Tag: statistics

Prosthet Orthot Int. 2021 Mar 25. doi: 10.1097/PXR.0000000000000008. Online ahead of print.

ABSTRACT

BACKGROUND: The medical community demands evidence for the benefits of medical devices such as bone-anchored prostheses (BAPs). MedTech20 is a novel instrument aiming to address general benefits of medical devices.

OBJECTIVE: To describe general patient-reported benefits of BAPs measured with MedTech20.

STUDY DESIGN: This is a cross-sectional descriptive survey.

METHODS: Patients treated in Sweden who had used a BAP for >1 year were mailed the MedTech20 Questionnaire. Responses to each attribute were described, and the MedTech20 Index (0-1), in which a higher figure represents larger benefits from the product, was calculated. Index values were compared based on demographic variables (sex, unilateral or bilateral transfemoral amputation (TFA), and those having experienced any complication of implant parts or the prosthetic connection device).

RESULTS: The response rate was 72%. The 62 participants (41 men and 21 women; mean age 57 years) had 11 ± 6.9 mean years of BAP experience. Single attributes stated as highly relevant and with high benefit for BAPs included perceived reliability, perceived safety, sense of control of the disability, facilitation of movement outside home, no discomfort at use, and ease of use. Attributes with less relevance included aid to remember tasks, reduction of barriers to a good sleep, and reduced sense of compromised integrity. The MedTech20 Index was 0.655 ± 0.188 and was not statistically significantly different based on any of the demographic variables.

CONCLUSIONS: By using a general measure on attributes of medical devices, this study provides new insights strengthening the evidence regarding the benefits that BAPs provide for patients with TFA who had difficulties with socket-suspended prostheses.

PMID:33856153 | DOI:10.1097/PXR.0000000000000008

Pediatr Pulmonol. 2021 Apr 15. doi: 10.1002/ppul.25423. Online ahead of print.

ABSTRACT

BACKGROUND: Machine-learning approaches have enabled promising results in efforts to simplify the diagnosis of pediatric obstructive sleep apnea (OSA). A comprehensive review and analysis of such studies increase the confidence level of practitioners and healthcare providers in the implementation of these methodologies in clinical practice.

OBJECTIVE: To assess the reliability of machine-learning- based methods to detect pediatric OSA.

DATA SOURCES: Two researchers conducted an electronic search on the Web of Science and Scopus using term, and studies were reviewed along with their bibliographic references.

ELIGIBILITY CRITERIA: Articles or reviews (year 2000 onwards) that applied machine learning to detect pediatric OSA; reported data included information enabling derivation of true positive, false negative, true negative, and false positive cases; polysomnography served as diagnostic standard.

APPRAISAL AND SYNTHESIS METHODS: Pooled sensitivities and specificities were computed for three apnea-hypopnea index (AHI) thresholds: 1 event/hour (e/h), 5 e/h, and 10 e/h. Random-effect models were assumed. Summary receiver-operating characteristics (SROC) analyses were also conducted. Heterogeneity (I ² ) was evaluated, and publication bias was corrected (trim and fill).

RESULTS: Nineteen studies were finally retained, involving 4,767 different pediatric sleep studies. Machine learning improved diagnostic performance as OSA severity criteria increased reaching optimal values for AHI=10 e/h (0.652 sensitivity; 0.931 specificity; and 0.940 area under the SROC curve). Publication bias correction had minor effect on summary statistics, but high heterogeneity was observed among the studies.

CONCLUSIONS: Machine learning can reliably detect severe OSA. However, further steps are needed to improve diagnostic performance for less severe pediatric OSA, and thus increase the confidence levels when using these approaches. This article is protected by copyright. All rights reserved.

PMID:33856128 | DOI:10.1002/ppul.25423

J Perinat Med. 2021 Apr 14. doi: 10.1515/jpm-2020-0324. Online ahead of print.

ABSTRACT

OBJECTIVES: Antenatal exposure to organic pollutants is a leading public health problem. Meconium is a unique matrix to perform prenatal studies because it enables us to retrospectively evaluate fetal exposure accumulated during the second and third trimester. The aim of the present study was to evaluate associations between organic pollutant levels in meconium and birth weight in NW Spain.

METHODS: In this study, we quantify the concentrations of 50 organic pollutants together with the total values of the most important chemical groups in meconium using gas chromatography coupled to tandem mass spectrometry.

RESULTS: Organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers were detected with the highest levels in meconium from small for gestational age newborns. It was estimated that several congeners were statistically significant (p<0.05). However, organophosphorus pesticides attained higher concentrations in newborns with an appropriate weight.

