1 / 20

Modeling the Prevalence of Breast Density Using SAS

Modeling the Prevalence of Breast Density Using SAS. Veronica Burt. Reading in the Data. options nofmterr ; data BCSC.data1; set BCSC.Dr238bs_sum_data_deid_v3_1012 ; run ;. Formatting the Data. proc format ; value age 1 = "40-44" 2 = "45-49" 3 = "50-54" 4 = "55-59"

aquarius
Download Presentation

Modeling the Prevalence of Breast Density Using SAS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Modeling the Prevalence of Breast Density Using SAS Veronica Burt

  2. Reading in the Data optionsnofmterr; data BCSC.data1; set BCSC.Dr238bs_sum_data_deid_v3_1012; run;

  3. Formatting the Data proc format; value age 1 = "40-44" 2= "45-49" 3= "50-54" 4= "55-59" 5= "60-64" 6= "65-69" 7= "70-74" 8= "75-79" 9= "80-84" 10= "85+"; valuebmi1 = "<18.5" 2= "18.5-<25" 3= "25-<30" 4= "30+"; valuedense 1 = "Entirely Fatty" 2= "Scattered Fibroglandular" 3= "Heterogeneously Dense" 4= "Extremely Dense";

  4. Selecting certain observations dataBCSC.current; set BCSC.data1; ifexamyear >= 2007;

  5. Summary Statistics by Density ods html style=journal body= 'Z:\Contingency tables with density\ current age group row'; procfreqdata=BCSC.current; tablesage_group*density_c / nocolnocumchisq; weight N; byimputation_flag; title'Frequency of Age group by BI-RADS density with row percentages'; formatage_groupage.density_cdense.; run; ods html close;

  6. ProcFreq: age*density

  7. Chisq option

  8. Summary Statistics by Density ods html style=journal body= 'Z:\Contingency tables with density\ current bmi row'; procfreqdata=BCSC.current; tablesbmigrp*density_c/ nocolnocumchisq; weight N; byimputation_flag; title'Frequency of BMI by BI-RADS density with row percentages'; formatbmigrpbmi.density_cdense.; run; ods html close;

  9. ProcFreq: bmi*density

  10. Creating dummy variables /*creating dummy variables for age and restricting data to 2007-2010*/ dataBCSC.current; set BCSC.data1; ifexamyear >= 2007; _Imputation_ = imputation_flag; ifage_group = 2then age47 = 1; else age47 = 0; ifage_group = 3then age52 = 1; else age52 = 0; ifage_group = 4then age57 = 1; else age57 = 0; ifage_group = 5then age62 = 1; else age62 = 0;

  11. Logistic Ordinal Regression /*Running logit ordinal regression for age*/ procgenmoddata=BCSC.currentrorder=internal; freq N; modeldensity_c = age47 age52 age57 age62 age67 age72 age77 age82 age87 / CovBdist=multinomial link=cumlogittype1; by _Imputation_; ods output CovB = BCSC.ageCovB; ods output ParameterEstimates = BCSC.agePE; title'Predicting density from age group Logit'; formatdensity_c dense.; run;

  12. Aligning Parameter names /*renaming variable levels to run procmianalyze*/ dataBCSC.agePE; setBCSC.agePE; if parameter = 'age47'then parameter = 'prm1'; if parameter = 'age52'then parameter = 'prm2'; if parameter = 'age57'then parameter = 'prm3'; if parameter = 'age62'then parameter = 'prm4'; if parameter = 'age67'then parameter = 'prm5'; if parameter = 'age72'then parameter = 'prm6'; if parameter = 'age77'then parameter = 'prm7'; if parameter = 'age82' then parameter = 'prm8'; if parameter = 'age87'then parameter = 'prm9';

  13. ProcMianalyze /*Combining the imputations for the Logit regression*/ ods html style=journal body= 'Z:\Age parameter estimates\Ordinal logit'; procmianalyzeparms=BCSC.agePEcovB=BCSC.ageCovBmult; modeleffects Intercept1 Intercept2 Intercept3 prm1 prm2 prm3 prm4 prm5 prm6 prm7 prm8 prm9; title'Treating age as ordinal using logit regression'; run; ods html close;

More Related