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The relative impact of chronic conditions and multimorbidity on health-related quality of life in Ontario long-stay home care clients

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Abstract

Purpose

To examine the relative impact of 16 common chronic conditions and increasing morbidity on health-related quality of life (HRQL) in a population-based sample of home care clients in Ontario, Canada.

Methods

Participants were adult clients assessed with the Resident Assessment Instrument for Home Care (RAI-HC) between January and June 2009 and diagnosed with one (or more) of 16 common chronic conditions. HRQL was evaluated using the Minimum Data Set-Health Status Index (MDS-HSI), a preference-based measure derived from items captured in the RAI-HC. Multivariable linear regression models assessed the relative impact of each condition, and increasing number of diagnoses, on MDS-HSI scores.

Results

Mean (SD) MDS-HSI score in the study population (n = 106,159) was 0.524 (0.213). Multivariable analysis revealed a statistically significant (p < 0.05) and clinically important (difference ≥ 0.03) decrease in MDS-HSI scores associated with stroke (−0.056), osteoarthritis (−0.036), rheumatoid arthritis (−0.033) and congestive heart failure (CHF, −0.030). Differences by age and sex were observed; most notably, the negative impact associated with dementia was greater among men (−0.043) than among women (−0.019). Further, HRQL decreased incrementally with additional diagnoses. In all models, chronic conditions and number of diagnoses accounted for a relatively small proportion of the variance observed in MDS-HSI.

Conclusion

Clinically important negative effects on HRQL were observed for clients with a previous diagnosis of stroke, osteo- and rheumatoid arthritis, or CHF, as well as with increasing levels of multimorbidity. Findings provide baseline preference-based HRQL scores for home care clients with different diagnoses and may be useful for identifying, targeting and evaluating care strategies toward populations with significant HRQL impairments.

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References

  1. Barnett, K., Mercer, S. W., Norbury, M., Watt, G., Wyke, S., & Guthrie, B. (2012). Epidemiology of multimorbidity and implications for health care, research, and medical education: A cross-sectional study. Lancet, 380, 37–43.

    Article  PubMed  Google Scholar 

  2. Pearson, W. S., Bhat-Schelbert, K., & Probst, J. C. (2012). Multiple chronic conditions and the aging of America: Challenge for primary care physicians. Journal of Primary Care & Community Health, 3(1), 51–56.

    Article  Google Scholar 

  3. World Health Organization. (2011). Global status report on noncommunicable diseases: 2010, 1–176. [Cited 2016 Mar 17] http://www.who.int/nmh/publications/ncd_report_full_en.pdf.

  4. Salive, M. E. (2013). Multimorbidity in older adults. Epidemiologic Reviews, 35, 75–83.

    Article  PubMed  Google Scholar 

  5. Thorpe, K. E., Ogden, L. L., & Galactionova, K. (2010). Chronic conditions account for rise in medicare spending from 1987 to 2006. Health Affairs, 29(4), 718–724.

    Article  PubMed  Google Scholar 

  6. Hung, W. W., Ross, J. S., Boockvar, K. S., & Siu, A. L. (2011). Recent trends in chronic disease, impairment and disability among older adults in the United States. BMC Geriatrics, 11(1), 47.

    Article  PubMed  PubMed Central  Google Scholar 

  7. Uijen, A. A., & van de Lisdonk, E. H. (2008). Multimorbidity in primary care: Prevalence and trend over the last 20 years. European Journal of General Practice, 14(s1), 28–32.

    Article  PubMed  Google Scholar 

  8. Daar, A. S., Singer, P. A., Leah Persad, D., Pramming, S. K., Matthews, D. R., Beaglehole, R., et al. (2007). Grand challenges in chronic non-communicable diseases. Nature, 450(7169), 494–496.

    Article  CAS  PubMed  Google Scholar 

  9. Wolff, J. L., Starfield, B., & Anderson, G. (2002). Prevalence, expenditures, and complications of multiple chronic conditions in the elderly. Archives of Internal Medicine, 162(20), 2269–2276.

