One of the main features of bipolar disorder is repletion of relapse overtime. Many studies have focused on time-to-first relapse using the most popular Cox proportional hazard model which discards subsequent information on recurrent relapses. The aim of this study was to identify some risk factors of time-to-recurrent relapses in bipolar disorder inpatients by using appropriate recurrent event model. Data on 206 inpatients, available at Amanuel mental specialized hospital, were collected by reviewing the medical records from September 11, 2013 to March 12, 2019. Different extended cox proportional hazard models including AG, PWP-TT, PWP-GT and semiparametric shared gamma frailty models were used. R package FrailtyEM package used to fit semi-parametric shared gamma frailty models through EM algorithm. The mean age of the patients was 33.33 years. Within the study time, a total of 418 inpatient admissions (relapses) were registered for 206 inpatients. Among these admissions, about 49.3% of the patients had first relapse and 50.7% of the patients had more than one relapses. The likelihood test results indicated that the appropriate model is the gap-time based semi-parametric shared gamma frailty model and the important risk factors that have effect on time since the end of the most recent relapse to the start of the next relapses are marital status, substance abuse, employment status and residence. Recurrent relapse may be reduced by giving more intensive forms of treatment and creating awareness on each risk factor.
Pub. online:4 Aug 2022Type:Research ArticleOpen Access
Journal:Journal of Data Science
Volume 18, Issue 3 (2020): Special issue: Data Science in Action in Response to the Outbreak of COVID-19, pp. 526–535
Abstract
COVID-19 is a disease caused by the severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) that was reported to spread in people in December 2019. Understanding epidemiological
features of COVID-19 is important for the ongoing global efforts to contain the virus. As a
complement to the available work, in this article we analyze the Kaggle novel coronavirus dataset
of 3397 patients dated from January 22, 2020 to March 29, 2020. We employ semiparametric
and nonparametric survival models as well as text mining and data visualization techniques to
examine the clinical manifestations and epidemiological features of COVID-19. Our analysis
shows that: (i) the median incubation time is about 5 days and older people tend to have a
longer incubation period; (ii) the median time for infected people to recover is about 20 days,
and the recovery time is significantly associated with age but not gender; (iii) the fatality rate
is higher for older infected patients than for younger patients
Pub. online:4 Aug 2022Type:Research ArticleOpen Access
Journal:Journal of Data Science
Volume 18, Issue 3 (2020): Special issue: Data Science in Action in Response to the Outbreak of COVID-19, pp. 483–495
Abstract
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronvirus, which was declared as a global pandemic by the World Health Organization on March 11, 2020. In this work, we conduct a cross-sectional study to investigate how the infection fatality rate (IFR) of COVID-19 may be associated with possible geographical or demographical features of the infected population. We employ a multiple index model in combination with sliced inverse regression to facilitate the relationship between the IFR and possible risk factors. To select associated features for the infection fatality rate, we utilize an adaptive Lasso penalized sliced inverse regression method, which achieves variable selection and sufficient dimension reduction simultaneously with unimportant features removed automatically. We apply the proposed method to conduct a cross-sectional study for the COVID-19 data obtained from two time points of the outbreak.
Pub. online:22 Feb 2021Type:Computing In Data Science
Journal:Journal of Data Science
Volume 19, Issue 2 (2021): Special issue: Continued Data Science Contributions to COVID-19 Pandemic, pp. 293–313
Abstract
The COVID-19 (COrona VIrus Disease 2019) pandemic has had profound global consequences on health, economic, social, behavioral, and almost every major aspect of human life. Therefore, it is of great importance to model COVID-19 and other pandemics in terms of the broader social contexts in which they take place. We present the architecture of an artificial intelligence enhanced COVID-19 analysis (in short AICov), which provides an integrative deep learning framework for COVID-19 forecasting with population covariates, some of which may serve as putative risk factors. We have integrated multiple different strategies into AICov, including the ability to use deep learning strategies based on Long Short-Term Memory (LSTM) and event modeling. To demonstrate our approach, we have introduced a framework that integrates population covariates from multiple sources. Thus, AICov not only includes data on COVID-19 cases and deaths but, more importantly, the population’s socioeconomic, health, and behavioral risk factors at their specific locations. The compiled data are fed into AICov, and thus we obtain improved prediction by the integration of the data to our model as compared to one that only uses case and death data. As we use deep learning our models adapt over time while learning the model from past data.