Table 2 Postoperative symptom severity and interference by type of instrument received among patients in the test set. Values are displayed as mean (standard deviation) [coefficient of variation] combining all postoperative days. Differences and 95% confidence intervals represent the decrease in mean score among those who received questionnaires with additional descriptors calculated using linear mixed effects regression model with the questionnaire score as the outcome with a nested random effect intercept varying among patients and among surgeries within each patient. The N’s are the number of surveys

From: A comparison of brief versus explicit descriptors for verbal rating scales: interrupted time series design