scispace - formally typeset
Search or ask a question
Author

Pawan Kumar Yadav

Bio: Pawan Kumar Yadav is an academic researcher from International Institute for Population Sciences. The author has contributed to research in topics: Life expectancy & Case fatality rate. The author has an hindex of 1, co-authored 5 publications receiving 14 citations.

Papers
More filters
Posted ContentDOI
16 May 2020-medRxiv
TL;DR: It is found that one person is likely to infect two to three persons in the absence of any control measures, and around three per cent of the population are at the risk of death within one-and-a-half months from the onset of disease COVID-19 in a generalised population.
Abstract: Background The outbreak of novel coronavirus disease of 2019 (COVID-19) has a wider geographical spread than other previous viruses such as Ebola and H1N1. The onset of disease and its transmission and severity has become a global concern. The policymakers have a serious concern for containing the spread and minimising the risk of death. Aim This study aims to provide the estimates of basic reproduction rate (R0) and case fatality rate (CFR) which applies to a generalised population. Methods A systematic review was carried out to retrieve the published estimates of reproduction rate and case fatality rate in peer-reviewed articles from PubMed MEDLINE database with defined inclusion and exclusion criteria in the period 15 December 2019 to 3 May 2020. The systematic review led to the selection of 24 articles for R0 and 17 articles for CFR. These studies used data from China and its provinces, other Asian countries such as Japan, Korea, the Philippines, and countries from other parts of the world such as Nigeria, Iran, Italy, Europe as a whole, France, Latin America, Turkey, the United Kingdom (UK), and the United States of America (USA). These selected articles gave an output of 30 counts of R0 and 29 counts of CFR which were used in a meta-analysis. A meta-analysis, with the inverse variance method, fixed- and random-effects model and the Forest plot, was performed to estimate the mean effect size or mean value of basic reproduction rate and case fatality rate. The Funnel plot is used to comprehend the publication bias. Results We estimated the robust estimate of R0 at 3.11 (2.49–3.71) persons and the robust estimate of CFR at 2.56 (2.06–3.05) per cent after accounting for heterogeneity among studies, using the random-effects model. The regional subgroup analysis in a meta-analysis was significant for R0 but was not significant for CFR. The R0 values varied from 1.90 (1.06–2.74) persons to 3.83 (2.44–5.22) persons across the regions. The Funnel plot confirms that the selected studies are significant at one per cent level of significance. Conclusion We found that one person is likely to infect two to three persons in the absence of any control measures, and around three per cent of the population are at the risk of death within one-and-a-half months from the onset of disease COVID-19 in a generalised population. The emergence of SARS-CoV-2 varies across regions, but the risk of death remains the same. Contribution The estimates of R0 and CFR are independent of data from a particular region or time or a homogeneous population. These estimates are applicable to a generalised population. Therefore, the estimates of R0 and CFR are unequivocally applicable to developing country like India and its states or districts, in ambivalence. The assessments of R0 and CFR values across the developed nations make all of us aware of consequences of COVID-19, and hence these estimates are of crucial importance for government authorities for the practical implementation of strategies and control measures to contain the disease. Research Highlights The robust estimate of Basic Reproduction Rate (R0) of COVID-19 based on a meta-analysis performed on the pieces of evidence available across countries is 3.11 (2.49–3.71) persons for a generalised population in the absence of any control measures The robust estimate of Case Fatality Rate (CFR) based on a meta-analysis performed on the pieces of evidence available across countries equals to 2.56 (2.06–3.05) per cent for a generalised population in approximately one-and-a-half months from the onset of the disease COVID-19. A significant regional variation is evident for the Basic Reproduction Rate (R0) but not for the Case Fatality Rate (CFR) The peer-reviewed articles with a small sample size do not suffer from publication bias in a meta-analysis of COVID-19. Added Value of this Study Out study combine available evidence of the parameter values, such as reproduction rate and case fatality rate, of the generalised epidemiological models for coronavirus disease of 2019 (COVID-19). In this way, we have reduced the dependency on data from a particular region or time or a homogeneous population. By applying meta-analysis, we estimated the robust estimate of reproduction rate and case fatality rate, which is applicable across heterogeneous populations. We proclaim that the reproduction rate of COVID-19 varies across subgroups of populations and regions and periods, but the case fatality rate remained the same. These estimates of reproduction rate and case fatality rate are worthwhile for developing countries like India and at a lower level of geography, in ambivalence.

