Updating readme on the repo

README.Rmd

 ---
 title: "AIDS Clinical Trial Group (ACTG) Study Dataset"
 author: "Sara Levintow"
-date: "10/6/2017"
+date: "`r Sys.Date()`"
 output: md_document
 ---
 # AIDS Clinical Trial Group (ACTG) Study Dataset #

README.md

 AIDS Clinical Trial Group (ACTG) Study Dataset
 ==============================================
 
-The ACTG study 320 compared a combination of three antiretroviral drugs
-against a pair.
+The AIDS Clinical Trials Group (ACTG) 320 compared a combination of
+three antiretroviral drugs (two nucleoside analogues, zidovudine and
+lamivudine, plus a protease inhibitor, indinavir) against a pair
+(zidovudine and lamivudine alone). The dataset consists of 1,156
+HIV-positive patients enrolled in the trial between January 29, 1996 and
+January 27, 1997. At screening, all patients had a CD4 cell count ≤200
+cells per cubic millimeter, at least 3 months of prior zidovudine
+therapy, and no previous treatment with lamivudine or protease
+inhibitors. Patients were stratified based on CD4 count (≤50 vs. 51-200)
+and randomly assigned to the three-drug or two-drug regimen. The outcome
+of interest was the occurrence of AIDS or death, and the findings from
+the trial were reported in Hammer's 1997 paper in the New England
+Journal of Medicine. Trial participants were followed until AIDS
+diagnosis, death, loss to follow-up, or administrative censoring.
+Covariates measured at baseline and available in the dataset are age,
+sex, race, ethnicity, Karnofsky score, CD4 cell count, and history of
+injection drug use.
 
 ### Installation
 
@@ -18,11 +33,11 @@ You can install the package from Bitbucket
 -   male: 1=male, 0=female
 -   black: 1=black, 0=non-black
 -   hispanic: 1=hispanic, 0=non-hispanic
--   idu: numeric variable for exposure (1=history of injection drug use,
-    0=no history)
--   idu\_f: factor variable for exposure (1=history of injection drug
-    use, 0=no history)
--   art: 1=triple therapy, 0=double therapy
+-   idu: 1=history of injection drug use, 0=no history of injection drug
+    use
+-   art: 1=triple therapy, 0=dual therapy
+-   art\_f: factor variable for treatment group (1=triple therapy,
+    0=dual therapy)
 -   r: 1=in subcohort, 0=not
 -   age: years of age at randomization
 -   karnof: Karnofsky score (100=normal, 0=dead)