فهرست مطالب

Journal of Biostatistics and Epidemiology
Volume:6 Issue: 2, Spring 2020

  • تاریخ انتشار: 1399/10/03
  • تعداد عناوین: 8
|
  • Marina Sooriyarachchi Pages 81-92
    Introduction

    According to the Oxford Medical Dictionary, Corona virus is the largest known viral RNA genome and causes devastating epizootics in livestock and poultry. Human corona viruses cause upper espiratory tract infections and severe acute respiratory syndrome (SARS). The initiative for this study was the extreme life threatening nature of this virus and the global pandemic it has caused. The responses were taken to be the number of deaths, number of recoveries and the number sick with the disease at a particular point in time,globally and the explanatory variables were climate variables.

    Method

    This is a survey type of study as the data has been extracted over a short period of time and the sampling method adopted is post cluster sampling. Simple descriptive statistics, clustering and generalized linear mixed models have been used for modelling.

    Results

    There was a strong regional effect of over three which was highly significant for every Covid 19 response. The air quality and temperature interaction and the air quality and humidity interaction were associated with the count of death at 0.0298 and 0.0027 levels of significance respectively. The count recovered was strongly associated with the temperature and humidity interaction and air quality at significance levels of 0.0002 and <0.0001 respectively. The Count at risk was strongly associated with the temperature, wind speeds and air quality three way interaction and this was significant at 0.0005 level.

    Discussion

    All four weather parameters effected one or more of the Covid 19 responses. The plots of Student
    residuals versus fitted values showed well-fitting models. The results of this research is useful in planning health care and allocating resources according to the region and the climate during a particular period.

    Keywords: Covid 19, Weather, Generalized linear mixedmodels (GLMM’s), Negative binomial, Cluster
  • Mohammad Noorchenarboo, Seyed Amirreza Mousavi, Hamed Moheimani* Pages 93-100
    Background

    COVID-19 mortality rates differ across countries. We aimed to construct a model that predicts mortality worldwide, by including only country-level socioeconomic and health system indicators and excluding variables related to short-term measures for pandemic management.

    Methods

    COVID-19 mortality data was collected from Johns Hopkins University resource center. Additional sources were public reports from the United Nations, the World Bank and the Heritage Foundation. We implemented multiple linear regression with backward elimination on the selected predictors.

    Results

    The final model constructed on seven Independent variables, significantly predicted COVID-19 mortality rate by country (F-statistic: 29.2, p<0.001). Regression coefficients (95% CI) in descending order of standardized effects: Annual tourist arrivals: 5.43 (4.03, 6.83); health expenditure per capita: 4.43 (2.92, 5.96); GDP (PPP): -4.60 (-6.81, -2.38); specialist surgical workforce per 100000: 2.63 (0.67, 4.59); number of physicians per 1000: -2.32 (-4.3, -0.28); economic freedom score: -1.35 (-2.60, -0.10); and total population:1.66 (-0.19, 3.52). All VIF values were below 5, showing acceptable collinearity. R-squared (52.65%), adjusted R-squared (50.25%) and predicted R-squared (42.33%) showed strong model fit.

    Conclusion

    limited country-level socioeconomic and health system indicators can explain COVID-19 mortality worldwide; emphasizing the priority of attending to these fundamental structures when planning for pandemic preparedness.

    Keywords: COVID-19, Health care, Mortality, Public health, Socioeconomic factors
  • Maryam Deldar, Samaneh Tahmasebi Ghorabi, Kourosh Sayehmiri Pages 101-106
    Background

    The Coronavirus 2019-nCOV (COVID-19) epidemic by SARS-CoV-2 is spreading worldwide, and by March 1, 2020, 67 countries, including Iran, have been affected. Many studies are being conducted at home and abroad to predict the outbreak of the disease so that they can make the necessary medical and health decisions in a timely manner. 

    Methods

    we used the SIR model to identify parameters to calculate epidemic features and some estimates of the new coronavirus. Data on the transmission of the novel coronavirus were extracted from the GitHub source in the covid19.analytics software package.

    Results

    According to our model estimates, the rate of infection β = 1 and the rate of removal γ = 0.667 and index R0 = 1.497 were obtained. Because the value of R0 is more than one, it is still an epidemic disease. Given that tfinal~132 days was estimated, we can expect the transmission of this epidemic to stop in Iran after July 3, 2020, provided that existing quarantine measures and patient isolation rates continue as usual. In comparison with the global SIR model, we reached the peak of the infection earlierthan the global model, but in improved and susceptible cases, we performed better than the global model. The graph of recovered and susceptible cases in Iran earlier than the global model cut off themselves.

    Conclusion

    Forecasts are set to be a useful guide for deciding whether to transfer COVID-19. According to the predictions and estimates made, more attention should be paid to control measures

    Keywords: Coronavirus, Epidemic, Covid-19, SIR model, Iran
  • Negin Badrooj, Seyed Ali Keshavarz, MirSaeed Yekaninejad, Khadijeh Mirzaei Pages 107-114
    Aim

    The aim of this study was to investigate the association between circadian rhythm with resting metabolic rate (RMR) in overweight\obese women

    Methods

    This cross-sectional study included 232 obese and overweight women. Morningness-Eveningness Questionnaire (MEQ) was used to assess the level of circadian rhythm. RMR was measured by indirect calorimetry after a 10-12 hour overnight fasting period by a trained nutritionist. We assessed body composition using multi-frequency bioelectrical impedance analyzer (BIA).

    Results

    The percentage of overweight and obese women were 48.7% (113) and 51.3% (119), respectively. The number of participants who were morningness, intermediate and eveningness was 28(12.1%),                           135(58.2%) and 69(29.7%) respectively. A significant relationship was found between MEQ and RMR.normal (p=0.011). According to linear regression model non-eveningness participants had 81.92 higher RMR compared to eveningness participants (p=0.027).