16 citations

Journal ArticleDOI
TL;DR: In this paper, the authors examined the association between physical limitations and self-reported depressive symptoms and moderating role of marital status in such association separately for men and women in the Longitudinal Ageing Study in India (LASI) wave 1, 2017-2018.
Abstract: Background Depression among the elderly is well-documented and associated with socio-economic factors, physical and mental health conditions. Few studies have focused on older adults' physical limitations and depressive symptoms. However, very little is known about marital status' role in such associations, especially in India. The present study examines the association between physical limitations and self-reported depressive symptoms and moderating role of marital status in such association separately for men and women. Methods The present study used data from the Longitudinal Ageing Study in India (LASI) wave 1, 2017-2018, a nationally and state representative longitudinal large-scale survey of ageing and health. For the present research, a total sample of 20,806 older adults aged 60+ years was selected after excluding missing values. Along with descriptive statistics, binary logistic regression analysis and interaction effect of marital status were applied to examine the association between physical limitations (functional limitations and mobility difficulty) with the depressive symptoms separately for men and women. Results About 58, 50, and 45% elderly reported having depressive symptoms and had difficulty in 2+ ADLs, 2+ IADLs, and 2+ mobility difficulties, respectively. By the marital status, the prevalence of depressive symptoms was higher among currently unmarried than currently married, irrespective of type and number of physical limitations. The unadjusted, marital and multivariate-adjusted association suggested that elderly with more than two ADLs, IADLs, and mobility difficulty had higher odds of depressive symptoms. The gender stratified interaction effect of marital status and physical limitations on depressive symptoms indicated that currently unmarried elderly, particularly unmarried older women with 2+ ADLs (OR = 2.85; CI 95% = 1.88-3.09), 2+ IADLs (OR = 2.01; CI 95% = 1.74-2.31) and 2+ mobility difficulty (OR = 2.20; CI 95% = 1.86-2.60) had higher odds of depressive symptoms. However, such association was only valid for unmarried men having mobility difficulty. Conclusion The study highlights that the elderly with physical limitations such as ADLs, IADLs, and mobility difficulty require attention and care. Although married elderly are less likely to have depressive symptoms even with all the mentioned physical limitations, unmarried women are more vulnerable to have depressive symptoms with physical limitations.

13 citations

Journal ArticleDOI
TL;DR: In this paper, the authors quantified excess deaths and their impact on life expectancy at birth (e0) provide a more comprehensive understanding of the burden of coronavirus disease of 2019 (COVID-19) on mortality.
Abstract: Background Quantifying excess deaths and their impact on life expectancy at birth (e0) provide a more comprehensive understanding of the burden of coronavirus disease of 2019 (COVID-19) on mortality. The study aims to comprehend the repercussions of the burden of COVID-19 disease on the life expectancy at birth and inequality in age at death in India. Methods The mortality schedule of COVID-19 disease in the pandemic year 2020 was considered one of the causes of death in the category of other infectious diseases in addition to other 21 causes of death in the non-pandemic year 2019 in the Global Burden of Disease (GBD) data. The measures e0 and Gini coefficient at age zero (G0) and then sex differences in e0 and G0 over time were analysed by assessing the age-specific contributions based on the application of decomposition analyses in the entire period of 2010-2020. Results The e0 for men and women decline from 69.5 and 72.0 years in 2019 to 67.5 and 69.8 years, respectively, in 2020. The e0 shows a drop of approximately 2.0 years in 2020 when compared to 2019. The sex differences in e0 and G0 are negatively skewed towards men. The trends in e0 and G0 value reveal that its value in 2020 is comparable to that in the early 2010s. The age group of 35-79 years showed a remarkable negative contribution to Δe0 and ΔG0. By causes of death, the COVID-19 disease has contributed - 1.5 and - 9.5%, respectively, whereas cardiovascular diseases contributed the largest value of was 44.6 and 45.9%, respectively, to sex differences in e0 and G0 in 2020. The outcomes reveal a significant impact of excess deaths caused by the COVID-19 disease on mortality patterns. Conclusions The COVID-19 pandemic has negative repercussions on e0 and G0 in the pandemic year 2020. It has severely affected the distribution of age at death in India, resulting in widening the sex differences in e0 and G0. The COVID-19 disease demonstrates its potential to cancel the gains of six to eight years in e0 and five years in G0 and has slowed the mortality transition in India.

