Tag: statistics

Health Informatics J. 2021 Oct-Dec;27(4):14604582211052259. doi: 10.1177/14604582211052259.

ABSTRACT

Online symptom checkers (SCs) are eHealth solutions that offer healthcare organizations the possibility to empower their patients to independently assess their symptoms. The successful implementation of eHealth solutions, such as SCs, requires a supportive organizational culture and leadership. However, there is limited knowledge about the factors associated with leaders’ support for the use of SCs. The aim of the study was to identify the factors associated to primary care leaders’ support for SCs in triage and their experiences of the benefits and challenges related to the use of SCs. An online survey was used to collect data from 84 Finnish primary care leaders. The data were analyzed using statistical analysis methods and content analysis. Vision clarity, perceiving efficiency improvements, and considering the service to be beneficial for patients were associated with leaders’ support for the service (β ranging from 0.41 to 0.44, p < 0.001). Leaders’ support for the service was also associated with how well the leaders provided information about the service to their subordinates (β =0.22, p < 0.048). SCs present slightly more challenges than benefits regarding health professionals’ work. The developers of SCs should focus more on features that decrease health professionals’ workload as well as how the solution can benefit patients.

PMID:34821152 | DOI:10.1177/14604582211052259

Radiol Oncol. 2021 Nov 19;55(4):426-432. doi: 10.2478/raon-2021-0043.

ABSTRACT

BACKGROUND: The aim of the study was to evaluate the diagnostic accuracy of p16/Ki-67 dual immunostaining (p16/ Ki-67 DS) in cervical cytology and the number of positive p16/Ki-67 cells to diagnose high grade cervical intraepithelial neoplasia (CIN2+) in colposcopy population.

SUBJECTS AND METHODS: We performed an analysis on a subset cohort of 174 women enrolled within a large-scale randomised controlled human papillomavirus (HPV) self-sampling project organised as part of the population-based Cervical Cancer Screening Programme ZORA in Slovenia. This subset cohort of patients was invited to the colposcopy clinic, underwent p16/Ki-67 DS cervical cytology and had the number of p16/Ki-67 positive cells determined.

RESULTS: Among analysed women, 42/174 (24.1%) had histologically confirmed CIN2+. The risk for CIN2+ was increasing with the number of positive cells (p < 0.001). The sensitivity of p16/Ki-67 DS for detection of CIN2+ was 88.1%, specificity was 65.2%, positive predictive value was 44.6% and negative predictive value was 94.5%.

CONCLUSIONS: Dual p16/Ki-67 immunostaining for the detection of CIN2+ has shown high sensitivity and high negative predictive value in our study, which is comparable to available published data. The number of p16/Ki-67 positive cells was significantly associated with the probability of CIN2+ detection. We observed a statistically significant and clinically relevant increase in specificity if the cut-off for a positive test was shifted from one cell to three cells.

PMID:34821133 | DOI:10.2478/raon-2021-0043

J Clin Periodontol. 2021 Nov 24. doi: 10.1111/jcpe.13576. Online ahead of print.

ABSTRACT

AIM: This study aimed to investigate effects of a six-week Mediterranean diet (MD) intervention on gingival inflammatory and anthropometric parameters of patients with gingivitis.

MATERIALS AND METHODS: Forty-two participants were allocated to MD group (MDG) or control group (CG). After a two weeks equilibration period regarding dental care procedures, only MDG changed their diet to MD for six weeks, supported by a diet counseling. Gingival and anthropometric parameters were assessed at baseline (T0), Week 2 (T1, beginning of MD intervention), and Week 8 (T2). Adherence to MD was assessed by the Mediterranean Diet Adherence Screener (MEDAS), dietary behavior was evaluated by the German Health Interview and Examination Survey for Adults Food Frequency Questionnaire (DEGS-FFQ).

RESULTS: Plaque values remained constant in both groups. Inflammatory periodontal and anthropometric parameters decreased in the MDG only (gingival index: T1 1.51±0.21, T2 1.49±0.24; bleeding on probing: T1 51.00±14.65, T2 39.93±13.74; body weight: T1 79.01±15.62, T2 77.29±17.00; waist circumference: T1 84.41±10.1, T2 83.17±10.47 (p < 0.05). MEDAS revealed a sufficient diet adherence for MDG.

