The Contribution of Ageing to Hospitalisation Days in Hong Kong: A Decomposition Analysis

Document Type : Original Article


1 HKJC Centre for Suicide Research and Prevention, The University of Hong Kong, Pokfulam, Hong Kong

2 Department of Social Work and Social Administration, The University of Hong Kong, Pokfulam, Hong Kong

3 Kwai Chung Hospital, Hospital Authority, Kwai Chung, Hong Kong


Ageing has become a serious challenge in Hong Kong and globally. It has serious implications for health expenditure, which accounts for nearly 20% of overall government expenditure. Here we assess the contribution of ageing and related factors to hospitalisation days in Hong Kong. We used hospital discharge data from all publicly funded hospitals in Hong Kong between 2001 and 2012.
A decomposition method was used to examine the factors that account for the change of total hospitalisation days during the two periods, 2001-2004 and 2004-2012. The five factors include two demographic factors – population size and age-gender composition – and three service components – hospital discharge rate, number of discharge episodes per patient, and average length of stay (LOS) – which are all measured at age-gender group level. In order to assess the health cost burden in the future, we also project the total hospitalisation days up to 2041, for a range of scenarios.
During the decreasing period of hospitalisation days (2001-2004), the reduction of LOS contributed to about 60% of the reduction. For the period of increase (2004-2012), ageing is associated with an increase in total hospitalisation days of 1.03 million, followed by an increase in hospital discharge rates (0.67 million), an increase in the number of discharge episodes per patient (0.62 million), and population growth (0.43 million). The reduction of LOS has greatly offset these increases (-2.19 million days), and has become one of the most significant factors in containing the increasing number of hospitalisation days. Projected increases in total hospitalisation days under different scenarios have highlighted that the contribution of ageing will become even more prominent after 2022.
Hong Kong is facing increasing healthcare burden caused by the rapid increase in demand for inpatient services due to ageing. Better management of inpatient services with the aim of increasing efficiency and reducing LOS, avoidable hospitalisation and readmission, without compromising patient satisfaction and quality of service, are crucial for containing the rapid and enormous increases in total hospitalisation days for Hong Kong. The results would be relevant to many rapidly ageing societies in this region.


