/** Krall, Uthoff, and Harley (1975) analyzed data from a study on multiple myeloma in which researchers treated 65 patients with alkylating agents. Of those patients, 48 died during the study and 17 survived. The variable Time represents the survival time in months from diagnosis. The variable VStatus consists of two values, 0 and 1, indicating whether the patient was alive or dead, respectively, at the end of the study. If the value of VStatus is 0, the corresponding value of Time is censored. The variables thought to be related to survival are LogBUN (log(BUN) at diagnosis [Blood Urea Nitrogen]), HGB (hemoglobin at diagnosis), Platelet (platelets at diagnosis: 0=abnormal, 1=normal), Age (age at diagnosis, in years), LogWBC (log(WBC) at diagnosis), Frac (fractures at diagnosis: 0=none, 1=present), LogPBM (log percentage of plasma cells in bone marrow), Protein (proteinuria at diagnosis), and SCalc (serum calcium at diagnosis). Interest lies in identifying important prognostic factors from these nine explanatory variables. Data Source: http://support.sas.com/documentation/cdl/en/statug/65328/HTML/default/viewer.htm#statug_phreg_examples01.htm **/ data myeloma; input Time VStatus LogBUN HGB Platelet Age LogWBC Frac LogPBM Protein SCalc; cards; 1.25 1 2.2175 9.4 1 67 3.6628 1 1.9542 12 10 1.25 1 1.9395 12.0 1 38 3.9868 1 1.9542 20 18 2.00 1 1.5185 9.8 1 81 3.8751 1 2.0000 2 15 2.00 1 1.7482 11.3 0 75 3.8062 1 1.2553 0 12 2.00 1 1.3010 5.1 0 57 3.7243 1 2.0000 3 9 3.00 1 1.5441 6.7 1 46 4.4757 0 1.9345 12 10 5.00 1 2.2355 10.1 1 50 4.9542 1 1.6628 4 9 5.00 1 1.6812 6.5 1 74 3.7324 0 1.7324 5 9 6.00 1 1.3617 9.0 1 77 3.5441 0 1.4624 1 8 6.00 1 2.1139 10.2 0 70 3.5441 1 1.3617 1 8 6.00 1 1.1139 9.7 1 60 3.5185 1 1.3979 0 10 6.00 1 1.4150 10.4 1 67 3.9294 1 1.6902 0 8 7.00 1 1.9777 9.5 1 48 3.3617 1 1.5682 5 10 7.00 1 1.0414 5.1 0 61 3.7324 1 2.0000 1 10 7.00 1 1.1761 11.4 1 53 3.7243 1 1.5185 1 13 9.00 1 1.7243 8.2 1 55 3.7993 1 1.7404 0 12 11.00 1 1.1139 14.0 1 61 3.8808 1 1.2788 0 10 11.00 1 1.2304 12.0 1 43 3.7709 1 1.1761 1 9 11.00 1 1.3010 13.2 1 65 3.7993 1 1.8195 1 10 11.00 1 1.5682 7.5 1 70 3.8865 0 1.6721 0 12 11.00 1 1.0792 9.6 1 51 3.5051 1 1.9031 0 9 13.00 1 0.7782 5.5 0 60 3.5798 1 1.3979 2 10 14.00 1 1.3979 14.6 1 66 3.7243 1 1.2553 2 10 15.00 1 1.6021 10.6 1 70 3.6902 1 1.4314 0 11 16.00 1 1.3424 9.0 1 48 3.9345 1 2.0000 0 10 16.00 1 1.3222 8.8 1 62 3.6990 1 0.6990 17 10 17.00 1 1.2304 10.0 1 53 3.8808 1 1.4472 4 9 17.00 1 1.5911 11.2 1 68 3.4314 0 1.6128 1 10 18.00 1 1.4472 7.5 1 65 3.5682 0 0.9031 7 8 19.00 1 1.0792 14.4 1 51 3.9191 1 2.0000 6 15 19.00 1 1.2553 7.5 0 60 3.7924 1 1.9294 5 9 24.00 1 1.3010 14.6 1 56 4.0899 1 0.4771 0 9 25.00 1 1.0000 12.4 1 67 3.8195 1 1.6435 0 