Background In India, around 20,000 women die every year due to abortion-related complications. In... more Background In India, around 20,000 women die every year due to abortion-related complications. In count data modeling, there is sometimes a prevalence of zero counts. This article is concerned with the estimation of various count regression models to predict the average number of spontaneous abortions among women in Punjab and few northern states in India. The study also assesses the factors associated with the number of spontaneous abortions. Methods This study includes 27,173 married women of Punjab obtained from the DLHS-4 survey (2012–13) to train the count models. The study predicts the average number of spontaneous abortions using various count regression models, and also identifies the determinants affecting the spontaneous abortions. Further, the best model is validated with other northern states of India using the latest data (NFHS-4, 2015–16). Results Statistical comparisons among four estimation methods reveals that the ZINB model provides the best prediction for the numb...
Introduction Suicide is a major social and health issue in India. Yearly statistics show a concer... more Introduction Suicide is a major social and health issue in India. Yearly statistics show a concerning increasing pattern of suicidal deaths in India which is higher in comparison to the global trend. There is limited evidence regarding historical analysis of suicide or any forecasting for suicide in India towards predicting the possible risks of death due to suicide. Methods This paper examines the trend of suicide rate and characteristics of suicide victims in India, based on the longitudinal time series data over the last 50 years—collected from the National Crime Record Bureau Reports (1969 to 2018) of the Government of India. In our analysis, we have used the time series model to forecast the suicide rates in India for the next decade. ARIMA (4,1,0) model is found to be the best fit model for forecasting the data. Findings There has been an observable and rising trend of suicide rates in India over the last five decades. The forecast indicates a continuance of rising suicide cas...
Background It is well known that urinary calculi are associated with urinary tract infections. Po... more Background It is well known that urinary calculi are associated with urinary tract infections. Post-operative sepsis is one of the major complications after various endourological procedures for stone surgeries. These episodes of sepsis occur even in negative urine cultures. Stones have been found to harbour bacteria which on fragmentation causes bacteremia and sepsis. Thus, usual practice of pre-operative urine culture cannot truly predict the occurrence of post-operative sepsis. It also seems logical that intra-operative stone cultures could guide us for early management of such episodes of sepsis. The purpose of this study was to determine if there exists any association between urine and stone cultures in patients undergoing endourological stone surgeries. Methods This is a prospective comparative observational study, in patients undergoing endoscopic procedures for calculus in urinary tract. Mid-stream urine cultures were obtained 3 to 5 days prior to surgery and crushed stone ...
Background: In this paper an attempt has been made to estimate the Case Fatality Ratio (CFR) for ... more Background: In this paper an attempt has been made to estimate the Case Fatality Ratio (CFR) for coronavirus disease of India and few selected countries. and Also, highlighted the pros and cons of obtaining crude and adjusted CFR of COVID-19 pandemic. Material and Methods: Data extracted from WHO situation report and University of Oxford website have been used for this analysis. The CFR and its 95% confidence interval were computed, trend and bar plot was used for graphical representation. Results: The worldwide crude CFR stands 6.73% (95% CI 6.69 to 6.76) based on 21, 83, 877 confirmed and 1,46,872 death cases(as on 17th April,2020). Belgium was highest CFR 13.95% as compared to others. However, India’s CFR was found to be around 3.26% (as on 17th April, 2020). Conclusion: In conclusion, the estimation and interpretation of CFR is critical in response to ongoing COVID-19. The initial CFR estimates are subject to change, still it is useful for healthcare planning over the coming mon...
Background: In India, around 20,000 women die every year due to abortion-related complications. I... more Background: In India, around 20,000 women die every year due to abortion-related complications. In count data modeling, there is sometimes a prevalence of zero counts. This article is concerned with the estimation of various count regression models to predict the average number of spontaneous abortions among women in Punjab and few northern states in India. The study also assesses the factors associated with the number of spontaneous abortions.
Background: Chronic non-communicable diseases:-such as epilepsy, are increasingly recognized as p... more Background: Chronic non-communicable diseases:-such as epilepsy, are increasingly recognized as public health problems in developing and African countries. This study aimed at finding determinants of the number of epileptic seizure attacks using different count data modeling techniques. Methods: Four common fixed-effects Poisson family models were reviewed to analyze the count data with a high proportion of zeros in longitudinal outcome, i.e., the number of seizure attacks in epilepsy patients. This is because, in addition to the problem of extra zeros, the correlation between measurements upon the same patient at different occasions needs to be taken into consideration. Results: The investigation remarkably identified some important factors associated with epileptic seizure attacks. As people grow old , the number of seizure attacks increased and male patients had more seizures than their female counterparts. In general , a patient's age, sex, monthly income, family history of epilepsy andservice satisfaction were some of the significant factors responsible for the frequency of seizure attacks (P value<0.05). Conclusion: This study suggests that zero-inflated negative binomial is the best model for predicting and describing the number of seizure attacks as well as identifying the potential risk factors. Addressing these risk factors will definitely contain the progression of seizure attack.
