这两个东西都是干吗的啊，之间有什么关系呢，能帮我解释一下下面这段话吗
The total costs attributable to relapse were estimated using a Poisson regression to take into account the skewness of the
distribution of the cost data .A modified Park test indicated that this specification was adequate relative to other types of distributions such as the Gamma or inverse-Gaussian.
谢谢！