Nevin Manimala

Biostatistics. 2022 Apr 13;23(2):380-396. doi: 10.1093/biostatistics/kxaa030.

ABSTRACT

Multi-state models for event history analysis most commonly assume the process is Markov. This article considers tests of the Markov assumption that are applicable to general multi-state models. Two approaches using existing methodology are considered; a simple method based on including time of entry into each state as a covariate in Cox models for the transition intensities and a method involving detecting a shared frailty through a stratified Commenges-Andersen test. In addition, using the principle that under a Markov process the future rate of transitions of the process at times $t > s$ should not be influenced by the state occupied at time $s$, a new class of general tests is developed by considering summaries from families of log-rank statistics where patients are grouped by the state occupied at varying initial time $s$. An extended form of the test applicable to models that are Markov conditional on observed covariates is also derived. The null distribution of the proposed test statistics are approximated by using wild bootstrap sampling. The approaches are compared in simulation and applied to a dataset on sleeping behavior. The most powerful test depends on the particular departure from a Markov process, although the Cox-based method maintained good power in a wide range of scenarios. The proposed class of log-rank statistic based tests are most useful in situations where the non-Markov behavior does not persist, or is not uniform in nature across patient time.

PMID:35417532 | DOI:10.1093/biostatistics/kxaa030

Arq Bras Oftalmol. 2022 Mar 7:S0004-27492022005004208. doi: 10.5935/0004-2749.20230025. Online ahead of print.

ABSTRACT

PURPOSE: To investigate ocular surface and meibomian glands in patients with treatment-naive acne vulgaris.

METHODS: The Ocular Surface Disease Index (OSDI) questionnaire, invasive tear film breakup time, fluorescein staining of the ocular surface, and Schirmer II test were performed for all subjects. Total eyelid and meibomian gland secretion scores were assessed. Non-contact meibography was performed with the Sirius corneal topographic device.

RESULTS: The right eyes of 35 patients with acne vulgaris and 35 healthy volunteers were included the study. While the OSDI and staining scores were significantly higher in the acne group than in the control group (p=0.01 and p=0.003, respectively), the invasive tear film breakup time and Schirmer measurements were significantly lower in the acne group (p=0.000 and p=0.003, respectively). The total eyelid and meibomian gland secretion scores were also higher in the acne group than in the control group (p=0.003 and p=0.000, respectively). On the morphological evaluation of the meibomian glands, the thickening, thinning, tortuosity, and presence of ghost areas were statistically significantly more common in the acne vulgaris group than in the control group (p=0.000, p=0.001, p=0.05, and p=0.006, respectively). The percentage of the meibomian gland loss area was significantly high in the acne vulgaris group on both upper and lower meibography. The meibomian gland loss area positively correlated with total eyelid and meibomian gland secretion scores.

CONCLUSION: Acne vulgaris may have a predisposition to meibomian gland dysfunction and ocular surface damage. Early recognition of meibomian gland and ocular surface alterations seems important, especially in acne vulgaris cases for which oral isotretinoin treatment is planned.

PMID:35417517 | DOI:10.5935/0004-2749.20230025

Arq Bras Oftalmol. 2022 Mar 7:S0004-27492022005004206. doi: 10.5935/0004-2749.20230023. Online ahead of print.

ABSTRACT

PURPOSE: To evaluate the impact of social isolation due to the COVID-19 pandemic on the number of new cases and therapeutic approaches at the Ocular Oncology division from the Universidade Federal de São Paulo (UNIFESP).

METHODS: A retrospective study was conducted by medical records review of new patients treated before the pandemic from March 2019 to September 2019 (pre-pandemic group) and during the pandemic from March 2020 to September 2020 (pandemic group). Data regarding age, sex, ethnicity, place of origin, clinical diagnosis, time since referral, and proposed therapy were analyzed.

RESULTS: We analyzed 186 new cases, 122 from the pre-pandemic group and 64 from the pandemic group, representing a decrease of 47.54% in new cases. There was no statistically significant change in sex, race, state of origin, history of cancer, age, or time with suspected cancer (p>0.05). A higher frequency of malignancies was observed in the pandemic group (68%) when compared to the pre-pandemic group (48.48%). Benign tumors were the most common diagnosis in the pre-pandemic group (41.80%), while conjunctival squamous cell carcinoma was the modal diagnosis in the pandemic group (31.25%). There was a decreasing trend (p=0.097) in the number of surgeries (-7.63%) and an increase in topical treatment (+10.68%). There was also a tendency to perform fewer surgeries in benign tumors and decreased follow-up visits.

