SURVIVAL 6.0.2 Last ChangesĄMedian of survival with 95% IC is now estimated and printed for the different groups.ĄNow if you double-clickin on a Text File or a Binary File created by the program theapplication is launched an the selected file is automatically loaded and opened.ĄIf you try to select a variable that has the same value than the Status variable orthe Time variable you get three beeps and the corresponding box flashes to warn you.Ą If you press the Option key down while selecting the Help item from the Apple menu,a full description of the available macro commands is displayed in the Help window,which may be printed with the Print option of the File Menu.If you don't press theoption key a Help window with a general description about the program and the differentMenu options is displayed.The Help id displayed in styled Text.Ą If the Option key is pressed while launching the application, a macro file is loadedin memory and the macro located in second position in the macro menu is automaticallyexecuted. The first position is left to allow the user to define a function for time-dependent survival analysis. The file should be named 'Survival Macros' and must belocated in the same folder than the application. If you don't press the Option keythe file is just loaded to be used from the Macros Menu.This option allows to link Survival with your current database for fully automatedsurvival analysis.Ą The MAKEBINS macro now lists the number of cases in each bin.Ą An Overlay Plot option has been added to the SURVIVAL CHART menu so you can show in a singleplot the baseline survival function against different levels of the covariates, for comparativeand illustrative purposes. If you press the Option key down while slecting this option theplots are displayed with dashed lines to identify the groups insted of colors.Usee the AdjustBit Mapp from the Page Setup option of your printer (if available)Ą Now the legends for both numerical and graphical Plots may be printed in SPANISH ifyou select the OUTPUT IN SPANISH item from the Outoput Options menu (welcome folks).Menus, Macro commands, Dialog boxs and warning messages are not changed (sorry folks, buthave you ever tried to translate the menu legends of an English program into Spanish so thatthe final product becomes as short as understandable for average people (try to translate intoSpanish, for example, the english word 'Hyphenating',. I've read something like 'guioneando'which is an aberration). Ą If the CONTROL key is pressed while selecting a covariate in the variable window ofthe DEFINE MODEL dialog a (c) sign appears in the rightmost side of the variable in the modelwindow.This ENABLES the internal transformation of categorical variables into K-1 INDICATOR orDEVIATION variables, where K is the max number of categories of the selected variable. If youwant to use DEVIATION coding, uncheck the 'USE INDICATOR VARIABLES' box.You may obtain the same results with the TRANSFORM option of the MODEL menu but you have tomanuallay include the different variables in the model.On the output window the coefficientes are labeled as VAR1-1, VAR1-2, etc. or as NAME-1,NAME-2, NAME-3 ... etc if you checked the LABEL VARIABLES option.*** VERY IMPORTANT -------------- All the variables selected as categorical (Control Key Down) must be done in ASCENDING ORDER.If you try to select,for example, variable 6 if you previously selected a variable whosecolumn number es equal or less than variable 6, the program beeps, the model window will beCLEARED and You'll have to start the variables selection again. This rule is also applied whenin a model you combine categoricial with non-categorical variables. Non-categorical variablesalone may be selected in any order ***I WAS COMPELLED to add this option to my program because a common error I observed in Survival analysis is the use of categorical variables 'as is' as covariates in regression models.You should be aware that if you use this type of variables you are making 'a priori' assumptionabout a lineal dependence of the hazard function with the different levels of the categoricalvariable, a fact that most of the times is WRONG (I repeat WRONG), unless otherwise demonstrated. If you use the INDICATOR coding scheme you compare the effect of a particular category withsome other category taken as reference (the first one in our case). The value and sign of thenew coefficients will tell you if that particular category increases (positive values)or decreases (negative values) the chance of survival.The value of the coefficient for thereference category (first one) is 0 and is not displayed. If you use the DEVIATION coding scheme you compare a particular category with the averageeffect for all categories. The coefficient for the reference category (first) is calculated asthe negative value of the sum of all coefficients for that category.Use the TEST OF HYPOTHESIS option to assess the joint effect upon hazard of the differente categories of the transformed variables or the different combinations ov covariates youconsider significant in your particular model. ** YOU CAN'T IMAGINE HOW MUCH YOUR RESULTS AND CONCLUSIONS MAY CHANGE IF YOU USE ANINAPPROPRIATE CODING OF YOUR VARIABLES WITH COX'S REGRESSION ANALYSIS **HERE ARE MY RECOMENDATIONS:1) USE BINARY VARIABLES (0,1) WHENEVER POSSIBLE.2) NEVER USE CATEGORICAL VARIABLES AS COVARIATES. TRANSFORM THEM INTO INDICATOR OR DEVIATION VARIABLES WITH THE ABOVE OPTIONS.3) IF YOU USE NUMERICAL VARIABLES MAKE AN ALTERNATIVE ANALYSIS BY TRANSFORMING THEM INTO DIFFERENT GROUPS OR CATEGORIES WITH THE 'MAKEBINS' MACRO (You'll love it) AND THEN TRANSFORMING THE CATEGORIES INTO INDICATOR OR DEVIATION VARIABLES. (Many times the effect of numerical variables upon the chance of survival is only significant for a limited interval of values, for example, between 60-70 years but not below or above that AGES. If you obtain a