Validity and reliability of the NEI VFQ-25 questionnaire in Indonesian leprosy patients

Abstract

Background: The National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) is one of the most frequently used questionnaires to assess visual function. However, its validity and reliability have not been documented in specific context of use in leprosy patients. Objectives: To provide additional support to the reliability and validity of the NEI VFQ-25 in leprosy patients. Methods: The reliability was assessed using internal consistency analysis (Cronbach's α formula). For validity assessment, item analysis was conducted by calculating the coefficient of corrected item-total correlation. Results: The result showed all items included in the analysis were considered valid, as the coefficient was >0.3. Internal consistency reliability (calculation of all the questions taken together), the Cronbach's α of the instrument was 0.934 and 0.937. Due to low socioeconomic and low educational status, the majority of the patients have no vehicles nor can drive, therefore, there is a high missing rate of ‘Driving’ subscale. Conclusion: The NEI VFQ-25 is a reliable and valid instrument, and can be used to assess vision-related quality of life in Indonesian leprosy patients.

Keywords

• Leprosy
• NEI VFQ-25
• Validity
• Reliability