    Article  PubMed  Google Scholar 

  10. Glynn, L. G., Valderas, J. M., Healy, P., Burke, E., Newell, J., Gillespie, P., & Murphy, A. W. (2011). The prevalence of multimorbidity in primary care and its effect on health care utilization and cost. Family Practice, 28(5), 516–523.

    Article  PubMed  Google Scholar 

  11. Bähler, C., Huber, C. A., Brüngger, B., & Reich, O. (2015). Multimorbidity, health care utilization and costs in an elderly community-dwelling population: A claims data based observational study. BMC Health Services Research, 15(1), 23.

    Article  PubMed  PubMed Central  Google Scholar 

  12. Rijken, M., van Kerkhof, M., Dekker, J., & Schellevis, F. G. (2005). Comorbidity of chronic diseases: Effects of disease pairs on physical and mental functioning. Quality of Life Research, 14(1), 45–55.

    Article  PubMed  Google Scholar 

  13. Tinetti, M. E., McAvay, G. J., Chang, S. S., Newman, A. B., Fitzpatrick, A. L., Fried, T. R., & Peduzzi, P. N. (2011). Contribution of multiple chronic conditions to universal health outcomes. Journal of the American Geriatrics Society, 59(9), 1686–1691.

    Article  PubMed  PubMed Central  Google Scholar 

  14. Feeny, D. (2013). Health-related quality-of-life data should be regarded as a vital sign. Journal of Clinical Epidemiology, 66(7), 706–709.

    Article  PubMed  Google Scholar 

  15. Agborsangaya, C. B., Lau, D., Lahtinen, M., Cooke, T., & Johnson, J. A. (2012). Health-related quality of life and healthcare utilization in multimorbidity: Results of a cross-sectional survey. Quality of Life Research, 22(4), 791–799.

    Article  PubMed  Google Scholar 

  16. Hunger, M., Thorand, B., Schunk, M., Döring, A., Menn, P., Peters, A., & Holle, R. (2011). Multimorbidity and health-related quality of life in the older population: Results from the German KORA-age study. Health and Quality of Life Outcomes, 9(1), 53.

    Article  PubMed  PubMed Central  Google Scholar 

  17. Schultz, S. E., & Kopec, J. A. (2003). Impact of chronic conditions. Health Reports, 14(4), 41–53.

    PubMed  Google Scholar 

  18. Parker, L., Moran, G. M., Roberts, L. M., Calvert, M., & McCahon, D. (2014). The burden of common chronic disease on health-related quality of life in an elderly community-dwelling population in the UK. Family Practice, 31(5), 557–563.

    Article  PubMed  Google Scholar 

  19. Franks, P., Hanmer, J., & Fryback, D. G. (2006). Relative disutilities of 47 risk factors and conditions assessed with seven preference-based health status measures in a national U.S. Sample. Medical Care, 44(5), 478–485.

    Article  PubMed  Google Scholar 

  20. Saarni, S. I., Härkänen, T., Sintonen, H., Suvisaari, J., Koskinen, S., Aromaa, A., & Lönnqvist, J. (2006). The impact of 29 chronic conditions on health-related quality of life: A general population survey in Finland using 15D and EQ-5D. Quality of Life Research, 15(8), 1403–1414.

    Article  PubMed  Google Scholar 

  21. Saarni, S. I., Suvisaari, J., Sintonen, H., Koskinen, S., Härkänen, T., & Lönnqvist, J. (2007). The health-related quality-of-life impact of chronic conditions varied with age in general population. Journal of Clinical Epidemiology, 60(12), 1288–1297.

    Article  PubMed  Google Scholar 

  22. Tsasis, P. (2009). Chronic disease management and the home-care alternative in Ontario Canada. Health Services Management Research, 22(3), 136–139.

    Article  PubMed  Google Scholar 

  23. Tsasis, P., & Bains, J. (2008). Management of complex chronic disease: Facing the challenges in the Canadian health-care system. Health Services Management Research, 21(4), 228–235.

    Article  PubMed  Google Scholar 

  24. Health Quality Ontario. (2013). In-home care for optimizing chronic disease management in the community: An evidence-based analysis. Ontario Health Technology Assessment Series, 13(5), 1–65.