CONCLUSION: Our findings showed a significant decrease in the number of new cases referred to the Ocular Oncology service. Moreover, the pandemic led to a switch in the therapeutic approach with preference to non-invasive treatments that would demand operating rooms. A drastic increase of cases perhaps in advanced stages might be expected because of the decrease observed in the first six months of quarantine.

PMID:35417515 | DOI:10.5935/0004-2749.20230023

PLoS One. 2022 Apr 13;17(4):e0266970. doi: 10.1371/journal.pone.0266970. eCollection 2022.

ABSTRACT

INTRODUCTION: Machine learning (ML) accelerometer data processing methods have potential to improve the accuracy of device-based assessments of physical activity (PA) in young children. Yet the uptake of ML methods by health researchers has been minimal and the use of cut-points (CP) continues to be the norm, despite evidence of significant misclassification error. The lack of studies demonstrating a relative advantage for ML approaches over CP methods maybe a key contributing factor.

PURPOSE: The current study compared the accuracy of PA intensity predictions provided by ML classification models and previously published CPs for preschool-aged children.

METHODS: In a free-living study, 31 preschool-aged children (mean age = 4.0 ± 0.9 y) wore wrist and hip ActiGraph GT3X+ accelerometers while completing a video recorded 20-minute free play session. Ground truth PA intensity was coded continuously using the Children’s Activity Rating Scale (CARS). Accelerometer data was classified as sedentary (SED), light intensity (LPA), or moderate-to-vigorous intensity (MVPA) using ML random forest PA classifiers and published CPs for preschool-aged children. Performance differences were evaluated in a hold-out sample by comparing weighted kappa statistics, classification accuracy for each intensity band, and equivalence testing.

RESULTS: ML classification models (hip: κ = 0.76; wrist: κ = 0.72) exhibited significantly higher agreement with ground truth PA intensity than CP methods (hip: κ = 0.38-0.49; wrist: κ = 0.31-0.44). For the ML models, classification accuracy for SED and LPA ranged from 83% – 88%, while classification accuracy for MVPA ranged from 68% – 78%. For the CP’s, classification accuracy ranged from 50% – 94% for SED, 19% – 75% for LPA, and 44% – 76.1% for MVPA. ML classification models showed equivalence (within ± 0.5 SD) with directly observed time in SED, LPA, and MVPA. None of the CP’s exhibited evidence of equivalence.

CONCLUSIONS: Under free living conditions, ML classification models for hip or wrist accelerometer data provide more accurate assessments of PA intensity in young children than CP methods. The results demonstrate the relative advantage of ML methods over threshold-based approaches and adds to a growing evidence base supporting the feasibility and accuracy of ML accelerometer data processing methods.

PMID:35417492 | DOI:10.1371/journal.pone.0266970

PLoS One. 2022 Apr 13;17(4):e0266276. doi: 10.1371/journal.pone.0266276. eCollection 2022.

ABSTRACT

During the COVID-19 pandemic, there is a growing interest in online information about coronavirus worldwide. This study aimed to investigate the digital health literacy (DHL) level, information-seeking behaviour, and satisfaction of information on COVID-19 among East and South-East Asia university students. This cross-sectional web-based study was conducted between April to June 2020 by recruiting students from universities in China, Malaysia, and the Philippines. University students who have Internet access were invited to participate in the study. Items on sociodemographic variables, DHL, information-seeking behaviour, and information satisfaction were included in the questionnaire. Descriptive statistics and logistic regression analysis were conducted. A total of 5302 university students responded to the survey. The overall mean score across the four DHL subscales was 2.89 (SD: 0.42). Search engines (e.g., Google, Bing, Yahoo) (92.0%) and social media (88.4%) were highly utilized by the students, whereas Websites of doctors or health insurance companies were of lower utilization (64.7%). Across the domains (i.e., adding self-generated content, determining relevance, evaluating reliability, and protecting privacy) higher DHL was positively associated with higher usage of trustworthy resources. Providing online information on COVID-19 at official university websites and conducting health talks or web-based information dissemination about the strategies for mental health challenges during pandemic could be beneficial to the students. Strengthening DHL among university students will enhance their critical thinking and evaluation of online resources, which could direct them to the quality and trustworthy information sources on COVID-19.

PMID:35417478 | DOI:10.1371/journal.pone.0266276

PLoS One. 2022 Apr 13;17(4):e0263144. doi: 10.1371/journal.pone.0263144. eCollection 2022.

