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Nevin Manimala Statistics

Change-plane analysis for subgroup detection with a continuous treatment

Biometrics. 2022 Sep 22. doi: 10.1111/biom.13762. Online ahead of print.

ABSTRACT

Detecting and characterizing subgroups with differential effects of a binary treatment has been widely studied and led to improvements in patient outcomes and population risk management. Under the setting of a continuous treatment, however, such investigations remain scarce. We propose a semiparametric change-plane model and consequently a doubly robust test statistic for assessing the existence of two subgroups with differential treatment effects under a continuous treatment. The proposed testing procedure is valid when either the baseline function for the covariate effects or the generalized propensity score function for the continuous treatment is correctly specified. The asymptotic distributions of the test statistic under the null and local alternative hypotheses are established. When the null hypothesis of no subgroup is rejected, the change-plane parameters that define the subgroups can be estimated. This paper provides a unified framework of the change-plane method to handle various types of outcomes, including the exponential family of distributions and time-to-event outcomes. Additional extensions with nonparametric estimation approaches are also provided. We evaluate the performance of our proposed methods through extensive simulation studies under various scenarios. An application to the Health Effects of Arsenic Longitudinal Study with a continuous environmental exposure of arsenic is presented. This article is protected by copyright. All rights reserved.

PMID:36134534 | DOI:10.1111/biom.13762

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Nevin Manimala Statistics

Distribution and statistical analysis of major and trace elements in the bee pollen from the territory of Republic of Kosovo

J Environ Sci Health A Tox Hazard Subst Environ Eng. 2022 Sep 22:1-11. doi: 10.1080/10934529.2022.2125738. Online ahead of print.

ABSTRACT

The objective of this study was the determination of major and trace elements in the bee pollen samples from the whole territory of Republic of Kosovo. Pollen, as a natural plant product, is exposed to different contaminations absorbed by plants from the soil through the root system or with water intake, as well as to pollutants of different origins, including anthropogenic ones, deposited directly on pollen. In total 67 pollen samples were collected in 2019. The samples were analyzed for 27 macro and microelements by using ICP-AES and ICP-MS. The mean content of major elements in bee pollen was 4065, 3455, 1375 and 549 mg/kg for K, P, Ca and Mg, respectively. The range of the contents for some potentially toxic elements was 11.9-139.1, 1.9-16, 0.11-6.25, 0.01-0.329 and 0.001-0.38 mg/kg for Zn, Cu, Pb, Cd and As, respectively. Three groups of elements of mixed origin were identified through factor analysis: the first and the third Factors, are mostly of geogenic origin (Ag, Li, Al, Fe, Ca, Sr, K, Mg and P and Co, Ni, Cr, Cu and Mn) and the second Factor association is related to anthropogenic processes (Sb, As, Pb, Tl, Sn and Cd).

PMID:36134509 | DOI:10.1080/10934529.2022.2125738

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Nevin Manimala Statistics

Reaction of OH radicals with CH3NH2 in the gas phase: experimental (11.7-177.5 K) and computed rate coefficients (10-1000 K)

Phys Chem Chem Phys. 2022 Sep 22. doi: 10.1039/d2cp03414j. Online ahead of print.

ABSTRACT

Nitrogen-bearing molecules, like methylamine (CH3NH2), can be the building blocks of amino acids in the interstellar medium (ISM). At the ultralow temperatures of the ISM, it is important to know its gas-phase reactivity towards interstellar radicals and the products formed. In this work, the kinetics of the OH + CH3NH2 reaction was experimentally and theoretically investigated at low- and high-pressure limits (LPL and HPL) between 10 and 1000 K. Moreover, the CH2NH2 and CH3NH yields were computed in the same temperature range for both pressure regimes. A pulsed CRESU (French acronym for Reaction Kinetics in a Uniform Supersonic Flow) apparatus was employed to determine the rate coefficient, k(T), in the 11.7-177.5 K range. A drastic increase of k(T) when the temperature is lowered was observed in agreement with theoretical calculations, evaluated by the competitive canonical unified statistical (CCUS) theory, below 300 K in the LPL regime. The same trend was observed in the HPL regime below 350 K, but the theoretical k(T) values were higher than the experimental ones. Above 200 K, the calculated rate coefficients are improved with respect to previous computational studies and are in excellent agreement with the experimental literature data. In the LPL, the formation of CH3NH becomes largely dominant below ca. 100 K. Conversely, in the HPL regime, CH2NH2 is the only product below 100 K, whereas CH3NH becomes dominant at 298 K with a branching ratio similar to the one found in the LPL regime (≈70%). At T > 300 K, both reaction channels are competitive independently of the pressure regime.

