Performance Measures for 21 Clinical Centers by Type of Center^*.

Performance Measure	Community-Based Center (n = 13)	University-Based Center (n = 8)
Patient accrual, No.	45	46.5
Scheduled examinations completed, %	91	94
2-y Masked vision examinations completed, %	81	88
Scheduled health-related quality-of-life telephone interviews† completed, %	81	90
Vision examination data transmitted promptly, %	76	86
Retina photographs arrived promptly, %	74	76

^*Data are given as medians.

^†Centrally administered health-related quality-of-life telephone interviews were undertaken to assess patient-centered outcomes. Interview instruments included the National Eye Institute Visual Function Questionnaire,¹² the 36-Item Short-Form Health Survey,¹³ the Hospital Anxiety and Depression Scale,¹⁴ and the SST Vision Preference Value Scale.¹⁵