Main Subjects

  1. Munoz E, Rosner F, Chalfin D, Goldstein J, Margolis IB, Wise L. Financial risk and hospital cost for elderly patients. Age- and non-age-stratified medical diagnosis related groups. Arch Intern Med. 1988;148(4):909-912.
  2. Schneider EL, Guralnik JM. The aging of America. Impact on health care costs. JAMA. 1990;263(17):2335-2340.
  3. Rosenthal GE, Landefeld CS. Do older medicare patients cost hospitals more - evidence from an academic medical-center. Arch Intern Med. 1993;153(1):89-96. doi:10.1001/archinte.153.1.89
  4. Metz D. Can the impact of ageing on health care costs be avoided? J Health Serv Res Policy. 1999;4(4):249-252.
  5. Breyer F, Costa-Font J, Felder S. Ageing, health, and health care. Oxford Rev Econ Policy. 2010;26(4):674-690. doi:10.1093/oxrep/grq032
  6. Colombier C, Weber W. Projecting health-care expenditure for Switzerland: further evidence against the 'red-herring' hypothesis. Int J Health Plann Manage. 2011;26(3):246-263. doi:10.1002/hpm.1068
  7. Morgan S, Cunningham C. Population aging and the determinants of healthcare expenditures: the case of hospital, medical and pharmaceutical care in british columbia, 1996 to 2006. Healthc Policy. 2011;7(1):68-79.
  8. Gregersen FA. The impact of ageing on health care expenditures: a study of steepening. Eur J Health Econ. 2014;15(9):979-989. doi:10.1007/s10198-013-0541-9
  9. Seshamani M, Gray AM. A longitudinal study of the effects of age and time to death on hospital costs. J Health Econ. 2004;23(2):217-235. doi:10.1016/j.jhealeco.2003.08.004
  10. Ha NT, Hendrie D, Moorin R. Impact of population ageing on the costs of hospitalisations for cardiovascular disease: a population-based data linkage study. BMC Health Serv Res. 2014;14:554. doi:10.1186/s12913-014-0554-9
  11. Dormont B, Grignon M, Huber H. Health expenditure growth: reassessing the threat of ageing. Health Econ. 2006;15(9):947-963. doi:10.1002/hec.1165
  12. Tchoe B, Nam SH. Aging risk and health care expenditure in Korea. Int J Environ Res Public Health. 2010;7(8):3235-3254. doi:10.3390/ijerph7083235
  13. Yip PSF, Cheung KS. Demography & dementia. The Alzheimer's Disease Conference: From Public Health To Therapeutic Insights; Hong Kong; 2010.
  14. Cheung KSL, Yip PS, Branch LG, Robine JM. Decreased proportion of dementia-free life expectancy in Hong Kong SAR. Dement Geriatr Cogn Disord. Forthcoming.
  15. Varela J, Castells X, Riu M, et al. Impact of aging on hospital caseload (In Spanish). Gac Sanit. 2000;14(3):203-209.
  16. DeGregori J. Challenging the axiom: does the occurrence of oncogenic mutations truly limit cancer development with age? Oncogene. 2013;32(15):1869-1875. doi:10.1038/onc.2012.281
  17. Puttapitakpong P, Chaikittisilpa S, Panyakhamlerd K, Nimnuan C, Jaisamrarn U, Taechakraichana N. Inter-correlation of knowledge, attitude, and osteoporosis preventive behaviors in women around the age of peak bone mass. BMC Womens Health. 2014;14(1):35. doi:10.1186/1472-6874-14-35
  18. Taylor AW, Shi ZM, Montgomerie A, Dal Grande E, Campostrini S. The use of a chronic disease and risk factor surveillance system to determine the age, period and cohort effects on the prevalence of obesity and diabetes in South Australian Adults-2003-2013. Plos One. 2015;10(4):e0125233. doi:10.1371/journal.pone.0125233
  19. Financial Secretary. The 2015-16 Budget. Accessed April 28, 2015. Published 2015.
  20. Department of Health. Health Facts of Hong Kong - 2014 Edition. Accessed April 28, 2015. Published 2014.
  21. World Health Orgranization (WHO). Health expenditure per capita - Data by country. Accessed April 28, 2015. Published 2014.
  22. Food and Health Bureau. Projection of Hong Kong's Healthcare Expenditure. Hong Kong SAR: Hong Kong SAR Government; 2008: Accessed March 15, 2016.
  23. Yip PS, Law CK. Assessment of the future resources and needs for hospitalization in Hong Kong SAR (Special Administrative District). Int J Health Plann Manage. 2002;17(2):113-122.
  24. Lagoe RJ, Westert GP, Kendrick K, Morreale G, Mnich S. Managing hospital length of stay reduction: a multihospital approach. Health Care Manage Rev. 2005;30(2):82-92.
  25. Food and Environmental Hygiene Department. Hong Kong's Domestic Health Accounts - Estimates of Domestic Health Expenditure, 1989/90 - 2011/12. Accessed May 15, 2015. Published 2015.
  26. Hospital Authority. Hospital Authority Annual Report 2012-2013. Published 2013.
  27. Yip PS, Lee CK, Chow CB, Lo WT. What makes the hospitalisation system more efficient? An application of the decomposition method to Hong Kong morbidity data. BMJ Open. 2014;4:e003903. doi:10.1136/bmjopen-2013-003903
  28. Census and Statistics Department. 2011 Population Census Thematic Report: Older Persons. Hong Kong SAR: Census and Statistics Department; 2013.
  29. Census and Statistics Department. Hong Kong Population Projections 2015-2064. Hong Kong SAR: Census and Statistics Department; 2015.
  30. Lozano R, Naghavi M, Foreman K, et al. Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet. 2012;380(9859):2095-2128. doi:10.1016/S0140-6736(12)61728-0
  31. Dietzenbacher E, Los B. Structural decomposition techniques: sense and sensitivity. Econ Syst Res. 1998;10(4):307-324.
  32. Census and Statistics Department. Population Estimates. Accessed May 4, 2015. Published 2015.
  33. Hospital Authority. Hospital Authority Statistical Report (2012-2013). Published 2014.
  34. Census and Statistics Department. Hong Kong Annual Digest of Statistics (2013 Edition). Hong Kong SAR: Census and Statistics Department; 2013.
  35. Clarke A. Length of in-hospital stay and its relationship to quality of care. Qual Saf Health Care. 2002;11(3):209-210.
  36. Murphy ME, Noetscher CM. Reducing hospital inpatient lengths of stay. J Nurs Care Qual. 1999;Spec No:40-54.
  37. Clarke A, Rosen R. Length of stay. How short should hospital care be? Eur J Public Health. 2001;11(2):166-170.
  38. Borghans I, Heijink R, Kool T, Lagoe RJ, Westert GP. Benchmarking and reducing length of stay in Dutch hospitals. BMC Health Serv Res. 2008;8:220. doi:10.1186/1472-6963-8-220
  39. Clarke A, Rowe P, Black N. Does a shorter length of hospital stay affect the outcome and costs of hysterectomy in southern England? J Epidemiol Community Health. 1996;50(5):545-550. doi:10.1136/jech.50.5.545
  40. Cleary PD, Greenfield S, Mulley AG, et al. Variations in length of stay and outcomes for six medical and surgical conditions in Massachusetts and California. JAMA. 1991;266(1):73-79.
  41. Wong EL, Coulter A, Cheung AW, Yam C, Yeoh E, Griffiths SM. Patient experiences with public hospital care: first benchmark survey in Hong Kong. Hong Kong Med J. 2012;18(5):371-380.
  42. Census and Statistics Department. Women and Men in Hong Kong Key Statiscs - 2014 Edition. Hong Kong SAR: Census and Statistics Department; 2014.
  43. Cheung KS, Yip PS. Trends in healthy life expectancy in Hong Kong SAR 1996-2008. Eur J Ageing. 2010;7(4):257-269. doi:10.1007/s10433-010-0171-3
  44. Borghans I, Kool RB, Lagoe RJ, Westert GP. Fifty ways to reduce length of stay: an inventory of how hospital staff would reduce the length of stay in their hospital. Health Policy. 2012;104(3):222-233. doi:10.1016/j.healthpol.2011.12.010
  45. OECD. Hospital average length of stay by diagnostic categories. Accessed April 30, 2015. Published 2015.
  46. Kripalani S, Theobald CN, Anctil B, Vasilevskis EE. Reducing hospital readmission rates: current strategies and future directions. Annu Rev Med. 2014;65:471-485. doi:10.1146/annurev-med-022613-090415
  • Receive Date: 23 December 2015
  • Revise Date: 05 August 2016
  • Accept Date: 06 August 2016
  • First Publish Date: 01 March 2017