Tag: statistics

Biom J. 2023 May 9:e2200183. doi: 10.1002/bimj.202200183. Online ahead of print.

ABSTRACT

Classical power analysis for sample size determination is typically performed in clinical trials. A “hybrid” classical Bayesian or a “fully Bayesian” approach can be alternatively used in order to add flexibility to the design assumptions needed at the planning stage of the study and to explicitly incorporate prior information in the procedure. In this paper, we exploit and compare these approaches to obtain the optimal sample size of a single-arm trial based on Poisson data. We adopt exact methods to establish the rejection of the null hypothesis within a frequentist or a Bayesian perspective and suggest the use of a conservative criterion for sample size determination that accounts for the not strictly monotonic behavior of the power function in the presence of discrete data. A Shiny web app in R has been developed to provide a user-friendly interface to easily compute the optimal sample size according to the proposed criteria and to assure the reproducibility of the results.

PMID:37160700 | DOI:10.1002/bimj.202200183

Biom J. 2023 May 9:e2100373. doi: 10.1002/bimj.202100373. Online ahead of print.

ABSTRACT

Feature screening is a useful and popular tool to detect informative predictors for ultrahigh-dimensional data before developing statistical analysis or constructing statistical models. While a large body of feature screening procedures has been developed, most methods are restricted to examine either continuous or discrete responses. Moreover, even though many model-free feature screening methods have been proposed, additional assumptions are imposed in those methods to ensure their theoretical results. To address those difficulties and provide simple implementation, in this paper we extend the rank-based coefficient of correlation to develop a feature screening procedure. We show that this new screening criterion is able to deal with continuous and binary responses. Theoretically, the sure screening property is established to justify the proposed method. Simulation studies demonstrate that the predictors with nonlinear and oscillatory trajectories are successfully retained regardless of the distribution of the response. Finally, the proposed method is implemented to analyze two microarray datasets.

PMID:37160692 | DOI:10.1002/bimj.202100373

Can J Neurol Sci. 2023 Jun;50(s1):s17-s25. doi: 10.1017/cjn.2023.18. Epub 2023 May 10.

ABSTRACT

Geographic, social, political, and economic factors shape access to advanced neurotechnologies, yet little previous research has explored the barriers, enablers, and areas of opportunity for equitable and meaningful access for diverse patient communities across Canada. We applied a mixed-mode approach involving semi-structured interviews and rating scale questions to consult with 24 medical experts who are involved in the care of patients who undergo functional neurosurgery targeting the brain. Seven major themes emerged from the qualitative analysis: Health care system, Neurotechnology features, Patient demographics, Target condition features, Ethics, Upstream barriers and enablers, and Areas of opportunity. Descriptive statistics of the Likert-scale responses suggest that interviewees perceive a disparity between the imperative of access to advanced neurotechnologies for people living in rural and remote areas and the likelihood of achieving such access. The results depict a complex picture of access to functional neurosurgery in Canada with pockets of excellence and a motivation to improve the availability of care for vulnerable populations through the expansion of distributed care models, improved health care system efficiencies, increasing funding and support for patient travel, and increasing awareness about and advocacy for advanced neurotechnologies.

PMID:37160675 | DOI:10.1017/cjn.2023.18

J Dent Educ. 2023 May 9. doi: 10.1002/jdd.13233. Online ahead of print.

ABSTRACT

OBJECTIVES: The aim of this study was to develop and evaluate the effect of a manual dexterity training program on manual dexterity, perception of self-confidence, quality of cavity preparations, and ergonomic work posture of dental students prior to preclinical training.

METHODS: Students in the first year of the undergraduate dentistry program (N = 63) participated in this study. The program consisted of eight phases in which students performed different types of activities. The dependent variables were: manual dexterity assessed by the modified Dental Manual Dexterity Assessment; self-confidence to perform a preclinical procedure using the VAS scale; quality of Class I cavity preparation; angular deviation from the neutral position of the neck, trunk, wrist and distance between the student’s eyes and the mannequin’s tooth. These variables were evaluated at two different times: before and after the application of the program. The independent variable was the preclinical manual dexterity training program. After meeting the assumption of normality, the paired t-Student test was performed, the significance level was 5%.

RESULTS: The results showed a statistically significant difference in relation to manual dexterity (p < 0.001), self-confidence (p < 0.001), quality of cavity preparations (p < 0.001), distance from the eyes of the student/mannequin (p < 0.001), deviation angle of the neutral position of the trunk (p = 0.007) and wrists (p < 0.001), with better results in posttraining.

CONCLUSION: It was possible to conclude that, in general, the proposed training positively influenced the self-confidence, dexterity, quality of work, and ergonomics of the evaluated students.

PMID:37160672 | DOI:10.1002/jdd.13233

Int Orthop. 2023 May 9. doi: 10.1007/s00264-023-05835-5. Online ahead of print.

