Table 3B. Variable Impact on the Apparent C-Statistic for the Colorectal Cancer Model in Women
VariableC-StatisticChange in C-StatisticVariables (n)
No Model0.50
Years of education0.6709090.0032433
Use of estrogen0.6740480.0031394
History of diabetes0.6766480.0026005
Pack-years of smoking0.6791230.0024766
Family history of colon cancer0.6809630.0018397
Regular use of multivitamins0.6824970.0015348
Body mass index0.6837960.0013009
Regular use of NSAIDs0.6848930.00109710
Alcoholic drinks per day0.6858690.00097611
Preference for well-done meat*0.6862680.00039912
Moderate physical activity per day (hours)*0.6865250.00025713
Regular use of aspirin*0.6867900.00026614
Red meat intake per day (oz)*0.6868690.00007815
History of cancer*0.686865-0.00000316 (Full)
  • The outcome was colorectal cancer.

  • * The variable was excluded from the final model because of the relatively small amount of additional prediction accuracy that it could have contributed to the model. The final model, which included 11 variables, had an apparent c-statistic of 0.6859, which was within 0.001 of the accuracy associated with the c-statistic of the full model, which was 0.6869.

  • NSAIDS, nonsteroidal anti-inflammatory drugs.