Gary Longton

Integrating the Predictiveness of a Marker with Its Performance as a Classifier (2008)

Pepe, Margaret S., Feng, Ziding, Huang, Ying, Longton, Gary, Prentice, Ross, Thompson, Ian M., ...

There are two popular statistical approaches to biomarker evaluation. One models the risk of disease (or disease outcome) with, for example, logistic regression. A marker is considered useful if it...

Limitations of the odds ratio in gauging the performance of a diagnostic, prognostic, or screening marker (2006)

Margaret Sullivan Pepe, Holly Janes, Gary Longton, Wendy Leisenring

A marker strongly associated with outcome (or disease) is often assumed to be effective for classifying persons according to their current or future outcome. However, for this assumption to be true,...

Limitations of the Odds Ratio in Gauging the Performance of a Diagnostic, Prognostic, or Screening Marker (2004)

Pepe, Margaret Sullivan, Janes, Holly, Longton, Gary, Leisenring, Wendy, Newcomb, Polly

A marker strongly associated with outcome (or disease) is often assumed to be effective for classifying persons according to their current or future outcome. However, for this assumption to be true,...

p27kip1 Deficiency Impairs G2/M Arrest in Response to DNA Damage, Leading to an Increase in Genetic Instabilityâ–¿

Payne, Shannon R., Zhang, Shulin, Tsuchiya, Karen, Moser, Russell, Gurley, Kay E., Longton, Gary, ...

p27kip1 is a cyclin-dependent kinase inhibitor and a tumor suppressor. In some tumors, p27 suppresses tumor growth by inhibition of cell proliferation. However, this is not universally observed,...

BNORMPDF: Stata module to calculate the bivariate normal density

Gary Longton

bnormpdf generates a new variable with the bivariate normal density for two supplied variables and their specified joint bivariate normal distribution.

DATESUM: Stata module to display summary statistics for date variables

Gary Longton

datesum displays summary distribution statistics for date variable(s) in date display format.

DISTINCT: Stata module to display distinct values of variables

Gary Longton, Nicholas J. Cox

distinct displays the number of distinct values for each variable in a varlist. The varlist may include both numeric and string variables.

ADDTXT: Stata module to add text to graphs

Gary Longton

addtxt adds text to the most recent graph, positioned at graph coordinates (x,y). This program translates graph coordinates into screen coordinates, and is otherwise a wrapper for the -gph text-...

Limitations of the Odds Ratio in Gauging the Performance of a Diagnostic or Prognostic Marker

Margaret Pepe, Holly Janes, Gary Longton, Wendy Leisenring, Polly Newcomb

A marker that is strongly associated with outcome (or disease) is often assumed to be effective for classifying individuals according to their current or future outcome. However, for this to be true,...

Accommodating covariates in receiver operating characteristic analysis

Holly Janes, Gary Longton, Margaret S. Pepe

Classification accuracy is the ability of a marker or diagnostic test to discriminate between two groups of individuals, cases and controls, and is com- monly summarized by using the receiver...

Estimation and comparison of receiver operating characteristic curves

Margaret S. Pepe, Gary Longton, Holly Janes

The receiver operating characteristic (ROC) curve displays the capacity of a marker or diagnostic test to discriminate between two groups of subjects, cases versus controls. We present a...