The novel coronavirus disease (COVID-19) has shaken the entire world in its devastating annihilat... more The novel coronavirus disease (COVID-19) has shaken the entire world in its devastating annihilation of humanity. The alarming increase in number of confirmed COVID cases in India requires an urgent step to monitor and control this spread. Thus, it is inevitable to develop a model which can predict future confirmed and death cases. Time series models are significant in predicting the impact of the COVID-19 outbreak. In this paper we have developed an Auto Regressive Integrated Moving Average (ARIMA) model to predict the number of COVID 19 cases for India and Odisha. The model prediction suggests that an increasing trend would be continuing for both Odisha and India as whole for next two weeks. The forecasted values are in good agreement with actual cases in both the scenario. These findings would be useful for government in formulating policy related to health care systems so that the system and medical professions can better prepared to combat the pandemic.
Background: Pulse Wave Velocity (PWV) is the propagation speed of the wave-induced along the aort... more Background: Pulse Wave Velocity (PWV) is the propagation speed of the wave-induced along the aorta and arterial tree, each time the heart beats. PWV increases with increased arterial stiffness, thus establishing it as a reliable prognostic marker for cardiovascular morbidity and mortality. On the other hand, total vascular resistance (TVR) is the overall resistance offered by sys-temic circulation and pulmonary circulation. This resistance needs to be overcome in order to create the flow of blood through the circulatory system. The goal of this study was to investigate the influence of different cardiovascular factors on arterial stiffness and vascular resistance in CVD patient from eastern India population. Methods: Total of 782 patients with cardiovascular disease (CVD) like hypertension, Ischemic heart disease, Congestive cardiac failure and peripheral arterial disease were included to evaluate the cardiovascular hemodynamic and non-hemodynamic parameter by oscillometric method and investigated those factors on PWV and TVR in subjects of both sexes aged between 15 to 87 years. Results: The old age (>55 years) was found to have greatest impact on PWV as compared with younger age group. Systolic blood pressure (SBP), heart rate (HR), augmentation pressure and body surface area (BSA) had a positive association with the PWV. Augmentation Index and body mass index (BMI) had a negative impact on the PWV. Conclusion: Despite the limitations, like unequal number of male and female participants, wide variation of the age of the subjects and analyzing association of many factors at a time, our large and community-based study show individual blood pressure and pulse pressure depending on complex interaction between large arteries and arterioles. This study sheds light on the relationship between proximal and distal part (PWV and TVR) of the arterial tree as well as their association with different hemodynamic and non-hemodynamic parameters.
The aim of the present study is to quantify the prevalence and distribution of hypertension among... more The aim of the present study is to quantify the prevalence and distribution of hypertension among adults in Empowered Action Group (EAG) states and also to determine the area level socioeconomic and spatial factors associated with the prevalence of hypertension in EAG states of India. The district level data of Census-2011 and NFHS-IV (2015-16) have been used for analysis. A stepwise linear regression model was used to determine the significant factors associated with the prevalence of hypertension. The factors viz., education level, proportion of widow/divorce/separated, proportion of female headed households, proportion of disabled population, proportion of unemployment rate (15-59 years age), sex ratio, proportion of urban population, proportion of household with tap water treated etc., are found to be significantly (p value<0.05) associated with the prevalence of hypertensions. The study reveals that there are uneven trends in prevalence of hypertension across the districts of EAG states. It also suggests that the public health policy maker should take into account the spatial variation while controlling the significant socio economic factors in reducing the prevalence of hypertension rate in the EAG states in India.
Objective: Under-five mortality is an essential indicator of the development of a country. In Eth... more Objective: Under-five mortality is an essential indicator of the development of a country. In Ethiopia under-five mortality rate is among the highest in the world. Nearly one out of 10 babies born in Ethiopia does not survive to celebrate its first birthday. Material and Methods: The data for the study was obtained from Ethiopian Demography and Health Survey data conducted in 2016. The Kaplan-Meier, Cox'sproportional hazards and gamma shared frailty models were employed for the analysis of under-five children data. Results: Results obtained by fitting both Cox-proportional hazard model and gamma shared frailty model: place of residence, Type of Birth, Birth order, sex of a child and preceding birth intervalwere found to be significant factors. Further more a high risk death of under-five children was found to be associated with place of residence at rural, multiple births, birth order at fifth and above, male children and preceding birth interval less than 24 months. From gamma shared frailty model (θ=0.145) we had enough evidence that the existence of unobserved heterogeneity at the regional level. Conclusion: The findings of this paper highlighted the potential associated with under-five child mortality in Ethiopia. The shared frailty model provided better estimates and also justified the presence of unobserved heterogeneity at regional level. Therefore, special attention should be given to these significant predictors, which ultimately reduce the under-five mortality. ÖZET Amaç: Beş yaş altı ölüm, bir ülkenin gelişiminde temel bir göstergedir. Etiyopya'da doğan neredeyse 10 bebekten biri ilk doğum gününü kutlayana kadar hayatta kalamamaktadır. Gereç ve Yöntemler: Çalışma verisi 2016 yılında yürütülen Etiyopya Demografi ve Sağlık Çalışması'ndan elde edilmiştir. Kaplan-Meier, Cox orantısal hazard modeli ve gamma kırılganlık modelleri beş yaş altı çocuklara ait verinin analizinde kullanılmıştır. Bulgular: Hem Cox orantısal hazard mo-deli hem de gamma kırılganlık modeli uygulanarak elde edilen sonuçlar: ikamet yeri, doğum tipi, doğum sırası, çocuğun cinsiyeti ve önceki doğum aralığı anlamlı faktörler olarak bulunmuştur. Ayrıca beş yaş altı çocuklardaki yüksek ölüm riskinin kırsal ikamet yeri, çoklu doğum, beş ya da daha fazla doğum sırası, erkek çocuk ve önceki doğum aralığının 24 aydan az olması ile ilişkili olduğu bulunmuştur. Gamma kırılganlık modelinden (θ=0.145) bölgesel düzeyde gözlenmeyen heterojenliğin varlığına dair yeterli kanıt elde edilmiştir. Sonuç: Bu makalenin bulguları Etiyop-ya'daki beş yaş altı çocuk ölümleri ile ilişkili potansiyeli vurgulamıştır. Kırılganlık modeli daha iyi tahminler sağlamış ve bölgesel düzeyde gözlenmeyen heterojenliği doğrulamıştır. Bu nedenle, beş yaş altı ölümü azaltmak için bu faktörlere özel ilgi verilmelidir. Anahtar Kelimeler: Beş yaş altı ölüm; Kaplan Meier; orantısal hazard modeli; gamma kırılganlık; sağkalım
