Regression Models
Fit various regression models, including Cox proportional hazard, normal, and log-normal, to censored data (e.g., survival data). Specifying survival times: There are three ways to specify survival times. You can select one (continuous dependent) variable with survival times (e.g., number of weeks surviving), you can select two (continuous dependent) variables with start and stop times for each observation (the analysis will be performed on the differences between the two values, i.e., on the elapsed times), or you can select six (continuous dependent) variables containing dates. Specifically, these variables should contain the month (1 to 12), day (1 to 31), and year when the particular observation began (e.g., when the patient was admitted to the hospital), and the month, day, and year when the observation was terminated (due to death/failure or censoring, e.g., when a patient was dismissed from the hospital). While processing the data, Survival Analysis will compute the number of days that elapsed between dates, and perform the analysis on this measure. Note that if the value of the year is less than 100, STATISTICA will automatically assume that the year refers to the 20th century; for example, the year 88 would be converted into 1988 (and 3 would be converted to 1903; make sure to enter 2003 explicitly into the year column to reference that year).
| Element Name | Description |
|---|---|
| General | |
| Detail of computed results reported | Specifies the level of computed results reported. If All results is requested, various results graphs are also reported. |
| Type of regression model | Choose from four different regression models: Proportional hazard (Cox) regression, Exponential regression, Lognormal regression, and Normal regression (see Regression Models). |
| Missing data deletion | Missing data can be deleted casewise (a case or observation will be excluded from the analysis if it has missing data for any variable in the analysis), or substituted by means. |
| Parameter correlations | Creates and reports the variance/covariance and correlation matrices for the parameter estimates. |
| Options for Proportional Hazard Models | |
| Equal coeffs, different baseline | This option is only applicable to Cox proportional hazard models when a stratified analysis (by group) is specified. If this option is selected, STATISTICA will fit a stratified model with constant coefficient vector for each group, but allowing for different baseline hazard (h0) in each group. |
| Survival for user-spec values | Creates and plot survival function for user defined covariate values. This option is only available for nonstratified analyses (analyses not broken down by a categorical predictor). |
| User-specified values | User-specified values for plot of survival function; enter either a single value for all covariates or a different value for each covariate. |