9 citations

Posted ContentDOI
18 Sep 2020-medRxiv
TL;DR: The exponential model unravels the uncertainty about the peak and curvature of COVID-19 disease, and shows that the SARIMA model is suitable for projecting daily confirmed cases.
Abstract: Introduction: Following the USA, India ranks the second position in the world for COVID 19 cases with the highest number of daily confirmed cases since September 2020. The peak of COVID-19 cases is the most warranted feature for understanding the curvature of COVID 19 cases. Aim: This study aims to analyse the growth rates of the daily confirmed cases and to provide an expected count of the peak of daily confirmed cases. Data: We retrieved data from an Application Programming Interface portal https://www.covid19india.org/ which is open access and publicly available. Methods: Exponential model was applied to estimate the growth rates of daily confirmed cases. The estimated growth rates were used for calculating the doubling time. The Lotka Euler method was applied to calculate the effective reproduction rate. SARIMA model was developed for the growth rates to predict daily confirmed cases. Results: Results show the best fit of the exponential model over the daily confirmed cases. The growth rates estimated from the exponential model shows an unsteady, modest decline. Doubling time shows a linear increase. The effective reproduction rate declined from 3.6 persons in the third week of March 2020 to 1.14 persons at the end of August 2020. The diagnosis of the developed SARIMA model confirmed no trends in the residuals, no outliers, and nearly constant variance. The forecast suggests the peak value of daily confirmed cases would waver around 105,000 counts in the last week of September 2020. The cumulative COVID-19 cases would account for approximately 105 lakhs at the end of December 2020. Conclusion: The exponential model unravels a shift and a modest decline in the growth of daily confirmed cases. The trends in R(t) show analogue with the trends in growth rates of daily confirmed cases. The study shows that the SARIMA model is suitable for projecting daily confirmed cases. The results shed light on the understanding of the trends and epidemiological stage of COVID-19 disease, in the cognisance of the peak. Contribution: This study based on moments of the distribution of the daily confirmed cases of COVID-19 disease unravels the uncertainty about the peak and curvature of COVID-19 disease. Keywords: COVID-19, SARS-CoV-2, Exponential model, ARIMA, Effective Reproduction rate, Growth rates, Pandemic

3 citations


Cited by
More filters
Journal ArticleDOI
19 Feb 2021-Science
TL;DR: The results indicate that, by using effective interventions, some countries could control the epidemic while avoiding stay-at-home orders, and this model accounts for uncertainty in key epidemiological parameters, such as the average delay from infection to death.
Abstract: Governments are attempting to control the COVID-19 pandemic with nonpharmaceutical interventions (NPIs). However, the effectiveness of different NPIs at reducing transmission is poorly understood. We gathered chronological data on the implementation of NPIs for several European, and other, countries between January and the end of May 2020. We estimate the effectiveness of NPIs, ranging from limiting gathering sizes, business closures, and closure of educational institutions to stay-at-home orders. To do so, we used a Bayesian hierarchical model that links NPI implementation dates to national case and death counts and supported the results with extensive empirical validation. Closing all educational institutions, limiting gatherings to 10 people or less, and closing face-to-face businesses each reduced transmission considerably. The additional effect of stay-at-home orders was comparatively small.

674 citations

Journal ArticleDOI
24 Mar 2021-PLOS ONE
TL;DR: In this paper, a representative longitudinal online survey of over 3000 adults from Australia that examines the demographic, attitudinal, political and social attitudes and COVID-19 health behavior correlates of vaccine hesitance and resistance to a COVID19 vaccine was conducted.
Abstract: BACKGROUND: High levels of vaccination coverage in populations will be required even with vaccines that have high levels of effectiveness to prevent and stop outbreaks of coronavirus. The World Health Organisation has suggested that governments take a proactive response to vaccine hesitancy 'hotspots' based on social and behavioural insights. METHODS: Representative longitudinal online survey of over 3000 adults from Australia that examines the demographic, attitudinal, political and social attitudes and COVID-19 health behavior correlates of vaccine hesitance and resistance to a COVID-19 vaccine. RESULTS: Overall, 59% would definitely get the vaccine, 29% had low levels of hesitancy, 7% had high levels of hesitancy and 6% were resistant. Females, those living in disadvantaged areas, those who reported that risks of COVID-19 was overstated, those who had more populist views and higher levels of religiosity were more likely to be hesitant or resistant while those who had higher levels of household income, those who had higher levels of social distancing, who downloaded the COVID-Safe App, who had more confidence in their state or territory government or confidence in their hospitals, or were more supportive of migration were more likely to intend to get vaccinated. CONCLUSIONS: Our findings suggest that vaccine hesitancy, which accounts for a significant proportion of the population can be addressed by public health messaging but for a significant minority of the population with strongly held beliefs, alternative policy measures may well be needed to achieve sufficient vaccination coverage to end the pandemic.