PMID:36134502 | DOI:10.1039/d2cp03414j

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Nevin Manimala Statistics

Investigation of care burden and musculoskeletal pain of parents of paediatric palliative care patients in Turkey

East Mediterr Health J. 2022 Aug 31;27(8):569-576. doi: 10.26719/emhj.22.063.

ABSTRACT

BACKGROUND: Caring for a paediatric patient is associated with psychological, physical and social challenges. It may be easy to identify the emotional effects of caregiving burden on parents, but the physical effects are often not known.

AIMS: We aimed to examine the relationship between caregiver burden and musculoskeletal pain in caregiver parents of children accessing palliative care services.

METHODS: This was a cross-sectional study among caregiving parents of paediatric palliative care patients, conducted between 15 July 2020 and 15 January 2021. The care burden was examined using the Zarit Caregiver Burden Questionnaire, and the physical complaints of parents with the Extended Nordic Musculoskeletal Questionnaire.

RESULTS: A total of 69 caregiving parents were included in the study. The median Zarit Caregiver Burden score was 54.0. In parents with pain complaints, the most common pain areas were lower back (62.3%), back (60.9%) and neck (42.0%). Pain was statistically significantly associated with the duration of the disease in the child, especially shoulder pain (P = 0.023) and wrist pain (P = 0.024).

CONCLUSION: Lower back pain was observed at a higher rate among caregiving parents. As the duration of the child’s illness increased, the number of caregiver parents with shoulder and wrist pain increased. It is important to extend support to caregivers of paediatric palliative care patients to alleviate their physical difficulties.

PMID:36134489 | DOI:10.26719/emhj.22.063

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Nevin Manimala Statistics

Ethnic and socioeconomic disparities in initiation of second-line antidiabetic treatment in people with type 2 diabetes in England: a cross-sectional study

Diabetes Obes Metab. 2022 Sep 22. doi: 10.1111/dom.14874. Online ahead of print.

ABSTRACT

AIMS: To assess any disparities in the initiation of second-line antidiabetic treatments prescribed among people with type 2 diabetes mellitus (T2DM) in England according to ethnicity and social deprivation.

MATERIAL AND METHODS: This cross-sectional study used linked primary (Clinical Practice Research Datalink) and secondary care data (Hospital Episode Statistics), and the Index of Multiple Deprivation (IMD). We included people aged 18 years or older with T2DM who intensified to second-line oral antidiabetic medication between 2014-2020 to investigate disparities in second-line antidiabetic treatment prescribing (one of sulfonylureas (SU), dipeptidyl peptidase 4 inhibitors (DPP4i), or sodium-glucose co-transporter 2 inhibitors (SGLT2i), in combination with metformin) by ethnicity (white, South Asian, black, mixed/other) and deprivation (IMD quintiles). We reported prescriptions of the alternative treatments by ethnicity and deprivation according to predicted percentages derived from multivariable, multinomial logistic regression.

RESULTS: Among 36,023 people, 85% were white, 10% South Asian, 4% black, and 1% mixed/other. After adjustment, the predicted percentages for SGLT2i prescribing by ethnicity were 21% [95% CI 19-23%], 20% [95% CI 18-22%], 19% [95% CI 16-22%], and 17% [95% CI 14-21%) among people with white, South Asian, black, and mixed/other ethnicity, respectively. After adjustment, the predicted percentages for SGLT2i prescribing by deprivation were 22% [95% CI 20-25%] and 19% [95% CI 17-21%] for the least deprived and the most deprived quintiles, respectively. When stratifying by prevalent cardiovascular disease (CVD) status, we found lower predicted percentages of people with prevalent CVD prescribed SGLT2i compared with people without prevalent CVD across all ethnicity groups and all levels of social deprivation.

CONCLUSIONS: Among people with T2DM, there were no substantial differences by ethnicity or deprivation in the percentage prescribed either SGLT2i, DPP4i, or SU as second-line antidiabetic treatment. This article is protected by copyright. All rights reserved.

PMID:36134467 | DOI:10.1111/dom.14874

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Nevin Manimala Statistics

The theoretical and practical arguments against the unilateral withdrawal of life-sustaining treatment during crisis standards of care: Does the Knobe effect apply to unilateral withdrawal?

Bioethics. 2022 Sep 22. doi: 10.1111/bioe.13093. Online ahead of print.

