Epidemiologic associations with cataract in the 1971-1972 National Health and Nutrition Examination Survey.

Data from the 1971-1972 National Health and Nutrition Examination Survey were used to examine the associations between cataract and age, race, sex, education, diabetes, systolic blood pressure, urban vs. rural residence, and average daily ultraviolet spectrum B (UV-B) radiation counts at the site of examination. The multivariate logistic risk function was applied to data on 2225 persons, aged 45-74, who had resided for at least half their lifetime in the state where their examination was conducted. Cataracts (cortical, nuclear or posterior subcapsular opacities consistent with best corrected visual acuity of 6/9 (20/30) or worse or aphakic status) were present in 413 persons. The multivariate analysis showed that they were more common among blacks, diabetics, and rural dwellers, and were positively associated with increasing age, increasing UV-B radiation counts at the site of the examination, and decreasing number of years spent in school. The association with cataracts was also present when latitude or sunlight hours was substituted for UV-B radiation counts.