Multi-state models are a flexible tool for analyzing complex time-to-event problems with multiple... more Multi-state models are a flexible tool for analyzing complex time-to-event problems with multiple endpoints, especially in chronic diseases where the patients move through different states. It provides a more detailed insight into the disease process as compared to other statistical models. The primary objective of this paper is to study the significance of CA15-3 as a disease marker in monitoring and evaluating the diseases progression of breast cancer patients using a multistate Markov model. Based on ranges of CA15-3 marker (< 25 U/ml and ≥ 25 U/ml) states have been defined and transition intensities, transition probabilities and expected state specific survival time have been estimated. Also, the effect of prognostic factors viz. age, tumor size, tumor grade, involve lymph nodes, ER status, PR status etc., on transition intensities have been explored.
Background: Worldwide rising cesarean section (CS) births is an issue of concern. In India, with ... more Background: Worldwide rising cesarean section (CS) births is an issue of concern. In India, with increase in institutional deliveries there has also been an increase in cesarean section births. Aim of the study is to quantify the prevalence of cesarean section births in public and private health facility, and also to determine the factors associated with cesarean section births. Methods: We analyzed data from district level household survey data 4 (DLHS-4) combined individual level dataset for 19 states/UTs of India comprising 24,398 deliveries resulting in 22,111 live births for year 2011. The percentages and Chi-square has been computed for the select variables viz. Socio demographic, maternal, antenatal care and delivery related based on type of births (CS Vs normal births). The multiple logistic regression model has been used to identify the potential risk factors associated with CS births.
In this paper, we have explored a quantile regression approach to study the factors affecting the... more In this paper, we have explored a quantile regression approach to study the factors affecting the child mortality in India. The annual health survey data has been used for application and the results of quantile regression have been compared with those of a linear regression (LR) model. Factors, such as safe delivery, private delivery, mothers' post natal check within 48 hours, breast feeding within 1 hour, full immunizations, fathers literacy rate., etc are found to be significantly associated with child mortality (P value < 0.05). The results have demonstrated that using quantile regression leads to better interpretation and more specific inference about the predictors of child mortality. Hence, we suggest that the quantile regression could be used as an alternative to LR in mortality analysis.
The cure fraction models are generally used to model lifetime data with long term survivors. In a... more The cure fraction models are generally used to model lifetime data with long term survivors. In a cohort of cancer patients, it has been observed that due to the development of new drugs some patients are cured permanently, and some are not cured. The patients who are cured permanently are called cured or long term survivors while patients who experience the recurrence of the disease are termed as susceptibles or uncured. Thus, the population is divided into two groups: a group of cured individuals and a group of susceptible individuals. The proportion of cured individuals after the treatment is typically known as the cure fraction. In this paper, we have introduced a three parameter Gompertz (viz. scale, shape and acceleration) or generalized Gompertz distribution in the presence of cure fraction, censored data and covariates for estimating the proportion of cure fraction through Bayesian Approach. Inferences are obtained using the standard Markov Chain Monte Carlo technique in openBUGS software.
Prediction of number of involved lymph nodes in breast cancer patients is an important criterion ... more Prediction of number of involved lymph nodes in breast cancer patients is an important criterion to assess the severity and progression of disease. The number of involved nodes is count data which often displays over-dispersion, hence the Poisson and Negative Binomial distribution is ultimate choice for modeling. In this paper we have made an attempt to estimate the number of involved lymph nodes in breast cancer patients using Bayesian regression approach assuming multivariate normal prior for the parameters. The posterior estimates have been derived using MCMC pack and the best model has been selected based on Deviance Information Criterion (DIC) values. The Bayesian Negative Binomial regression over performed than the Poisson regression. The predictors' viz., tumor size, tumor grade, CA 15-3 marker and progesterone receptor status are significantly associated with the involved lymph nodes of the breast cancer patients.
Objective: The aim of the study is to estimate the sub-distribution hazard ratio of HIV/ AIDS pat... more Objective: The aim of the study is to estimate the sub-distribution hazard ratio of HIV/ AIDS patients undergoing anti-retroviral therapy for an interval censored data in the presence of loss to follow up as a competing risk. Methodology: Exact survival times of interval censored cases are imputed using multiple imputation with loss to follow up as a competing risk. Fine and Grey competing risk regression model is then applied to the right censored data to estimate sub-distribution hazard ratios in the presence of different covariates. To compare the results, midpoint imputation and multiple imputation considering loss to follow up as right censoring only are also performed. Results: In all the three methods the predictors, viz., sex, CD4 cell count, hemoglobin, weight, area of residence and opportunistic infection are found to be significantly associated with mortality. In both methods (multiple as well as midpoint imputation), the sub-distribution hazard ratios of death due to HIV/ AIDS for different covariates are comparable. Conclusion: When the loss to follow up is informative, it is better to use it as a competing risk. Multiple imputation with loss to follow up as a competing risk provides better results than those obtained from midpoint imputation and multiple imputation without loss to follow up as a competing risk in terms of lower standard error.
