Mortality Risk after Diagnosis of Early-Onset Alzheimer’s Disease versus Late-Onset Alzheimer’s Disease: A Propensity Score Matching Analysis

Article type: Research Article

Authors: Chang, Ki Jung^a | Hong, Chang Hyung^{a; i; j} | Lee, Kang Soo^b | Kang, Dae Ryong^g | Lee, Jeong Dong^g | Choi, Seong Hye^c | Kim, Seong Yoon^d | Na, Duk L.^e | Seo, Sang Won^e | Kim, Do-Kwan^f | Lee, Yunhwan^{h; i} | Chung, Young Ki^a | Lim, Ki Young^a | Noh, Jai Sung^a | Park, Jungsik^k | Son, Sang Joon^{a; *}

Affiliations: [a] Department of Psychiatry, Ajou University School of Medicine, Suwon, Republic of Korea | [b] Department of Psychiatry, CHA University School of Medicine, CHA Hospital, Gangnam, Republic of Korea | [c] Department of Neurology, Inha University college of Medicine, Incheon, Republic of Korea | [d] Department of Psychiatry, Asan Medical Center, Seoul, Republic of Korea | [e] Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea | [f] Department of Psychiatry, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea | [g] Department of Biostatstics, Ajou University School of Medicine, Suwon, Republic of Korea | [h] Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Republic of Korea | [i] Institute on Aging, Ajou University Medical Center, Suwon, Republic of Korea | [j] Memory impairment center, Ajou University Hospital, Suwon, Republic of Korea | [k] College of Humanities, Ajou University, Suwon, 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, Republic of Korea. Tel.: +82 31 219 5180; Fax: +82 31 219 5179; E-mail: sjsonpsy@ajou.ac.kr.

Abstract: Background/Objective: We aimed to compare the risk of mortality in patients with early-onset Alzheimer’s disease (EOAD) versus those with late-onset AD (LOAD) using a large number of study subjects. We applied propensity score matching (PSM) to minimize confounding biases in the comparison between EOAD and LOAD. Methods: We obtained data from elderly Korean subjects with AD (n = 3,611) at baseline from the CREDOS cohort study, which was conducted from November 2005 to July 2013. We conducted PSM to reduce the bias due to confounding variables related to survival in patients with AD. The risks of mortality associated with EOAD and LOAD were evaluated by Cox proportional hazard analyses, controlling for relevant covariates. Results: After propensity score matching, 312 subjects with EOAD and 624 subjects with LOAD were selected for further analysis. The Cox proportional hazard analysis showed that patients with EOAD are at a greater risk for mortality compared to those with LOAD (Hazard Ratio: 2.01, 95% CI: 1.01–4.00, p-value: 0.04) when controlling for the direct effect of aging on mortality. The results did not change after adjusting for age at diagnosis, general cognitive function, nutritional factor related to body mass index, and physical disability using activities of daily living. The results support the assumption that EOAD takes a more malignant course than LOAD. Conclusions: Our results provide support for the idea that EOAD takes a clinical course that is distinct from that of LOAD, especially as pertains to the risk of mortality.

Keywords: Early-onset Alzheimer’s disease, late-onset Alzheimer’s disease, mortality, propensity score matching

DOI: 10.3233/JAD-161181

Journal: Journal of Alzheimer's Disease, vol. 56, no. 4, pp. 1341-1348, 2017