| 1. | Huang C, Wang Y, Li X,  et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet, 2020, 395(10223): 497-506. | 
				                                                        
				                                                            
				                                                                | 2. | Dent E, Martin FC, Bergman H,  et al. Management of frailty: opportunities, challenges, and future directions. Lancet, 2019, 394(10206): 1376-1386. | 
				                                                        
				                                                            
				                                                                | 3. | Fried LP, Tangen CM, Walston J,  et al. Frailty in older adults: evidence for a phenotype. J Gerontol A Biol Sci Med Sci, 2001, 56(3): M146-M156. | 
				                                                        
				                                                            
				                                                                | 4. | Yamada M, Kimura Y, Ishiyama D,  et al. The Influence of the COVID-19 pandemic on physical activity and new incidence of frailty among initially non-frail older adults in Japan: a follow-up online survey. J Nutr Health Aging, 2021, 25(6): 751-756. | 
				                                                        
				                                                            
				                                                                | 5. | Subramaniam A, Shekar K, Afroz A,  et al. Frailty and mortality associations in patients with COVID-19: a systematic review and meta-analysis. Intern Med J, 2022, 52(5): 724-739. | 
				                                                        
				                                                            
				                                                                | 6. | Zhang XM, Jiao J, Cao J,  et al. Frailty as a predictor of mortality among patients with COVID-19: a systematic review and meta-analysis. BMC Geriatr, 2021, 21(1): 186. | 
				                                                        
				                                                            
				                                                                | 7. | Dumitrascu F, Branje KE, Hladkowicz ES,  et al. Association of frailty with outcomes in individuals with COVID-19: a living review and meta-analysis. J Am Geriatr Soc, 2021, 69(9): 2419-2429. | 
				                                                        
				                                                            
				                                                                | 8. | Lee YK, Motwani Y, Brook J,  et al. Predictors of COVID-19 outcomes: interplay of frailty, comorbidity, and age in COVID-19 prognosis. Medicine (Baltimore), 2022, 101(51): e32343. | 
				                                                        
				                                                            
				                                                                | 9. | De Smet R, Mellaerts B, Vandewinckele H, et al. Frailty and mortality in hospitalized older adults with COVID-19: retrospective observational study. J Am Med Dir Assoc, 2020, 21(7): 928-932. e1. | 
				                                                        
				                                                            
				                                                                | 10. | Davis P, Gibson R, Wright E,  et al. Atypical presentations in the hospitalised older adult testing positive for SARS-CoV-2: a retrospective observational study in Glasgow, Scotland. Scott Med J, 2021, 66(2): 89-97. | 
				                                                        
				                                                            
				                                                                | 11. | Wijeysundera HC, Abdel-Qadir H, Qiu F,  et al. Relationship of frailty with excess mortality during the COVID-19 pandemic: a population-level study in Ontario, Canada. Aging Clin Exp Res, 2022, 34(10): 2557-2565. | 
				                                                        
				                                                            
				                                                                | 12. | Salive ME. Multimorbidity in older adults. Epidemiol Rev, 2013, 35: 75-83. | 
				                                                        
				                                                            
				                                                                | 13. | Masnoon N, Shakib S, Kalisch-Ellett L,  et al. What is polypharmacy? A systematic review of definitions. BMC Geriatr, 2017, 17(1): 230. | 
				                                                        
				                                                            
				                                                                | 14. | Gobbens RJ, van Assen MA, Luijkx KG,  et al. The tilburg frailty indicator: psychometric properties. J Am Med Dir Assoc, 2010, 11(5): 344-355. | 
				                                                        
				                                                            
				                                                                | 15. | 司華新, 金雅茹, 喬曉霞, 等. 中文版 Tilburg 衰弱量表在養老機構老年人中的信效度檢驗. 中國老年學雜志, 2018, 38(16): 4046-4049. | 
				                                                        
				                                                            
				                                                                | 16. | Spinato G, Fabbris C, Conte F,  et al. COVID-Q: validation of the first COVID-19 questionnaire based on patient-rated symptom gravity. Int J Clin Pract, 2021, 75(12): e14829. | 
				                                                        
				                                                            
				                                                                | 17. | Chen P, Nirula A, Heller B,  et al. SARS-CoV-2 neutralizing antibody LY-CoV555 in outpatients with Covid-19. N Engl J Med, 2021, 384(3): 229-237. | 
				                                                        
				                                                            
				                                                                | 18. | 高志華, 楊紹清, Juergen Margraf, 等. Wagnild-Young 心理彈性量表 (RS-11) 中文版的信效度檢驗. 中國健康心理學雜志, 2013, 21(9): 1324-1326. | 
				                                                        
				                                                            
				                                                                | 19. | Rohrmann S. Epidemiology of frailty in older people. Adv Exp Med Biol, 2020, 1216: 21-27. | 
				                                                        
