumour necrosis factor-alpha (TNF-α) and interleukin -17 (IL-17)] in patients with nail psoriasis and compared these to psoriasis patients without nail involvement, as well as in non-psoriatic healthy controls. Methods Adult psoriasis patients with (Group I, n = 30) and without nail involvement (Group-II, n = 30) were sequentially recruited. In addition, non-psoriatic healthy controls (Group-III, n = 20) were recruited. The nail disease severity by NAPSI score was determined for patients in Group I. Cutaneous disease severity (by PASI score) and presence of psoriatic arthritis (through CASPAR criteria) were evaluated for patients in Groups I and II. Serum levels of TNF-α, IL-17, erythrocyte sedimentation rate (ESR), rheumatoid factor (RA factor), and anti-cyclic citrullinated peptide antibody (Anti-CCP) were evaluated for all three groups. Results The median age was significantly higher for Group I as compared to Group II patients (41 ± 12.6 years vs 30 ± 12.4 years, p = 0.017). Group I patients also had higher median PASI score than Group II patients, although the difference was not statistically significant (10 ± 11.41 vs 6.50 ± 5.46, p = 0.275). The mean serum IL-17 levels were significantly higher for Group-I (113.39 ± 251.30 pg/mL) than Group II (27.91 ± 18.22 pg/mL, p = 0.002) and Group III (25.67 ± 12.08 pg/mL, p = 0.005). A weak positive correlation was found between NAPSI and serum IL-17 levels (Spearman’s Rho = 0.355) though not statistically significant (p = 0.054). Correlation between serum IL-17 and PASI was poor for Group-I patients (Spearman’s Rho = 0.13, p = 0.944) and strongly negative for Group-II patients (Spearman’s Rho = -0.368, statistically significant with p = 0.045). The mean serum levels of TNF-α were below the detection threshold of the assay kit, hence no meaningful comparison could be made. Limitations A small sample size and low sensitivity of TNF-α assay kit. Conclusion Our study showed that nail psoriasis could be independently associated with an elevation of IL-17. This can help choose appropriate drugs and estimate drug response in patients with nail psoriasis.

PMID:38841938 | DOI:10.25259/IJDVL_367_2023

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Nevin Manimala Statistics

Simultaneous clustering and estimation of networks in multiple graphical models

Biostatistics. 2024 Jun 5:kxae015. doi: 10.1093/biostatistics/kxae015. Online ahead of print.

ABSTRACT

Gaussian graphical models are widely used to study the dependence structure among variables. When samples are obtained from multiple conditions or populations, joint analysis of multiple graphical models are desired due to their capacity to borrow strength across populations. Nonetheless, existing methods often overlook the varying levels of similarity between populations, leading to unsatisfactory results. Moreover, in many applications, learning the population-level clustering structure itself is of particular interest. In this article, we develop a novel method, called Simultaneous Clustering and Estimation of Networks via Tensor decomposition (SCENT), that simultaneously clusters and estimates graphical models from multiple populations. Precision matrices from different populations are uniquely organized as a three-way tensor array, and a low-rank sparse model is proposed for joint population clustering and network estimation. We develop a penalized likelihood method and an augmented Lagrangian algorithm for model fitting. We also establish the clustering accuracy and norm consistency of the estimated precision matrices. We demonstrate the efficacy of the proposed method with comprehensive simulation studies. The application to the Genotype-Tissue Expression multi-tissue gene expression data provides important insights into tissue clustering and gene coexpression patterns in multiple brain tissues.

PMID:38841872 | DOI:10.1093/biostatistics/kxae015

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Nevin Manimala Statistics

Rationale for issuing neuroimaging requests for patients with primary headaches in China

Brain Behav. 2024 Jun;14(6):e3583. doi: 10.1002/brb3.3583.

ABSTRACT

OBJECTIVE: To investigate the prevalence of neuroimaging in patients with primary headaches and the clinician-based rationale for requesting neuroimaging in China.

DATA SOURCES AND STUDY SETTING: This study included patients with primary headaches admitted to hospitals and clinicians in China. We identified whether neuroimaging was requested and the types of neuroimaging conducted.

STUDY DESIGN: This was a cross-sectional study, and convenience sampling was used to recruit patients with primary headaches. Clinicians were interviewed using a combination of personal in-depth and topic-selection group interviews to explore why doctors requested neuroimaging.