ABSTRACT

Some argue that it is ethically justifiable to unilaterally withdraw life-sustaining treatment during crisis standards of care without the patient’s consent in order to reallocate it to another patient with a better chance of survival. This justification has been supported by two lines of argument: the equivalence thesis and the rule of the double effect. We argue that there are theoretical issues with the first and practical ones with the second, as supported by an experiment aimed at exploring whether the Knobe effect, which affects the folk concept of intention, applies to situations of unilateral withdrawal. Fifty-two critical care physicians from one university were asked to ascribe intention in two hypothetical scenarios A and B in which outcomes differ-the patient from whom life-sustaining treatment is withdrawn dies in scenario A but survives in scenario B-but the intention, to save the other patient regardless of the outcome of the other, is the same. The survey was administered via a web-based survey and all answers were anonymous. A paired proportion test was used to compare responses to both questions. All 52 surveyed individuals responded in scenario A and 30 (57.7%) ascribed intention when outcomes were unfavorable, whereas 50 responded in scenario B and 8 (16%) ascribed intention when outcomes were favorable, a difference that was statistically significant (p < 0.001). There are theoretical and practical issues with the arguments proposed to justify the unilateral withdrawal of life-sustaining treatment based on the equivalence thesis and the rule of double effect.

PMID:36134462 | DOI:10.1111/bioe.13093

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Nevin Manimala Statistics

Telediagnosis of dental caries: Possible or impossible? A pilot cross-sectional study

Clin Exp Dent Res. 2022 Sep 22. doi: 10.1002/cre2.663. Online ahead of print.

ABSTRACT

OBJECTIVES: The aims of this study were to evaluate the effectiveness of teledentistry (based on a home intraoral imaging protocol) in detecting dental caries and to assess the accuracy of this method compared to clinical examination.

METHODS: Forty-three patients were recruited for the study. Using a protocol for taking intraoral photographs at home with a smartphone proposed by the Dental School of Verona, a remote diagnosis of dental caries (TD) was performed by an experienced dentist. The same caries sites were also assessed by clinical diagnosis (CD) by a second experienced dentist. Ten photos were taken at home in five different perspectives, with and without flash, and emailed to one of the authors. The best five photos were selected for telediagnosis. The International Caries Detection and Assessment System (ICDAS II) score was used for caries diagnosis. Statistical tests were performed: Sensitivity and specificity of TD, the positive and negative predictive value of TD (PPV-NPV), and Spearman correlation to evaluate the relationship between the scores of TD and CD.

RESULTS: A total of 430 photographs were submitted; TD was performed on 215 photographs and 43 patients were visited. A total of 1201 teeth were analyzed. The sensitivity of TD was 74.0, the specificity was 99.1, the PPV of TD was 91.7, and the NPV was 96.4. The Spearman correlation was 0.816, showing a very strong correlation between the values obtained with TD and CD.

CONCLUSIONS: The study showed good potential for TD, which proved to be a feasible method to combine with routine caries diagnosis in daily preventive dentistry practice.

PMID:36134446 | DOI:10.1002/cre2.663

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Nevin Manimala Statistics

Burden and Determinants of Anemia among Under-Five Children in Africa: Systematic Review and Meta-Analysis

Anemia. 2022 Sep 11;2022:1382940. doi: 10.1155/2022/1382940. eCollection 2022.

ABSTRACT

INTRODUCTION: Globally, anemia among under-five children is a serious public health problem. Even if there are pocket studies here and there, there is limited evidence on the pooled prevalence of anemia among under-five children in Africa. Therefore, the aim of this study was to determine the pooled prevalence and determinants of anemia. Methods and Analysis. This systematic review and meta-analysis was done following the PRISMA guidelines. A comprehensive search was made in PubMed/MEDLINE, Cochrane Library, HINARI, and Ethiopian Journal of Health Development for studies published since 2009. It was supplemented with Google Scholar search. Study selection, data extraction, and quality of studies were assessed by eight reviewers. The Cochrane Q test and I 2 test statistic were used to test the heterogeneity of studies. A random-effects model of DerSimonian-Laird method was used.

RESULT: A total of 37 articles were included in this systematic review and meta-analysis. The pooled prevalence of anemia among under-five children in Africa was 59% (95% CI: 55, 63). Being female (AOR = 0.71; 95% CI: 0.57, 0.87), maternal education (AOR = 1.47; 95% CI: 1.31, 1.66), residence (AOR = 0.80; 95% CI: 0.67, 0.95), and family size (AOR = 0.93; 95% CI: 0.89, 0.98) were the determinants of anemia among African under-five children. Conclusion and Recommendation. This pooled study revealed that anemia was a severe public health problem. Sex, maternal education, residence, and family size were the determinants of anemia. Therefore, anemia prevention strategy should include sex consideration, educating mothers through youth education, area specific intervention, and encouraging birth spacing.

