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Bayesian Bent-Cable Tobit Models for Longitudinal and Survival Data: Application to AIDS Studies
| Content Provider | Semantic Scholar |
|---|---|
| Author | Dagne, Getachew A. |
| Copyright Year | 2018 |
| Abstract | In prospective studies, there is often a response variable which may be associated with a time to an event of interest. For example, in HIV (Human Immunodeciency Virus) clinical trials, a longitudinal response variable, viral load or HIV RNA (Ribonucleic Acid), may be related to the time to the first decrease to CD4/CD8 (clusters of differentiation 4 and 8 T-cell co-receptors) ratio. Such an association throws light on important indicators of risk of disease progression [1,2]. In addition, the viral load has a Lower Detection Limit (LOD) and a developmental growth curve with phasic changes over time [3-5]. The viral load growth curves of patients, After Receiving Antiretroviral (ARV) drugs, may decrease over time up to a point and then start increasing upwards [6]. These phasic changes may also occur gradually instead of abruptly because of a biological process of developing resistance to ARV drugs over time [7]. To simultaneously model these features of viral load, we extend the bent-cable method [8,9] by incorporating (i) the relationship between viral load proles and time to first decrease of CD4/CD8 ratio; (ii) two-part modeling of left-censored viral load to account for heterogeneity of patients who are either progressing to AIDS (viral load above detection limit and rebound) or non-progressing to AIDS after receiving treatment (having viral load below detection limit and decreasing over time); and (iii) skewness of response variable. |
| Starting Page | 1 |
| Ending Page | 10 |
| Page Count | 10 |
| File Format | PDF HTM / HTML |
| DOI | 10.36876/smjbb.1025 |
| Volume Number | 3 |
| Alternate Webpage(s) | https://www.jsmcentral.org/sm-biometrics-biostatistics/smjbb-v3-1025.pdf |
| Alternate Webpage(s) | https://doi.org/10.36876/smjbb.1025 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
