Browsing by Author "Kumar, Ashish"

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    ItemOpen Access
    A Causal View of the Role and Potential Limitations of Capitation in Promoting Whole Health System Performance.
    (International journal of environmental research and public health, 2023-03) Matchar, David Bruce; Lai, Wei Xuan; Kumar, Ashish; Ansah, John Pastor; Ng, Yeuk Fan
    For several decades, health systems in developed countries have faced rapidly rising healthcare costs without concomitant improvements in health outcomes. Fee for service (FFS) reimbursement mechanisms (RMs), where health systems are paid based on volume, contribute to this trend. In Singapore, the public health service is trying to curb rising healthcare costs by transitioning from a volume-based RM to a capitated payment for a population within a geographical catchment area. To provide insight into the implications of this transition, we developed a causal loop diagram (CLD) to represent a causal hypothesis of the complex relationship between RM and health system performance. The CLD was developed with input from government policymakers, healthcare institution administrators, and healthcare providers. This work highlights that the causal relationships between government, provider organizations, and physicians involve numerous feedback loops that drive the mix of health services. The CLD clarifies that a FFS RM incentivizes high margin services irrespective of their health benefits. While capitation has the potential to mitigate this reinforcing phenomenon, it is not sufficient to promote service value. This suggests the need to establish robust mechanisms to govern common pool resources while minimizing adverse secondary effects.
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    ItemOpen Access
    Analysis of DNA methylation at birth and in childhood reveals changes associated with season of birth and latitude.
    (Clinical epigenetics, 2023-09) Kadalayil, Latha; Alam, Md Zahangir; White, Cory Haley; Ghantous, Akram; Walton, Esther; Gruzieva, Olena; Merid, Simon Kebede; Kumar, Ashish; Roy, Ritu P; Solomon, Olivia; Huen, Karen; Eskenazi, Brenda; Rzehak, Peter; Grote, Veit; Langhendries, Jean-Paul; Verduci, Elvira; Ferre, Natalia; Gruszfeld, Darek; Gao, Lu; Guan, Weihua; Zeng, Xuehuo; Schisterman, Enrique F; Dou, John F; Bakulski, Kelly M; Feinberg, Jason I; Soomro, Munawar Hussain; Pesce, Giancarlo; Baiz, Nour; Isaevska, Elena; Plusquin, Michelle; Vafeiadi, Marina; Roumeliotaki, Theano; Langie, Sabine AS; Standaert, Arnout; Allard, Catherine; Perron, Patrice; Bouchard, Luigi; van Meel, Evelien R; Felix, Janine F; Jaddoe, Vincent WV; Yousefi, Paul D; Ramlau-Hansen, Cecilia H; Relton, Caroline L; Tobi, Elmar W; Starling, Anne P; Yang, Ivana V; Llambrich, Maria; Santorelli, Gillian; Lepeule, Johanna; Salas, Lucas A; Bustamante, Mariona; Ewart, Susan L; Zhang, Hongmei; Karmaus, Wilfried; Röder, Stefan; Zenclussen, Ana Claudia; Jin, Jianping; Nystad, Wenche; Page, Christian M; Magnus, Maria; Jima, Dereje D; Hoyo, Cathrine; Maguire, Rachel L; Kvist, Tuomas; Czamara, Darina; Räikkönen, Katri; Gong, Tong; Ullemar, Vilhelmina; Rifas-Shiman, Sheryl L; Oken, Emily; Almqvist, Catarina; Karlsson, Robert; Lahti, Jari; Murphy, Susan K; Håberg, Siri E; London, Stephanie; Herberth, Gunda; Arshad, Hasan; Sunyer, Jordi; Grazuleviciene, Regina; Dabelea, Dana; Steegers-Theunissen, Régine PM; Nohr, Ellen A; Sørensen, Thorkild IA; Duijts, Liesbeth; Hivert, Marie-France; Nelen, Vera; Popovic, Maja; Kogevinas, Manolis; Nawrot, Tim S; Herceg, Zdenko; Annesi-Maesano, Isabella; Fallin, M Daniele; Yeung, Edwina; Breton, Carrie V; Koletzko, Berthold; Holland, Nina; Wiemels, Joseph L; Melén, Erik; Sharp, Gemma C; Silver, Matt J; Rezwan, Faisal I; Holloway, John W

    Background

    Seasonal variations in environmental exposures at birth or during gestation are associated with numerous adult traits and health outcomes later in life. Whether DNA methylation (DNAm) plays a role in the molecular mechanisms underlying the associations between birth season and lifelong phenotypes remains unclear.

    Methods

    We carried out epigenome-wide meta-analyses within the Pregnancy And Childhood Epigenetic Consortium to identify associations of DNAm with birth season, both at differentially methylated probes (DMPs) and regions (DMRs). Associations were examined at two time points: at birth (21 cohorts, N = 9358) and in children aged 1-11 years (12 cohorts, N = 3610). We conducted meta-analyses to assess the impact of latitude on birth season-specific associations at both time points.

    Results

    We identified associations between birth season and DNAm (False Discovery Rate-adjusted p values < 0.05) at two CpGs at birth (winter-born) and four in the childhood (summer-born) analyses when compared to children born in autumn. Furthermore, we identified twenty-six differentially methylated regions (DMR) at birth (winter-born: 8, spring-born: 15, summer-born: 3) and thirty-two in childhood (winter-born: 12, spring and summer: 10 each) meta-analyses with few overlapping DMRs between the birth seasons or the two time points. The DMRs were associated with genes of known functions in tumorigenesis, psychiatric/neurological disorders, inflammation, or immunity, amongst others. Latitude-stratified meta-analyses [higher (≥ 50°N), lower (< 50°N, northern hemisphere only)] revealed differences in associations between birth season and DNAm by birth latitude. DMR analysis implicated genes with previously reported links to schizophrenia (LAX1), skin disorders (PSORS1C, LTB4R), and airway inflammation including asthma (LTB4R), present only at birth in the higher latitudes (≥ 50°N).

    Conclusions

    In this large epigenome-wide meta-analysis study, we provide evidence for (i) associations between DNAm and season of birth that are unique for the seasons of the year (temporal effect) and (ii) latitude-dependent variations in the seasonal associations (spatial effect). DNAm could play a role in the molecular mechanisms underlying the effect of birth season on adult health outcomes.
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    ItemOpen Access
    Hydrogel nanotubes with ice helices as exotic nanostructures for diabetic wound healing
    (Materials Horizons) Singh, Aarti; Bhattacharya, Rohan; Shakeel, Adeeba; Sharma, Arun Kumar; Jeevanandham, Sampathkumar; Kumar, Ashish; Chattopadhyay, Sourav; Bohidar, Himadri B; Ghosh, Sourabh; Chakrabarti, Sandip; Rajput, Satyendra K; Mukherjee, Monalisa

    Hydrogel nanotubes with ice helices entrapped within their internal conduits are a promising material for diabetic wound healing.