Category: Statistics

Cornea. 2021 Oct 1;40(10):1322-1329. doi: 10.1097/ICO.0000000000002632.

ABSTRACT

PURPOSE: To evaluate the ABCD grading system in pediatric keratoconus.

METHODS: A retrospective cohort analysis of all children with keratoconus followed up at the Shamir medical center between 2010 and 2017. A recommendation by the treating physician to undergo corneal crosslinking (CXL) was used as an estimate for clinically significant disease progression. The ABCD grading was not available to the treating physician and was computed post hoc. The ABCD grading was compared between patients who required CXL with those who did not. A single eye of each patient was included.

RESULTS: Fifty eyes of 50 children were analyzed. The mean age at presentation was 15.56 ± 1.36 years. In 23 eyes, progression of keratoconus was recorded and CXL was performed (CXL-group). On presentation, the stable and CXL groups did not differ significantly in their clinical parameters. In the CXL-group, a statistically significant increase was seen in the ABCD staging (P < 0.001). In the stable group, the ABCD staging did not change significantly in parallel visits (P = 0.87). An increase of 1 point in the sum of the ABCD staging showed a 5-fold risk for undergoing CXL (odds ratio = 5.28; 95% CI, 1.82-15.34). There was no significant change in the Amsler-Krumeich classification in the CXL group.

CONCLUSIONS: Among a cohort of pediatric patients with keratoconus, worsening in the ABCD grading was associated with disease progression, whereas no significant change was demonstrated in the Amsler-Krumeich classification The ABCD grading system is a useful tool for initial assessment of disease progression in the pediatric population, in which early recognition is of paramount importance.

PMID:34481408 | DOI:10.1097/ICO.0000000000002632

Neuroimage. 2021 Sep 1;243:118517. doi: 10.1016/j.neuroimage.2021.118517. Online ahead of print.

ABSTRACT

Magnetic resonance current density imaging (MRCDI) of the human brain aims to reconstruct the current density distribution caused by transcranial electric stimulation from MR-based measurements of the current-induced magnetic fields. So far, the MRCDI data acquisition achieves only a low signal-to-noise ratio, does not provide a full volume coverage and lacks data from the scalp and skull regions. In addition, it is only sensitive to the component of the current-induced magnetic field parallel to the scanner field. The reconstruction problem thus involves coping with noisy and incomplete data, which makes it mathematically challenging. Most existing reconstruction methods have been validated using simulation studies and measurements in phantoms with simplified geometries. Only one reconstruction method, the projected current density algorithm, has been applied to human in-vivo data so far, however resulting in blurred current density estimates even when applied to noise-free simulated data. We analyze the underlying causes for the limited performance of the projected current density algorithm when applied to human brain data. In addition, we compare it with an approach that relies on the optimization of the conductivities of a small number of tissue compartments of anatomically detailed head models reconstructed from structural MR data. Both for simulated ground truth data and human in-vivo MRCDI data, our results indicate that the estimation of current densities benefits more from using a personalized volume conductor model than from applying the projected current density algorithm. In particular, we introduce a hierarchical statistical testing approach as a principled way to test and compare the quality of reconstructed current density images that accounts for the limited signal-to-noise ratio of the human in-vivo MRCDI data and the fact that the ground truth of the current density is unknown for measured data. Our results indicate that the statistical testing approach constitutes a valuable framework for the further development of accurate volume conductor models of the head. Our findings also highlight the importance of tailoring the reconstruction approaches to the quality and specific properties of the available data.

PMID:34481368 | DOI:10.1016/j.neuroimage.2021.118517

Schizophr Res. 2021 Sep 1;236:104-114. doi: 10.1016/j.schres.2021.08.011. Online ahead of print.

ABSTRACT

BACKGROUND: Brain magnetic resonance imaging studies have not investigated the cortical surface comprehensively in schizophrenia subjects by assessing thickness, surface area and gyrification separately during the first-episode of psychosis (FEP) or chronic schizophrenia (ChSch).

METHODS: We investigated cortical surface abnormalities in 137 FEP patients and 240 ChSch subjects compared to 297 Healthy Controls (HC) contributed by five cohorts. Maps showing results of vertexwise between-group comparisons of cortical thickness, area, and gyrification were produced using T1-weighted datasets processed using FreeSurfer 5.3, followed by validated quality control protocols.

RESULTS: FEP subjects showed large clusters of increased area and gyrification relative to HC in prefrontal and insuli cortices (Cohen’s d: 0.049 to 0.28). These between-group differences occurred partially beyond the effect of sample. ChSch subjects displayed reduced cortical thickness relative to HC in smaller fronto-temporal foci (d: -0.73 to -0.35), but not beyond the effect of sample. Differences between FEP and HC subjects were associated with male gender, younger age, and earlier illness onset, while differences between ChSch and HC were associated with treatment-resistance and first-generation antipsychotic (FGA) intake independently of sample effect.

