Tag: statistics

PLoS Genet. 2021 Jun 3;17(6):e1009562. doi: 10.1371/journal.pgen.1009562. eCollection 2021 Jun.

ABSTRACT

Levels of sex differences for human body size and shape phenotypes are hypothesized to have adaptively reduced following the agricultural transition as part of an evolutionary response to relatively more equal divisions of labor and new technology adoption. In this study, we tested this hypothesis by studying genetic variants associated with five sexually differentiated human phenotypes: height, body mass, hip circumference, body fat percentage, and waist circumference. We first analyzed genome-wide association (GWAS) results for UK Biobank individuals (~194,000 females and ~167,000 males) to identify a total of 114,199 single nucleotide polymorphisms (SNPs) significantly associated with at least one of the studied phenotypes in females, males, or both sexes (P<5×10-8). From these loci we then identified 3,016 SNPs (2.6%) with significant differences in the strength of association between the female- and male-specific GWAS results at a low false-discovery rate (FDR<0.001). Genes with known roles in sexual differentiation are significantly enriched for co-localization with one or more of these SNPs versus SNPs associated with the phenotypes generally but not with sex differences (2.73-fold enrichment; permutation test; P = 0.0041). We also confirmed that the identified variants are disproportionately associated with greater phenotype effect sizes in the sex with the stronger association value. We then used the singleton density score statistic, which quantifies recent (within the last ~3,000 years; post-agriculture adoption in Britain) changes in the frequencies of alleles underlying polygenic traits, to identify a signature of recent positive selection on alleles associated with greater body fat percentage in females (permutation test; P = 0.0038; FDR = 0.0380), directionally opposite to that predicted by the sex differences reduction hypothesis. Otherwise, we found no evidence of positive selection for sex difference-associated alleles for any other trait. Overall, our results challenge the longstanding hypothesis that sex differences adaptively decreased following subsistence transitions from hunting and gathering to agriculture.

PMID:34081690 | DOI:10.1371/journal.pgen.1009562

PLoS One. 2021 Jun 3;16(6):e0251920. doi: 10.1371/journal.pone.0251920. eCollection 2021.

ABSTRACT

The brassica leaf beetle Phaedon brassicae is a notorious defoliator of cruciferous vegetables. However, few molecular studies of this pest have been conducted due to limited sequence data. Recently, RNA sequencing has offered a powerful platform to generate numerous transcriptomic data, which require RT-qPCR to validate target gene expression. The selection of reliable reference genes to normalize RT-qPCR data is a prerequisite for gene expression analysis. In the present study, the expression stabilities of eight candidate reference genes under biotic conditions (development stages and various tissues) and abiotic perturbations (thermal stress and pesticide exposure) were evaluated using four different statistical algorithms. The optimal suites of reference genes were recommended for the respective experimental conditions. For tissue expression analysis, RPL32 and EF-1α were recommended as the suitable reference genes. RPL19 and TBP were the optimal reference genes across different developmental stages. RPL32 and TBP were identified as the most suitable references for thermal stress. Furthermore, RPL32 and RPL19 were ranked as the best references for insecticide exposure. This work provides a systematic exploration of the optimal reference genes for the respective experimental conditions, and our findings would facilitate molecular studies of P. brassicae.

PMID:34081693 | DOI:10.1371/journal.pone.0251920

PLoS One. 2021 Jun 3;16(6):e0252499. doi: 10.1371/journal.pone.0252499. eCollection 2021.

ABSTRACT

Models of contact tracing often over-simplify the effects of quarantine and isolation on disease transmission. We develop a model that allows us to investigate the importance of these factors in reducing the effective reproduction number. We show that the reduction in onward transmission during quarantine and isolation has a bigger effect than tracing coverage on the reproduction number. We also show that intuitively reasonable contact tracing performance indicators, such as the proportion of contacts quarantined before symptom onset, are often not well correlated with the reproduction number. We conclude that provision of support systems to enable people to quarantine and isolate effectively is crucial to the success of contact tracing.