CONCLUSION: Within this study, gingival inflammatory parameters were significantly reduced by MD, whereas plaque parameters remained constant. The diet counseling achieved sufficient adherence with beneficial changes in weight loss and waist circumference.

PMID:34818686 | DOI:10.1111/jcpe.13576

Gynecol Obstet Invest. 2021 Nov 24. doi: 10.1159/000520979. Online ahead of print.

ABSTRACT

OBJECTIVE: This study aims to evaluate the risk factors for subjective recurrence and complications of patients who underwent transvaginal synthetic mesh surgery. Design：This retrospective cohort study included patients who received transvaginal mesh (TVM) surgery between January 2005 and June 2019.

METHODS: The information of patients was collected, including basic characteristics, subjective recurrence, and mesh-related complications. The clinical characteristics of patients with and without subjective recurrence were compared. The sexual activities of patients before and after the operation were recorded. SPSS 20.0 was used for the statistical analysis.

RESULTS: A total of 257 patients were included. Among them, 62 (24.1%) patients were lost to follow-up. The median follow-up time was 80 months (12 months, 170 months). Finally, 195 patients were followed up, 11 (5.6%) patients had a subjective recurrence of pelvic organ prolapse, and 26 (13.3%) patients had mesh-related complications (11 patients with de novo pain and 15 patients with mesh exposure). We found significant differences in age (68.9±5.1 vs. 63.4±5.8 years old), years of post-menopause (17.5±6.3 vs. 13.3±6.9 years), previous hysterectomy (27.3% vs. 6.0%), and concomitant hysterectomy (45.5% vs. 81.0%) between patients with and without subjective recurrence (P<0.05). The mesh exposure proportion of patients with total vaginal mesh (47.6%) was significantly higher than that with anterior vaginal mesh (2.9%) (P<0.05). Furthermore, 6.7% of sexually active patients reported do novo dyspareunia.

LIMITATION: The investigators could only record the subjective recurrence of patients, thus there is a lack of objective recurrence data.

CONCLUSION: Age, years of post-menopause and previous hysterectomy are risk factors for subjective recurrence of transvaginal mesh surgery; however，concomitant hysterectomy is a protective factor. Mesh exposure is the most common complication, especially for total vaginal mesh repair surgery.

PMID:34818651 | DOI:10.1159/000520979

Eur Surg Res. 2021 Nov 24:1-13. doi: 10.1159/000519718. Online ahead of print.

ABSTRACT

Backgroud/Objectives: Transoral laser laryngeal microsurgery (LTLM) has been widely used in the treatment of early-stage glottic laryngeal squamous cell carcinoma (LSCC) for the past few decades. Although T stage, tumor grade, anterior commissure involvement, type of cordectomy, positive surgical margin, and postoperative additional therapies were accused as the prognostic factors for recurrence, there is still controversy about these data in the literature. The purpose of this study was to evaluate the oncological results of our patients with early glottic LSCC treated with LTLM as a single-modality therapy in a single-center study.

METHODS: Patients with early-stage (Tis-1-2/N0) glottic LSCC who underwent LTLM as a primary treatment from 2011 to 2019 were retrospectively reviewed. The clinicopathological factors and oncologic outcomes were analyzed.

RESULTS: One hundred and sixty-one patients were enrolled in this study. The 5-year overall (OS), disease-specific (DSS), disease-free (DFS), and laryngectomy-free survival rates were 84.5%, 97.9%, 79.2%, and 93.5%, respectively. The most common stage, histopathological type, and type of endoscopic cordectomy were T1 stage, well-differentiated cancer, and type 2 cordectomy, respectively. A positive surgical margin was defined in 20 (12.4%) patients. There was a significant relationship between histopathological grade and positive surgical margins (p = 0.038). OS and DSS rates of “wait and see” modality were lower, while DFS of radiotherapy was lower than that of other treatment modalities in patients with positive surgical margins, but the differences were not statistically significant. Nineteen (11.8%) patients had a recurrence. DSS was statistically significantly lower in patients with recurrence (p < 0.001).

CONCLUSION: The results of our study showed that anterior commissure involvement, surgical margin positivity, and higher T stage statistically did not reduce survival rates in early-stage LSCC patients treated with LTLM. As the histopathological grade of the tumor worsens, the risk of surgical margin positivity increases. RT may have a negative effect on recurrence and organ preservation in the additional treatment of patient with positive surgical margins.

