Table 2.

Observed and expected rates and detection rates for MCI and dementia by age, 2017 to 2019

	Age (in years)
	65–69	70–74	75–79	80–84	≥ 85
Included beneficiaries	8,913,079	12,030,038	8,682,044	5,750,802	5,829,511
MCI
Observed rate	0.008	0.011	0.017	0.023	0.026
Expected rate	0.127	0.155	0.202	0.256	0.315
Detection ratea	0.060	0.071	0.086	0.090	0.083
Dementia
Observed rate	0.024	0.039	0.079	0.149	0.294
Expected rate	0.028	0.041	0.072	0.122	0.256
Detection ratea	0.831	0.942	1.110	1.221	1.147

MCI Mild cognitive impairment

^aThe detection rate is the ratio of the observed to the expected rate, where the expected rate is computed based on a predictive model