Table 1.

Incidence rates of any MCI, amnestic MCI, and nonamnestic MCI by several demographic characteristics^a

Abbreviations: aMCI = amnestic mild cognitive impairment; CI = confidence interval; MCI = mild cognitive impairment; naMCI = nonamnestic mild cognitive impairment.

^aIncidence (per 1,000 person-years) estimated using incidence density methods, directly standardized by age and sex to the Olmsted County, MN, population on October 1, 2004, and adjusted for nonparticipation at baseline using reciprocal probability weighting. Incidence rates for aMCI and naMCI do not sum up to total MCI because the MCI subtype could not be determined for 24 incident MCI cases who were assessed only by telephone at follow-up and 12 subjects who progressed directly from cognitively normal to dementia.

^bAge at baseline.

^cSecondary analyses. The incidence rates including MCI from in-person evaluation and from telephone-only participants were 93.3 (77.1–109.6) overall, 102.5 (84.9–120.2) for men, and 86.7 (71.4–102.0) for women. The incidence rates including MCI from in-person evaluation, from telephone-only participants, and from review of medical records were 95.2 (79.0–111.4) overall, 106.6 (88.8–124.4) for men, and 87.0 (72.0–102.1) for women.

^dIncidence rates for subjects with ≤12 vs >12 years of education were 80.2 (56.5–103.9) vs 48.3 (31.1–65.5) for any MCI, 42.6 (25.8–59.3) vs 32.5 (18.6–46.4) for aMCI, and 20.3 (8.9–31.6) vs 10.2 (2.5–18.0) for naMCI.

^eThe incidence rate of aMCI was 25.5 (16.5–34.5) for single-domain and 11.7 (5.8–17.5) for multiple-domain.

^fThe incidence rate of naMCI was 10.2 (4.7–15.8) for single-domain and 4.4 (0.6–8.2) for multiple-domain.