Application of Cox Regression in Modeling Survival Rate of Drug Abuse

摘要

Drug and substance abuse is a serious health problem in many countries. In Kenya drug abuse is one of the leading causes of mortality. Modeling the rate of survival of drug users involves determining time to relapse of drug users and the number of treatment episodes for full recovery. A study of the treatment programs that the subjects are enrolled was conducted. Those subjects who completed the treatment program and fully recovered from drug use were said to have survived while those who dropped out of the treatment program were said to have not survived. The objective of this study was to fit a cox repression model in determining a set of significant covariates for survival of drug users in Kenya. The dependent variable was survival time of the subject and the independent variables were age, gender, residence, marital status, job status, mode of drug abused and the type of drug abused. The study used data on drug use from Mathari National Hospital. Cox proportional hazards model was used to establish the hazard rate of a subject entering into drug use at different stages of life. Survival rate was 36.37% with the females having higher survival rates compared to male drug users. Age, gender, marital status and employment status were significant predictors of survival rate of drug users. The study recommended that subjects who were aged below 30 years, single and jobless required more intensive and specialized treatment. More intervention programs should be targeted to these subjects.