Tag: statistics

J Neurovirol. 2022 Oct 7. doi: 10.1007/s13365-022-01051-w. Online ahead of print.

ABSTRACT

Human immunodeficiency virus-associated distal sensory polyneuropathy (HIV-DSP) affects up to 50% of people with HIV and is associated with depression, unemployment, and generally worsened quality of life. Previous work on the cortical mechanism of HIV neuropathy found decreased gray matter volume in the bilateral midbrain, thalamus, and posterior cingulate cortex, but structural connectivity in this context remains under-studied. Here we examine alterations in white matter microstructure using diffusion imaging, hypothesizing that cortical white matter degeneration would be observed in continuation of the peripheral white matter atrophy previously observed in HIV-DSP. Male HIV seropositive patients (n = 57) experiencing varying degrees of HIV neuropathy underwent single-shell diffusion tensor imaging with 51 sampling directions. The scans were pooled using tractography and connectometry to create a quantitative map of white matter tract integrity, measured in generalized fractional anisotropy (GFA). The relationship between GFA and neuropathy severity was evaluated with linear regression. Correction for multiple comparisons was done using false discovery rate (FDR), a statistical method commonly used in genomics and imaging to minimize false positives when thousands of individual comparisons are made. Neuropathy severity was associated with decreased GFA along thalamocortical radiations leading along the lateral thalamus to sensorimotor cortex, with r = -0.405 (p < 0.001; FDR), as well as with the superior bilateral cingulum (r = -0.346 (p < 0.05; FDR)). Among a population of HIV neuropathy patients, greater neuropathy severity was correlated with lower white matter integrity running from midbrain to somatosensory cortex. This suggests ascending deafferentation extending from damaged peripheral nerves further downstream than seen previously, into the axons of third-order neurons. There is also evidence of cingulum degeneration, implying some more complex mechanism beyond the ascending atrophy observed here.

PMID:36207560 | DOI:10.1007/s13365-022-01051-w

S D Med. 2022 Jun;75(6):263-267.

ABSTRACT

INTRODUCTION: The coronavirus pandemic has posed many challenges for healthcare facilities. One patient population particularly affected was pregnant women who delivered during the 2020 year. Many antenatal and postpartum services normally available were altered during the pandemic, including the number of available lactation consultants. This change in the availability of lactation consultants led to a decrease in face-to-face breastfeeding education and support for postpartum women. This study aimed to identify if the coronavirus pandemic had a negative effect on breastfeeding prevalence in a single tertiary healthcare center.

METHOD: This study was a retrospective chart review with data collected from March 1, 2019-March 1, 2021. The study population was defined as pregnant women age 18 and older who delivered at a single hospital. The prevalence of women who stated they intended to exclusively breastfeed during the pandemic (March 1, 2020-March 1, 2021) was compared to the pre-pandemic year (March 1, 2019-Feb. 29, 2020) as a control. This breastfeeding prevalence was also compared to monthly county-specific coronavirus cases from the South Dakota Department of Health.

RESULTS: The prevalence of women who stated they intended to exclusively breastfeed at the time of delivery during the study population was statistically less when compared to the previous pre-pandemic year.

CONCLUSIONS: The coronavirus pandemic has posed many challenges for healthcare facilities. One patient populationThe exclusive breastfeeding prevalence was negatively affected during the coronavirus pandemic in this single tertiary health center. Knowledge of this demonstrates patient fears regarding breastfeeding during a pandemic and the importance of lactation education and consultation.

PMID:36206567

Ultrasound Obstet Gynecol. 2022 Oct 7. doi: 10.1002/uog.26093. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate national preterm birth (PTB) prevalence (delivery before 37 weeks) rates in relation to local professional guidelines recommending second trimester ultrasound cervical length measurement.