CONCLUSIONS: The occurrence of transplacental transfer can be confirmed. Prenatal exposure to organic pollutants was associated with a decrease in birth weight and, therefore, organic pollutants could have an impact on fetal growth. Nevertheless, these results need validation in larger sample sized studies.

PMID:33856139 | DOI:10.1515/jpm-2020-0324

Minerva Gastroenterol (Torino). 2021 Apr 15. doi: 10.23736/S2724-5985.21.02826-9. Online ahead of print.

ABSTRACT

BACKGROUND: There have been long debates on the introduction of proton pump inhibitors into acute pancreatitis therapy as standard treatment.

SETTINGS AND DESIGN: The aim of the study was to assess endoscopic lesions of the upper gastrointestinal tract in patients hospitalized for acute pancreatitis.

METHODS AND MATERIAL: We carried out a prospective analysis of patients hospitalized in one surgical centre who had an upper gastrointestinal tract endoscopic examination performed during the first 48 hours of hospitalization.

STATISTICAL ANALYSIS USED: We performed analysis of basic descriptive statistics along with the Shapiro-Wilk test, logistic order regression analysis, one-way analysis of variance, and Student’s t-test for independent trials.

RESULTS: From January 2016 to December 2019, 476 patients were hospitalized because of acute pancreatitis. The upper gastrointestinal tract endoscopic examination was performed in 85 patients (n) in the first 48 hours. From the examined group 45 patients (52.94%) developed mild acute pancreatitis, 28 (32.94%) – moderate pancreatitis and 12 (14.12%) – severe pancreatitis. Lesions in the endoscopic imaging were observed in 80 patients (94.12%).

CONCLUSIONS: A very high percentage of patients hospitalized for acute pancreatitis present lesions in the endoscopic imaging of the upper gastrointestinal tract. The standard treatment of AP is the administration of non-steroidal anti-inflammatory drugs, which themselves can cause gastric and duodenal mucosal defects. All these factors indicate the need for standard use of proton pump inhibitors in patients hospitalized for acute pancreatitis.

PMID:33856142 | DOI:10.23736/S2724-5985.21.02826-9

Mol Ecol. 2021 Apr 14. doi: 10.1111/mec.15920. Online ahead of print.

ABSTRACT

Much of what we know about the genetic basis of herbicide resistance has come from detailed investigations of monogenic adaptation at known target-sites, despite the increasingly recognized importance of polygenic resistance. Little work has been done to characterize the broader genomic basis of herbicide resistance, including the number and distribution of genes involved, their effect sizes, allele frequencies, and signatures of selection. In this work, we implemented genome-wide association (GWA) and population genomic approaches to examine the genetic architecture of glyphosate (Round-up^® ) resistance in the problematic agricultural weed, Amaranthus tuberculatus. A GWA was able to correctly identify the known target-gene but statistically controlling for two causal target-site mechanisms revealed an additional 250 genes across all 16 chromosomes associated with non-target-site resistance (NTSR). The encoded proteins had functions that have been linked to NTSR, the most significant of which is response to chemicals, but also showed pleiotropic roles in reproduction and growth. The architecture of NTSR was enriched for large effect sizes and low allele frequencies, suggesting the role of pleiotropic constraints on its evolution. The enrichment of rare alleles also suggested that the genetic architecture of NTSR may be population-specific and heterogeneous across the range. Despite their rarity, we found signals of recent positive selection on NTSR-alleles by both window- and haplotype-based statistics, and an enrichment of amino-acid changing variants. In our samples, genome-wide SNPs explain a comparable amount of the total variation in glyphosate resistance to monogenic mechanisms, even in a collection of individuals where 80% of resistant individuals have large-effect TSR mutations, indicating an underappreciated polygenic contribution to the evolution of herbicide resistance in weed populations.

PMID:33853196 | DOI:10.1111/mec.15920

Stat Med. 2021 Apr 14. doi: 10.1002/sim.8982. Online ahead of print.

ABSTRACT

It is of great practical importance to compare and combine data from different studies in order to carry out appropriate and more powerful statistical inference. We propose a partition based measure to quantify the compatibility of two datasets using their respective posterior distributions. We further propose an information gain measure to quantify the information increase (or decrease) in combining two datasets. These measures are well calibrated and efficient computational algorithms are provided for their calculations. We use examples in a benchmark dose toxicology study, a six cities pollution data and a melanoma clinical trial to illustrate how these two measures are useful in combining current data with historical data and missing data.