DATA COLLECTION: We searched for the diagnosis of primary headache in the outpatient and inpatient systems according to the International Classification of Diseases-10 code of patients admitted to six hospitals in three provincial capitals by 2022.We selected three public and three private hospitals with neurology specialties that treated a corresponding number of patients.

PRINCIPLE FINDINGS: Among the 2263 patients recruited for this study, 1942 (89.75%) underwent neuroimaging. Of the patients, 1157 (51.13%) underwent magnetic resonance imaging (MRI), 246 (10.87%) underwent both head computed tomography (CT) and MRI, and 628 (27.75%) underwent CT. Fifteen of the 16 interviewed clinicians did not issue a neuroimaging request for patients with primary headaches. Furthermore, we found that doctors issued a neuroimaging request for patients with primary headaches mostly, to exclude the risk of misdiagnosis, reduce uncertainty, avoid medical disputes, meet patients’ medical needs, and complete hospital assessment indicators.

CONCLUSIONS: For primary headaches, the probability of clinicians requesting neuroimaging was higher in China than in other countries. There is considerable room for improvement in determining appropriate strategies to reduce the use of low-value care for doctors and patients.

PMID:38841826 | DOI:10.1002/brb3.3583

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Nevin Manimala Statistics

Shape variation in cranium, mandible and teeth in selected mouse strains

Anat Histol Embryol. 2024 Jul;53(4):e13064. doi: 10.1111/ahe.13064.

ABSTRACT

There are different strains of laboratory mouse used in many different fields. These strains differ anatomically. In order to determine these anatomical differences, shape analysis was conducted according to species. CD-1, C57bl/6 and Balb-c strains were preferred to study these differences. Forty-eight adult mouse strains belonging to these strains were utilized. The bones were photographed and geometric morphometry was applied to these photographs. Principal Component Analysis was applied to determine shape variations. In Principal component 1 for cranium, CD-1 and C57bl/6 strain groups showed different shape variations, while Balb-c strain group showed similar shape variations to the other strain groups. Principal Component 1 for the mandible separated the CD-1 and C57bl/6 strain groups in terms of shape variation. Principal Component 2 explained most of the variation between the C57bl/6 and CD-1 lineage groups. In PC1 for molars, the CD-1 group showed a different shape variation from the other groups. Mahalanobis distances and Procrustes distances were measured using Canonical variance analysis to explain the differences between the lineage groups. These measurements were statistically significant. For cranium, in canonical variate 1, CD-1 group of mouse and Balb-c group of mouse were separated from each other. In canonical variate 2, C57bl/6 group of mouse were separated from the other groups. For mandible, Balb-c group of mouse in canonical variate 1 and CD-1 group of mouse in canonical variate 2 were separated from the other groups. For molars, CD-1 group of mouse in canonical variate 1 and Balb-c group of mouse in canonical variate 2 were separated from the other groups. It was thought that these anatomical differences could be caused by genotypic factors as well as dietary differences and many different habits that would affect the way their muscles work.

PMID:38841825 | DOI:10.1111/ahe.13064

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Nevin Manimala Statistics

Uniportal Full-endoscopic Foraminotomy for Lumbar Foraminal Stenosis: Clinical Characteristics and Functional Outcomes

Orthop Surg. 2024 Jun 6. doi: 10.1111/os.14102. Online ahead of print.

ABSTRACT

OBJECTIVE: Uniportal full-endoscopic foraminotomy offers a promising alternative to conventional surgical methods for individuals afflicted by lumbar foraminal stenosis. This study aims to evaluate the efficacy and clinical outcomes of uniportal full-endoscopic foraminotomy in patients diagnosed with lumbar foraminal stenosis.