ABSTRACT

PURPOSE: The modified anterolateral approach (Röttinger) for total hip arthroplasty (THA) offers great advantages over conventional approaches, especially concerning early postoperative symptoms, which are mild and well tolerated by patients. Robotic-assisted implantation might facilitate rapid adoption of the modified anterolateral approach without exposing surgeons to risks encountered during the learning curve. This study posits that the use of robotic assistance in conjunction with the modified anterolateral approach for total hip arthroplasty (THA) can provide a substantial enhancement in the accuracy of cup placement in comparison to manual surgery.

METHODS: Thirty-two robotic-assisted THAs met the inclusion criteria and were matched to 32 conventional cases. Acetabular cup inclination, anteversion, limb-length discrepancy, and acetabular offset were assessed using certified planning software by two independent observers using pre- and postoperative anterior-posterior radiographs. Data was analyzed for normal distribution. Chi² test was used to determine whether implanted acetabular cups that were within Lewinnek’s safe zones were influenced by type of implantation. Effect size estimates and statistical power analysis were also performed to appreciate the appropriateness of the chosen sample size.

RESULTS: Robotic-assisted implantation was found to significantly improve acetabular cup placement in terms of inclination (p < 0.001) but not anteversion (p = 0.783). Although mean postoperative limb-length discrepancy and mean acetabular offset did not differ between groups, a significantly smaller variance was found in the robotic-assisted group (p < 0.001) and (p = 0.04), respectively. There were no significant differences between the two groups in terms of consistently implanting the acetabular cup within the Lewinnek safe zones p = 0.641 for anteversion and p = 0.230 for inclination, respectively.

CONCLUSIONS: Our results show that although robotic-assisted acetabular cup implantation performed through the modified anterolateral approach did not significantly differ from conventional implantation, it did offer increased accuracy in cup positioning, acetabular bone preservation, and limb-length restoration.

PMID:37160646 | DOI:10.1007/s00264-023-05835-5

Trop Anim Health Prod. 2023 May 9;55(3):197. doi: 10.1007/s11250-023-03609-0.

ABSTRACT

This pilot study used an alternative and economically efficient technique, the Kompetitive Allele-Specific Polymerase Chain Reaction (KASP-PCR) to examine 48 SNPs from 11 parasite-resistance genes found on 8 chromosomes in 110 animals from five sheep breeds reared in Hungary; Hungarian Tsigai, White Dorper, Dorper, Ile de France, and Hungarian Merino. Allele and genotype frequencies, fixation index, observed heterozygosity, expected heterozygosity, F statistic, and their relationship with the Hardy-Weinberg equilibrium (WHE) and the polymorphic information content (PIC) were determined, followed by principal component analysis (PCA). As much as 32 SNPs out of the 48 initially studied were successfully genotyped. A total of 9 SNPs, 4 SNPs in TLR5, 1 SNP in TLR8, and 4 SNPs in TLR2 genes, were polymorphic. The variable genotype and allele frequency of the TLRs gene indicated genetic variability among the studied sheep breeds, with the Hungarian Merino exhibiting the most polymorphisms, while Dorper was the population with the most SNPs departing from the HWE. According to the PIC value, the rs430457884-TLR2, rs55631273-TLR2, and rs416833129-TLR5 were found to be informative in detecting polymorphisms among individuals within the populations, whereas the rs429546187-TLR5 and rs424975389-TLR5 were found to have a significant influence in clustering the population studied. This study reported a moderate level of genetic variability and that a low to moderate within-breed diversity was maintained in the studied populations.

PMID:37160635 | DOI:10.1007/s11250-023-03609-0

Tech Coloproctol. 2023 Jun;27(6):481-490. doi: 10.1007/s10151-023-02800-7. Epub 2023 Apr 25.

ABSTRACT

PURPOSE: To evaluate the potential benefits associated with the short-term (6 months) treatment with transanal irrigation (TAI) in patients suffering from functional constipation (FC), functional fecal incontinence (FI), and low anterior resection syndrome (LARS).

METHODS: A multicenter observational study (12 centers; 369 patients) was conducted to assess the following primary and secondary objectives: to evaluate the level of satisfaction regarding bowel control and quality of life (QoL); to evaluate bowel symptoms severity and dropout frequency and reason. To this aim, validated questionnaires were provided to the patients at baseline (T0) and after 6 months of TAI treatment (T6) performed with the medical device Peristeen^® Plus (Coloplast A/S, Denmark). Statistical analyses were conducted to compare the outcomes obtained at T0 and T6.

RESULTS: A 6-month treatment with TAI enabled a statistically significant (p < 0.05) improvement of QoL scores, satisfaction scores regarding bowel control, and severity indexes of disorder-related symptoms in patients suffering from FC, FI, and LARS. Globally, 8.0% of patients discontinued the treatment after 6 months as a result of occurrence of symptoms (2.4%) or other justifications (3.8%) such as personal reasons. None of the dropouts were due to treatment inefficacy.

CONCLUSION: Results of the present study suggest that short-term TAI treatment is beneficial for patients suffering from functional bowel disorders and LARS. Future analysis of prospective data will focus on the clinical outcomes associated with the long-term use (up to 24 months) of TAI when dealing with these types of medical conditions.