METHODS: The 2012 guidelines specified cervical length be measured transabdominally, or if not visible transvaginally, at the 19-25 weeks ultrasound anomaly scan; < 25 mm would indicate further work-up and treatment, although the type was unspecified. In 2000, the Israel Ministry of Health issued a legal requirement for the submission of delivery records to a national registry. These data were used to compare PTB prevalence before and after the guidelines, as well as trends within each time period. Information was available on multiple pregnancies, maternal age, and parity, as well as low birth-weight. During 2000-2020 there were 3,403,976 live born infants; 1,797,657 before and 1,606,319 after the guidelines.

RESULTS: PTB prevalence was 7.64% [95% CI 7.52-7.77] before the guidelines and 6.84% [6.43-7.24] afterwards (P<0.0002, 2-tail). Annual PTB prevalence was static in the first period, but declined by 0.18% per annum during the second period. The proportional reduction in PTB prevalence between the periods was 9%, 18% and 24% at 33-36, 28-32 and <28 weeks, respectively. Reduced prevalence was observed among singletons (5.49% vs. 4.83%, P<0.0001), but not among infants in twin or grand multiple pregnancies. This reduction was statistically significant in the 19-39 years age group, and in both primiparous and multiparous women. Even though reductions were also noted in high risk groups (<19 years and over 40 years of age), these did not reach statistical significance. There was a similar reduction in the prevalence of birth-weight under 2,500 g.

CONCLUSIONS: National guidelines on routine cervical length screening were associated with a fall in PTB prevalence. Whilst direct evidence linking screening with prevalence is lacking, considering the alternatives, this is the most likely explanation. Screening can be readily incorporated into the second trimester anomaly scan. This article is protected by copyright. All rights reserved.

PMID:36206549 | DOI:10.1002/uog.26093

Blood. 2022 Oct 7:blood.2022017814. doi: 10.1182/blood.2022017814. Online ahead of print.

ABSTRACT

Chronic lymphocytic Leukemia (CLL) and Monoclonal B-Lymphocytosis (MBL) patients have impaired response to COVID-19 vaccination. A total 258 patients (215 CLL and 43 MBL) had anti-spike levels evaluable for statistical analysis. The overall seroconversion rate for CLL was 94.2% (anti-spike ³50AU/mL Abbott Diagnostics) and for MBL 100%. After 3 doses (post-D3) in 167 CLL patients, 73.7% were seropositive, 17.4% had anti-spike levels 50-999AU/mL, and 56.3% ≥1000AU/mL with a median rise from 144.6AU/mL to 1800.7AU/mL. Of patients seronegative post-D2, 39.7% seroconverted post-D3. For those who then remained seronegative after their prior dose, seroconversion occurred in 40.6% post-D4, 46.2% post-D5, 16.7% post-D6, and 0% after D7 or D8. Following seroconversion, most had a progressive increment in anti-spike antibody level: in CLL after the latest dose, 70.2% achieved anti-spike level ≥1,000AU/mL, 48.1% ≥5,000AU/mL, and 30.3% ≥10,000AU/mL. Neutralization was associated with higher anti-spike levels, more vaccines and earlier COVID variants; 65.3% detected neutralizing antibody against early clade D614G, 52.0% against Delta, and 36.5% against Omicron. COVID-specific T-cell production of IFN-γ occurred in 73.9% and IL-2 in 60.9% of 23 tested, and more consistently with higher anti-spike levels. After multiple vaccine doses, by multivariate analysis, IgM ≥0.53g/L (OR=2.90, p=0.0314), IgG3 ≥0.22g/L (OR=3.26, p=0.0057), and lack of current CLL therapy (OR=2.48, p=0.0574) were independent predictors of positive serological responses. Strong neutralization and T-cell responses had high concordance with high anti-spike levels. Multiple sequential COVID-19 vaccination significantly increased seroconversion and anti-spike antibody levels in CLL and MBL.

PMID:36206503 | DOI:10.1182/blood.2022017814

Orthopedics. 2022 Oct 6:1-4. doi: 10.3928/01477447-20221003-03. Online ahead of print.

