Table 1.

Observed and expected rates and detection rates for MCI and dementia over time

	Observation window
	2015–2017	2016–2018	2017–2019
Included beneficiaries	38,739,387	39,965,446	41,205,474
MCI
Observed rate	0.012	0.014	0.015
Expected rate	0.199	0.197	0.196
Detection ratea	0.062	0.071	0.079
Dementia
Observed rate	0.098	0.097	0.095
Expected rate	0.090	0.088	0.086
Detection ratea	1.086	1.093	1.104

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