Prevalence of cognitive impairment amongst Singapore's elderly Chinese: a community-based study using the ECAQ and the IQCODE.

OBJECTIVES

This study examined the prevalence of cognitive impairment in the elderly Chinese living in the Queenstown district of Singapore using two locally-validated cognitive screening instruments: the Elderly Cognitive Assessment Questionnaire (ECAQ), and the Informant Questionnaire on the Cognitive Decline of the Elderly (IQCODE).

METHODS

234 elderly Chinese subjects were randomly selected from the Queenstown district and administered the ECAQ, while their principal relatives were administered the IQCODE. The screening instruments' respective cut-off scores to identify cognitive impairment indicative of dementia were based on local validation work.

RESULTS

The prevalence of cognitive impairment was computed based on the percentage of failed scores on the two screening instruments. We found the prevalence of cognitive impairment to be 7.7% by ECAQ (95% Confidence Intervals (CI): 4.6%-10.1%) and 13.2% by IQCODE (95% CI: 9.4%-17.7%). A similar study in 1990 using ECAQ on elderly Chinese from the Henderson district in Singapore showed a cognitive impairment prevalence of 4%. This ECAQ-based variation between the two studies, likely indicates a true difference in prevalence rates between the two communities. On the other hand, the different ECAQ and IQCODE prevalence rates within our Queenstown study probably reflect spectrum bias, with IQCODE detecting earlier stages of dementia than ECAQ.

CONCLUSION

We have found the prevalence of cognitive impairment amongst Singapore's elderly to be higher than previously reported. These findings imply that current resources may be inadequate for the effective care and management of the cognitively-impaired elderly in our aging community.