    Google Scholar 

  25. Hirdes, J. P., Fries, B. E., Morris, J. N., Steel, K., Mor, V., Frijters, D., et al. (1999). Integrated health information systems based on the RAI/MDS series of instruments. Healthcare Management Forum, 12(4), 30–40.

    Article  CAS  PubMed  Google Scholar 

  26. Koné Pefoyo, A. J., Bronskill, S. E., Gruneir, A., Calzavara, A., Thavorn, K., Petrosyan, Y., et al. (2015). The increasing burden and complexity of multimorbidity. BMC Public Health, 15(1), 415.

    Article  PubMed Central  Google Scholar 

  27. Lane, N. E., Maxwell, C. J., Gruneir, A., Bronskill, S. E., & Wodchis, W. P. (2015). Absence of a socioeconomic gradient in older adults’ survival with multiple chronic conditions. EBIOM, 2(12), 2094–2100.

    Article  Google Scholar 

  28. Public Health Agency of Canada. (2010). The Chief Public Health Officer’s Report on the State of Public Health in Canada, 2010, 1–151. [Cited 2016 Mar 17] http://www.phac-aspc.gc.ca/cphorsphc-respcacsp/2010/fr-rc/pdf/cpho_report_2010_e.pdf.

  29. Public Health Agency of Canada. (2014). Economic Burden of Illness in Canada, 2005–2008 (pp. 1–111). [Cited 2016 Mar 17] http://www.phac-aspc.gc.ca/publicat/ebic-femc/2005-2008/assets/pdf/ebic-femc-2005-2008-eng.pdf.

  30. Canadian Institute for Health Information. (2010). Seniors and the Health Care System: What Is the Impact of Multiple Chronic Conditions? (pp. 1–23). [Cited 2016 Mar 17] https://secure.cihi.ca/free_products/air-chronic_disease_aib_en.pdf.

  31. Austin, P. C., Daly, P. A., & Tu, J. V. (2002). A multicenter study of the coding accuracy of hospital discharge administrative data for patients admitted to cardiac care units in Ontario. American Heart Journal, 144(2), 290–296.

    Article  PubMed  Google Scholar 

  32. Schultz, S. E., Rothwell, D. M., Chen, Z., & Tu, K. (2013). Identifying cases of congestive heart failure from administrative data: A validation study using primary care patient records. Chronic Diseases and Injuries in Canada, 33(3), 160–166.

    CAS  PubMed  Google Scholar 

  33. Gershon, A. S., Wang, C., Guan, J., Vasilevska-Ristovska, J., Cicutto, L., & To, T. (2009). Identifying patients with physician-diagnosed asthma in health administrative databases. Canadian Respiratory Journal, 16(6), 183–188.

    Article  PubMed  PubMed Central  Google Scholar 

  34. Gershon, A. S., Wang, C., Guan, J., Vasilevska-Ristovska, J., Cicutto, L., & To, T. (2009). Identifying individuals with physcian diagnosed COPD in health administrative databases. COPD: Journal of Chronic Obstructive Pulmonary Disease, 6(5), 388–394.

    Article  CAS  PubMed  Google Scholar 

  35. Hux, J. E., Ivis, F., Flintoft, V., & Bica, A. (2002). Diabetes in Ontario: Determination of prevalence and incidence using a validated administrative data algorithm. Diabetes Care, 25(3), 512–516.

    Article  PubMed  Google Scholar 

  36. Tu, K., Campbell, N. R., Chen, Z.-L., Cauch-Dudek, K. J., & McAlister, F. A. (2007). Accuracy of administrative databases in identifying patients with hypertension. Open Medicine, 1(1), e18–e26.

    PubMed  PubMed Central  Google Scholar 

  37. Tu, K., Wang, M., Young, J., Jaakkimainen, L., Ivers, N. M., Butt, D., et al. (2013). Validation of administrative data algorithms to determine population prevalence and incidence of Alzheimer’s disease, dementia, multiple sclerosis, epilepsy and Parkinson’s disease. A Report to the Public Health Agency of Canada.