PMID:34818662 | DOI:10.1159/000519718

Phys Med Biol. 2021 Nov 24. doi: 10.1088/1361-6560/ac3d15. Online ahead of print.

ABSTRACT

Recent medical image segmentation methods heavily rely on large-scale training data and high-quality annotations. However, these resources are hard to obtain due to the limitation of medical images and professional annotators. How to utilize limited annotations and maintain the performance is an essential yet challenging problem. In this paper, we try to tackle this problem in a self-learning manner by proposing a Generative Adversarial Semi-supervised Network (GASNet). We use limited annotated images as main supervision signals, and the unlabeled images are manipulated as extra auxiliary information to improve the performance. More specifically, we modulate a segmentation network as a generator to produce pseudo labels for unlabeled images. To make the generator robust, we train an uncertainty discriminator with generative adversarial learning to determine the reliability of the pseudo labels. To further ensure dependability, we apply feature mapping loss to obtain statistic distribution consistency between the generated labels and the real labels. Then the verified pseudo labels are used to optimize the generator in a self-learning manner. We validate the effectiveness of the proposed method on right ventricle dataset, Sunnybrook dataset, STACOM, ISIC dataset, and Kaggle lung dataset. We obtain 0.8402 to 0.9121, 0.8103 to 0.9094, 0.9435 to 0.9724, 0.8635 to 0.886, and 0.9697 to 0.9885 dice coefficient with 1/8 to 1/2 proportion of densely annotated labels, respectively. The improvements are up to 28.6 points higher than the corresponding fully supervised baseline.

PMID:34818627 | DOI:10.1088/1361-6560/ac3d15

J Phys Condens Matter. 2021 Nov 24. doi: 10.1088/1361-648X/ac3cef. Online ahead of print.

ABSTRACT

We report a experimental study of the motion of 1μm single particles interacting with functionalized walls at low and moderate ionic strengths conditions. The 3D particle’s trajectories were obtained by analyzing the diffracted particle images (point spread function). The studied particle/wall systems include negatively charged particles interacting with bare glass, glass covered with polyelectrolytes and glass covered with a lipid monolayer. In the low salt regime (pure water) we observed a retardation effect of the short-time diffusion coefficients when the particle interacts with a negatively charged wall; this effect is more severe in the perpendicular than in the lateral component. The decrease of the diffusion as a function of the particle-wall distance h was similar regardless the origin of the negative charge at the wall. When surface charge was screened or salt was added to the medium (10mM), the diffusivity curves recover the classical hydrodynamic behavior. Electroviscous theory based on the thin electrical double layer (EDL) approximation reproduces the experimental data except for small h. On the other hand, 2D numerical solutions of the electrokinetic equations showed good qualitative agreement with experiments. The numerical model also showed that the hydrodynamic and Maxwellian part of the electroviscous total drag tend to zero as h → 0 and how this is linked with the merging of both EDL’s at close proximity.

PMID:34818642 | DOI:10.1088/1361-648X/ac3cef

Comput Biol Med. 2021 Sep 30;139:104909. doi: 10.1016/j.compbiomed.2021.104909. Online ahead of print.

ABSTRACT

A phenomenon called alternans, which is a beat-to-beat alternation in action potential (AP) duration, sometimes precedes fatal cardiac arrhythmias. Alternans-suppressing electrical stimulus protocols are often represented as perturbations to the dynamics of membrane potential or AP duration variables in nonlinear models of cardiac tissue. Controllability analysis has occasionally been applied to cardiac AP models to determine whether different control or perturbation strategies are capable of suppressing alternans or other unwanted behavior. Since almost all previous cardiac controllability studies have focused on low-dimensional models, we conducted the present study to assess controllability of a higher-dimensional model, specifically the Luo Rudy dynamic (LRd) model of a cardiac ventricular myocyte. Higher-dimensional models are of interest because they provide information on the influence of a wider range of measurable quantities, including ionic concentrations, on controllability. After computing modal controllability measures, we found that larger eigenvalues of a linearized LRd model were on average more strongly controllable through perturbations to calcium-ion concentrations compared with perturbations to other variables. When only membrane potential was adjusted, the best time to apply perturbations (in the sense of maximizing controllability of the largest alternans eigenvalue) was near the AP peak time for shorter cycle lengths. Controllability results were found to be similar for both the default model parameters and for an alternans-promoting parameter set. Additionally, we developed several alternans-suppressing state feedback controllers that were tested in simulations. For the scenarios examined, our controllability measures correctly predicted which strategies and perturbation timings would lead to better feedback controller performance.