ABS TRACT Objective: The present paper demonstrates the applications of Accelerated Failure Time
... more ABS TRACT Objective: The present paper demonstrates the applications of Accelerated Failure Time (AFT) model with gamma and inverse Gaussian frailty distributions to estimate the effect of prognostic factors on the survival of HIV/AIDS patients undergoing Antiretroviral Therapy (ART) in Delhi, India. Material and Methods: The results of both these models have been compared to without frailty model. Akaike Information Criterion (AIC) and Bayesian Information criterion (BIC) have been used to select best model for HIV/AIDS data. Results: The prognostic factors sex, mode of transmission, baseline hemoglobin and weight are found to be statistically significant (P-value <0.05) for HIV/AIDS patients on ART. Gamma shared frailty model with lognormal as baseline distribution is found to be the best model for HIV/AIDS patients. The model also reflected there is strong evidence of high degree of heterogeneity in the HIV/AIDS patients. Conclusion: Therefore shared frailty model is an appropriate approach for analyzing the HIV/AIDS data than without frailty model. Tu ur rk ki iy ye e K Kl li in ni ik kl le er ri i J J B Bi io os st ta at t 2 20 01 16 6; ;8 8((1 1)): :1 13 3-2 20 0
The objective of this study was to determine patterns and frequency of antimicrobial drug use amo... more The objective of this study was to determine patterns and frequency of antimicrobial drug use among hospitalized patients with community-acquired pneumonia (CAP). A retrospective 5 years (April 2007-March 2012) detailed medical record review of patients diagnosed with CAP and discharged to home from Non-Intensive Care Unit respiratory medicine wards of two public hospitals in Delhi. A total of 261 medical records were analyzed. Over the 5 years, 82.0% (2007-08), 78.6% (2008-09), 59.5% (2009-10), 64.7% (2010-11), and 67.8% (2011-12) patients were prescribed two antimicrobials. In the last two study years, the proportion of patients receiving three antimicrobials increased (from 2.0% to 26.5% and 28.8%), while the proportion receiving monotherapy decreased (from 16.0% to 8.8% and 3.4%). In accordance with guidelines, beta-lactams and macrolides were the two most frequently prescribed antimicrobials (34.1%). However, newer generation beta-lactams were prescribed. A total of 37 patients were prescribed beta-lactam-tazobactam combination preparations. Overall, beta-lactams constituted more than 40% of prescriptions while macrolides were the second most prescribed class. Cephalosporin prescriptions significantly increased (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and penicillin prescriptions significantly decreased over study periods. The prescription of fluoroquinolones also decreased (21.5-6.0%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and aminoglycoside prescription ranged from 9.7% to 16.4%, over 5 years. Reasons for prescribing three antimicrobials, use of aminoglycosides, or higher-end/reserve antibiotics were not mentioned in the medical records. There were no hospital-specific guidelines for doctors to follow in the treatment of CAP. These findings suggest the need for implementing antimicrobial treatment guidelines. Adequate documentation and monitoring of antibiotic use for feedback are also lacking. An antimicrobial stewardship program may offer the most comprehensive solution for appropriate use of antimicrobials.
The main purpose of this study is to assess the impact of Antiretroviral Therapy (ART) by using a... more The main purpose of this study is to assess the impact of Antiretroviral Therapy (ART) by using a multistate Markov model to estimate transition intensities and transition probabilities among various states (transient as well as absorbing) of the AIDS patients. A total of 580 AIDS patients were included in this study who are undergoing Antiretroviral Therapy treatment in the ART centre in New Delhi during the period of April 2004 to April 2011. The patients are classified in different states on the basis of their available CD4 cell counts. The authors also estimated the mean sojourn time and total length of stay in each state before absorption, and also examined the effects of explanatory variables (i.e Age, Sex, Mode of transmission) on the rates of transition using Cox's proportional hazard model.
Background In India, around 20,000 women die every year due to abortion-related complications. In... more Background In India, around 20,000 women die every year due to abortion-related complications. In count data modeling, there is sometimes a prevalence of zero counts. This article is concerned with the estimation of various count regression models to predict the average number of spontaneous abortions among women in Punjab and few northern states in India. The study also assesses the factors associated with the number of spontaneous abortions. Methods This study includes 27,173 married women of Punjab obtained from the DLHS-4 survey (2012–13) to train the count models. The study predicts the average number of spontaneous abortions using various count regression models, and also identifies the determinants affecting the spontaneous abortions. Further, the best model is validated with other northern states of India using the latest data (NFHS-4, 2015–16). Results Statistical comparisons among four estimation methods reveals that the ZINB model provides the best prediction for the numb...
