A Follow-Up Study on Survival Trend of AIDS Patients Reported at ART Center in Delhi & Variation According to Age, Sex, Stages & Mode of Transmissions.

Incubation period of HIV to AIDS is a vital tool that plays an important role in estimating the longevity or survivability of the HIV infected patients. However, death of AIDS patients when considered as end point becomes meaningful while finding the actual survivability of an individual. The present study is focused in analyzing the data on 343 AIDS patients who were recommended to undergo treatment in the ART centre followed up for a period of 6 years. The study included a cohesive treatment of censored observations based on lost to follow-up, deaths, recovered and alive cases till the end of study as well as uncensored observations. On the basis of diagnosed AIDS cases, the estimates of survivability under various conditions have been obtained. This paper also incorporates the trend of survivability for the reported AIDS patients with respect to age, sex, stages and mode of transmission across these 6 years. Kaplan Meier estimation method and Cox proportional hazard model were applied to determine the effect of various covariates that may be responsible for the death of the AIDS patients, survival pattern.

On the Estimation of Survival and Death Probabilities under Myocardial Infarctions in the Presence of Competing Risks Based on an Illness-Death Model.

This paper is concerned with the development of an illness-death model for the study of survivability of heart patients. The Myocardial Infarctions (MI) experienced in heart disease have been categorized as fatal and nonfatal. Fatal MI’s are easily recognizable and identified and are always reported in the case history of the patient suffering from heart disease whereas non-fatal MI’s are not easily identified and are rarely reported in the case history of the patient. Also, in the case of human population, all individuals are not equally healthy and the chance of dying varies from one person to another. Moreover illness and death are two different types of events. Illness may be transient, repetitive and reversible, whereas death is an irreversible or absorbing state. Further complexity is introduced by competition among various risks of death. The probability of an individual dying from one cause is influenced by the presence of competition from other causes. Here in our problem we have taken two health states viz. normal state and illness state due to non-fatal MI’s, and two death states viz. death state due to fatal MI and death state due to competing risk. The study population of n individuals is divided into two groups viz. n individuals who are in the normal state and n individuals 1 2 who are in the illness state due to non-fatal MI’s, at the time of start of the study. The expressions for survival and death probabilities have been obtained by using the concep of crude probability of death under competing risks. The likelihood estimates of the survival and death probabilities have also been obtained. Application of the model is discussed.

A Study of Cardiovascular Risk Factors in Delhi, India.

Acute myocardial infarction (AMI) is a leading cause of mortality and disability of adults in urban and rural India, and occurs at younger age than in western populations. In this paper an attempt has been made to determine the risk factors for non- fatal AMI among Indian men and women and to study the difference in proportion of risk factors by taking non- AMI group along with healthy group as controls. Mantel Haenzel test showed that while comparing AMI with non-AMI group, diabetes mellitus (p<0.05), family history of MI (p<0.0001) and smoking (p<0.0001) are significantly associated with AMI after adjusting the effects of hypertension. The same test was carried out in comparing AMI with healthy group which showed that diabetes mellitus (p<0.05), family history of MI (p<0.0001) and smoking (p<0.0001) are significantly associated with AMI after adjusting the effects of hypertension. Similarly, while comparing CVD group with healthy group, family history of MI (p<0.0001) and smoking (p<0.0001) are significantly associated with CVD after adjusting the effects of hypertension. Stepwise logistic regression showed that while comparing AMI cases with non- AMI controls, arrhythmias (odds ratio (OR) = 5.196, p < 0.0001), angina (OR = 3.599, p < 0.0001), CHF (OR = 3.121, p<0.0001), hypertension (OR=2.717, p<0.0001), smoking (OR=1.993, p<0.0001) and family history of MI (OR=1.819, p<0.01) were important risk factors for a first myocardial infarction. Moreover, while comparing AMI cases with healthy controls, family history of AMI (OR=15.925, p<0.0001), smoking (OR=2.806, p<0.001), hypertension (OR=2.718, p<0.0001), gender (OR=2.410, p<0.01) and age (OR=2.410, p<0.05) were important predictors of AMI; and while comparing CVD cases (AMI and non-AMI) with healthy group, family history of MI(OR=10.377,p<0.01), hypertension (OR=8.237, p<0.01) and smoking (OR=4.454, p<0.01), were important predictors of cardiovascular disease.

A Comprehensive Study on Survival Trend in Iranian Patients with HIV Infection and Variations According to Age and Mode of Transmission : A 14-year follow-up study.

One of the epidemiological descriptor of a fatal infectious disease is the time it takes from infection to death or the survival period. The present study has focused on trend in survival and death of Iranian nonhemophiliac HIV patients from 1988 to 2002 and has estimated the nonparametric distribution of the survival function of HIV patients with respect to different variables of interest, like mode of transmission, gender and age at the time of diagnosis.

Nonparametric estimation of survival function of HIV+ patients with doubly censored data.

In the analysis of follow-up studies of patients who have been or may be infected by the Type-1 human immunodeficiency virus (HIV-1), which causes the acquired immune deficiency syndrome (AIDS), one problem of interest is the estimation of distribution of the survival function when the origin and end points defining the survival time suffer interval censoring. In this paper, we have compared Kaplan-Meier, midpoint estimation and sun (1997), by analysis of a cohort study data of Iranian Injecting Drug Users (IDU) who became HIV infected through the using common infected syringe.

On the construction of clinical life table for studying the survivability of diagnosed AIDS cases.

In this paper, an attempt has been made to estimate the various survival functions of clinically diagnosed AIDS cases by the life table method. The actuarial life table method has already been applied to clinical data for many decades. To exhibit computations for the clinical life table, we have used the clinical data gathered on diagnosed 731 male and female AIDS patients recorded from Dec.1993 up to Dec.2002 in Delhi. The method is also used to study the nature of the survival functions for the AIDS patients with different causes of death. The comparisons among various survival functions are shown with the help of the graphs.

Survival pattern of reported HIV infected individuals in the city of Delhi (India).

There is very little data on the survival period of HIV in India. In this paper survival experience of 836 HIV infected patients was studied whose illness was diagnosed upto Dec. 2003. On analysis, it was observed that the mortality was maximum in the age-group of 41-50 years (25%), 24.4% in males and 24.2% in females. For patients with tuberculosis morality was 23% and was higher among those with unsafe sex (24.5%) as a risk factor. Mortality of AIDS patients in Delhi decreased from 63.2% in 1994 to 24.2% in the year 2003. Also tuberculosis was found to be the major opportunistic infection affecting 83.2% of the patients. An increasing trend was observed with tuberculosis from 84.2% in 1994 to 89.1% in 1997 (p<0.05), but overall tendency was around 84% during the period 1994 to 2003. In AIDS related symptoms chronic diarrheoa accounted for only 5.2%. The median length of survival of HIV infected patients with all subjects was 75 months. The hazard rate showed an increasing trend and reached its peak at 102 months. The survival of HIV infected patients in Delhi was found to be shorter than that of patients in developed countries and developing African countries.