METHODS: A comprehensive retrospective analysis was conducted on individuals who underwent full-endoscopic foraminotomy in our medical center, between January 2018 and December 2019. The investigation encompassed the demographic data of patients and key clinical metrics such as the visual analogue scale of leg (VAS-L) and back pain (VAS-B), Oswestry disability index (ODI) scores, the Short Form-36 Health Survey physical component summary (SF-36 PCS) and the mental component summary (SF-36 MCS), as well as modified MacNab grades, were systematically assessed and compared. Furthermore, radiological parameters: Coronal Cobb angle (CCA), Intervertebral angle changes (IAC), Disc height index (DHI), the foraminal cross-sectional area (FCSA) and the FCSA enlargement ratio were also compared. A variety of statistical analyses including Student t-test, chi-square tests, Fisher’s exact tests, Pearson’s and Spearman’s correlation analyses, and Interclass Correlation Coefficients (ICCs) were employed.

RESULTS: 64 patients, including 34 males and 30 females were enrolled. The mean follow-up period extended to 22.66 ± 7.05 months. Distribution by affected segments revealed 26.6% at L4-5, 67.1% at L5-S1 level, and 6.25% at both L4-L5 and L5-S1 levels. At the final follow-up, VAS-L decreased from 7.26 ± 1.19 to 1.37 ± 1.25, while VAS-B decreased from 6.95 ± 0.54 to 1.62 ± 1.13 (p < 0.001). ODI score also demonstrated a substantial decrease from 74.73 ± 8.68 to 23.27 ± 8.71 (p < 0.001). Both SF-36 PCS and SF-36 MCS scores improved significantly (p < 0.001). Modified MacNab criteria revealed 58 excellent-good patients (90.7%), and 6 fair-poor patients (9.3%). No significant differences were founded in the CCA (p = 0.1065), IAC (p = 0.5544), and DHI (p = 0.1348) between pre-operation and the final follow-up. However, the FCSA significantly increased from 73.41 ± 11.75 to 173.40 ± 18.62 mm2 (p < 0.001), and the enlargement ratio was 142.9% ± 49.58%. Notably, the final follow-up FCSA and the FCSA enlargement ratio were found to be larger in the excellent and good group compared to the fair and poor group, according to the modified MacNab criteria.

CONCLUSION: The utilization of uniportal full-endoscopic foraminotomy has demonstrated its safety and efficacy in addressing lumbar foraminal stenosis. The clinical success of this procedure appears to be closely associated with the radiological decompression of the intervertebral foramen area. Importantly, the application of this technology does not seem to compromise the overall stability of the lumbar region.

PMID:38841821 | DOI:10.1111/os.14102

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Nevin Manimala Statistics

Comparison of Doses to Parotid, Temporomandibular Joint, and Pharyngeal Constrictor Muscles Using Different Techniques in Radiotherapy for Oropharyngeal Cancer

Technol Cancer Res Treat. 2024 Jan-Dec;23:15330338241260646. doi: 10.1177/15330338241260646.

ABSTRACT

OBJECTIVE: The purpose of this research was to compare two treatment techniques for oropharyngeal cancers: conventional linac-based static intensity-modulated radiotherapy (sIMRT) and helical tomotherapy (HT). The study examined several parameters, including target coverage, organs at risk, integral dose, and beam on time. Additionally, the study evaluated the doses to the parotid, temporomandibular joint, and pharyngeal constrictor muscles, which are important for swallowing.

METHOD: The present study retrospectively analyzed the data of 13 patients with oropharyngeal cancer who underwent radiotherapy between 2019 and 2021. The treatment plans for each patient were regenerated using both sIMRT and HT treatment planning systems with the sequential boost method. The techniques were evaluated and compared based on dose-volume histogram, homogeneity index, and conformity index parameters. The target coverage and organs at risk were statistically compared for two techniques. Additionally, the doses received by the healthy tissue volume were obtained for integral dose evaluation. The beam on time for each technique was assessed.

RESULTS: When considering planning target volume evaluation, there was no difference in Dmeans between the two techniques and sIMRT demonstrated higher D2% values compared to the HT. The HT technique had better results for all organs at risk, such as the parotid, temporomandibular joint, and pharyngeal constrictor muscle. As for integral dose, it has been shown that the sIMRT technique provides better protection compared to HT. In addition, the beam on time was also longer with the HT technique.

CONCLUSION: Both techniques may provide optimal target coverage for patients with oropharyngeal cancer. HT conferred notable advantages, especially with regard to critical structures implicated in swallowing, such as the parotid, temporomandibular joint, and pharyngeal constrictor muscle, in comparison to sIMRT.