PMID:34818582 | DOI:10.1016/j.compbiomed.2021.104909

Med Image Anal. 2021 Nov 11;75:102304. doi: 10.1016/j.media.2021.102304. Online ahead of print.

ABSTRACT

Disease heterogeneity is a significant obstacle to understanding pathological processes and delivering precision diagnostics and treatment. Clustering methods have gained popularity for stratifying patients into subpopulations (i.e., subtypes) of brain diseases using imaging data. However, unsupervised clustering approaches are often confounded by anatomical and functional variations not related to a disease or pathology of interest. Semi-supervised clustering techniques have been proposed to overcome this and, therefore, capture disease-specific patterns more effectively. An additional limitation of both unsupervised and semi-supervised conventional machine learning methods is that they typically model, learn and infer from data using a basis of feature sets pre-defined at a fixed anatomical or functional scale (e.g., atlas-based regions of interest). Herein we propose a novel method, “Multi-scAle heteroGeneity analysIs and Clustering” (MAGIC), to depict the multi-scale presentation of disease heterogeneity, which builds on a previously proposed semi-supervised clustering method, HYDRA. It derives multi-scale and clinically interpretable feature representations and exploits a double-cyclic optimization procedure to effectively drive identification of inter-scale-consistent disease subtypes. More importantly, to understand the conditions under which the clustering model can estimate true heterogeneity related to diseases, we conducted extensive and systematic semi-simulated experiments to evaluate the proposed method on a sizeable healthy control sample from the UK Biobank (N = 4403). We then applied MAGIC to imaging data from Alzheimer’s disease (ADNI, N = 1728) and schizophrenia (PHENOM, N = 1166) patients to demonstrate its potential and challenges in dissecting the neuroanatomical heterogeneity of common brain diseases. Taken together, we aim to provide guidance regarding when such analyses can succeed or should be taken with caution. The code of the proposed method is publicly available at https://github.com/anbai106/MAGIC.

PMID:34818611 | DOI:10.1016/j.media.2021.102304

J Speech Lang Hear Res. 2021 Nov 24:1-23. doi: 10.1044/2021_JSLHR-20-00205. Online ahead of print.

ABSTRACT

PURPOSE: Meaningful changes in picture naming responses may be obscured when measuring accuracy instead of quality. A statistic that incorporates information about the severity and nature of impairments may be more sensitive to the effects of treatment.

METHOD: We analyzed data from repeated administrations of a naming test to 72 participants with stroke aphasia in a clinical trial for anomia therapy. Participants were divided into two groups for analysis to demonstrate replicability. We assessed reliability among response type scores from five raters. We then derived four summary statistics of naming ability and their changes over time for each participant: (a) the standard accuracy measure, (b) an accuracy measure adjusted for item difficulty, (c) an accuracy measure adjusted for item difficulty for specific response types, and (d) a distance measure adjusted for item difficulty for specific response types. While accuracy measures address the likelihood of a correct response, the distance measure reflects that different response types range in their similarity to the target. Model fit was assessed. The frequency of significant improvements and the average magnitude of improvements for each summary statistic were compared between treatment groups and a control group. Effect sizes for each model-based statistic were compared with the effect size for the standard accuracy measure.

RESULTS: Interrater and intrarater reliability were near perfect, on average, though compromised somewhat by phonological-level errors. The effects of treatment were more evident, in terms of both frequency and magnitude, when using the distance measure versus the other accuracy statistics.

CONCLUSIONS: Consideration of item difficulty and response types revealed additional effects of treatment on naming scores beyond those observed for the standard accuracy measure. The results support theories that assume naming ability is decomposable into subabilities rather than being monolithic, suggesting new opportunities for measuring treatment outcomes. Supplemental Material https://doi.org/10.23641/asha.17019515.

PMID:34818508 | DOI:10.1044/2021_JSLHR-20-00205