214 citations

Posted ContentDOI
26 Nov 2020-medRxiv
TL;DR: The findings suggest that vaccine hesitancy can be addressed by public health messaging but that for a significant minority of the population with strongly held beliefs, alternative policy measures may well be needed to achieve sufficient vaccination coverage to end the pandemic.
Abstract: Background: High levels of vaccination coverage in populations will be required even with vaccines that have high levels of effectiveness to prevent and stop outbreaks of coronavirus. The World Health Organisation has suggested that governments take a proactive response to vaccine hesitancy hotspots based on social and behavioural insights. Methods: Representative longitudinal online survey of over 3000 adults from Australia that examines the demographic, attitudinal, political and social attitudes and COVID-19 health behavior correlates of vaccine hesitance and resistance to a COVID-19 vaccine. Results: Overall, 59% would definitely get the vaccine, 29% had low levels of hesitancy, 7% had high levels of hesitancy and 6% were resistant. Females, those living in disadvantaged areas, those who reported that risks of COVID-19 was overstated, those who had more populist views and higher levels of religiosity were more likely to be hesitant or resistant while those who had higher levels of household income, those who had higher levels of social distancing, who downloaded the COVID-Safe App, who had more confidence in their state or territory government or confidence in their hospitals, or were more supportive of migration were more likely to intend to get vaccinated. Conclusions: Our findings suggest that vaccine hesitancy, which accounts for a significant proportion of the population can be addressed by public health messaging but for a significant minority of the population with strongly held beliefs, alternative policy measures may well be needed to achieve sufficient vaccination coverage to end the pandemic.

148 citations

Posted ContentDOI
02 Jun 2020-medRxiv
TL;DR: The results suggest a surprisingly large role for schools in COVID-19 transmission, a contribution to the ongoing debate about the relevance of asymptomatic carriers in disease spreading.
Abstract: Background: Existing analyses of nonpharmaceutical interventions (NPIs) against COVID19 transmission have concentrated on the joint effectiveness of large-scale NPIs. With increasing data, we can move beyond estimating joint effects towards disentangling individual effects. In addition to effectiveness, policy decisions ought to account for the burden placed by different NPIs on the population. Methods: To our knowledge, this is the largest data-driven study of NPI effectiveness to date. We collected chronological data on 9 NPIs in 41 countries between January and April 2020, using extensive fact-checking to ensure high data quality. We infer NPI effectiveness with a novel semi-mechanistic Bayesian hierarchical model, modelling both confirmed cases and deaths to increase the signal from which NPI effects can be inferred. Finally, we study how much perceived burden different NPIs impose on the population with an online survey of preferences using the MaxDiff method. Results: Eight NPIs have a >95% posterior probability of being effective: closing schools (mean reduction in R: 50%; 95% credible interval: 39%-59%), closing nonessential businesses (34%; 16%-49%), closing high-risk businesses (26%; 8%-42%), and limiting gatherings to 10 people or less (28%; 8%-45%), to 100 people or less (17%; -3%-35%), to 1000 people or less (16%; -2%-31%), issuing stay-at-home orders (14%; -2%-29%), and testing patients with respiratory symptoms (13%; -1%-26%). As validation is crucial for NPI models, we performed 15 sensitivity analyses and evaluated predictions on unseen data, finding strong support for our results. We combine the effectiveness and preference results to estimate effectiveness-to-burden ratios. Conclusions: Our results suggest a surprisingly large role for schools in COVID-19 transmission, a contribution to the ongoing debate about the relevance of asymptomatic carriers in disease spreading. We identify additional interventions with good effectiveness-burden tradeoffs, namely symptomatic testing, closing high-risk businesses, and limiting gathering size. Closing most nonessential businesses and issuing stay-at-home orders impose a high burden while having a limited additional effect.

87 citations

Journal ArticleDOI
TL;DR: In this article , the authors estimate life expectancy changes in 29 countries since 2020 (including most of Europe, the United States and Chile), attribute them to mortality changes by age group and compare them with historic life expectancy shocks.
Abstract: Abstract The COVID-19 pandemic triggered an unprecedented rise in mortality that translated into life expectancy losses around the world, with only a few exceptions. We estimate life expectancy changes in 29 countries since 2020 (including most of Europe, the United States and Chile), attribute them to mortality changes by age group and compare them with historic life expectancy shocks. Our results show divergence in mortality impacts of the pandemic in 2021. While countries in western Europe experienced bounce backs from life expectancy losses of 2020, eastern Europe and the United States witnessed sustained and substantial life expectancy deficits. Life expectancy deficits during fall/winter 2021 among people ages 60+ and <60 were negatively correlated with measures of vaccination uptake across countries ( r 60+ = −0.86; two-tailed P < 0.001; 95% confidence interval, −0.94 to −0.69; r <60 = −0.74; two-tailed P < 0.001; 95% confidence interval, −0.88 to −0.46). In contrast to 2020, the age profile of excess mortality in 2021 was younger, with those in under-80 age groups contributing more to life expectancy losses. However, even in 2021, registered COVID-19 deaths continued to account for most life expectancy losses.

54 citations