    Conclusion

    We found that non-eveningness participants had higher RMR compared to eveningness participants that can lead to obesity, diabetes type2 and other health disorders.

    Keywords: Circadian rhythm, Resting metabolicrate, Obesity
  • Elham Nazari, MohammadHasan Shahriari, Hamed Tabesh* Pages 115-119
    Background

    The rapid outbreak of Coronavirus has led to the worrying situation. Prevention strategies such as a stay at home offer great opportunities for transmission reduction of the virus. Therefore, the purpose of current study has developed a questionnaire to investigate the reasons for not staying at home in Iran.

    Methods

    In this study a self-administered questionnaire was designed in two Delphi rounds and based on 50 expert and 10 expert opinions from different fields of study.

    Results

    In the first Delphi round 11 questions were obtained and in the second round 14 questions were confirmed. The mean of CVR and CVI for the questionnaire was 95.33 and 94.67, respectively. A questionnaire was designed and developed according to the purpose.

    Conclusion

    Using the designed questionnaire, the reasons why some people do not pay attention to home quarantine can be examined and solutions can be considered for them. This can prevent further corona spread.

    Keywords: Coronavirus, Prevention, Outbreak, Reasons, Iran
  • Maria Manca, Francesco Russo, Vladimir Georgiev, Stefano Taddei Pages 120-125
    Background

    Based on data from the Ministry of Health, which highlighted the earlier onset of Covid-19 epidemic in Italy, compared with the Europe, we would like to present a statistical elaboration on the impact of measures taken by the Government, during the phase 1 and the start of phase 2.

    Methods

    After the implementation of a Bayesian changepoint detection method, we looked for a best fit model, based on the first part of time series data, in order to observe the progress of the data in the presence and absence of the restriction measures introduced.

    Results

    Both the implementation of changepoint detection method and the analysis of the curves showed that the decree that marked the start of lockdown has had the effect of slowing down the epidemic by allowing the start of a plateau between 21 and 25 March. Moreover, the decree that decided the beginning of phase 2 on 4 May did not have a negative impact.

    Conclusion

    This statistical analysis supports the hypothesis that stringent measures decreased hospitalization, thanks to a slowing down in the evolution of the epidemic compared with what was expected.

    Keywords: Changepoint detectionmethod, Covid-19, Italy, Phase 1, Phase 2
  • Zenaw Ayele, Mekonnen Tadesse, Zelalem Tazu Pages 126-142
    Introduction

    Respiratory distress syndrome (RDS) is not only the most common respiratory disorder in premature infants but also the main cause of neonatal mortality.

    Methods

    Competing risk framework was used to examine and identify potential prognostic factors of the health status of preterm infants with respiratory distress syndrome. Preterm infants with RDS admitted to the neonatal intensive care units (NICUs) of selected hospitals in Ethiopia were followed for 28 days and only neonates with complete cases were included in the analysis. The Fine-Gray or sub-distribution hazard model was used to identify significant prognostic factors. Three outcome variables (death due to RDS, death due to other causes and discharged alive) were considered.

    Results

    The Fine-Gray model fit results revealed that anemia, multiple pregnancies, birth-weight and gestational age were the prognostic factors significantly associated with the death of neonates due to Respiratory distress syndrome problem while Pneumonia, meningitis, anemia and gestational age of neonates were the significant prognostic factors for death of neonates due to other causes. Moreover, pneumonia, birth weight and gestational age were identified as the prognostic factors associated with neonates being discharged alive.

    Conclusion

    Offering intensive and adequate treatments for neonates with lowest birth-weights and gestational age may be useful to reduce neonatal mortality and increase the incidence of being discharged alive.

    Keywords: competing risk, Death of neonates, Ethiopia, Fine-gray model, Respiratory distresssyndrome
  • Reza Nejat, Ahmad Shahir Sadr, David Najafi Pages 143-161

    Introduction :

    Neuroinflammation is the inflammatory reaction in the central nervous system (CNS) provoked by diverse insults. This phenomenon results in a cascade of release of inflammatory mediators and intracellular messengers such as reactive oxygen species. The elicited responses are the cause of many neurological and neurodegenerative disorders. Erythropoietin (EPO) has been considered effective in attenuating this inflammatory process in the CNS, yet its administration in COVID-19 needs meticulously designed studies.

     Discussion:

     Neuroinflammation in COVID-19 due to probable contribution of renin-angiotensin system dysregulation resulting in surplus of Ang II and owing to the synergistic interaction between this octapeptide and EPO needs special consideration. Both of these compounds increase intracellular Ca2+ which may induce release of cytokine and inflammatory mediators leading to aggravation of neuroinflammation. In addition, Ang II elevates HIF even in normoxia which by itself increases EPO. It is implicated that EPO and HIF may likely increase in patients with COVID-19 which makes administration of EPO to these patients hazardous. Furthermore, papain-like protease of SARS-CoV2 as a deubiquitinase may also increase HIF.

    Conclusion:

     It is hypothesized that administration of EPO to patients with COVID-19-induced neuroinflammation may not be safe and in case EPO is needed for any reason in this disease adding of losartan may block AT1R-mediated post-receptor harmful effects of Ang II in synergism with EPO. Inhibition of papain-like protease might additionally decrease HIF in this disease. More in vitro, in vivo and clinical studies are needed to validate these hypotheses.

    Keywords: COVID -19, SARS-CoV2, Calcium, Neuroinflammation, Erythropoietin, Ang II, HIF, papain-like protease, excitotoxicity