PMID:38841792 | DOI:10.1177/15330338241260646

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Nevin Manimala Statistics

Causes of Death in Patients Asking for Polyclinic Care for Coronary Heart Disease

Kardiologiia. 2024 May 31;64(5):11-17. doi: 10.18087/cardio.2024.5.n2341.

ABSTRACT

AIM: Retrospective analysis of the underlying causes for death of patients who did and did not seek outpatient medical care (OPMC) for ischemic heart disease (IHD), and discussion of a possibility for using administrative anonymized but individualized databases for analysis.

MATERIAL AND METHODS: The electronic database of the Central Administration of the Civil Registry Office of the Moscow Region (Unified State Register of the Civil Registry Office of the Moscow Region), including medical death certificates (MDC) for 2021, was used to select all cases of fatal outcomes with the disease codes of the International Classification of Diseases, Tenth Revision (ICD-10) (codes of external causes, injuries, poisonings excluded) that were indicated as the primary cause of death (PCD). Personalized data of the deceased were combined with data from electronic medical records of patients who sought OPMC at institutions of the Moscow Region within up to 2 years before death. In addition to IHD, the following PCD codes were taken into account: malignant tumors, COVID-19, diabetes mellitus, cerebrovascular diseases, hypertension, chronic obstructive pulmonary disease, alcohol-associated diseases, and, as examples of unspecified PCD, old age and unspecified encephalopathy.Results In total, among those who died from diseases, the proportion of those who died from IHD was 18.9%; for another 8.4%, IHD was indicated as a comorbid disease in Part II of the MDC. Among those who sought OPMC for IHD, the IHD proportion indicated as PCD was 27.5%, and among those who did not seek OPMC 17.4% (p &lt;0.0001). Those who died from IHD and who had sought OPMC were older (mean age, 75.59 ± 10.94 years) than those who died from IHD and had not sought OMPM (mean age, 73.96 ± 10.94 years; p &lt; 0.0001). The frequency of myocardial infarction as PCD among those who had and had not sought OPMC was the same (12%), chronic forms of IHD were 83.9% and 79.7%, the frequencies of “unspecified” acute forms of IHD (codes I24.8-9) were 4.1% and 8.3%, respectively. The proportion of deaths from COVID-19 was the highest (21.7% and 24.3%, respectively), from malignant neoplasms 11.6% and 12.7%, respectively, and from unspecified encephalopathy 10.6% and 10.7%, respectively.

CONCLUSION: Only 25% of patients who had sought OPMC for IHD died from IHD, otherwise the causes of death were the same as for patients who had not sought OPMC for IHD. Analysis of administrative databases allows identifying disparities in the PCD structure and to direct the efforts of specialists to reconciling the criteria for death from various forms of IHD.

PMID:38841784 | DOI:10.18087/cardio.2024.5.n2341

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Nevin Manimala Statistics

Investigation of the behavior of tinnitus patients under varying listening conditions with simultaneous electroencephalography and pupillometry

Brain Behav. 2024 Jun;14(6):e3571. doi: 10.1002/brb3.3571.

ABSTRACT

OBJECTIVE: This study aims to control all hearing thresholds, including extended high frequencies (EHFs), presents stimuli of varying difficulty levels, and measures electroencephalography (EEG) and pupillometry responses to determine whether listening difficulty in tinnitus patients is effort or fatigue-related.

METHODS: Twenty-one chronic tinnitus patients and 26 matched healthy controls having normal pure-tone averages with symmetrical hearing thresholds were included. Subjects were evaluated with 0.125-20 kHz pure-tone audiometry, Montreal Cognitive Assessment Test (MoCA), Tinnitus Handicap Inventory (THI), EEG, and pupillometry.

RESULTS: Pupil dilatation and EEG alpha power during the “encoding” phase of the presented sentence in tinnitus patients were less in all listening conditions (p < .05). Also, there was no statistically significant relationship between EEG and pupillometry components for all listening conditions and THI or MoCA (p > .05).

CONCLUSION: EEG and pupillometry results under various listening conditions indicate potential listening effort in tinnitus patients even if all frequencies, including EHFs, are controlled. Also, we suggest that pupillometry should be interpreted with caution in autonomic nervous system-related conditions such as tinnitus.

PMID:38841736 | DOI:10.1002/brb3.3571