ABSTRACT

Distal femur fractures above a total knee arthroplasty (TKA) are challenging. These fractures can be fixed with a retrograde intramedullary nail (rIMN), but the design of the femoral component of the TKA influences the starting point for an rIMN. We performed a biomechanical study to evaluate how different TKA components influence the starting point for an rIMN and how that can lead to a deformity in the sagittal plane. We simulated a distal femur fracture with three different arthroplasty components. We used three different implants to simulate fracture reduction and measured the resultant sagittal plane deformity. Low and moderate femoral component ratio (FCR) design components were able to maintain fracture alignment within 5° of anatomic. High FCR component (more posterior starting point) sagittal plane deformities of up to 15° were observed with both the straight and medium Herzog bend nails, which was statistically significant (P<.001). Use of a high Herzog bend nail decreased the deformity by an average of 6°, which was statistically significant (P<.001). There is variability in how the TKA design affects the starting point and thus the sagittal plane alignment after fixation. This study helps quantify the effect of arthroplasty component design on fracture alignment. [Orthopedics. 20XX;XX(X):xx-xx.].

PMID:36206509 | DOI:10.3928/01477447-20221003-03

Exerc Sport Sci Rev. 2022 Oct 10. doi: 10.1249/JES.0000000000000308. Online ahead of print.

ABSTRACT

Researchers in neuromechanics should upgrade their statistical toolbox. We propose linear mixed-effects models in place of commonly used statistical tests to better capture subject-specific baselines and treatment-associated effects that naturally occur in neuromechanics. Researchers can use this approach to handle sporadic missing data, avoid the assumption of conditional independence in observations, and successfully model complex experimental protocols.

PMID:36206407 | DOI:10.1249/JES.0000000000000308

Dermatol Surg. 2022 Oct 6. doi: 10.1097/DSS.0000000000003601. Online ahead of print.

ABSTRACT

BACKGROUND: Extramammary Paget disease (EMPD) is a rare, slow growing neoplasm that presents most commonly in the anogenital region of older adults.

OBJECTIVE: To analyze the difference in local recurrence rates of EMPD in patients treated with wide local excision (WLE) versus Mohs micrographic surgery (MMS).

MATERIALS AND METHODS: A systematic review of the literature and meta-analysis were performed. Inclusion criteria were adults greater than 18 years of age with a diagnosis of EMPD who have undergone surgical intervention and had follow-up data. Studies were independently reviewed by 2 coinvestigators with discrepancies resolved by the principal investigator.

RESULTS: Twenty-seven studies met the inclusion criteria. Patients had a 2.67 times higher chance of local recurrence after WLE than MMS (95% confidence interval [CI]:1.47, 4.85; p = .001). Meta-analysis of single-arm studies revealed a 7.3% local recurrence rate after MMS (95% CI: 0.039, 0.107; p < .001) versus a 26.3% recurrence rate after WLE (95% CI: 0.149, 0.376; p < .001). After excluding recurrent tumors, the odds ratio for recurrence in WLE versus MMS was 2.3 (95% CI: 0.285, 18.43, p = .435).

CONCLUSION: There is a clinically and statistically increased risk of local recurrence of EMPD after WLE compared with MMS.

PMID:36206405 | DOI:10.1097/DSS.0000000000003601

J Pharm Pract. 2022 Oct 7:8971900221131933. doi: 10.1177/08971900221131933. Online ahead of print.

