Yueqin Huang MD MPH PhD Professor of psychiatric epidemiology

1. Epidemiological study of mild cognitive impairment and pilot evaluation of methods of early dementia detection in Chinese community Yueqin Huang MD MPH PhD Professor of psychiatric epidemiology Institute of Mental Health, Peking University Beijing, People’s Republic of China

2. Background • Aging is occurring at an unprecedented rate, especially in developing countries. • Dementia is one of the diseases among elderly. It causes huge burden both for the families and societies. • Mild Cognitive Impairment (MCI) is considered to be an intermediate status between “normal ageing” and dementia. • Focus on MCI among dementia study has been widely considered. That makes it possible for early detection for patients with Alzheimer's Disease.

3. The role of informants during dementia screening • Information from patients, as well as informants are both important when accessing the mental status of patients. • Researchers have reported that the validity of informant questionnaire is more satisfied than the questionnaire for patients. • Hall’s study showed that the score of informant questionnaire has independent function for the diagnose of dementia. • 10/66 dementia project has developed a simple case-finding method, which has been proved to be feasible in India and Brazil.

4. Objectives • To describe the prevalence of mild cognitive impairment (MCI) in urban and rural communities in Beijing • To explore the social-demographic factors of MCI • To describe the outcome and related factors of MCI from a follow-up study • To evaluate the validity of simple case-finding method for dementia and the informant questionnaire of community screening instrument for dementia (CSID)

5. Instruments • Simple case-finding method • Community screening instrument for dementia (CSID) • 10/66 questionnaires • Cognitive questionnaire • Geriatricmentalstate (GMS) questionnaire • Informant questionnaire • Background and risk factor questionnaire • Follow-up questionnaire • Physical examination

6. Subjects and methods • Cross-sectional study: 2609 elderly of 65 year-old and over • Follow-up study: 109 elderly with MCI, 109 control and 72 demented elderly from cross-sectional study, totally 290 persons • Test of simple case-finding method: trained staffs from local neighborhood committees nominated dementia persons and then ICD-10 was used as gold standard to test its validity • Test of CSID informant questionnaire : 10/66 diagnostic algorithm and ICD-10 were used as gold standards independently to test the validly of CSID informant questionnaire from the care-takers of the 2609 elderly.

7. Results (1) Prevalence of MCI • Respondent rate: 82.9% • There is no statistical difference in age and gender between the interviewed elderly and missing elderly. • The prevalence of MCI according to Petersen criteria

8. Urban and rural difference and MCI

9. Gender and MCI

10. Age and MCI *P<0.05

11. Education and MCI

12. Marital status and MCI * *P<0.05

13. Behaviors and MCI * *P<0.05

14. Stoke and MCI * *P<0.05 Transient ischaemic attack (TIA) history, hypertension, or diabetes were not the risk factors of MCI.

15. Depression and MCI * *P<0.05

16. Key findings from MCI prevalence study • The prevalence of MCI was 5.0%. • Elder age, widow, and history of depression and stoke predicted MCI.

17. Results (2) Follow-up study of MCI • General information about follow-up • After 780±114 days (26±3.8 months) follow-up for the 290 elderly, 212 (73.1%) were alive, 50(17.2%) were dead, and 28(9.7%) were loss of follow-up. • Among 50 dead elderly, there were 12 MCI elderly, 9 control and 29 demented elderly.

18. Follow up information • There was no difference of the mortality ratio between the MCI and control group. • The mortality risk ratio for demented elderly was 3.3 times of MCI elderly.

19. The transition from MCI to dementia • The two-year cumulative conversion rate from MCI to dementia was 10.3% (9/87), with average annul rate of 5.3% (95%CI: 0.6%-10.0%). • Age, gender, education, living area, life behaviors, or history of stoke or depression did not predict the incidence of dementia • Widowed marital status predicted dementia • Nobody developed dementia among control group.

20. Neuropsychological features of the transition • It was found that the deficiencies of cognitive status in terms of second time immediate 10-word recall, delayed 10-word recall, orientation, and fluency of language were more sever among MCI persons who developed dementia.

21. COX regression results for the transition • Results from COX regression showed that 10-word delayed recall (RR=3.03, 95%CI: 1.18-7.69) predicted dementia after adjusting age and gender.

22. The incidence of MCI • The two-year cumulative conversion rate from normal cognitive status to MCI was 6.5% (6/92), with average annul rate of 3.3% (95%CI: 0.0%-7.0%). • The average of 6 new MCI elderly was 80.5±9.7 year-old, which was elder than the elderly without MCI (74.4±6.2, t=2.236, P=0.028).

23. The death information among MCI group • The two-year cumulative mortality ratio among MCI group was 11.0% (12/109), with the average annul ratio of 5.7% and SMR of 1.6. • Among the dead elderly, 4 persons died of cerebrovascular disease (33.3%); 4 persons died of systemic failure (33.3%); 2 persons died of heart disease (16.7%); 1 person died of lung infection (8.3%); and 1 person died of digestive diseases (8.3%). • Elder age (RR=6.43), drinking history (RR=5.93), and history of TIA (RR=9.50) predicted the death.

24. Key findings from MCI follow-up study • The two-year cumulative conversion rate from MCI to dementia was 10.3% (9/87). Widowed marital status predicted dementia. Nobody developed dementia among control group. • The deficiencies of cognitive status in terms of second time immediate 10-word recall, delayed 10-word recall, orientation, and fluency of language were more sever among MCI persons who developed dementia two years later.

25. Key findings from MCI follow-up study • The two-year cumulative conversion rate from normal cognitive status to MCI was 6.5% (6/92). Elderly with new MCI were elder than those without MCI. • The two-year cumulative mortality ratio among MCI group was 11.0% (12/109). It was similar as the mortality ratio among control group.

26. Results (3) Test of case-finding method • Key informant: staffs of local neighborhood committees • Fifty-eight elderly were nominated as possible dementia patient by trained staffs • Fifteen of them were diagnosed dementia. The positive predictive value was 25.9%.

27. Results (4) Test of CSID • General information • Carer of the elderly were the informants. • 45.1% informants were spouses, and 40.1% informants were children. • 93.8% of informants lived with the elderly.

28. The reliability of CSID • The Spearman-Brown split reliability of cognitive factor, activity of daily life factor, and total score of CSID were 0.85 (P<0.05), 0.79 (P<0.05) and 0.85 (P<0.05). That means high correlations among items of each factor. • Both Cronbachαof the two factors were larger than 0.8. That means high correlations between items and factors, which indicated a satisfied homogeneity reliability.

29. The validity of CSID The results were similar when using the two gold standards.

30. ROC curve when using ICD-10 as gold standard

31. ROC curve when using 10/66 algorithms as gold standard

32. Who can provide more accurate information? • Dependent variable: if the informant accurately provided dementia information or not • Independent variable: informants’ gender, relationship with the elderly, and living status • Results: Spouse (OR= 1.77, P=0.04), and informant who lived in urban area (OR=2.04, P=0.02) could provide more accurate information.

33. Key findings from early dementia detection study • Simple case-finding method conducted by staffs from the local neighborhood committees was not satisfied in Beijing. • CSID informant questionnaire had satisfied reliability and validity in Beijing. Urban dwellers and spouses provided more accurate information.

34. Conclusion • Older age, stroke and depression are risk factors of MCI occurrence. • Less score of delayed recall is a predictor of converting MCI into dementia. • The mortality risk ratio of MCI is lower than that of dementia. • The validity of simple case-finding method for dementia is not satisfied. • CSID informant questionnaire has higher sensitivity and can be used for dementia screening in community.

35. Thank you