Mplus Users Guide v6.. - Muthén & Muthén

Examples: Multilevel Modeling With Complex Survey DataIn this example, the two-level continuous-time survival analysis modelshown in the picture above is estimated. This is the Cox regressionmodel with a random intercept (Klein & Moeschberger, 1997; Hougaard,2000). The profile likelihood method is used for estimation(Asparouhov et al., 2006).The SURVIVAL option is used to identify the variables that containinformation about time to event and to provide information about thetime intervals in the baseline hazard function to be used in the analysis.The SURVIVAL option must be used in conjunction with theTIMECENSORED option. In this example, t is the variable thatcontains time to event information. By specifying the keyword ALL inparenthesis following the time-to-event variable, the time intervals aretaken from the data. The TIMECENSORED option is used to identifythe variables that contain information about right censoring. In thisexample, this variable is named tc. The information in parenthesesspecifies that the value zero represents no censoring and the value onerepresents right censoring. This is the default. The BASEHAZARDoption of the ANALYSIS command is used with continuous-timesurvival analysis to specify if a non-parametric or a parametric baselinehazard function is used in the estimation of the model. The setting OFFspecifies that a non-parametric baseline hazard function is used. This isthe default.The MODEL command is used to describe the model to be estimated. Inmultilevel models, a model is specified for both the within and betweenparts of the model. In the within part of the model, the loglinearregression of the time-to-event t on the covariate x is specified. In thebetween part of the model, the linear regression of the random intercept ton the cluster-level covariate w is specified. The default estimator forthis type of analysis is maximum likelihood with robust standard errors.The estimator option of the ANALYSIS command can be used to selecta different estimator. An explanation of the other commands can befound in Example 9.1.287