1. Choosing outcome variables: global assessment and diaries
Bruce D Naliboff 
Gastroenterology 
Volume 126, Pages S129-S134 (January 2004)
DOI: /j.gastro

2. Figure 1
Examples of (A) a numerical scale and (B) a categorical scale used in symptom assessment. For the numerical scale, patients were asked to self-rate the overall severity of gastrointestinal symptoms on a scale of 0 (no symptoms) to 20 (the most intense symptoms imaginable). For the categorical scale, the same patients were asked to self-rate symptoms from “none” to “very severe.”
Gastroenterology  , S129-S134DOI: ( /j.gastro )