10 26.00 1 1.2304 11.2 1 49 3.6021 1 2.0000 27 11 32.00 1 1.3222 10.6 1 46 3.6990 1 1.6335 1 9 35.00 1 1.1139 7.0 0 48 3.6532 1 1.1761 4 10 37.00 1 1.6021 11.0 1 63 3.9542 0 1.2041 7 9 41.00 1 1.0000 10.2 1 69 3.4771 1 1.4771 6 10 41.00 1 1.1461 5.0 1 70 3.5185 1 1.3424 0 9 51.00 1 1.5682 7.7 0 74 3.4150 1 1.0414 4 13 52.00 1 1.0000 10.1 1 60 3.8573 1 1.6532 4 10 54.00 1 1.2553 9.0 1 49 3.7243 1 1.6990 2 10 58.00 1 1.2041 12.1 1 42 3.6990 1 1.5798 22 10 66.00 1 1.4472 6.6 1 59 3.7853 1 1.8195 0 9 67.00 1 1.3222 12.8 1 52 3.6435 1 1.0414 1 10 88.00 1 1.1761 10.6 1 47 3.5563 0 1.7559 21 9 89.00 1 1.3222 14.0 1 63 3.6532 1 1.6232 1 9 92.00 1 1.4314 11.0 1 58 4.0755 1 1.4150 4 11 4.00 0 1.9542 10.2 1 59 4.0453 0 0.7782 12 10 4.00 0 1.9243 10.0 1 49 3.9590 0 1.6232 0 13 7.00 0 1.1139 12.4 1 48 3.7993 1 1.8573 0 10 7.00 0 1.5315 10.2 1 81 3.5911 0 1.8808 0 11 8.00 0 1.0792 9.9 1 57 3.8325 1 1.6532 0 8 12.00 0 1.1461 11.6 1 46 3.6435 0 1.1461 0 7 11.00 0 1.6128 14.0 1 60 3.7324 1 1.8451 3 9 12.00 0 1.3979 8.8 1 66 3.8388 1 1.3617 0 9 13.00 0 1.6628 4.9 0 71 3.6435 0 1.7924 0 9 16.00 0 1.1461 13.0 1 55 3.8573 0 0.9031 0 9 19.00 0 1.3222 13.0 1 59 3.7709 1 2.0000 1 10 19.00 0 1.3222 10.8 1 69 3.8808 1 1.5185 0 10 28.00 0 1.2304 7.3 1 82 3.7482 1 1.6721 0 9 41.00 0 1.7559 12.8 1 72 3.7243 1 1.4472 1 9 53.00 0 1.1139 12.0 1 66 3.6128 1 2.0000 1 11 57.00 0 1.2553 12.5 1 66 3.9685 0 1.9542 0 11 77.00 0 1.0792 14.0 1 60 3.6812 0 0.9542 0 12 run; /*unadjusted K-M survival curves for fractures at diagnosis*/ ods graphics on; ODS OUTPUT CensoredSummary =_censorsum Means =_mean Quartiles =_quartiles; proc lifetest data =myeloma plot=(s all) censoredsymbol=none outsurv=surv; time time*VStatus(0); strata Frac/ test=(all); run; /*adjusted survival curves for fractures at diagnosis by LogBUN and HGB****/ ods graphics on; ods output ParameterEstimates = overall; proc phreg data=myeloma plots(overlay)=survival; class FRAC(REF="0"); model time*VStatus(0)=LogBUN HGB Frac /rl; baseline covariates=myeloma out =overall2 survival=_all_/diradj group=FRAC; assess ph / resample ; run; ods graphics off; /***Interpretation // LogBUN: HR=5.54 //The Hazard Ratio for a 1 unit increase in LogBUN is 5.54. This tells you that an additional unit in LogBUN is associated // with 5.54 times higher rate of dying from multiple myeloma. For example, subjects with LogBUN=2 // were 5.54 as likely to die than persons with LogBUN=1.