PMID:36134386 | PMC:PMC9482935 | DOI:10.1155/2022/1382940

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Nevin Manimala Statistics

Inverse Probability Weighting Enhances Absolute Risk Estimation in Three Common Study Designs of Nosocomial Infections

Clin Epidemiol. 2022 Sep 14;14:1053-1064. doi: 10.2147/CLEP.S357494. eCollection 2022.

ABSTRACT

PURPOSE: When studying nosocomial infections, resource-efficient sampling designs such as nested case-control, case-cohort, and point prevalence studies are preferred. However, standard analyses of these study designs can introduce selection bias, especially when interested in absolute rates and risks. Moreover, nosocomial infection studies are often subject to competing risks. We aim to demonstrate in this tutorial how to address these challenges for all three study designs using simple weighting techniques.

PATIENTS AND METHODS: We discuss the study designs and explain how inverse probability weights (IPW) are applied to obtain unbiased hazard ratios (HR), odds ratios and cumulative incidences. We illustrate these methods in a multi-state framework using a dataset from a nosocomial infections study (n = 2286) in Moscow, Russia.

RESULTS: Including IPW in the analysis corrects the unweighted naïve analyses and enables the estimation of absolute risks. Resulting estimates are close to the full cohort estimates using substantially smaller numbers of patients.

CONCLUSION: IPW is a powerful tool to account for the unequal selection of controls in case-cohort, nested case-control and point prevalence studies. Findings can be generalized to the full population and absolute risks can be estimated. When applied to a multi-state model, competing risks are also taken into account.

PMID:36134385 | PMC:PMC9482967 | DOI:10.2147/CLEP.S357494

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Nevin Manimala Statistics

Value assessment of medicinal products by the Italian Medicines Agency (AIFA) and French National Authority for Health (HAS): Similarities and discrepancies

Front Med Technol. 2022 Sep 5;4:917151. doi: 10.3389/fmedt.2022.917151. eCollection 2022.

ABSTRACT

The evaluation of pharmaceutical innovation and therapeutic value is an increasingly complex exercise for which different approaches are adopted at the national level, despite the need for standardisation of processes and harmonisation of public health decisions. The objective of our analysis was to compare the approaches of the AIFA (Agenzia Italiana del Farmaco) and the HAS (Haute Autorité de Santé) in assessing the same medicinal products. In Italy, the 1525/2017 AIFA Deliberation introduces a transparent scheme for the evaluation of innovative status (innovative, conditional, not innovative) based on the therapeutic added value (TAV), therapeutic need, and quality of evidence. In contrast, in France, the HAS makes judgements using the effective clinical benefit (Service Médical Rendu) and improvement of effective clinical benefit (Amélioration du Service Médical Rendu, ASMR). This analysis focused on medicinal products evaluated both by the AIFA and by the HAS from July 2017 to September 2021. Similarities between AIFA and HAS evaluations were investigated in terms of the TAV, recognition of innovativeness, and the ASMR. Both total and partial agreements were considered relevant. Therefore, raw agreement, Cohen’s kappa (weighted and unweighted), and Bangdiwala’s B-statistic were estimated. A total of 102 medicinal products were included in this study. Out of these, 38 (37.2%) were orphan drugs, while 56 (54.9%) had a clinical indication for the treatment of cancer. The AIFA and HAS reached a higher level of agreement on the innovativeness status compared with the TAV. A moderate total agreement emerged in the recognition of innovativeness (k = 0.463, p-value ≤0.0001), and partial agreement was substantial (equal weight k = 0.547, squared k = 0.638), while a lack of agreement resulted in a comparison of the TAV according to the AIFA and the ASMR recognised by the HAS. Indeed, whereas the AIFA determined the TAV to be important, the HAS considered it to be moderate. In addition, whereas the AIFA identified a bias towards a moderate TAV, the HAS identified a bias towards a minor ASMR. A higher level of agreement was reached, both on the TAV and on innovative status, for less critical medical products (non-cancer-related, or non-orphan, or with a standard European Medicines Agency approval). These results underline the importance of implementing European procedures that are more broadly aligned in terms of value definition criteria.

PMID:36134249 | PMC:PMC9483157 | DOI:10.3389/fmedt.2022.917151