PMID:37160596 | DOI:10.1007/s10151-023-02800-7

Jpn J Radiol. 2023 May 9. doi: 10.1007/s11604-023-01419-w. Online ahead of print.

ABSTRACT

PURPOSE: The white matter hyperintensity penumbra (WMH-P) is the subtly changed normal-appearing white matter (NAWM) that surrounds white matter hyperintensities (WMHs). The goal of this study was to define WMH-P in cerebral small vessel disease (CSVD) by arterial spin labeling (ASL) and diffusion tensor imaging (DTI)/diffusion kurtosis imaging (DKI).

MATERIALS AND METHODS: We prospectively analyzed 42 patients with CSVD. To determine the range of cerebral blood flow (CBF) and DTI/DKI penumbras around white matter hyperintensities, we generated NAWM layer masks from periventricular WMHs (PVWMHs) and deep WMHs (DWMHs). Mean values of CBF, fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity, mean kurtosis, axial kurtosis, and radial kurtosis within the WMHs and their corresponding NAWM layer masks were analyzed. Paired sample t tests were used for analysis, and differences were considered statistically significant if the associated p value was ≤ 0.05.

RESULTS: For DWMHs, the CBF penumbras were 13 mm, and the DTI/DKI penumbras were 8 mm. For PVWMHs, the CBF penumbras were 14 mm, and the DTI/DKI penumbras were 14 mm.

CONCLUSIONS: Our findings revealed that DTI/DKI and ASL can show structural and blood flow changes in brain tissue surrounding WMHs. In DWMHs, the blood flow penumbra was larger than the structural penumbra, while in PVWMHs, the blood flow penumbra was almost the same as the structural penumbra.

PMID:37160589 | DOI:10.1007/s11604-023-01419-w

Int Ophthalmol. 2023 May 9. doi: 10.1007/s10792-023-02730-1. Online ahead of print.

ABSTRACT

PURPOSE: To evaluate the operative duration and clinical performance of ophthalmology residents performing standard phacoemulsification cataract surgeries using information available from electronic health records (EHR).

METHODS: This is a retrospective cohort study. De-identified surgical records of all standard phacoemulsifications performed in a tertiary institution between 1st January 2015 and 8th August 2018 were retrieved from the hospital EHR. The main outcome measures were improvement in operative duration with case experience, corrected distance visual acuity (CDVA) improvement, and intra-operative complication rates.

RESULTS: Twelve ophthalmology residents performed a total of 1427 standard phacoemulsifications. The median operative duration was 27 min (interquartile range, 22-34 min), which improved from 31 to 24 min (before the 101st case [Group 1] versus 101st case onwards [Group 2], p < 0.001). Gradient change analysis (non-linear regression) showed significant reduction until the 100th case (p = 0.043). Older patients (0.019), worse pre-operative CDVA (0.343), and surgery performed by Group 1 (1.115) were significantly associated with operative duration above 30 min. LogMAR CDVA improved from a mean of 0.57 ± 0.52 pre-operatively to 0.10 ± 0.18 post-operatively (p < 0.001). Posterior capsule rupture (PCR) rate decreased from 4.0% [Group 1] to 2.1% [Group 2] (p = 0.096), while overall complication rate decreased from 8.9% to 3.1% (p < 0.001).

CONCLUSION: The median operative duration reduced consistently with surgical experience for the first 100 cases. Older patients, poorer pre-operative VA, and surgical experience of less than 100 cases were significantly associated with an operative duration above 30 min. There was a statistically significant decrease in complication rate between Group 1 and 2.

PMID:37160586 | DOI:10.1007/s10792-023-02730-1

Eur J Clin Microbiol Infect Dis. 2023 May 9. doi: 10.1007/s10096-023-04615-8. Online ahead of print.

ABSTRACT

Acute respiratory infections (ARIs) are caused by a variety of microorganisms. Of all ARIs, 80% are caused by viruses such as human respiratory syncytial virus, metapneumovirus, influenza, parainfluenza, rhinovirus, and, more recently, Sars-CoV-2, which has been responsible for the COVID-19 pandemic. The objective of our study was to evaluate clinical data from a viral panel performed in children hospitalized with SARS or COVID-19 in the infirmary or ICU of 5 pediatric hospitals in the city of Goiânia, Goiás, Brazil. Demographic, clinical, and laboratory data were collected for analysis, and data on the outcomes underwent statistical treatment. A total of 128 patients were selected for the study, 54% of whom were male and 46% female. The viral panel included rhinovirus, COVID-19, metapneumovirus, adenovirus, and parainfluenza. Descriptive analyses of age profile showed differences in the involvement of particular viruses. The percentage of patients who required hospitalization in the ICU, infirmary, as well as individuals who were discharged after therapy or who died, were described. Our work shows that epidemiological surveillance measures are indispensable, especially if used in the continued analysis of viral panels in all pediatric patients with SARS.

PMID:37160574 | DOI:10.1007/s10096-023-04615-8