背景：失智症患者會增加跌倒死亡的風險。但是，過去研究大多樣本數較少且觀察時間較短，因此無法進行分層比較或趨勢分析。
目標：探討死亡證明書提及失智症者同時提及跌倒為死因之相關性，及其年代別、性別、年齡別與傷害別差異。
方法：本研究使用美國1981-2010年、臺灣2003-2012年多重死因資料進行分析。首先分析死亡診斷書提及失智症者(ICD-9：290, 331, ICD-10：F01-F03, G30)又提及跌倒(ICD-9：E880-E886, E888, ICD-10：W00-W19)之百分比。接著計算失智症患者不同特徵間提及跌倒之勝算比。再以提及跌倒為病例組，提及他殺為對照組，以多變項邏輯斯迴歸，估計各特徵分層下提及失智症為死因之調整後勝算比。
結果：美國死亡診斷書提及失智症又提及跌倒為死因之百分比，30年之趨勢變化為先下降後上升，男性高於女性，隨年齡增加而增加。臺灣之百分比，也是男性高於女性，但是年齡卻是高齡者較低。失智組相對於各種對照組提及跌倒為死因之調整後勝算比分別為，缺血性心臟病1.13(95%CI 1.12-1.15)、糖尿病1.30(95%CI 1.27-1.32)。跌倒組相對於各種對照組提及失智症為死因之勝算比分別為，交通事故組11.5(95%CI 10.8-12.2)、自殺組19.7(95%CI 17.9-21.6)、哽塞組0.32(95%CI 0.32-0.33)。選定他殺組做為跌倒組的對照時，提及失智症為死因之勝算比為4.4(95%CI 3.9-5.1)；男性為7.5(95%CI 5.8-9.6)、女性為3.2(95%CI 2.8-3.8)；年齡從65-74歲組的11.1(95%CI 7.5-16.5)降到85歲以上組的2.6(95%CI 2.1-3.1)；年代趨勢為先增後減。如果再將跌倒細分為髖部骨折與頭部外傷，勝算比分別為6.9(95%CI 6.0-7.9)與3.1(95%CI 2.7-3.6)。
結論：雖然死亡診斷書同時提及失智症與跌倒為死因之百分比，近十年呈現上升趨勢，但是如果考慮對照組之變化趨勢，同時提及失智症與跌倒為死因之勝算比近十年呈現下降趨勢。未來研究，應進一步探討不同嚴重度失智症患者跌倒風險與機轉之差異，提供跌倒防制更具體之參考資訊。

「英文延伸摘要」Summary
Fatal death risk increase in dementia. However, past literature has too small sample size/observation time to be analyzed for stratification/time trend. To analyse the association of reporting fall and dementia in death certificates, we use multiple-cause-of-death data of U.S.A.(1981-2010) and Taiwan(2003-2012). We calculate the amount of reporting dementia (ICD-9：290, 331, ICD-10：F01-F03, G30) and percentage of reporting fall (ICD-9：E880-E886, E888, ICD-10：W00-W19), then focus on dementia group and calculate the odds ratios of reporting fall between characteristics. We use multivariate logistic regression model to analyse the adjusted odds ratios of reporting dementia fall(vs. assault) group. In U.S.A., percentage of reporting fall in dementia decrease then increase in recent 30 years; increase in men; and increase with age. Percentage in Taiwan is also higher in men, but lower in older group. The adjusted odds ratios of reporting dementia in fall (vs. assault) group are 4.4(95%CI 3.9-5.1); 7.5(95%CI 5.8-9.6) in men, 3.2(95%CI 2.8-3.8) in women; decrease from 11.1(95%CI 7.5-16.5) (65-74 age) to 2.6(95%CI 2.1-3.1)(85+ age); increase then decrease in recent 30 years. The adjusted odds ratios in fall-related hip fracture and fall-related traumatic brain injury are 6.9(95%CI 6.0-7.9) and 3.1(95%CI 2.7-3.6). Although the percentage of reporting fall in dementia group has increased time trend in recent 10 years, the adjusted odds ratio of reporting dementia in fall group(vs. assault group) has decreased time trend in recent 10 years. Future studies should analyse the risk and mechanism in different severity of dementia.

Allan, L. M., Ballard, C. G., Rowan, E. N., & Kenny, R. A. (2009). Incidence and prediction of falls in dementia: a prospective study in older people. PLoS One, 4(5), e5521.