***/ /* 7.6.Framingham.log * * Proportional hazards regression analysis of the effect of gender * and baseline diastolic blood pressure (DBP) on coronary heart * disease (CHD) adjusted for age, body mass index (BMI) and serum * cholesterol (SCL). */ options nofmterr; data Framingham; set biom505.Framingham; run; /****look at the distribution of Diastolic Blood Pressure****/ proc sgplot data=Framingham; histogram dbp; run; /*****categorize Diastolic Blood Pressure****/ data Framingham; length dbpgr $50; set Framingham; if dbp le 60 then dbpgr=" DBP <= 60"; if dbp le 70 and dbp gt 60 then dbpgr=" 60 < DBP <= 70"; if dbp le 80 and dbp gt 70 then dbpgr=" 70 < DBP <= 80"; if dbp le 90 and dbp gt 80 then dbpgr=" 80 < DBP <= 90"; if dbp le 100 and dbp gt 90 then dbpgr=" 90 < DBP <= 100"; if dbp le 110 and dbp gt 100 then dbpgr=" 100 < DBP <= 110"; if dbp gt 110 then dbpgr="110 < DBP"; if dbp=. then dbpgr=""; run; /*****check if baseline diastolic blood pressure (DBP) is associated with coronary heart disease (CHD)***/ proc freq data=Framingham; table dbpgr*chdfate/chisq; run; /******create a follow up time variable in years*****/ data Framingham; set Framingham; time= followup/365.25; run; /*******create K-M survival (from coronary heart disease) curves for diastolic blood pressure (DBP) categories*********/ ods graphics on; ODS OUTPUT CensoredSummary =_censorsum Means =_mean Quartiles =_quartiles; proc lifetest data =Framingham plot=(SURVIVAL(NOCENSOR) all) censoredsymbol=none outsurv=surv; time time*chdfate(0); strata dbpgr/ test=(all); run; /*******create adjusted survival (from coronary heart disease) curves for diastolic blood pressure (DBP) categories adjustment is mode for age, sex, BMI, and SCL *********/ ods graphics on; ods output ParameterEstimates = overall; proc phreg data=Framingham plots(overlay)=survival; class dbpgr SEX; model time*chdfate(0)=dbpgr sex age bmi scl/rl; baseline covariates=Framingham out =overall2 survival=_all_/diradj group=dbpgr; *assess ph / resample ; run; ods graphics off; /****Create unadjusted survival curves for gender*****/ ods graphics on; ODS OUTPUT CensoredSummary =_censorsum Means =_mean Quartiles =_quartiles; proc lifetest data =Framingham plot=(SURVIVAL(NOCENSOR) all) censoredsymbol=none outsurv=surv; time time*chdfate(0); strata sex/ test=(all); run; /* Calculate the hazard ratio of CHD for men relative to women****/ ods graphics on; ods output ParameterEstimates = overall; proc phreg data=Framingham plots(overlay)=survival; class SEX; model time*chdfate(0)=sex/rl; baseline covariates=Framingham out =overall2 survival=_all_/diradj group=sex; *assess ph / resample ; run; ods graphics off; /*****get adjusted survival curves for gender [adjusted by dbp age sbp scl bmi]***/ ods graphics on; ods output ParameterEstimates = overall; proc phreg data=Framingham plots(overlay)=survival; class SEX; model time*chdfate(0)=sex dbp age sbp scl bmi/rl; baseline covariates=Framingham out =overall2 survival=_all_/diradj group=sex; *assess ph / resample ; run; ods graphics off;