Demographic variables, including age at the time of the clinic
examination, gender, race, and years of education, were compiled from
the home interview. Cognitive status was assessed with the MMSE, and
the number of comorbidities was elicited with a structured medical
history questionnaire, both administered during the home interview.
Comorbidities included arthritis, broken hip, cardiovascular disease,
hypertension, diabetes, emphysema, asthma, Parkinson’s disease,
cancer, and stroke. Depression was assessed with the depression scale
of the General Health Questionnaire as part of the clinic examination.