CONCLUSIONS: Separate assessments of FEP and ChSch revealed abnormalities that differed in regional distribution, phenotypes affected and effect size. In FEP, associations of greater cortical area and gyrification abnormalities with earlier age of onset suggest an origin on anomalous neurodevelopment, while thickness reductions in ChSch are at least partially explained by treatment-resistance and FGA intake. Associations of between-group differences with clinical variables retained statistical significance beyond the effect of sample.

PMID:34481405 | DOI:10.1016/j.schres.2021.08.011

ESMO Open. 2021 Sep 1;6(5):100254. doi: 10.1016/j.esmoop.2021.100254. Online ahead of print.

ABSTRACT

BACKGROUND: The advanced lung cancer inflammation index [ALI: body mass index × serum albumin/neutrophil-to-lymphocyte ratio (NLR)] reflects systemic host inflammation, and is easily reproducible. We hypothesized that ALI could assist guidance of non-small-cell lung cancer (NSCLC) treatment with immune checkpoint inhibitors (ICIs).

PATIENTS AND METHODS: This retrospective study included 672 stage IV NSCLC patients treated with programmed death-ligand 1 (PD-L1) inhibitors alone or in combination with chemotherapy in 25 centers in Greece and Germany, and a control cohort of 444 stage IV NSCLC patients treated with platinum-based chemotherapy without subsequent targeted or immunotherapy drugs. The association of clinical outcomes with biomarkers was analyzed with Cox regression models, including cross-validation by calculation of the Harrell’s C-index.

RESULTS: High ALI values (>18) were significantly associated with longer overall survival (OS) for patients receiving ICI monotherapy [hazard ratio (HR) = 0.402, P < 0.0001, n = 460], but not chemo-immunotherapy (HR = 0.624, P = 0.111, n = 212). Similar positive correlations for ALI were observed for objective response rate (36% versus 24%, P = 0.008) and time-on-treatment (HR = 0.52, P < 0.001), in case of ICI monotherapy only. In the control cohort of chemotherapy, the association between ALI and OS was weaker (HR = 0.694, P = 0.0002), and showed a significant interaction with the type of treatment (ICI monotherapy versus chemotherapy, P < 0.0001) upon combined analysis of the two cohorts. In multivariate analysis, ALI had a stronger predictive effect than NLR, PD-L1 tumor proportion score, lung immune prognostic index, and EPSILoN scores. Among patients with PD-L1 tumor proportion score ≥50% receiving first-line ICI monotherapy, a high ALI score >18 identified a subset with longer OS and time-on-treatment (median 35 and 16 months, respectively), similar to these under chemo-immunotherapy.

CONCLUSIONS: The ALI score is a powerful prognostic and predictive biomarker for patients with advanced NSCLC treated with PD-L1 inhibitors alone, but not in combination with chemotherapy. Its association with outcomes appears to be stronger than that of other widely used parameters. For PD-L1-high patients, an ALI score >18 could assist the selection of cases that do not need addition of chemotherapy.

PMID:34481329 | DOI:10.1016/j.esmoop.2021.100254

ESMO Open. 2021 Sep 1;6(5):100255. doi: 10.1016/j.esmoop.2021.100255. Online ahead of print.

ABSTRACT

BACKGROUND: The cancer burden in adolescents and young adults (AYAs) deserves more attention. However, global cancer statistics for AYAs are often presented as aggregates, concealing important heterogeneity. This study aimed to describe the worldwide profile of cancer incidence, mortality, and corresponding trends from 1990 to 2019 among 15-39-year olds by focusing on the patterns by age, sex, sociodemographic index (SDI), and regions.

PATIENTS AND METHODS: Global, regional, and country data on the number of cancer cases and cancer-related deaths for 29 cancer types were collected from the 2019 Global Burden of Disease (GBD) Study. We also summarized the results using five levels of the SDI and 21 GBD regions.

RESULTS: In 2019, an estimated 1 335 100 new cancer cases and 397 583 cancer-related deaths occurred among AYAs worldwide. While the incidence rate increased mildly, the death rate decreased significantly between 1990 and 2019, with an estimated annual percentage change of 0.38 (95% confidence interval 0.36-0.39) and -0.93 (95% confidence interval -0.95 to -0.92), respectively. The cancer burden was disproportionally greater among women than among men. The cancer profiles varied substantially across geographical regions, with the highest burden being in South Asia and East Asia. Besides, the cancer incidence in the high SDI regions was four times higher than that in the low SDI regions; however, the mortality burden in the high SDI region was lower than that in the low SDI region, which reflected the differences in cancer profiles across SDI regions and the inferior outcomes in the low SDI regions.

