Purchase this article with an account.
D. Mink, K. L. Miller, S. D. Mathias, J. G. Walt; Multiple Methods to Estimate the Minimal Clinically Important Difference of the Ocular Surface Disease Index®. Invest. Ophthalmol. Vis. Sci. 2007;48(13):409.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To assess the minimal clinically important difference (MCID) of the Ocular Surface Disease Index® (OSDI®) using multiple computation methods.
The OSDI is a 12-item patient-reported outcomes (PRO) questionnaire specifically designed to quantify ocular disability due to dry eye disease. The Overall OSDI score ranges from 0 to 100; with the scores categorized by ocular disease severity, i.e. normal (0-12), mild (13-22), moderate (23-32) and severe (33-100). To estimate the MCID for the OSDI, we used data from the RESTORE Registry study, which collects clinical, efficacy, PRO data, including the OSDI, and safety data from patients with dry eye disease. We applied three anchor-based approaches to a clinician’s global impression rating (CGI) and a subject global assessment (SGA). In each analysis, we computed one-way ANOVA with different subsets of responses: (1) using all anchor responses (7 for the CGI and 5 for the SGA); (2) using categories in which we collapsed the improvement responses and the worsening responses; and (3) using anchor responses around the ‘no change’ response (minimal improvement/worsening for the CGI and improvement/worsening for the SGA). Patients were included in our analysis if they completed the OSDI at baseline and at a subsequent follow-up visit and completed the SGA or their clinician completed the CGI.
Data from 160 patients were available. 84% of patients were Caucasian, 85% female, and mean age was 59.7 years. Both the CGI and the SGA were significantly correlated with the OSDI score (r=-.350, p<.0001 and r=-.443, p<.0001). Most patients reported an improvement in OSDI scores. MCID results ranged from a 4.9-point to 9.0-point change across methods.
Although these results are preliminary, the OSDI demonstrated its usefulness in monitoring change. The ongoing data collection from the RESTORE Registry will allow for future analyses of larger samples sizes to finalize the MCID estimates.
This PDF is available to Subscribers Only