PMID:34081709 | DOI:10.1371/journal.pone.0252499

J Public Health Manag Pract. 2021 Jun 1. doi: 10.1097/PHH.0000000000001392. Online ahead of print.

ABSTRACT

CONTEXT: To determine if radon mitigation is needed to protect occupants of multifamily housing, reliable testing procedures are needed. Yet, protocols on how many ground-contact housing units must be tested vary from 10% to 25% to 100%.

OBJECTIVES: To estimate the probability of failing to identify a building containing at least one unit with elevated radon level when all ground-contact units are not tested.

DESIGN: Retrospective analysis of previously collected data from licensed (ie, certified) radon measurement professionals using hypergeometric and Monte Carlo statistical methods to estimate the confidence that there are no units with radon levels of 4 picoCuries/liter of air (pCi/L) or more based on various testing percentages.

SETTING: Testing data were obtained from 29 US states for 7892 ground-contact units in 687 multifamily buildings, primarily 5 to 20 units per building.

MAIN OUTCOME MEASURE: Probability of failing to identify elevated radon levels in untested units.

RESULTS: About 15% (n = 1163) of the units had radon levels of more than 4 pCi/L (the EPA action level); 59 units had more than 20 pCi/L (maximum of 96 pCi/L). For building sizes of 5 to 20 ground-contact units, the 2018 federal testing protocols that currently require testing of 10% and 25% of ground-contact units in each building failed to identify 47%-69% and 32%-46% of the units, respectively, depending on building size.

CONCLUSIONS: Measurement of 90% of the ground-contact units in buildings with 5 to 20 ground-contact units results in up to 4% of the units with elevated radon levels being missed. To achieve 95% confidence that no units in the building have radon levels of 4 pCi/L or more in buildings up to 20 units, 100% sampling is required. For the vast majority of multifamily buildings, all ground-contact units in multifamily buildings should be tested for radon.

PMID:34081671 | DOI:10.1097/PHH.0000000000001392

Med Care. 2021 Jun 3. doi: 10.1097/MLR.0000000000001587. Online ahead of print.

ABSTRACT

BACKGROUND: Prescription opioid mortality doubled 2002-2016 in the United States. Given the association between high-dose opioid prescribing and opioid mortality, several states have enacted morphine equivalent daily dose (MEDD) policies to limit high-dose prescribing. The study objective is to evaluate the impact of state-level MEDD policies on opioid prescribing among the privately insured.

METHODS: Claims data, 2010-2015 from 9 policy states and 2 control states and a comparative interrupted time series design were utilized. Primary outcomes were any monthly opioid use and average monthly MEDD. Stratified analyses evaluated theorized weaker policies (guidelines) and theorized stronger policies (passive alert systems, legislative acts, and rules/regulations) separately. Patient groups explicitly excluded from policies (eg, individuals with cancer diagnoses or receiving hospice care) were also examined separately. Analyses adjusted for covariates, state fixed effects, and time trends.

RESULTS: Both guideline and strong policy implementation were both associated with 15% lower odds of any opioid use, relative to control states. However, there was no statistically significant change in the use of high-dose opioids in policy states relative to control states. There was also no difference in direction and significance of the relationship among targeted patient groups.

CONCLUSIONS: MEDD policies were associated with decreased use of any opioids relative to control states, but no change in high-dose prescribing was observed. While the overall policy environment in treatment states may have discouraged opioid prescribing, there was no evidence of MEDD policy impact, specifically. Further research is needed to understand the mechanisms through which MEDD policies may influence prescribing behavior.

PMID:34081679 | DOI:10.1097/MLR.0000000000001587

J Public Health Manag Pract. 2021 Jun 1. doi: 10.1097/PHH.0000000000001387. Online ahead of print.

ABSTRACT

Research has consistently found a link between hourly nurse rounding and patient outcomes, including reduced falls, reduced pressure ulcers, reduced call light usage, and improved patient experience; however, little research exists specific to patient falls and nurse rounding in acute care settings. This study adds to the body of knowledge by statistically quantifying and providing linkages between nurse rounding frequency and patient fall rates using data from 31 military treatment facilities comprehensively over a period from fiscal year (FY) 2017 through FY2019. Poisson regression results indicated that hourly nurse rounding was associated with a reduction of more than 21% in fall rates (incidence rate ratio = 0.79, P < .01) relative to infrequent rounding, and poorly rated nurse communication was associated with an 8.6-fold increase in patient fall rates relative to highly rated nurse communication (incidence rate ratio = 8.6, P < .01).