ABSTRACT

Background: Understanding risk factors for nonadherence can help specialty pharmacies optimize resources to prevent nonadherence and inform risk-stratification processes. Objective: To determine which individual and community-level characteristics are associated with nonadherence to specialty medications. Methods: We analyzed a cohort of patients enrolled in a prospective randomized controlled trial having filled a specialty medication at least 4 times in the previous 12 months with a proportion of days (PDC) covered < 0.90. We collected patient age, gender, race, medication administration type, therapy start date, home address, insurance type, and online patient portal status from the electronic health record. An ordinal logistic regression model was used to assess the association of nonadherence with individual and community-level patient characteristics. Results: Most patients were female (68%), white (82%), and held commercial insurance (58%) with a median age of 53 (interquartile range [IQR] 40, 64) years. Patients were mostly from the adult rheumatology (35%), multiple sclerosis (20%) and lipid (17%) clinics. Given a 10-year increase in age, patients had lower odds of having lower PDC (odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.71-0.94, P = 0.005). Patients on therapy greater than or equal to 1 year had half the odds of having lower PDC relative to patients on therapy less than 1 year (OR = 0.52, CI = 0.35 – 0.75, P < 0.001). No statistically significant associations were found between PDC and gender, race, insurance type, route of administration, clinic type, patient portal status, median income, percent receiving government assistance, or percent with no health insurance. Conclusion: Patients with younger age and shorter duration on treatment may be at-risk for lower adherence. Specialty pharmacies may benefit from targeting adherence interventions to these groups.

PMID:36206399 | DOI:10.1177/08971900221131933

Hum Brain Mapp. 2022 Oct 7. doi: 10.1002/hbm.26105. Online ahead of print.

ABSTRACT

Understanding the impact of variation in lesion topography on the expression of functional impairments following stroke is important, as it may pave the way to modeling structure-function relations in statistical terms while pointing to constraints for adaptive remapping and functional recovery. Multi-perturbation Shapley-value analysis (MSA) is a relatively novel game-theoretical approach for multivariate lesion-symptom mapping. In this methodological paper, we provide a comprehensive explanation of MSA. We use synthetic data to assess the method’s accuracy and perform parameter optimization. We then demonstrate its application using a cohort of 107 first-event subacute stroke patients, assessed for upper limb (UL) motor impairment (Fugl-Meyer Assessment scale). Under the conditions tested, MSA could correctly detect simulated ground-truth lesion-symptom relationships with a sensitivity of 75% and specificity of ~90%. For real behavioral data, MSA disclosed a strong hemispheric effect in the relative contribution of specific regions-of-interest (ROIs): poststroke UL motor function was mostly contributed by damage to ROIs associated with movement planning (supplementary motor cortex and superior frontal gyrus) following left-hemispheric damage (LHD) and by ROIs associated with movement execution (primary motor and somatosensory cortices and the ventral brainstem) following right-hemispheric damage (RHD). Residual UL motor ability following LHD was found to depend on a wider array of brain structures compared to the residual motor ability of RHD patients. The results demonstrate that MSA can provide a unique insight into the relative importance of different hubs in neural networks, which is difficult to obtain using standard univariate methods.

PMID:36206326 | DOI:10.1002/hbm.26105

Hum Brain Mapp. 2022 Oct 7. doi: 10.1002/hbm.26098. Online ahead of print.

ABSTRACT

Although a large number of case-control statistical and machine learning studies have been conducted to investigate structural brain changes in schizophrenia, how best to measure and characterize structural abnormalities for use in classification algorithms remains an open question. In the current study, a convolutional 3D autoencoder specifically designed for discretized volumes was constructed and trained with segmented brains from 477 healthy individuals. A cohort containing 158 first-episode schizophrenia patients and 166 matched controls was fed into the trained autoencoder to generate auto-encoded morphological patterns. A classifier discriminating schizophrenia patients from healthy controls was built using 80% of the samples in this cohort by automated machine learning and validated on the remaining 20% of the samples, and this classifier was further validated on another independent cohort containing 77 first-episode schizophrenia patients and 58 matched controls acquired at a different resolution. This specially designed autoencoder allowed a satisfactory recovery of the input. With the same feature dimension, the classifier trained with autoencoded features outperformed the classifier trained with conventional morphological features by about 10% points, achieving 73.44% accuracy and 0.8 AUC on the internal validation set and 71.85% accuracy and 0.77 AUC on the external validation set. The use of features automatically learned from the segmented brain can better identify schizophrenia patients from healthy controls, but there is still a need for further improvements to establish a clinical diagnostic marker. However, with a limited sample size, the method proposed in the current study shed insight into the application of deep learning in psychiatric disorders.

PMID:36206321 | DOI:10.1002/hbm.26098