Asada, T., Kariya, T., Kinoshita, T., Asaka, A., Morikawa, S., Yoshioka, M., & Kakuma, T. (1996). Predictors of fall-related injuries among community-dwelling elderly people with dementia. Age Ageing, 25(1), 22-28.
Attems, J., König, C., Huber, M., Lintner, F., & Jellinger, K. A. (2005). Cause of death in demented and non-demented elderly inpatients; an autopsy study of 308 cases. Journal of Alzheimer's Disease, 8(1), 57-62.
Bah, S., & Rahman, M. M. (2009). Measures of multiple-cause mortality: a synthesis and a notational framework. Genus, 65(3).
Baker, N. L., Cook, M. N., Arrighi, H. M., & Bullock, R. (2011). Hip fracture risk and subsequent mortality among Alzheimer's disease patients in the United Kingdom, 1988–2007. Age Ageing, 40(1), 49-54.
Ballard, C. G., Shaw, F., Lowery, K., McKeith, I., & Kenny, R. (1999). The prevalence, assessment and associations of falls in dementia with Lewy bodies and Alzheimer's disease. Dement Geriatr Cogn Disord, 10(2), 97-103.
Betz, M. E., Kelly, S. P., & Fisher, J. (2008). Death certificate inaccuracy and underreporting of injury in elderly people. J Am Geriatr Soc, 56(12), 2267-2272.
Brauer, C. A., Coca-Perraillon, M., Cutler, D. M., & Rosen, A. B. (2009). Incidence and mortality of hip fractures in the United States. Jama, 302(14), 1573-1579.
Brookmeyer, R., Evans, D. A., Hebert, L., Langa, K. M., Heeringa, S. G., Plassman, B. L., & Kukull, W. A. (2011). National estimates of the prevalence of Alzheimer’s disease in the United States. Alzheimer's & Dementia, 7(1), 61-73.
Brunnström, H., & Englund, E. (2009). Cause of death in patients with dementia disorders. European Journal of Neurology, 16(4), 488-492.
Buchner, D. M., & Larson, E. B. (1987). Falls and fractures in patients with Alzheimer-type dementia. Jama, 257(11), 1492-1495.
Cesari, M., Landi, F., Torre, S., Onder, G., Lattanzio, F., & Bernabei, R. (2002). Prevalence and risk factors for falls in an older community-dwelling population. J Gerontol A Biol Sci Med Sci, 57(11), M722-726.
Chandra, V., Bharucha, N. E., & Schoenberg, B. S. (1986). Conditions associated with Alzheimer's disease at death Case‐control study. Neurology, 36(2), 209-209.
Chen, J. C., Borson, S., & Scanlan, J. M. (2000). Stage-specific prevalence of behavioral symptoms in Alzheimer's disease in a multi-ethnic community sample. Am J Geriatr Psychiatry, 8(2), 123-133.
Control, C. f. D., & Prevention. (2006). Fatalities and Injuries from Falls Among Older Adults---United States, 1993--2003 and 2001--2005. MMWR: Morbidity and Mortality Weekly Report, 55(45), 1221-1224.
Crews, D. E., Stamler, J., & Dyer, A. (1991). Conditions other than underlying cause of death listed on death certificates provide additional useful information for epidemiologic research. Epidemiology, 271-275.
Deshpande, S. (1997). Value of statistics of multiple causes of death. Paper presented at the Regional Health Forum.
Faul, M., Xu, L., Wald, M., & Coronado, V. G. (2010). Traumatic brain injury in the United States: emergency department visits, hospitalizations and deaths 2002–2006. Atlanta, GA: Centers for Disease Control and Prevention, National Center for Injury Prevention and Control, 2-70.
Fisher, A. A., Davis, M. W., Srikusalanukul, W., & Budge, M. M. (2006). Six-fold increased risk of hip fracture in older Australians (≥60 years) with dementia. Archives of Osteoporosis, 1(1-2), 13-19.
Fu, C., Chute, D. J., Farag, E. S., Garakian, J., Cummings, J. L., & Vinters, H. V. (2004). Comorbidity in dementia: an autopsy study. Archives of pathology & laboratory medicine, 128(1), 32-38.
Gruber-Baldini, A. L., Zimmerman, S., Morrison, R. S., Grattan, L. M., Hebel, J. R., Dolan, M. M., . . . Magaziner, J. (2003). Cognitive impairment in hip fracture patients: timing of detection and longitudinal follow-up. J Am Geriatr Soc, 51(9), 1227-1236.