PMID:33853200 | DOI:10.1002/sim.8982

Klin Monbl Augenheilkd. 2021 Apr 14. doi: 10.1055/a-1327-3999. Online ahead of print.

ABSTRACT

BACKGROUND: Glaucoma is one of the leading causes of permanent visual disability around the world. However, the available literature lacks data on the prevalence of glaucoma in Central Asia, particularly in the Republic of Kazakhstan.

OBJECTIVE: The study was aimed at assessing the prevalence of glaucoma in the population of the Republic of Kazakhstan over 40 years old in 2019.

METHODS: A retrospective study was based on the analysis of the results of glaucoma screenings in 171 832 patients over 40 years old living in Kazakhstan (in 14 counties). Glaucoma cases were confirmed by Goldmann tonometry, fundus photography, and visual field testing. Demographic indicators, territorial differences, and hereditary predisposition were studied and analysed. In addition, blood pressure was measured.

RESULTS: Of 171 832 patients examined, 452 with verified glaucoma were identified. The average age of the patients was 63.9 ± 9.4. In rural areas, the prevalence of glaucoma was higher compared to the urban population. The overall prevalence of glaucoma among people over 40 years old was 2.37 ± 0.17. The prevalence of glaucoma among women was higher than for men, with an indicator of 1.91 (95% CI relative risk 1.78 – 2.03) (p < 0.05). The highest prevalence was found in the 71 – 75 age group [equals to 14.2% (95% CI 11.7 – 19.9)], with a statistically significant difference (p < 0.05). The highest prevalence of glaucoma was observed in the group of people with a hereditary predisposition, with an indicator of 14.7% (95% CI 0.6 – 1.9) (p < 0.05). Among all patients with concomitant arterial hypertension (n = 90, 19.9%), women (60%) compared with men (40%) had a 2.4% higher risk of glaucoma morbidity (95% CI 1.2% – 3.8%).

CONCLUSION: This study provides updated information on the prevalence of glaucoma in Kazakhstan. The results obtained confirm that the increase in the prevalence of glaucoma in Kazakhstan is directly proportional to the increase in the patients’ age. These results showed the importance of screening for a timely diagnosis, especially for patients with high risk factors such as hereditary predisposition. Moreover, the results indicate that the early detection of systemic hypertension and increased intraocular pressure can be used for the prevention of undesirable outcomes such as an irreversible blindness.

PMID:33853192 | DOI:10.1055/a-1327-3999

Klin Monbl Augenheilkd. 2021 Apr 14. doi: 10.1055/a-1386-3170. Online ahead of print.

ABSTRACT

BACKGROUND: To report the efficacy of ab externo canaloplasty by exclusively using only a nonabsorbable suture as a standalone operation or combined with phacoemulsification in terms of mean intraocular pressure (IOP), medication reduction, and intra- and postoperative complication rates as well as additional glaucoma surgery.

PATIENTS AND METHODS: Forty-eight patients with primary open-angle glaucoma (POAG) and 50 eyes were divided into two groups according to the operation performed (Group A canaloplasty, n = 34 and Group B canaloplasty combined with phaco, n = 16), respectively. The success criteria were evaluated between three IOP ranges: a) IOP ≤ 16 mmHg, b) ≤ 18 mmHg, and c) ≤ 21 mmHg. Complete success was considered the percentage of eyes reaching these goals with no medication and qualified success with or without medication. Groups A and B were compared with the Kaplan-Meier test. Mean IOP and medication reduction as well as additional glaucoma surgery were also evaluated. The follow-up time was 6 months. Statistical importance was given at p < 0.05.

RESULTS: Fail rate and intraoperative conversion of canaloplasty to other surgery (trabeculotomy due to extensive cheese-wiring) accounted for 12% (6 eyes), while a mandatory usage of the iTrack 250A microcatheter to successfully overcome intracanalicular bridging of the Schlemm’s canal accounted for 20% (10 eyes). The most common early postoperative complications in both groups were hyphema, cheese wiring, and transient IOP rising. The mean IOP in Group A reduced from 23.67 ± 6.06 mmHg to 13.35 ± 4.23 mmHg and in Group B, it reduced from 23.55 ± 6.19 mmHg to 12.75 ± 1.5 mmHg at 6 months (p < 0.001). Group A’s absolute success rates accounted for a) 44%, b) 47.1%, and c) 52.9% in comparison to Group B [a) 50%, b) 50%, and c) 56.3%] at 6 months (p < 0.05). Qualified success with or without medication showed no statistical differences between the groups. The mean medication reduction was significantly lower (p < 0.001) in both groups (Group A from baseline 3.2 ± 1.23 to 0.95 ± 1.35 and Group B from 3.12 ± 0.88 to 1.12 ± 0.75 at 6 months, respectively). Five eyes (10%) required additional glaucoma surgery.