PMID:34081670 | DOI:10.1097/PHH.0000000000001387

Optom Vis Sci. 2021 Jun 2. doi: 10.1097/OPX.0000000000001708. Online ahead of print.

ABSTRACT

SIGNIFICANCE: Fixation disparity tests with various characteristics of fusional stimulus are very important for assessment of decompensated heterophoria. The results suggest that there was no reasonable agreement between the fixation disparity curve’s parameters of the modified near Mallett unit and the Sheedy disparometer.

PURPOSE: The purpose of this study was to determine the agreement of the fixation disparity curve parameters between the modified near Mallett unit and the Sheedy disparometer in patients with decompensated near heterophoria.

METHODS: A total of 147 young adults (mean age, 22.7 ± 4.8 years) participated in this cross-sectional study. After applying the exclusion criteria, the statistical analysis was done on the data of 134 individuals. All participants underwent preliminary optometric examinations including the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, and unilateral and alternating cover tests. The fixation disparity was evaluated using the modified near Mallett unit and the Sheedy disparometer at 40 cm, and forced-vergence fixation disparity curves were generated.

RESULTS: There were statistically significant differences in the fixation disparity curve parameters (except the center of symmetry) between the two devices. The median fixation disparity measured by the Sheedy disparometer was more positive compared with the modified near Mallett unit (toward more esodisparity or less exodisparity). The median associated phoria measured by the Sheedy disparometer was more positive compared with the Mallett unit. Also, the slope of the curve obtained by the Mallett unit was steeper. The wide limits of agreement indicated the poor agreement of all fixation disparity curve parameters between the two instruments.

PMID:34081653 | DOI:10.1097/OPX.0000000000001708

J Public Health Manag Pract. 2021 Jun 1. doi: 10.1097/PHH.0000000000001383. Online ahead of print.

ABSTRACT

OBJECTIVE: To identify potential strategies to mitigate COVID-19 transmission in a Utah meat-processing facility and surrounding community.

DESIGN/SETTING: During March-June 2020, 502 workers at a Utah meat-processing facility (facility A) tested positive for SARS-CoV-2. Using merged data from the state disease surveillance system and facility A, we analyzed the relationship between SARS-CoV-2 positivity and worker demographics, work section, and geospatial data on worker residence. We analyzed worker survey responses to questions regarding COVID-19 knowledge, beliefs, and behaviors at work and home.

PARTICIPANTS: (1) Facility A workers (n = 1373) with specimen collection dates and SARS-CoV-2 RT-PCR test results; (2) residential addresses of all persons (workers and nonworkers) with a SARS-CoV-2 diagnostic test (n = 1036), living within the 3 counties included in the health department catchment area; and (3) facility A workers (n = 64) who agreed to participate in the knowledge, attitudes, and practices survey.

MAIN OUTCOME MEASURES: New cases over time, COVID-19 attack rates, worker characteristics by SARS-CoV-2 test results, geospatially clustered cases, space-time proximity of cases among workers and nonworkers; frequency of quantitative responses, crude prevalence ratios, and counts and frequency of coded responses to open-ended questions from the COVID-19 knowledge, attitudes, and practices survey.

RESULTS: Statistically significant differences in race (P = .01), linguistic group (P < .001), and work section (P < .001) were found between workers with positive and negative SARS-CoV-2 test results. Geographically, only 6% of cases were within statistically significant spatiotemporal case clusters. Workers reported using handwashing (57%) and social distancing (21%) as mitigation strategies outside work but reported apprehension with taking COVID-19-associated sick leave.

CONCLUSIONS: Mitigating COVID-19 outbreaks among workers in congregate settings requires a multifaceted public health response that is tailored to the workforce.