				                                                            
				                                                                | 20. | Marengoni A, Vetrano DL, Manes-Gravina E,  et al. The relationship between COPD and frailty: a systematic review and meta-analysis of observational studies. Chest, 2018, 154(1): 21-40. | 
				                                                        
				                                                            
				                                                                | 21. | Hanlon P, Fauré I, Corcoran N,  et al. Frailty measurement, prevalence, incidence, and clinical implications in people with diabetes: a systematic review and study-level meta-analysis. Lancet Healthy Longev, 2020, 1(3): e106-e116. | 
				                                                        
				                                                            
				                                                                | 22. | Palmer K, Vetrano DL, Padua L,  et al. Frailty syndromes in persons with cerebrovascular disease: a systematic review and meta-analysis. Front Neurol, 2019, 10: 1255. | 
				                                                        
				                                                            
				                                                                | 23. | Alvarez-Nebreda ML, Bentov N, Urman RD,  et al. Recommendations for preoperative management of frailty from the society for perioperative assessment and quality improvement (SPAQI). J Clin Anesth, 2018, 47: 33-42. | 
				                                                        
				                                                            
				                                                                | 24. | Renne I, Gobbens RJ. Effects of frailty and chronic diseases on quality of life in Dutch community-dwelling older adults: a cross-sectional study. Clin Interv Aging, 2018, 13: 325-334. | 
				                                                        
				                                                            
				                                                                | 25. | Evans NR, Todd OM, Minhas JS,  et al. Frailty and cerebrovascular disease: concepts and clinical implications for stroke medicine. Int J Stroke, 2022, 17(3): 251-259. | 
				                                                        
				                                                            
				                                                                | 26. | Griffith LE, Raina P, Kanters D,  et al. Frailty differences across population characteristics associated with health inequality: a cross-sectional analysis of baseline data from the Canadian Longitudinal Study on Aging (CLSA). BMJ Open, 2021, 11(7): e047945. | 
				                                                        
				                                                            
				                                                                | 27. | St John PD, Montgomery PR, Tyas S. Social position and frailty. Can J Aging, 2013, 32(3): 250-259. | 
				                                                        
				                                                            
				                                                                | 28. | Chamberlain AM, St Sauver JL, Jacobson DJ,  et al. Social and behavioural factors associated with frailty trajectories in a population-based cohort of older adults. BMJ Open, 2016, 6(5): e011410. | 
				                                                        
				                                                            
				                                                                | 29. | Welstead M, Jenkins ND, Russ TC,  et al. A systematic review of frailty trajectories: their shape and influencing factors. Gerontologist, 2021, 61(8): e463-e475. | 
				                                                        
				                                                            
				                                                                | 30. | 謝思琦, 馬穎, 崔敏, 等. 老年人心理彈性與生活質量關系的 meta 分析. 中國心理衛生雜志, 2022, 36(1): 56-61. | 
				                                                        
				                                                            
				                                                                | 31. | Kohler S, Rametta R, Poulter M,  et al. Resilience, frailty and outcomes in geriatric rehabilitation. Australas J Ageing, 2020, 39(2): e205-e209. | 
				                                                        
				                                                            
				                                                                | 32. | 雷鵬瓊, 劉春娜, 高穎, 等. 心理社會因素與社區老年人衰弱的相關性研究. 中國全科醫學, 2018, 21(2): 180-185. | 
				                                                        
				                                                            
				                                                                | 33. | Padilha de Lima A, Macedo Rogero M, Araujo Viel T,  et al. Interplay between inflammaging, frailty and nutrition in Covid-19: preventive and adjuvant treatment perspectives. J Nutr Health Aging, 2022, 26(1): 67-76. | 
				                                                        
				                                                            
				                                                                | 34. | She Q, Chen B, Liu W,  et al. Frailty pathogenesis, assessment, and management in older adults with COVID-19. Front Med (Lausanne), 2021, 8: 694367. | 
				                                                        
				                                                            
				                                                                | 35. | Wang Y, van Boxel-Dezaire AH, Cheon H,  et al. STAT3 activation in response to IL-6 is prolonged by the binding of IL-6 receptor to EGF receptor. Proc Natl Acad Sci U S A, 2013, 110(42): 16975-16980. | 
				                                                        
				                                                            
				                                                                | 36. | Zhu Y, Sealy MJ, Jager-Wittenaar H,  et al. Frailty and risk of hospitalization from COVID-19 infection among older adults: evidence from the dutch lifelines COVID-19 cohort study. Aging Clin Exp Res, 2022, 34(11): 2693-2702. | 
				                                                        
				                                                            
				                                                                | 37. | Ali AM, Kunugi H. Screening for sarcopenia (physical frailty) in the COVID-19 era. Int J Endocrinol, 2021, 2021: 5563960. |