Use of latent class analyses for the estimation of prevalence of cognitiveimpairment, and signs of stroke and Parkinson's disease among African-American elderly of central Harlem: Results of the Harlem aging project

A probability sample (response rate of 79.4%) of 164 African-American elder ly residing in central Harlem was assessed using several standard cognitive screening measures and scales measuring stroke and Parkinson's symptoms, r espectively. Both traditional cutting scores and the methods of latent clas s analysis were used to estimate point prevalence. The latent class prevale nce ratio estimates range from 10 to 14%. The confidence intervals for cogn itive impairment ranged from 5 to 18% with an average estimate of 12%. The latent class estimate for stroke effects was 11% and for two measures of ne urological signs associated with Parkinson's disease 7 and 12%. About 2-3% of the sample were communication disordered, and 5% had significant ambulat ion disorder. These results indicate that a relatively large proportion of elderly community residents of central Harlem evidenced or reported health problems, any or all of which may constitute a public health challenge.