The loss of independence in activities of daily living: the role of low normal cognitive function in elderly nuns.

OBJECTIVES. This study investigated the role of low normal cognitive function in the subsequent loss of independence in activities of daily living. METHODS. Of the 678 elderly nuns who-completed cognitive and physical function assessments in 1992/93, 575 were reassessed in 1993/94. Mini-Mental State Examination scores were divided into three categories and related to loss of independence in six activities of daily living. RESULTS. Participants with low normal cognitive function at first assessment had twice the risk of losing independence in three activities of daily living by second assessment relative to those with high normal cognitive function. This relationship was largely due to a progression from low normal cognitive function at first assessment to impaired cognitive function at second assessment and was associated with an elevated risk of losing independence in the six activities. CONCLUSIONS. Progression from low normal to impaired cognitive function was associated with loss of independence in activities of daily living. Thus low normal cognitive function could be viewed as an early warning of impending cognitive impairment and loss of physical function.