Härlein, J., Dassen, T., Halfens, R. J., & Heinze, C. (2009). Fall risk factors in older people with dementia or cognitive impairment: a systematic review. J Adv Nurs, 65(5), 922-933.
Harlein, J., Halfens, R. J., Dassen, T., & Lahmann, N. A. (2011). Falls in older hospital inpatients and the effect of cognitive impairment: a secondary analysis of prevalence studies. J Clin Nurs, 20(1-2), 175-183.
Hartholt, K. A., Stevens, J. A., Polinder, S., van der Cammen, T. J., & Patka, P. (2011). Increase in fall-related hospitalizations in the United States, 2001-2008. J Trauma, 71(1), 255-258.
Hasegawa, Y., Suzuki, S., & Wingstrand, H. (2007). Risk of mortality following hip fracture in Japan. J Orthop Sci, 12(2), 113-117.
Holmes, J., & House, A. (2000). Psychiatric illness predicts poor outcome after surgery for hip fracture: a prospective cohort study. Psychol Med, 30(4), 921-929.
Hope, T., Keene, J., McShane, R. H., Fairburn, C. G., Gedling, K., & Jacoby, R. (2001). Wandering in dementia: a longitudinal study. Int Psychogeriatr, 13(2), 137-147.
Horikawa, E., Matsui, T., Arai, H., Seki, T., Iwasaki, K., & Sasaki, H. (2005). Risk of falls in Alzheimer's disease: a prospective study. INTERNAL MEDICINE-TOKYO-JAPANESE SOCIETY OF INTERNAL MEDICINE-, 44(7), 717.
Hu, F., Jiang, C., Shen, J., Tang, P., & Wang, Y. (2012). Preoperative predictors for mortality following hip fracture surgery: a systematic review and meta-analysis. Injury, 43(6), 676-685.
Hu, G., & Baker, S. P. (2010). Recent increases in fatal and non-fatal injury among people aged 65 years and over in the USA. Injury prevention, 16(1), 26-30.
Hu, G., & Baker, S. P. (2012). An explanation for the recent increase in the fall death rate among older Americans: a subgroup analysis. Public Health Reports, 127(3), 275.
Hughes, C. P., Berg, L., Danziger, W. L., Coben, L. A., & Martin, R. L. (1982). A new clinical scale for the staging of dementia. Br J Psychiatry, 140, 566-572.
Hy, L. X., & Keller, D. M. (2000). Prevalence of AD among whites A summary by levels of severity. Neurology, 55(2), 198-204.
Israel, R. A., Rosenberg, H. M., & Curtin, L. R. (1986). Analytical potential for multiple cause-of-death data. American journal of epidemiology, 124(2), 161-181.
Johansson, C., & Skoog, I. (1996). A population-based study on the association between dementia and hip fractures in 85-year olds. Aging Clinical and Experimental Research, 8(3), 189-196.
Kukull, W. A., Brenner, D., Speck, C., Nochlin, D., Bowen, J., McCormick, W., . . . Larson, E. (1994). Causes of death associated with Alzheimer disease: variation by level of cognitive impairment before death. J Am Geriatr Soc.
Lu, T. H., Hsiao, A., Chang, P. C., Chao, Y. C., Hsu, C. C., Peng, H. C., . . . Kawachi, I. (2013). Counting injury deaths: a comparison of two definitions and two countries. Inj Prev.
Melton 3rd, L., Beard, C. M., Kokmen, E., Atkinson, E. J., & O'Fallon, W. M. (1994). Fracture risk in patients with Alzheimer's disease. J Am Geriatr Soc, 42(6), 614-619.
Miettinen, O. S., & Wang, J.-D. (1981). An alternative to the proportionate mortality ratio. American journal of epidemiology, 114(1), 144-148.
Nakamura, T., Meguro, K., & Sasaki, H. (1996). Relationship between falls and stride length variability in senile dementia of the Alzheimer type. Gerontology, 42(2), 108-113.
Nightingale, S., Holmes, J., Mason, J., & House, A. (2001). Psychiatric illness and mortality after hip fracture. Lancet, 357(9264), 1264-1265.
