Moumita Chatterjee
University of Calcutta, India
Title: An extensive survival study of the patients with cystic fibrosis
Biography
Biography: Moumita Chatterjee
Abstract
The motivation of the study is a data on patients with cystic fibrosis. Cystic fibrosis is a genetic disorder, where owing to severe bacterial infection caused as a result of abnormal salt and water transport, leukocytes release some extracellular deoxyribonucleic acid (DNA) that accumulates in the airways that may even cause death. The enzyme Deoxyribonuclease I (DNase I) present in the human lungs has a tendency to digest the extracellular DNA. In 1992, a randomized double blind trial was conducted to compare the rhDNase, a clone of DNase I, which helps to cut the extracellular DNA and clear the airways, with a placebo to see if improvements in the patients can be achieved through the administration of rhDNase. 647 patients, with 325 on placebo and the rest 322 on rhDNase, were involved in the study. Since the infection was recurrent, observations on both the time to cure as also the time to the next infection were recorded along with measures on Fixed Expiratory Volume (FEV) of the patients for five recurrent cycles. The data was previously analyzed a number of times, but the correlation between time to cure and time to relapse between the several recurrent cycles haven’t been accounted for.
In this paper we develop methods to study the effects of the treatment and the FEV on the time to cure and the time to relapse over the different cycles. A copula based method as well as a Semi parametric Cox type model have been developed taking care of the two way correlation structure. The results that we have got using this method are very much significant with respect to the data. This method can also be applied to analyze several data of this kind.