Cohort comparison of vision and hearing in 75- and 80-year-old men and women born 28 years apart

Purpose We compared the vision and hearing of older men and women born 28 years apart. In addition, we explored factors explaining the possible cohort differences. Methods Two independent cohorts of 75- and 80-year-old men and women were assessed as a part of the Evergreen study in 1989-1990 (n=500) and the Evergreen II study in 2017-2018 (n=726). Studies were conducted with similar protocols, and differences between cohorts were compared for distance visual acuity and hearing acuity. We also studied whether educational level and health factors (i.e. total cholesterol, blood pressure, BMI, and smoking status) underlie the possible cohort differences. Independent samples t-test, Pearson chi-squared test, and linear regression analyses were used as statistical analyses. Results Across age and sex groups, the later-born cohort had better visual acuity and a lower prevalence of visual impairment compared to the earlier-born cohort. In hearing, 75-year-old men in the later-born cohort had better hearing acuity, with average hearing level at 32 dB compared to 36 dB in the earlier-born cohort, and 80-year-old men had a lower prevalence of severe hearing impairment (74% vs. 54%) than men in the earlier-born cohort. Similar differences were not observed for women. The cohort differences in distance visual acuity and hearing acuity attenuated when adjusting for education level. Conclusions Today older adults retain better vision longer than before, but cohort differences in hearing are less obvious. Differences between cohorts may be partly due to advances in education.