Introduction Suicide is a major social and health issue in India. Yearly statistics show a concer... more Introduction Suicide is a major social and health issue in India. Yearly statistics show a concerning increasing pattern of suicidal deaths in India which is higher in comparison to the global trend. There is limited evidence regarding historical analysis of suicide or any forecasting for suicide in India towards predicting the possible risks of death due to suicide. Methods This paper examines the trend of suicide rate and characteristics of suicide victims in India, based on the longitudinal time series data over the last 50 years—collected from the National Crime Record Bureau Reports (1969 to 2018) of the Government of India. In our analysis, we have used the time series model to forecast the suicide rates in India for the next decade. ARIMA (4,1,0) model is found to be the best fit model for forecasting the data. Findings There has been an observable and rising trend of suicide rates in India over the last five decades. The forecast indicates a continuance of rising suicide cas...
Background It is well known that urinary calculi are associated with urinary tract infections. Po... more Background It is well known that urinary calculi are associated with urinary tract infections. Post-operative sepsis is one of the major complications after various endourological procedures for stone surgeries. These episodes of sepsis occur even in negative urine cultures. Stones have been found to harbour bacteria which on fragmentation causes bacteremia and sepsis. Thus, usual practice of pre-operative urine culture cannot truly predict the occurrence of post-operative sepsis. It also seems logical that intra-operative stone cultures could guide us for early management of such episodes of sepsis. The purpose of this study was to determine if there exists any association between urine and stone cultures in patients undergoing endourological stone surgeries. Methods This is a prospective comparative observational study, in patients undergoing endoscopic procedures for calculus in urinary tract. Mid-stream urine cultures were obtained 3 to 5 days prior to surgery and crushed stone ...
Background: In this paper an attempt has been made to estimate the Case Fatality Ratio (CFR) for ... more Background: In this paper an attempt has been made to estimate the Case Fatality Ratio (CFR) for coronavirus disease of India and few selected countries. and Also, highlighted the pros and cons of obtaining crude and adjusted CFR of COVID-19 pandemic. Material and Methods: Data extracted from WHO situation report and University of Oxford website have been used for this analysis. The CFR and its 95% confidence interval were computed, trend and bar plot was used for graphical representation. Results: The worldwide crude CFR stands 6.73% (95% CI 6.69 to 6.76) based on 21, 83, 877 confirmed and 1,46,872 death cases(as on 17th April,2020). Belgium was highest CFR 13.95% as compared to others. However, India’s CFR was found to be around 3.26% (as on 17th April, 2020). Conclusion: In conclusion, the estimation and interpretation of CFR is critical in response to ongoing COVID-19. The initial CFR estimates are subject to change, still it is useful for healthcare planning over the coming mon...
Background: In India, around 20,000 women die every year due to abortion-related complications. I... more Background: In India, around 20,000 women die every year due to abortion-related complications. In count data modeling, there is sometimes a prevalence of zero counts. This article is concerned with the estimation of various count regression models to predict the average number of spontaneous abortions among women in Punjab and few northern states in India. The study also assesses the factors associated with the number of spontaneous abortions.
Background: Chronic non-communicable diseases:-such as epilepsy, are increasingly recognized as p... more Background: Chronic non-communicable diseases:-such as epilepsy, are increasingly recognized as public health problems in developing and African countries. This study aimed at finding determinants of the number of epileptic seizure attacks using different count data modeling techniques. Methods: Four common fixed-effects Poisson family models were reviewed to analyze the count data with a high proportion of zeros in longitudinal outcome, i.e., the number of seizure attacks in epilepsy patients. This is because, in addition to the problem of extra zeros, the correlation between measurements upon the same patient at different occasions needs to be taken into consideration. Results: The investigation remarkably identified some important factors associated with epileptic seizure attacks. As people grow old , the number of seizure attacks increased and male patients had more seizures than their female counterparts. In general , a patient's age, sex, monthly income, family history of epilepsy andservice satisfaction were some of the significant factors responsible for the frequency of seizure attacks (P value<0.05). Conclusion: This study suggests that zero-inflated negative binomial is the best model for predicting and describing the number of seizure attacks as well as identifying the potential risk factors. Addressing these risk factors will definitely contain the progression of seizure attack.
The novel coronavirus disease (COVID-19) has shaken the entire world in its devastating annihilat... more The novel coronavirus disease (COVID-19) has shaken the entire world in its devastating annihilation of humanity. The alarming increase in number of confirmed COVID cases in India requires an urgent step to monitor and control this spread. Thus, it is inevitable to develop a model which can predict future confirmed and death cases. Time series models are significant in predicting the impact of the COVID-19 outbreak. In this paper we have developed an Auto Regressive Integrated Moving Average (ARIMA) model to predict the number of COVID 19 cases for India and Odisha. The model prediction suggests that an increasing trend would be continuing for both Odisha and India as whole for next two weeks. The forecasted values are in good agreement with actual cases in both the scenario. These findings would be useful for government in formulating policy related to health care systems so that the system and medical professions can better prepared to combat the pandemic.