ABSTRACT

Citrus is a valuable crop in Pakistan. It is rich in vitamin C, other nutrients and antioxidants. Huanglongbing (HLB) caused by a bacterium “Candidatus liberibacter asiaticus” (CLas), africanus and americanus has an influence on citrus production around the world. Beside HLB there exist several other bacterial species in citrus groves in Pakistan. The structure and diversity of bacterial species in various ecosystems can be quickly examined using NGS. This approach is considerably quicker and more precise than outdated methods. Healthy or citrus greening infected leaf samples of Grapefruit (Citrus paradisi), C. aurantifolia, and C. reticulata Blanco were used for diversity analysis. In this study high throughput, NGS technique was used to access the population of both cultivable and non-cultivable bacterial endophytes from citrus leaves, by using PCR amplicons of 16S rDNA sequences (V5-V7 regions) with Illumina Hi seq. As a result, a total number of 68,722 sequences were produced from the test samples. According to the NGS-based diversity classification, the most common genera of exploited bacterial endophytes were Proteobacteria, Firmicutes, Bacteroides, Cyanobacteria, and Actinobacteria. C. aurantifolia and C. paradisi showed almost equal diversity, whereas C. reticulata Blanco had a higher proportion of Proteobacteria and Cyanobacteria in their leaves. To determine alpha diversity (AD), additional data was analyzed using statistical indices such as Shannon, Chao1, and Simpson. According to the inverse Simpson diversity index, the abundance of the microbial population in six different citrus samples was 0.48, 0.567, and 0.163, respectively. The metagenomics of microbiota in plant tissues was successfully recorded by NGS technology, which can help us learn more about the interactions between plants and microbes. This research is the first step toward a better understanding of 16SrRNA-based metagenomics from citrus in Pakistan using Illumina (Hi seq) Technology.

PMID:35417473 | DOI:10.1371/journal.pone.0263144

PLoS One. 2022 Apr 13;17(4):e0266364. doi: 10.1371/journal.pone.0266364. eCollection 2022.

ABSTRACT

The COVID-19 crisis forced many changes to occur within organizations, which were necessary to keep the continuance of the organization’s operations. Job performance seems to be an important factor determining such continuance, through its influence on the performance of entire organization. Shaping and keeping job performance in times of COVID-19 pandemic was a challenge for organizations, due to its negative impact on employees, causing their stress or lack of sense of security. There is a growing role of HRM specialists in appropriately shaping HRM strategies that can positively shape job-related attitudes, resulting in enhanced job performance during such difficult times. Therefore, this study aims to explain the role of COVID-19 oriented HRM strategies in shaping job performance through job-related attitudes such as work motivation, job satisfaction, and organizational commitment in a time of crisis occurring in the organization due to the COVID-19 pandemic. The study was conducted among 378 organizations operating in Poland during 2nd wave of COVID-19 pandemic. To verify the hypotheses, descriptive statistics were calculated using IBM SPSS and path analysis was performed using IBM AMOS. The result shows that combined set of “hard” HRM strategies related to the financial aspects and “soft” HRM strategies related to keeping employees’ wellbeing during the crisis gives the best results in shaping job performance through job-related attitudes and consequently strengthening organizational performance. This study contributes to the knowledge concerning the development of COVID-19 oriented HRM strategies, which may also have practical application.

PMID:35417468 | DOI:10.1371/journal.pone.0266364

PLoS One. 2022 Apr 13;17(4):e0265662. doi: 10.1371/journal.pone.0265662. eCollection 2022.

ABSTRACT

Alternative pet foods may offer benefits concerning environmental sustainability and the welfare of animals processed into pet foods. However, some worry these may compromise the welfare of pets. We asked 2,639 dog guardians about one dog living with them, for at least one year. Among 2,596 involved in pet diet decision-making, pet health was a key factor when choosing diets. 2,536 provided information relating to a single dog, fed a conventional meat (1,370 = 54%), raw meat (830 = 33%) or vegan (336 = 13%) diet for at least one year. We examined seven general indicators of ill health: unusual numbers of veterinary visits, medication use, progression onto a therapeutic diet after initial maintenance on a vegan or meat-based diet, guardian opinion and predicted veterinary opinion of health status, percentage of unwell dogs and number of health disorders per unwell dog. Dogs fed conventional diets appeared to fare worse than those fed either of the other two diets. Dogs fed raw meat appeared to fare marginally better than those fed vegan diets. However, there were statistically significant differences in average ages. Dogs fed raw meat were younger, which has been demonstrated to be associated with improved health outcomes. Additionally, non-health related factors may have improved apparent outcomes for dogs fed raw meat, for three of seven general health indicators. We also considered the prevalence of 22 specific health disorders, based on predicted veterinary assessments. Percentages of dogs in each dietary group considered to have suffered from health disorders were 49% (conventional meat), 43% (raw meat) and 36% (vegan). Significant evidence indicates that raw meat diets are often associated with dietary hazards, including nutritional deficiencies and imbalances, and pathogens. Accordingly, the pooled evidence to date indicates that the healthiest and least hazardous dietary choices for dogs, are nutritionally sound vegan diets.