Orces, C. H. (2013). Emergency department visits for fall-related fractures among older adults in the USA: a retrospective cross-sectional analysis of the National Electronic Injury Surveillance System All Injury Program, 2001–2008. BMJ Open, 3(1).
Panula, J., Pihlajamäki, H., Mattila, V. M., Jaatinen, P., Vahlberg, T., Aarnio, P., & Kivelä, S.-L. (2011). Mortality and cause of death in hip fracture patients aged 65 or older-a population-based study. BMC musculoskeletal disorders, 12(1), 105.
Prince, M., Bryce, R., Albanese, E., Wimo, A., Ribeiro, W., & Ferri, C. P. (2013). The global prevalence of dementia: a systematic review and metaanalysis. Alzheimer's & Dementia, 9(1), 63-75. e62.
Redelings, M. D., Wise, M., & Sorvillo, F. (2007). Using multiple cause-of-death data to investigate associations and causality between conditions listed on the death certificate. American journal of epidemiology, 166(1), 104-108.
Rocca, W. A., Petersen, R. C., Knopman, D. S., Hebert, L. E., Evans, D. A., Hall, K. S., . . . White, L. R. (2011). Trends in the incidence and prevalence of Alzheimer's disease, dementia, and cognitive impairment in the United States. Alzheimers Dement, 7(1), 80-93.
Romero, J. P., Benito-León, J., Louis, E. D., & Pareja, F. B. (2014). Under Reporting of Dementia Deaths on Death Certificates: A Systematic Review of Population-based Cohort Studies. Journal of Alzheimer's Disease.
Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern epidemiology: Lippincott Williams & Wilkins.
Salvà, A., Roqué, M., Rojano, X., Inzitari, M., Andrieu, S., Schiffrin, E. J., . . . Vellas, B. (2012). Falls and risk factors for falls in community-dwelling adults with dementia (NutriAlz trial). Alzheimer Disease & Associated Disorders, 26(1), 74-80.
Sato, Y., Kanoko, T., Satoh, K., & Iwamoto, J. (2004). Risk factors for hip fracture among elderly patients with Alzheimer's disease. J Neurol Sci, 223(2), 107-112.
Stevens, J. A., & Anne Rudd, R. (2010). Declining hip fracture rates in the United States. Age Ageing, 39(4), 500-503.
Stevens, J. A., & Rudd, R. A. (2013). The impact of decreasing U.S. hip fracture rates on future hip fracture estimates. Osteoporos Int, 24(10), 2725-2728.
Tejada-Vera, B. (2013). Mortality from Alzheimer's disease in the United States: data for 2000 and 2010. NCHS Data Brief(116), 1-8.
Thies, W., & Bleiler, L. (2013). 2013 Alzheimer's disease facts and figures. Alzheimers Dement, 9(2), 208-245.
Thomas, K. E., Stevens, J. A., Sarmiento, K., & Wald, M. M. (2008). Fall-related traumatic brain injury deaths and hospitalizations among older adults—United States, 2005. Journal of safety research, 39(3), 269-272.
Todd, S., Barr, S., & Passmore, A. (2013). Cause of death in Alzheimer’s disease: a cohort study. QJM, 106(8), 747-753.
Van Doorn, C., Gruber‐Baldini, A. L., Zimmerman, S., Richard Hebel, J., Port, C. L., Baumgarten, M., . . . Magaziner, J. (2003). Dementia as a risk factor for falls and fall injuries among nursing home residents. J Am Geriatr Soc, 51(9), 1213-1218.
Weller, I., & Schatzker, J. (2004). Hip fractures and Alzheimer's disease in elderly institutionalized Canadians. Annals of epidemiology, 14(5), 319-324.
Wilkins, K., Parsons, G. F., Gentleman, J. F., & Forbes, W. F. (1999). Deaths due to dementia: An analysis of multiple-cause-of-death data. Chronic Diseases in Canada, 20(1), 26.
Wise, M., Finelli, L., & Sorvillo, F. (2010). Prognostic factors associated with hepatitis C disease: a case-control study utilizing US multiple-cause-of-death data. Public Health Reports, 125(3), 414.
傅中玲. (2008). 台灣失智症現況. 台灣老年醫學暨老年學雜誌, 3(3), 169-181.
鍾其祥, 白璐, 吳秉勳, 賴建丞, & 簡戊鑑. (2010). 臺灣地區跌倒墜落死亡長期趨勢分析. 中華職業醫學雜誌, 17(3), 151-162.