Background: Pulse Wave Velocity (PWV) is the propagation speed of the wave-induced along the aort... more Background: Pulse Wave Velocity (PWV) is the propagation speed of the wave-induced along the aorta and arterial tree, each time the heart beats. PWV increases with increased arterial stiffness, thus establishing it as a reliable prognostic marker for cardiovascular morbidity and mortality. On the other hand, total vascular resistance (TVR) is the overall resistance offered by sys-temic circulation and pulmonary circulation. This resistance needs to be overcome in order to create the flow of blood through the circulatory system. The goal of this study was to investigate the influence of different cardiovascular factors on arterial stiffness and vascular resistance in CVD patient from eastern India population. Methods: Total of 782 patients with cardiovascular disease (CVD) like hypertension, Ischemic heart disease, Congestive cardiac failure and peripheral arterial disease were included to evaluate the cardiovascular hemodynamic and non-hemodynamic parameter by oscillometric method and investigated those factors on PWV and TVR in subjects of both sexes aged between 15 to 87 years. Results: The old age (>55 years) was found to have greatest impact on PWV as compared with younger age group. Systolic blood pressure (SBP), heart rate (HR), augmentation pressure and body surface area (BSA) had a positive association with the PWV. Augmentation Index and body mass index (BMI) had a negative impact on the PWV. Conclusion: Despite the limitations, like unequal number of male and female participants, wide variation of the age of the subjects and analyzing association of many factors at a time, our large and community-based study show individual blood pressure and pulse pressure depending on complex interaction between large arteries and arterioles. This study sheds light on the relationship between proximal and distal part (PWV and TVR) of the arterial tree as well as their association with different hemodynamic and non-hemodynamic parameters.
The aim of the present study is to quantify the prevalence and distribution of hypertension among... more The aim of the present study is to quantify the prevalence and distribution of hypertension among adults in Empowered Action Group (EAG) states and also to determine the area level socioeconomic and spatial factors associated with the prevalence of hypertension in EAG states of India. The district level data of Census-2011 and NFHS-IV (2015-16) have been used for analysis. A stepwise linear regression model was used to determine the significant factors associated with the prevalence of hypertension. The factors viz., education level, proportion of widow/divorce/separated, proportion of female headed households, proportion of disabled population, proportion of unemployment rate (15-59 years age), sex ratio, proportion of urban population, proportion of household with tap water treated etc., are found to be significantly (p value<0.05) associated with the prevalence of hypertensions. The study reveals that there are uneven trends in prevalence of hypertension across the districts of EAG states. It also suggests that the public health policy maker should take into account the spatial variation while controlling the significant socio economic factors in reducing the prevalence of hypertension rate in the EAG states in India.
Objective: Under-five mortality is an essential indicator of the development of a country. In Eth... more Objective: Under-five mortality is an essential indicator of the development of a country. In Ethiopia under-five mortality rate is among the highest in the world. Nearly one out of 10 babies born in Ethiopia does not survive to celebrate its first birthday. Material and Methods: The data for the study was obtained from Ethiopian Demography and Health Survey data conducted in 2016. The Kaplan-Meier, Cox'sproportional hazards and gamma shared frailty models were employed for the analysis of under-five children data. Results: Results obtained by fitting both Cox-proportional hazard model and gamma shared frailty model: place of residence, Type of Birth, Birth order, sex of a child and preceding birth intervalwere found to be significant factors. Further more a high risk death of under-five children was found to be associated with place of residence at rural, multiple births, birth order at fifth and above, male children and preceding birth interval less than 24 months. From gamma shared frailty model (θ=0.145) we had enough evidence that the existence of unobserved heterogeneity at the regional level. Conclusion: The findings of this paper highlighted the potential associated with under-five child mortality in Ethiopia. The shared frailty model provided better estimates and also justified the presence of unobserved heterogeneity at regional level. Therefore, special attention should be given to these significant predictors, which ultimately reduce the under-five mortality. ÖZET Amaç: Beş yaş altı ölüm, bir ülkenin gelişiminde temel bir göstergedir. Etiyopya'da doğan neredeyse 10 bebekten biri ilk doğum gününü kutlayana kadar hayatta kalamamaktadır. Gereç ve Yöntemler: Çalışma verisi 2016 yılında yürütülen Etiyopya Demografi ve Sağlık Çalışması'ndan elde edilmiştir. Kaplan-Meier, Cox orantısal hazard modeli ve gamma kırılganlık modelleri beş yaş altı çocuklara ait verinin analizinde kullanılmıştır. Bulgular: Hem Cox orantısal hazard mo-deli hem de gamma kırılganlık modeli uygulanarak elde edilen sonuçlar: ikamet yeri, doğum tipi, doğum sırası, çocuğun cinsiyeti ve önceki doğum aralığı anlamlı faktörler olarak bulunmuştur. Ayrıca beş yaş altı çocuklardaki yüksek ölüm riskinin kırsal ikamet yeri, çoklu doğum, beş ya da daha fazla doğum sırası, erkek çocuk ve önceki doğum aralığının 24 aydan az olması ile ilişkili olduğu bulunmuştur. Gamma kırılganlık modelinden (θ=0.145) bölgesel düzeyde gözlenmeyen heterojenliğin varlığına dair yeterli kanıt elde edilmiştir. Sonuç: Bu makalenin bulguları Etiyop-ya'daki beş yaş altı çocuk ölümleri ile ilişkili potansiyeli vurgulamıştır. Kırılganlık modeli daha iyi tahminler sağlamış ve bölgesel düzeyde gözlenmeyen heterojenliği doğrulamıştır. Bu nedenle, beş yaş altı ölümü azaltmak için bu faktörlere özel ilgi verilmelidir. Anahtar Kelimeler: Beş yaş altı ölüm; Kaplan Meier; orantısal hazard modeli; gamma kırılganlık; sağkalım
Multi-state models are a flexible tool for analyzing complex time-to-event problems with multiple... more Multi-state models are a flexible tool for analyzing complex time-to-event problems with multiple endpoints, especially in chronic diseases where the patients move through different states. It provides a more detailed insight into the disease process as compared to other statistical models. The primary objective of this paper is to study the significance of CA15-3 as a disease marker in monitoring and evaluating the diseases progression of breast cancer patients using a multistate Markov model. Based on ranges of CA15-3 marker (< 25 U/ml and ≥ 25 U/ml) states have been defined and transition intensities, transition probabilities and expected state specific survival time have been estimated. Also, the effect of prognostic factors viz. age, tumor size, tumor grade, involve lymph nodes, ER status, PR status etc., on transition intensities have been explored.