IMPLICATIONS FOR POLICY AND PRACTICE: Tailored, multifaceted mitigation strategies are crucial for reducing COVID-19-associated health disparities among disproportionately affected populations.

PMID:34081669 | DOI:10.1097/PHH.0000000000001383

Optom Vis Sci. 2021 Jun 2. doi: 10.1097/OPX.0000000000001710. Online ahead of print.

ABSTRACT

SIGNIFICANCE: The performance of the Eye Refract (Luneau Technology, Chartres, France), a new instrument to perform aberrometry-based automated subjective refraction, has been previously evaluated in healthy subjects. However, its clinical implications in other ocular conditions are still unknown.

PURPOSE: The purpose of this study was to evaluate the agreement between the Eye Refract and the traditional subjective refraction, as the criterion standard, in keratoconus patients with and without intracorneal ring segments (ICRSs).

METHODS: A total of 50 eyes of 50 keratoconus patients were evaluated, dividing the sample into 2 groups: 27 eyes without ICRS (37.78 ± 9.35 years) and 23 eyes with ICRS (39.26 ± 13.62 years). An optometrist conducted the refraction with the Eye Refract, and another different optometrist conducted the traditional subjective refraction on the same day. Spherical equivalent (M), cylindrical vectors (J0 and J45), and corrected distance visual acuity were compared between both methods of refraction. In addition, Bland-Altman analysis was performed to assess the agreement between both methods of refraction.

RESULTS: There were no statistically significant differences (P ≥ .05) between the Eye Refract and the traditional subjective refraction for all the variables under study in either group. Without ICRS, the mean difference and 95% limits of agreement (upper, lower) were -0.20 (+1.50, -1.89) D for M, -0.14 (+1.40, -1.68) D for J0, and +0.05 (+1.23, -1.14) D for J45. With ICRS, these values worsened to -0.62 (+3.89, -5.12) D for M, +0.06 (+2.46, -2.34) D for J0, and -0.02 (+2.23, -2.28) D for J45.

CONCLUSIONS: The Eye Refract seems to offer similar results compared with the traditional subjective refraction in keratoconus patients not implanted with ICRS. However, some patients could show abnormal measurements, especially those with ICRS, who should be treated with caution in clinical practice.

PMID:34081650 | DOI:10.1097/OPX.0000000000001710

Optom Vis Sci. 2021 Jun 2. doi: 10.1097/OPX.0000000000001709. Online ahead of print.

ABSTRACT

SIGNIFICANCE: The present study is the first population-based study to examine the prevalence of convergence insufficiency and its associations specifically in the geriatric population. Knowledge of the population-based determination of prevalence of this disorder in the elderly is necessary to support proper clinical diagnosis and management.

PURPOSE: This study aimed to determine the prevalence of convergence insufficiency and its associated factors in a geriatric population.

METHODS: In this study, all residents older than 60 years in Tehran city were selected through random stratified cluster sampling. All participants underwent a complete ocular examination including the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, binocular vision assessments including unilateral and alternating cover tests, measurement of the near point of convergence, the positive fusional vergence, and finally ocular health examination.

RESULTS: In this population-based sample of 1793 participants, the overall prevalences of two-sign and three-sign convergence insufficiency were 29.6% (95% confidence interval, 27.2 to 32.0%) and 21.5% (95% confidence interval, 19.5 to 23.6%), respectively. There were no statistically significant differences in the prevalence of both two-sign (P = .19) and three-sign (P = .41) convergence insufficiency between men and women. The highest and lowest prevalences of two-sign and three-sign convergence insufficiency were in the age groups 70 to 74 and 75 to 79 years, respectively. The prevalence showed no significant trend with age (P = .26 for two-sign convergence insufficiency, P = .33 for three-sign convergence insufficiency). In the multiple logistic regression model, none of the variables, including age, sex, and refractive errors, showed a significant relationship with convergence insufficiency (all, P > .05).

CONCLUSIONS: The results of the present study showed a high prevalence of convergence insufficiency in the geriatric population. Clinicians should give special attention to this binocular vision disorder in this age group.

PMID:34081652 | DOI:10.1097/OPX.0000000000001709