CONCLUSION: This study updates the previous epidemiological data of the cancer burden of AYAs. The cancer burden in AYAs varied substantially according to age, sex, SDI, and geographical regions. These findings highlight that the specific cancer profile of AYA patients requires targeted cancer control measures to reduce the cancer burden in this age group.

PMID:34481330 | DOI:10.1016/j.esmoop.2021.100255

Breast. 2021 Aug 26;60:62-69. doi: 10.1016/j.breast.2021.08.016. Online ahead of print.

ABSTRACT

BACKGROUND: Recent data suggest that human epidermal growth factor receptor 2 (HER2)-low breast cancer may represent a distinct entity. We aimed to compare disease characteristics and outcomes between HER2-low and HER2-0 in estrogen receptor (ER) positive, early-stage breast cancer.

METHODS: A single center retrospective study comprising all women with ER positive, HER2 negative early breast cancer, for whom an Oncotype DX test was performed between 2005 and 2012. Women were grouped to HER2-low (immunohistochemistry +1 or +2 and in situ hybridization not amplified) or HER2-0. Clinico-pathological features and Oncotype recurrence score (RS) were collected. Data on overall-survival (OS), disease-free survival (DFS) and distant disease-free survival (DDFS) were evaluated according to HER2 expression status.

RESULTS: 608 women were included, of which 304 women had HER2-0 and 304 had HER2-low disease. Lobular subtype was significantly more common in HER-0 compared to HER2-low disease (17% vs. 8%, p = 0.005). The prevalence of other clinic-pathological characteristics and long-term prognosis were comparable between both groups. For women with high genomic risk (RS > 25), HER2-low expression was associated with significantly favorable OS (HR = 0.31, 95% CI 0.11-0.78, p = 0.01), DFS (HR = 0.40, 95% CI 0.20-0.82, p = 0.01) and DDFS (HR = 0.26, 95% CI 0.11-0.63, P = 0.002) compared to women with HER2-0. For women with low genomic risk (RS ≤ 25), long-term prognosis was unrelated to HER2 expression.

CONCLUSION: The prognostic impact of HER2-low expression in early-stage luminal disease varies across the genomic risk, with significant favorable outcomes of HER2-low expression compared to HER2-0 in women with high genomic risk.

PMID:34481367 | DOI:10.1016/j.breast.2021.08.016

Seizure. 2021 Jul 20;92:94-99. doi: 10.1016/j.seizure.2021.07.019. Online ahead of print.

ABSTRACT

BACKGROUND: Obesity and overweight have been well established as comorbidities of epilepsy in adults. However, the effects of overweight and obesity on the risk of adult drug-resistant epilepsy (DRE) has not been fully assessed. Thus, the objective of this study was to investigate the relationships between categories of body mass index (BMI) and DRE.

METHODS: This was a case-control study. Patients with epilepsy hospitalized for Video electroencephalogram were included in the study from 2015 to 2020. Low/normal weight, overweight, and obesity were defined as BMI<23 and 23-24.9 and ≥25 kg/m², respectively. The proportions of patients diagnosed with DRE in each category were calculated.

RESULTS: A total of 1272 patients with drug-responsive epilepsy and 345 patients with DRE were included in this study. More men than women had DRE (P=0.012). Higher proportions of patients with DRE had a history of status epilepticus (P<0.001), CNS infection (P=0.027), developmental delay (P=0.001), and comorbidity (P<0.001). Obesity (BMI≥25 kg/m²) was associated with an increased risk of DRE (adjusted OR, 2.339; 95% CI, 1.724-3.171). No significant increase in the risk of DRE was found to be associated with overweight. Further stratified analyses by valproic acid (VPA) treatment attenuated the obesity-DRE relationship, but the associations remained statistically significant (adjusted OR, 1.79; 95% CI, 1.15-2.80).

CONCLUSION: Obesity, but not overweight, potentially plays a role in DRE, although confounders, such as antiseizure medications (ASMs) use, need to be explored. In the future, well-designed trials are needed to elucidate this issue.

PMID:34481323 | DOI:10.1016/j.seizure.2021.07.019

Nurse Educ Today. 2021 Aug 28;107:105115. doi: 10.1016/j.nedt.2021.105115. Online ahead of print.

ABSTRACT

BACKGROUND: Perfectionism in the medical field turns healthcare professionals into second victims of patient safety incidents. They suffer physically and psychologically, which makes them consider changing occupations. Nursing students may also have similar negative experiences during clinical practice.