CONCLUSIONS: Ab externo canaloplasty by exclusively using only a nonabsorbable suture as a standalone operation or combined with phacoemulsification seems to lower the mean IOP and medication sufficiently. However, they pose a greater surgical challenge and intraoperative complication rate. Additional glaucoma surgery or medication following both procedures may be necessary to achieve an optimal target IOP.

PMID:33853193 | DOI:10.1055/a-1386-3170

Klin Monbl Augenheilkd. 2021 Apr 14. doi: 10.1055/a-1396-4749. Online ahead of print.

ABSTRACT

PURPOSE: To compare nutritional and lifestyle factors between glaucoma patients and an age-matched control group.

METHODS: One hundred and ninety (190) glaucoma patients were enrolled in this study. The control group comprised 97 age-matched participants. Data on physical activity, nicotine smoking, and several nutritional habits like coffee and alcohol consumption as well as high-salt and high-protein intake were collected using a standardised questionnaire.

RESULTS: Age and gender were not statistically significantly different between the groups. There was a tendency for higher physical activity in the glaucoma group in comparison to the control group (47.3 vs. 35.4%; p = 0.056). Statistically significantly more glaucoma patients were nonsmokers (n = 169; 89.4%) compared to the control group (n = 64; 66.7%; p = 0.001). Glaucoma patients were also more often teetotal compared to the control group (21.6% compared to 14.4%; p < 0.001). Similarly, more glaucoma patients drank larger amounts of coffee in comparison to the control group (p = 0.001). One hundred and seventy-six (96.7%) glaucoma patients and 88 (90.7%) control subjects had high-protein intake (p = 0.035). High-salt intake was significantly lower in the glaucoma group (69.3 vs. 73.2%; p = 0.018). Of the 190 glaucoma patients, 81 had early visual field impairments (MD > – 6 dB) and 109 patients had moderate (MD between – 6 dB and – 12 dB) to severe (MD < – 12 dB) visual field defects. The severity of visual field defects, whether early, moderate, or severe, had no statistically significant impact on lifestyle parameters.

CONCLUSION: Contrary to our original hypothesis that glaucoma patients would tend to follow an unhealthier lifestyle than the control group, the opposite was seen. Presumably, the cause of this healthier lifestyle is the desire to contribute positively through the course of the disease.

PMID:33853194 | DOI:10.1055/a-1396-4749

Klin Monbl Augenheilkd. 2021 Apr 14. doi: 10.1055/a-1340-0066. Online ahead of print.

ABSTRACT

PURPOSE: To analyze the central macular thickness (CMT), retinal nerve fiber layer thickness (RNFLT), ganglion cell layer thickness (GCLT), and choroidal thickness (ChT) measurements in patients with coronavirus disease 2019 (COVID-19).

METHODS: The study was conducted cross-sectionally 4 weeks after the completed treatment of COVID-19. The diagnosis of COVID-19 was based on the polymerase chain reaction test and/or clinical and radiological findings. The patients with treated COVID-19 were enrolled in the COVID-19 group; age- and sex-matched healthy participants served as the control group. All patients in the COVID-19 group were hospitalized and treated with favipiravir, moxifloxacin, and heparin without the requirement for intubation. The measurements of CMT, RNFLT (in four quadrants), GCLT (in six sectors of two different boundaries), and ChT (in five locations) were performed by swept-source optical coherence tomography (SS-OCT).

RESULTS: Similar visual acuity (p = 0.582) and intraocular pressure (p = 0.766) values were observed between the COVID-19 and control groups. Regarding SS-OCT measurements, all mean CMT, RNFLT (in four quadrants), GCLT (in six sectors of two different boundaries), and ChT (in five locations) values were similar in the COVID-19 and control groups (p > 0.05 for all). In the COVID-19 group, a statistically significant negative correlation was noted between the mean ferritin level and temporal RNFLT (r = – 0.378, p = 0.014) and a positive correlation was observed between the mean ferritin level and nasal RNFLT (r = + 0.371, p = 0.016).

CONCLUSION: SS-OCT measurements showed no retinal neurodegenerative and choroidal thickness alterations in COVID-19 patients. Nonsignificant results might be due to the examination of the patients in the early period of the COVID-19 after the treatment. Therefore, late period OCT measurements should be reviewed with new studies in the future.

PMID:33853186 | DOI:10.1055/a-1340-0066