Responsiveness and minimal clinically important difference of the Chinese version of the Low Vision Quality of Life Questionnaire after cataract surgery

AIM: To investigate the Chinese version of the Low Vision Quality of Life Questionnaire (CLVQOL) as an instrument for obtaining clinically important changes after cataract surgery. METHODS: Patients underwent cataract surgery in Shanghai General Hospital, Shanghai Jiao Tong University, who fit the inclusion criteria were recruited. Two CLVQOLs were administered, including a preoperative CLVQOL and a CLVQOL at the end of the 3mo follow-up period, and were completed using face-to-face interviews or phone interviews conducted by trained investigators. The minimal clinically important difference (MCID) was calculated using an anchor-based method and a distribution method. In addition, the responsiveness of the questionnaire was measured. RESULTS: A total of 155 residents were enrolled. The average visual acuity (VA) preoperatively was 0.08 (SD=0.05), and it increased to 0.47 (SD=0.28) at the end of follow-up. Statistically significant positive changes in the CLVQOL scores indicated significant improvement of vision related quality of life after cataract surgery. With the larger value between the two results as the final value, the MCID values of the CLVQOL (scores of the four scales as well as the total score) were 8.94, 2.61, 4.34, 3.10 and 17.63, respectively. The CLVQOL has both good internal and external responsiveness. CONCLUSION: CLVQOL scores are appropriate instruments for obtaining clinically important changes after cataract surgery. This study is an effective exploration for establishing cataract surgery efficacy standards, which helps clinical and scientific research workers in ophthalmology to gain a more in-depth understanding when using CLVQOL.