OBJECTIVE: To describe the second victim phenomenon among nursing students after patient safety incidents during their clinical practice.

DESIGN: A descriptive cross-sectional study using an online questionnaire.

SETTING AND PARTICIPANTS: Fourth-year nursing students (n = 354) who encountered patient safety incidents directly or indirectly during clinical practice. Participants were recruited through convenience and snowball sampling methods using personal contacts, professional networks, and online platforms.

METHODS: The questionnaire addressed the characteristics of patient safety incidents, and physical and psychological responses after the most significant patient safety incident. Descriptive statistics and a chi-square test were performed for data analysis.

RESULTS: Of the participants, 22.6% were directly involved in patient safety incidents and 77.4% had indirectly encountered patient safety incidents, such as witnessing incidents with colleagues or other healthcare professionals. After patient safety incidents, of those, 67.8% experienced shock at the time of the incident, 47.2% feared experiencing a similar incident, and 28.2% were still affected although time had passed. Additionally, 26.3% reported experiencing long-term embitterment; of them, 7.3% were experiencing severe embitterment. Furthermore, 31.9% and 27.1% of the students experienced sleeping and eating difficulties, respectively, and these rates were higher when incidents were encountered directly rather than indirectly.

CONCLUSIONS: Nursing students may become second victims of patient safety incidents during clinical practice. Therefore, nursing education institutions need to develop comprehensive support strategies to help nursing students cope with experiencing the second victim phenomenon.

PMID:34481312 | DOI:10.1016/j.nedt.2021.105115

Nurse Educ Today. 2021 Aug 28;107:105116. doi: 10.1016/j.nedt.2021.105116. Online ahead of print.

ABSTRACT

BACKGROUND: Physical examination and health assessment skills are essential components of nursing practice, and the critical elements to be taught merit further investigation.

OBJECTIVES: To develop and evaluate a physical examination and health assessment course based on a self-directed learning framework.

DESIGN: An action research design was employed.

SETTINGS: A baccalaureate nursing program of the university of science and technology in central Taiwan.

PARTICIPANTS: A convenience sample comprising 23 teaching faculty members and 41 enrolled second-year students was recruited.

METHODS: Structured questionnaires were developed for data collection. A paired t-test and the Kruskal-Wallis test were used for data analysis.

RESULTS: The course consisted of four parts: health history taking from a holistic perspective, examination skills in diverse systems, case exercise and discussion, and final objective structured clinical examination. Statistical significance was found in the areas of physical examination skills, critical thinking, and case analysis. Participants with mid-to high-level self-directed learning had significantly higher scores than those with low-level self-directed learning on physical examination skills and problem assessment. Internal and discriminant validity were supported.

CONCLUSION: The study results provide evidence supporting the use of self-directed learning framework in curriculum design. The course integrated necessary knowledge and skills enabled students to practice physical examination, and assessment skills may enhance student confidence in approaching patients in clinical encounters. However, the study was a descriptive design. The generalization of the results needs to be further validated by an experimental study.

PMID:34481313 | DOI:10.1016/j.nedt.2021.105116

Public Health. 2021 Aug 4;198:208-210. doi: 10.1016/j.puhe.2021.07.041. Online ahead of print.

ABSTRACT

OBJECTIVES: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) leading to coronavirus disease 2019 (COVID-19) in China at the end of 2019 has resulted in a global pandemic. On 11 March 2020, the first case of COVID-19 was reported in Turkey. The aim of this study was to evaluate SARS-CoV-2 Real-Time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) test results from the Medical Microbiology Laboratory of a pandemic hospital according to demographic data.

STUDY DESIGN: Retrospective cohort study.

METHODS: SARS-CoV-2 RT-PCR test results of 413,013 samples from 194,062 patients were retrospectively analysed. Tests were carried out between 27 March and 31 December 2020 using two commercial kits. The patient’s age and gender were recorded, in addition to the percentage of positive test results per month (i.e. monthly positivity). Pearson’s Chi-squared test was used to analyse statistical significance.

RESULTS: Overall SARS-CoV-2 positivity in the pandemic hospital was 19.9%. Female gender and younger age (0-18 years) had a statistically significant higher positivity (P < 0.05). There was a statistically significant higher positivity in August and September.

CONCLUSIONS: Higher positivity among the younger population and females may be the leading cause of low COVID-19 mortality rates in Turkey as these population groups are less likely to die from the disease. Governments should disaggregate COVID-19 data by age and gender, and vaccine studies focussing on younger populations should be accelerated because this population group represents an important source of infection.

PMID:34481276 | DOI:10.1016/j.puhe.2021.07.041