Category: Statistics

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

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

Klin Monbl Augenheilkd. 2021 Apr 14. doi: 10.1055/a-1403-2218. Online ahead of print.

ABSTRACT

BACKGROUND: The SpeedWheel (SW) test is an objective test of visual acuity (VA) using suppression of the optokinetic nystagmus (OKN). Here, we established prediction intervals of the SW measures compared to Snellen acuity in adults and children.

SUBJECTS AND METHODS: In this prospective, single center study, subjects aged at least 4 years underwent testing of VA with SW, Landolt-C, and Tumbling-E symbols (Freiburg acuity test: FrACT-C, FrACT-E). Prediction intervals were established for SW compared to FrACT-C or -E and for FrACT-E compared to FrACT-C. Mixed linear effect models were applied for statistical analysis.

RESULTS: From 241 subjects, 471 eyes were included: median age 36 years, range 4 – 88 years, 43.6% male, 56.4% female. Eyes included were either healthy or had various underlying ophthalmic conditions. Prediction intervals for SW to estimate FrACT-C or -E acuity showed a similar range compared to the prediction interval of FrACT-C for the estimation of FrACT-E acuity. For each acuity step, there was no influence of age. Up to an SW acuity of 0.7 logMAR, 80% of the subjects had a FrACT-C acuity that was at most 1.6 logMAR lines below, and for an SW acuity of 1.0 logMAR, FrACT-C acuity was not worse than 4 logMAR lines. Prediction intervals for eyes with refractive error, cataract, visual field loss and retinal disease did not differ significantly from healthy eyes in contrast to eyes with amblyopia or multiple ophthalmic disorders. SW correlated well to FrACT tests and results of a previous study fell within our prediction estimates.

CONCLUSION: Our prediction intervals for SW acuity may be used to estimate Snellen acuity (FrACT-C and -E) in the clinic in adults and children unable to cooperate in other acuity testing.

PMID:33853189 | DOI:10.1055/a-1403-2218

Klin Monbl Augenheilkd. 2021 Apr 14. doi: 10.1055/a-1333-3199. Online ahead of print.

ABSTRACT

BACKGROUND: Evaluation of the three currently most common techniques for intraocular lens (IOL) sclera fixation: (1) Prolene suture with Hoffman sclera pocket (2) four-point GoreTex suture technique (3) sutureless flanged intrascleral IOL fixation with double-needle (“Yamane”) technique.

MATERIAL AND METHODS: Retrospective, clinical case series (chart review) at the Department of Ophthalmology, Ludwig-Maximilians-University (LMU), Munich, Germany. Enrolled in the study were 51 patients with 55 eyes. Best-corrected visual acuity (BCVA); manifest refraction (OR); corneal tomography (central corneal thickness, CCT); biometry; central macular thickness (CMT) by optical coherence tomography (OCT); intraocular pressure (IOP); and IOL type and IOL power were recorded and compared prior to and 3 – 12 months post IOL sclera fixation surgery. Pre- and postsurgery difference analysis was performed by Wilcoxon rank sum testing (z).

RESULTS: Intrascleral fixation by GoreTex suture was performed in 14 (25.5%) eyes, by Prolene suture in 19 (34.5%,) and by Yamane technique in 22 (40.0%) eyes. Within the 3 – 12 months follow-up post scleral fixation, a total of 2 (14.3%) eyes from the GoreTex, 3 (15.8%) from the Prolene and 1 (4.5%) eye from the Yamane group required refixation. Pre- and post-surgery analysis revealed a statistically significant difference in the total patient population BCVA (exact Wilcoxon test: z = – 3.202; p = 0.001; n = 55) and the Yamane subgroup (exact Wilcoxon test: z = – 2.068; p = 0.001; n = 22). The GoreTex (n = 14) and Prolene (n = 19) subgroups revealed no statistically significant differences versus preoperative baseline. Across groups, there was no statistically significant difference in IOP, CMT, and CCT. No retinal complications were observed, neither intraoperatively nor during follow-up.

CONCLUSION: The volume of IOL revision surgery is increasing. Often, the only option left for visual rehabilitation is scleral IOL fixation. All three scleral fixation techniques studied demonstrated a good safety profile with no statistically significant impact on IOP, CMT, CCT, but with a notable revision rate. Visual rehabilitation to preoperative baseline levels (GoreTex [n = 14] and Prolene [n = 19]) and a statistically significant increase in visual acuity (total cohort [n = 55] and Yamane [n = 22]) seems possible. Unlike iris fixation, scleral fixation is surgically more complex and the surgeon must master a steeper learning curve.

PMID:33853190 | DOI:10.1055/a-1333-3199