Purpose: To assess whether treatment comparison of National Eye Institute Visual Function Questionnaire (NEI-VFQ) scores in a clinical trial is influenced by general health to warrant adjusting for it.
Design: Two randomized pilot trials.
Methods: Patients enrolled in two randomized pilot trials of submacular surgery versus observation for choroidal neovascularization had quality of life interviews (NEI-VFQ and the Short Form-36 Health Survey) 24 months after enrollment. Information on comorbidities was collected through chart reviews. Data from 120 patients were analyzed using linear regression methods.
Results: Adjustment for comorbidities did not change the magnitude of the treatment effect on NEI-VFQ scores. However, adjustment for Short Form-36 physical and mental component summaries produced changes in the estimated treatment effect when NEI-VFQ scores were compared.
Conclusions: Adjustment of NEI-VFQ scores for general health may be advisable. The Short Form-36 summary scores may be appropriate for this purpose.