Background: Worldwide rising cesarean section (CS) births is an issue of concern. In India, with ... more Background: Worldwide rising cesarean section (CS) births is an issue of concern. In India, with increase in institutional deliveries there has also been an increase in cesarean section births. Aim of the study is to quantify the prevalence of cesarean section births in public and private health facility, and also to determine the factors associated with cesarean section births. Methods: We analyzed data from district level household survey data 4 (DLHS-4) combined individual level dataset for 19 states/UTs of India comprising 24,398 deliveries resulting in 22,111 live births for year 2011. The percentages and Chi-square has been computed for the select variables viz. Socio demographic, maternal, antenatal care and delivery related based on type of births (CS Vs normal births). The multiple logistic regression model has been used to identify the potential risk factors associated with CS births.
In this paper, we have explored a quantile regression approach to study the factors affecting the... more In this paper, we have explored a quantile regression approach to study the factors affecting the child mortality in India. The annual health survey data has been used for application and the results of quantile regression have been compared with those of a linear regression (LR) model. Factors, such as safe delivery, private delivery, mothers' post natal check within 48 hours, breast feeding within 1 hour, full immunizations, fathers literacy rate., etc are found to be significantly associated with child mortality (P value < 0.05). The results have demonstrated that using quantile regression leads to better interpretation and more specific inference about the predictors of child mortality. Hence, we suggest that the quantile regression could be used as an alternative to LR in mortality analysis.
The cure fraction models are generally used to model lifetime data with long term survivors. In a... more The cure fraction models are generally used to model lifetime data with long term survivors. In a cohort of cancer patients, it has been observed that due to the development of new drugs some patients are cured permanently, and some are not cured. The patients who are cured permanently are called cured or long term survivors while patients who experience the recurrence of the disease are termed as susceptibles or uncured. Thus, the population is divided into two groups: a group of cured individuals and a group of susceptible individuals. The proportion of cured individuals after the treatment is typically known as the cure fraction. In this paper, we have introduced a three parameter Gompertz (viz. scale, shape and acceleration) or generalized Gompertz distribution in the presence of cure fraction, censored data and covariates for estimating the proportion of cure fraction through Bayesian Approach. Inferences are obtained using the standard Markov Chain Monte Carlo technique in openBUGS software.
Prediction of number of involved lymph nodes in breast cancer patients is an important criterion ... more Prediction of number of involved lymph nodes in breast cancer patients is an important criterion to assess the severity and progression of disease. The number of involved nodes is count data which often displays over-dispersion, hence the Poisson and Negative Binomial distribution is ultimate choice for modeling. In this paper we have made an attempt to estimate the number of involved lymph nodes in breast cancer patients using Bayesian regression approach assuming multivariate normal prior for the parameters. The posterior estimates have been derived using MCMC pack and the best model has been selected based on Deviance Information Criterion (DIC) values. The Bayesian Negative Binomial regression over performed than the Poisson regression. The predictors' viz., tumor size, tumor grade, CA 15-3 marker and progesterone receptor status are significantly associated with the involved lymph nodes of the breast cancer patients.
Objective: The aim of the study is to estimate the sub-distribution hazard ratio of HIV/ AIDS pat... more Objective: The aim of the study is to estimate the sub-distribution hazard ratio of HIV/ AIDS patients undergoing anti-retroviral therapy for an interval censored data in the presence of loss to follow up as a competing risk. Methodology: Exact survival times of interval censored cases are imputed using multiple imputation with loss to follow up as a competing risk. Fine and Grey competing risk regression model is then applied to the right censored data to estimate sub-distribution hazard ratios in the presence of different covariates. To compare the results, midpoint imputation and multiple imputation considering loss to follow up as right censoring only are also performed. Results: In all the three methods the predictors, viz., sex, CD4 cell count, hemoglobin, weight, area of residence and opportunistic infection are found to be significantly associated with mortality. In both methods (multiple as well as midpoint imputation), the sub-distribution hazard ratios of death due to HIV/ AIDS for different covariates are comparable. Conclusion: When the loss to follow up is informative, it is better to use it as a competing risk. Multiple imputation with loss to follow up as a competing risk provides better results than those obtained from midpoint imputation and multiple imputation without loss to follow up as a competing risk in terms of lower standard error.