PMID:35417464 | DOI:10.1371/journal.pone.0265662

PLoS One. 2022 Apr 13;17(4):e0263872. doi: 10.1371/journal.pone.0263872. eCollection 2022.

ABSTRACT

Environmental challenges are as wide as the universe so that its different dimensions can be the subject of diverse studies. In this research, using 17 data from Asia-Pacific during the period 2000 to 2017, an attempt has been made to investigate the economic factors responsible for the ecological footprint in the fishing sector. The main contribution of the present study is to investigate the effects of nine economic freedom indicators along with other control variables on environmental pressure on the status of fishery resources. Based on the results, the Kuznets curve hypothesis was confirmed in the fishing grounds footprint, so that the growth of GDP per capita shows a positive and significant effect, while its squared form coefficient is negative. Other control variables including natural resource rents, urbanization, and energy intensity, do not show significant effects on the fishing footprint. The different components of economic freedom show different effects, while their cumulative effects in the form of the total economic freedom index have a positive effect on the footprint of fishing and lead to increased extraction from fishing resources. The results show that the Government Integrity, Tax Burden, Business Freedom, Monetary Freedom indices increase the fishing footprint, while the indices of trade freedom and investment freedom, by revealing the negative effects on the fishing footprint, have beneficial environmental effects in reducing the pressure on the aquatic resources of countries. The results of the present study reveal the need to examine how the various dimensions of economic freedom affect to provide the proper management of fishery resources.

PMID:35417457 | DOI:10.1371/journal.pone.0263872

Clin Orthop Relat Res. 2022 Apr 13. doi: 10.1097/CORR.0000000000002212. Online ahead of print.

ABSTRACT

BACKGROUND: Strength testing of shoulder rotation is commonly used in clinical examinations of the shoulder. People prone to shoulder injury, such as overhead athletes and manual trade workers, place their shoulders under tremendous amounts of stress when the cervical spine is in nonneutral positions. If these nonneutral cervical spine positions result in decreased shoulder strength, it may help explain the etiology of the high prevalence of shoulder injuries in these populations. Given standard clinical strength assessments are performed with a neutral cervical spine, an investigation into the effects of cervical spine rotation is warranted.

QUESTIONS/PURPOSES: We sought to compare isokinetic shoulder rotation strength while in a neutral position with rotated cervical spine positions, specifically (1) with the cervical spine rotated contralaterally with the shoulder elevated in the frontal plane and (2) with the cervical spine rotated ipsilaterally and the shoulder elevated in the scapular plane.

METHODS: A convenience sample of 52 individuals (height 170 ± 10 cm; weight 73 ± 18 kg, age 21 ± 2 years; 18 males, 34 females), without shoulder or cervical spine pathology participated in this study. Participants were screened for eligibility via questionnaire. Concentric shoulder internal and external rotation torque was measured through a 90° arc on an isokinetic dynamometer with the shoulder elevated 90° in the frontal plane, and again 45° anterior to the frontal plane (scapular plane). Two repetitions were performed in a single testing session with the participant’s cervical spine in neutral in both planes, maximally rotated contralaterally in the frontal plane, and maximally rotated ipsilaterally with the shoulder in the scapular plane; the second repetition was used for analysis. The testing order was randomized. Data were imported into a platform for statistical parametric mapping analysis (a technique that allows data from the entire arc of motion to be compared with data from another arc to identify differences in the wave form) to compare strength between positions throughout 90° arc of motion.

RESULTS: Rotating the cervical spine contralaterally with the shoulder in the frontal plane resulted in a decrease in external (2.24 Nm or 12% average difference; p < 0.001) and internal (2.22 Nm or a 6% average difference; p = 0.02) rotation strength with the forearm within 15° and 20° of the vertical position. Rotating the cervical spine ipsilaterally with the shoulder in the scapular plane resulted in a decrease in external rotation strength (1.27 Nm or a 6% average difference; p < 0.001) throughout nearly all the motion, with peaks approximately 20° and 60° from the horizontal position, and internal rotation strength (1.78 Nm or 5% average difference; p < 0.001) the last 60° towards the horizontal position.

CONCLUSION: Patient populations who require strenuous use of their shoulders in altered cervical spine positions may be at increased risk for injury from decreased shoulder rotator strength.

CLINICAL RELEVANCE: Clinicians should assess shoulder strength in the position the patient requires to use their shoulder because cervical spine position may cause weakness that would be missed in standard testing positions.

PMID:35417438 | DOI:10.1097/CORR.0000000000002212