Clinical Conversion or Reversion of Mild Cognitive Impairment in Community versus Hospital Based Studies: GDEMCIS (Gwangju Dementia and Mild Cognitive Impairment Study) and CREDOS (Clinical Research Center for Dementia of South Korea)

Article type: Research Article

Authors: Roh, Hyun Woong^{a; c} | Hong, Chang Hyung^{a; c} | Lee, Yunhwan^{b; c} | Lee, Kang Soo^d | Chang, Ki Jung^{a; c} | Kang, Dae Ryong^e | Lee, Jung-Dong^e | Choi, Seong Hye^f | Kim, Seong Yoon^g | Na, Duk L.^h | Seo, Sang Won^h | Kim, Doh Kwanⁱ | Back, Joung Hwan^j | Chung, Young Ki^a | Lim, Ki Young^a | Noh, Jai Sung^a | Son, Sang Joon^{a; c; *}

Affiliations: [a] Department of Psychiatry, Ajou University School of Medicine, Suwon, Republic of Korea | [b] Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Republic of Korea | [c] Institute on Aging, Ajou University Medical Center, Suwon, Republic of Korea | [d] Department of Psychiatry, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea | [e] Department of Medical Humanities & Social Medicine, Office of Biostatistics, Ajou University School of Medicine, Suwon, Republic of Korea | [f] Department of Neurology, Inha University college of Medicine, Incheon, Republic of Korea | [g] Department of Psychiatry, Asan Medical Center, Seoul, Republic of Korea | [h] Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea | [i] Department of Psychiatry, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea | [j] Health Insurance Police Research Institute, National Health Insurance Service, Seoul, Republic of Korea

Correspondence: [*] Correspondence to: Sang Joon Son, MD, PhD, Ajou University School of Medicine, 164 World cup-ro, Yeongtong-gu, Suwon 443-721, Korea. Tel.: +82 31 219 5180; Fax: +82 31 219 5179; E-mail: [email protected].

Abstract: Background: In keeping with increasing interest in dementia, few recent studies suggest that clinical course of mild cognitive impairment vary across different studies with hospital-based subjects showing higher rates of conversion than community-based subjects. Objective: The main objective of the present study was to assess whether the clinical conversion or reversion rates differ according to recruitment source. Methods: The baseline study subjects comprised of patients who were diagnosed with mild cognitive impairment in community-based GDEMCIS or hospital-based CREDOS. The two studies had nearly the same protocol and were performed over a similar period. We used propensity score matching for baseline comparability. After that, Cox proportional hazards regression analyses were conducted to estimate the hazard ratios and 95% confidence intervals of clinical conversion or reversion. Results: Based on 89 GDEMCIS subjects, 1 : 4 propensity score matching was conducted and 356 CREDOS subjects were selected. After adjusting for covariates including baseline demographics, comorbidity, depression, disability, and neuropsychological result, Cox proportional hazard regression analysis for time to clinical conversion indicated that recruitment from hospital-based CREDOS exhibited hazard ratio of 2.13 (95% CI, 1.08–4.21), as compared to recruitment from community-based GDEMCIS. Similarly, Cox proportional hazard regression analysis for time to reversion indicated that recruitment from hospital-based CREDOS exhibited hazard ratio of 0.34 (95% CI, 0.20–0.59), as compared to recruitment from community-based GDEMCIS. Conclusion: The present study demonstrated that even after the matching process and adjustments for baseline covariates, recruitment source greatly affected the course of mild cognitive impairment.

Keywords: Clinical conversion, community, dementia, hospital, mild cognitive impairment, reversion, recruitment source

DOI: 10.3233/JAD-160341

Journal: Journal of Alzheimer's Disease, vol. 53, no. 2, pp. 463-473, 2016