GHREG is a command-line program for the semiparametric analysis of short-term and long-term effects of potentially time-dependent covariates on right-censored failure time data in cohort studies. Standard statistical analysis of failure time data using the Cox model can yield very misleading results when the proportional hazards assumption of constant relative risk is violated. GHREG implements valid and efficient likelihood-based statistical methods that allow non-constant hazard ratios over time, as described in Diao, Zeng and Yang (to be submitted). The current release performs semiparametric regression analysis of right-censored failure time data with time-independent covariates. We are working intensely to improve the capabilities of GHREG, so please check back frequently for updates.
We implement the algorithm of Diao and Lin (The American Journal of Human Genetics, 2005) for the semiparametric QTL mapping method in general pedigrees in a console application for the Linux platform.
The efficient and reliable algorithms of Diao and Lin (Genetic Epidemiology, 2006) for the semiparametric family-based tests of association are available for the Linux platform.
The semiparametric variance-component models for linkage and association analysis of censored trait data, as described in Diao and Lin (Genetic Epidemiology, 2006), are implemented in a Linux console application.