ABS TRACT Objective: The present paper demonstrates the applications of Accelerated Failure Time
... more ABS TRACT Objective: The present paper demonstrates the applications of Accelerated Failure Time (AFT) model with gamma and inverse Gaussian frailty distributions to estimate the effect of prognostic factors on the survival of HIV/AIDS patients undergoing Antiretroviral Therapy (ART) in Delhi, India. Material and Methods: The results of both these models have been compared to without frailty model. Akaike Information Criterion (AIC) and Bayesian Information criterion (BIC) have been used to select best model for HIV/AIDS data. Results: The prognostic factors sex, mode of transmission, baseline hemoglobin and weight are found to be statistically significant (P-value <0.05) for HIV/AIDS patients on ART. Gamma shared frailty model with lognormal as baseline distribution is found to be the best model for HIV/AIDS patients. The model also reflected there is strong evidence of high degree of heterogeneity in the HIV/AIDS patients. Conclusion: Therefore shared frailty model is an appropriate approach for analyzing the HIV/AIDS data than without frailty model. Tu ur rk ki iy ye e K Kl li in ni ik kl le er ri i J J B Bi io os st ta at t 2 20 01 16 6; ;8 8((1 1)): :1 13 3-2 20 0
The objective of this study was to determine patterns and frequency of antimicrobial drug use amo... more The objective of this study was to determine patterns and frequency of antimicrobial drug use among hospitalized patients with community-acquired pneumonia (CAP). A retrospective 5 years (April 2007-March 2012) detailed medical record review of patients diagnosed with CAP and discharged to home from Non-Intensive Care Unit respiratory medicine wards of two public hospitals in Delhi. A total of 261 medical records were analyzed. Over the 5 years, 82.0% (2007-08), 78.6% (2008-09), 59.5% (2009-10), 64.7% (2010-11), and 67.8% (2011-12) patients were prescribed two antimicrobials. In the last two study years, the proportion of patients receiving three antimicrobials increased (from 2.0% to 26.5% and 28.8%), while the proportion receiving monotherapy decreased (from 16.0% to 8.8% and 3.4%). In accordance with guidelines, beta-lactams and macrolides were the two most frequently prescribed antimicrobials (34.1%). However, newer generation beta-lactams were prescribed. A total of 37 patients were prescribed beta-lactam-tazobactam combination preparations. Overall, beta-lactams constituted more than 40% of prescriptions while macrolides were the second most prescribed class. Cephalosporin prescriptions significantly increased (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and penicillin prescriptions significantly decreased over study periods. The prescription of fluoroquinolones also decreased (21.5-6.0%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and aminoglycoside prescription ranged from 9.7% to 16.4%, over 5 years. Reasons for prescribing three antimicrobials, use of aminoglycosides, or higher-end/reserve antibiotics were not mentioned in the medical records. There were no hospital-specific guidelines for doctors to follow in the treatment of CAP. These findings suggest the need for implementing antimicrobial treatment guidelines. Adequate documentation and monitoring of antibiotic use for feedback are also lacking. An antimicrobial stewardship program may offer the most comprehensive solution for appropriate use of antimicrobials.
The main purpose of this study is to assess the impact of Antiretroviral Therapy (ART) by using a... more The main purpose of this study is to assess the impact of Antiretroviral Therapy (ART) by using a multistate Markov model to estimate transition intensities and transition probabilities among various states (transient as well as absorbing) of the AIDS patients. A total of 580 AIDS patients were included in this study who are undergoing Antiretroviral Therapy treatment in the ART centre in New Delhi during the period of April 2004 to April 2011. The patients are classified in different states on the basis of their available CD4 cell counts. The authors also estimated the mean sojourn time and total length of stay in each state before absorption, and also examined the effects of explanatory variables (i.e Age, Sex, Mode of transmission) on the rates of transition using Cox's proportional hazard model.
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Papers by Prafulla Swain
(AFT) model with gamma and inverse Gaussian frailty distributions to estimate the effect of prognostic
factors on the survival of HIV/AIDS patients undergoing Antiretroviral Therapy (ART) in
Delhi, India. Material and Methods: The results of both these models have been compared to without
frailty model. Akaike Information Criterion (AIC) and Bayesian Information criterion (BIC) have
been used to select best model for HIV/AIDS data. Results: The prognostic factors sex, mode of transmission,
baseline hemoglobin and weight are found to be statistically significant (P-value <0.05) for
HIV/AIDS patients on ART. Gamma shared frailty model with lognormal as baseline distribution is
found to be the best model for HIV/AIDS patients. The model also reflected there is strong evidence
of high degree of heterogeneity in the HIV/AIDS patients. Conclusion: Therefore shared frailty model
is an appropriate approach for analyzing the HIV/AIDS data than without frailty model.
Tu ur rk ki iy ye e K Kl li in ni ik kl le er ri i J J B Bi io os st ta at t 2 20 01 16 6; ;8 8((1 1)): :1 13 3-2 20 0
(AFT) model with gamma and inverse Gaussian frailty distributions to estimate the effect of prognostic
factors on the survival of HIV/AIDS patients undergoing Antiretroviral Therapy (ART) in
Delhi, India. Material and Methods: The results of both these models have been compared to without
frailty model. Akaike Information Criterion (AIC) and Bayesian Information criterion (BIC) have
been used to select best model for HIV/AIDS data. Results: The prognostic factors sex, mode of transmission,
baseline hemoglobin and weight are found to be statistically significant (P-value <0.05) for
HIV/AIDS patients on ART. Gamma shared frailty model with lognormal as baseline distribution is
found to be the best model for HIV/AIDS patients. The model also reflected there is strong evidence
of high degree of heterogeneity in the HIV/AIDS patients. Conclusion: Therefore shared frailty model
is an appropriate approach for analyzing the HIV/AIDS data than without frailty model.
Tu ur rk ki iy ye e K Kl li in ni ik kl le er ri i J J B Bi io os st ta at t 2 20 01 16 6; ;8 8((1 1)): :1 13 3-2 20 0