Purpose: To establish an initial estimation of the MCID of the University of North Carolina Dry Eye Management Scale (UNC DEMS) and assess its association with patient perceptions of symptom change. Methods: Thirty-three patients (33.3% men, 67.7% women, mean age 60.5 yrs) with previous DEMS scores were recruited from a UNC ophthalmology clinic in spring 2014. We used anchor-based methods, categorizing important symptom change, to compare the change in the DEMS scores across visits to patient assessments of change; linear regression coefficients estimated the MCID. We correlated clinical assessments, patient perceptions, and DEMS scores. Results: DEMS score changes correlated with global anchors [20.4229 (P = 0.014)]. Unadjusted linear regression yielded a beta coefficient of 20.54 (confidence interval, 20.97 to 20.12, R2 = 0.18, P = 0.014), which estimated the DEMS MCID. Adjusting the regression model for days since the last visit and DEMS score improved the association (beta = 20.56; confidence interval, 20.99 to 20.13; R2 = 0.43; P = 0.013). Descriptive statistics produced an MCID of 1 point. Patients said that 2 points would represent a significant change. The DEMS modestly correlated with the Schirmer test (20.4045, P = 0.0266), Oxford Grading Scheme (+0.3713, P = 0.0364), and tear breakup time (20.3559, P = 0.0456). Conclusions: The UNC DEMS is a valid, responsive patient-reported outcome measure instrument, which is easy to use in the clinic and capable of showing an MCID of 1 point