significant P value for a numerical variable and you don't explore this possibility you would draw the conclusion, otherwise wrong, that the chance of survival decreases for increasing age values).4) I PERSONALLY PREFER THE DEVIATION CODING SCHEME.5) NEVER BECOME A SLAVE OF THE 'P < 0.05' EXPRESSION OR LET IT BE A SUBSTITUTE OF YOUR NEURONS OR THE COMMON SENSE.6) MODELLING THE RISK IS THE BEST CHALLANGE AND THE BEST WAY TO TEST YOUR KNOWLEDGE ON A PARTICULAR CLINICAL INVESTIGATION PROBLEM. USE THE LIKELIHOOD RATIO TEST TO ASSESS IF A GIVEN COVARIATE IN A MODEL, WITH NO SIGNIFICANT P VALUE, SHOULD BE LEFT OR REMOVED FROM THE MODEL.7) STICK ALWAYS TO THE BASIC PRINCIPLE OF SCIENCE: THE 'PARSIMONY' AND TRY TO DESCRIBE YOUR PROBLEM WITH SIMPLE MODELS AND USING THE LEAST POSSIBLE NUMBER OF VARIABLES. NEW MACROS :Ą SURVPLOT; activates the plot of both Kaplan-Meier and Model Survival function. It must be used before the ESTIMATE macro command. This macro substitutes the GRAPHPLOT('true','false') command of previous versions.Ą LOGPLOT; activates the plot of Log -(Log) of Survival function, which is used for testing the proportionality assumption.It must be used after the ESTIMATE macro commandĄ INTPLOT(number); actives the plot of the Confidence Intervals for the current survival function. It must be used after the ESTIMATE command. 'number' is 1 for 95% CI and 2 for 99% CI.Ą RESPLOT; activates the plot of the Cumulative Function for Residuals, which is used to Test the goodness of fit of data to model.It must also be used after the ESTIMATE macro command.Ą SAVEPICT('name') saves the picture displayed in the active plot window to disk in the same folder than the application. This command should be used after the SURVPLOT, INTPLOT, LOGPLOT and RESPLOT macro commands, if you pretend to make different survival analysis with a single macro and want to save the graphical output.This macro also closes the active Plot window after saving to the disk. If you use an empty string as the 'name' argument, until you start a new analysis the graphic plots ar saved as Kaplan-Meier.PICTn, Model.PICTn, LogLog.PICTn, Intervals.PICTn and Residuals.PICTn, where 'n' is automatically increased for each saved file of the same graphic type. Use a Path if you want the pictures saved in a different folder This option is not available with the Macro Command submenu.Ą RUNMACRO(number); excutes the macro located in the position 'number' in the Macro Menu. Useful for linking different macros in complex automated survival analysis. Read carefully the macros in the 'Survival Macros' to learn how to use these commands.Ą SORTBY(column1,column2); sorts data array in ascending order by 'column1' and 'column2'. If you put a zero for the value in 'column2' the data array is only sorted by the ascending order of values in 'column1'.Ą CLEAR; clears the active output window. This option is not available with the Macro Command submenu for System versions less than 7.xx.Ą FIXDATA; makes permanente the changes in data array. You need to reload your data file if you want your original data back.Ą CATEGORIES(Var1,var2,..option). Indentifies the categorical variables in the data arrayincluded in the model that have to be transformed into DEVIATION (option = 0) or INDICATOR(option = 1) variables.STATISTICAL MACROS:This macros help a lot for an on line assessment of summary statistics of ourdata array in memory. Using these macros with standar Pascal procedures you mayeven compute other statistical Tests and compute the exact probability associatedto the test value. Ŕ DO YOU DARE ? ĄSTAT(var,var, ...) computes descriptive statistics (average, SD, SE, Min,Max and Range) for the specified 'vars'. If you use a minus sign as argument (-) the statistics for all variables in the active data array are computed.ĄCHITEST(var1,var2); computes a Chi-Square Test for categories in the 'var1' column of the data array by the categories in the 'var2'column of the data array. Results are presented in a contingency table where the rows are the max number of categories in 'var1' and the columns the max number of categories in 'var2' The maximum number of categories is seven and the categories should be numerated from 1 to N categories.ĄTTEST(var1,var2,[Var3]); computes a Student T-Test betwen Var1 and Var2. If youuse the same value for Var1 and Var2 and use Var3, which is optional, a T-Test iscomputed for the groups in Var3. The number of groups must be two (use the RECODE orCOMPUTE MACRO if necessary) otherwise you'll get an error message.ĄCHIPROB(chi,df); computes the exact P value for ChiSquare distribution 'chi' with 'df' degrees of freedom.ĄFPROB(F,df1,df2); computes the exact P value for F distribution 'F' with 'df1' and 'df2' degrees of freedom.ĄNORMPROB(Z); computes the exact P value for Normal distribution 'Z'.ĄTPROB(T,df); computes the exact P value for Student T distribution 'T' with 'df' degrees of freedom.You may acces the numerical results of these Tests for further processing withina standard pascal procedure or macro with the TEMP[] Token as follows:==================================================================================== Temp[1] Temp[2] Temp[3] Temp[4] Temp[5] Temp[6]-CHITEST Chi-Value P-value df - - --TTEST T-Value P-Value df-CHIPROB Chi-Value P-Value df - - --NORMPROB Z-Value P-Value - - - --TPROB T-Value P-Value df - - --FPROB F-Value P-Value df1 df2 - --STAT(x) Mean(x) SD(x) SE(x) Min(x) Max(x) Range(x)-----------------------------------------------------------------------------------Example if Temp[2] < 0.05 the RUNMACRO(2) else EXIT; --- Bug corrections ----- a bug that prevented to save the model when the number of selected vars was ONE has been fixed- a bug that bombed when trying to save the Data array as 'Application File' under system 6.7x has been fixed. Please report any problem or bug you detect to: Manuel Urrutia Avisrror urrutia@gugu.usal.es