Resetting of the NEI-RQL-42 scale model for spectacle and contact lens wearers

Background The NEI Refractive Error Quality of Life Instrument 42 (NEI-RQL-42) was developed to assess how refractive error compensation affects quality of life. The purpose of this study was to reset the NEI-RQL-42 scale model to develop specific scales related to the use of ophthalmic lenses and contact lenses (CLs). Methods A prospective study was designed. Healthy volunteers between 18 and 70 years of age completed the NEI-RQL-42 questionnaire twice, once for spectacles use and once for CLs use. Confirmatory factor analysis was used to evaluate the original factor and refine the subscales to improve the psychometric properties of the NEI-RQL-42 and detect differences between spectacles and CLs. Results Seventy-five healthy subjects (58 women and 17 men with an average age of 30.53 ± 12.51 years) were included. The original factor structure did not show an acceptable fit for spectacles or CLs. Several items were removed from the spectacles and CLs datasets, and some modifications of the subscales based on modification indices were introduced to obtain acceptable models for both samples. Spectacle users showed significantly higher scores (p < 0.01) on the clarity of vision, diurnal fluctuations, symptoms and satisfaction with correction subscales. On the other hand, CLs users had higher scores on the “activity limitations” subscale (p < 0.01). Conclusion analysis of the NEI-RQL-42 score with an adequate statistical approach allows us to identify the differences between the effects of spectacles and CLs wear on patients’ QoL, providing useful information regarding the impact of refractive error compensation on QoL. Our results suggest that it is unlikely that the same scale can be used for different methods of refractive error compensation, such as spectacles or CLs.