Abstracts 5 7 S

telephone interview. Standardized genetic and vision-slxmific measures (e.g., Sickness Impact Profile, CES-D depression scale, and Visual Activities Questionnaire) operationalize Patrick and Erickson's conceptual framework. A Symptom and Health Problem Chart and questions about comorbidities, compliance, and satisfaction with treatment were developed for this trial. A number of associations were assessed using Spearman rank order correlations, Student's t- tests, and analysis of variance tests. Results: There were consistently significant positive correlations between generic QOL measures, vision-specific QOL measures, and clinical measures. Females, blacks, and younger patients (25-54 years old) reported that a glaucoma diagnosis had a greater impact on their health perceptions, physical and psychosocial well- being, and glaucoma-related symptoms than males, non-blacks, and older patients (p < .05). Conchtsion: The relatively low correlations suggest that one cannot infer QOL impact from visual field, visual acuity, or intraocular pressure. The administration of multiple measures, both generic and vision-specific, over time will help determine the impact of glaucoma and its treatment on quality of life. Supported by NIH grant U10 EY09148

36 CONTRIBUTION OF CONDITION-SPECIFIC QUALITY OF

LIFE (QOL) MEASUREMENT TO SF-36

Mac Gordon, Julia Beiser, Kenneth Schectman, Joseph Barr, Timothy Edrington, Donald Everett, Karla Zadnik

Washington University School of Medicine St. Louis, Missouri

The correlation between generic and condition-specific quality of life (QOL) scales is potentially very high. How much independent, additional information do condition-specific QOL questionnaires provide? The National Eye Institute Visual Functioning Questionnaire (NEI-VFQ) consists of 11 scales and 25 items to assess visual functioning as well as vision- specific social functioning, mental health, role difficulties, and dependency. The NEI-VFQ has demonstrated good responsivity, good diagnostic discrimination, high test-retest reliability and high internal-consistency reliability. The potential for redundancy between the SF-36 and NEI-VFQ is highest for social functioning, pain, role difficulty, and mental health scales which are in both instruments.

If the condition-specific NEI-VFQ and generic SF-36 scales are highly correlated, both scales needn't be administered. The NEI-VFQ and the SF-36 were administered to 1,128 patients enrolled in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. None of the SF-36 scale scores were lower than age-specific norms. However, 10 of the 11 NEI-VFQ scales were markedly lower than the comparison group. The correlations between the generic and condition-specific scales for social functioning, pain, mental health and role difficulty were 0.35, 0.24, 0.40, and 0.41 respectively. These results suggest that administration of the NEI-VFQ is strongly justified because it contributes important, independent information missed by the SF-36, even for those scales that appear to sample similar content. Supported by NIH grants EY10419, EY10069, EY10077, and EY02687.

37 MEASURING COGNITIVE PROGRESSION IN ALZHEIMER'S DISEASE

Julie D. Berg, Ronald G. Thomas, Leon J. Thai, and Mary Sano University of California, San Diego

La Jolla, California

Understanding the rate of cognitive progression in Alzheimer's disease is important both in planning long-term care for patients and in designing effective clinical trials for potential treatments. A number of issues need to be addressed in the application of statistical methods