  38. Wodchis, W. P., Hirdes, J. P., & Feeny, D. H. (2003). Health-related quality of life based on the minimum data set. International Journal of Technology Assessment in Health Care, 19(3), 490–506.

    Article  PubMed  Google Scholar 

  39. Furlong, W. J., Feeny, D. H., Torrance, G. W., & Barr, R. D. (2001). The Health Utilities Index (HUI) system for assessing health-related quality of life in clinical studies. Annals of Medicine, 33(5), 375–384.

    Article  CAS  PubMed  Google Scholar 

  40. Drummond, M. (2001). Introducing economic and quality of life measurements into clinical studies. Annals of Medicine, 33(5), 344–349.

    Article  CAS  PubMed  Google Scholar 

  41. Horsman, J., Furlong, W., Feeny, D., & Torrance, G. (2003). The Health Utilities Index (HUI): Concepts, measurement properties and applications. Health and Quality of Life Outcomes, 1, 54. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC293474/.

  42. Kralj, B. (2009). Measuring Rurality—RIO2008_BASIC: Methodology and Results, 1–20. [Cited 2016 Mar 17] https://www.oma.org/Resources/Documents/2008RIO-FullTechnicalPaper.pdf.

  43. Brettschneider, C., Leicht, H., Bickel, H., Dahlhaus, A., Fuchs, A., Gensichen, J., et al. (2013). Relative Impact of multimorbid chronic conditions on health-related quality of life—results from the MultiCare cohort study. PLoS One, 8(6), e66742.

    Article  PubMed  PubMed Central  Google Scholar 

  44. Fortin, M., Lapointe, L., Hudon, C., Vanasse, A., Ntetu, A. L., & Maltais, D. (2004). Multimorbidity and quality of life in primary care: A systematic review. Health and Quality of Life Outcomes, 2, 51.

    Article  PubMed  PubMed Central  Google Scholar 

  45. Lam, J. M. C., & Wodchis, W. P. (2010). The relationship of 60 disease diagnoses and 15 conditions to preference-based health-related quality of life in Ontario hospital-based long-term care residents. Medical Care, 48(4), 380–387.

    Article  PubMed  Google Scholar 

  46. Fortin, M., Dubois, M.-F., Hudon, C., Soubhi, H., & Almirall, J. (2007). Multimorbidity and quality of life: A closer look. Health and Quality of Life Outcomes, 5(1), 52.

    Article  PubMed  PubMed Central  Google Scholar 

  47. Morris, J. N., Fries, B. E., & Morris, S. A. (1999). Scaling ADLs within the MDS. Journal of Gerontology, 54(11), M546–M553.

    CAS  Google Scholar 

  48. Morris, J. N., Fries, B. E., Mehr, D. R., Hawes, C., Phillips, C., Mor, V., & Lipsitz, L. A. (1994). MDS cognitive performance scale. Journal of Gerontology, 49(4), M174–M182.

    Article  CAS  PubMed  Google Scholar 

  49. Hirdes, J. P., Frijters, D. H., & Teare, G. F. (2003). The MDS-CHESS scale: A new measure to predict mortality in institutionalized older people. Journal of the American Geriatrics Society, 51(1), 96–100.

    Article  PubMed  Google Scholar 

  50. Ovbiagele, B., Goldstein, L. B., Higashida, R. T., Howard, V. J., Johnston, S. C., Khavjou, O. A., et al. (2013). Forecasting the future of stroke in the United States: A policy statement from the American heart association and American stroke association. Stroke, 44(8), 2361–2375.

    Article  PubMed  Google Scholar 

  51. Ferri, C. P., Prince, M., Brayne, C., Brodaty, H., Fratiglioni, L., Ganguli, M., et al. (2005). Global prevalence of dementia: A Delphi consensus study. The Lancet, 366(9503), 2112–2117.

    Article  Google Scholar 

  52. Wild, S., Roglic, G., Green, A., Sicree, R., & King, H. (2004). Global prevalence of diabetes: Estimates for the year 2000 and projections for 2030. Diabetes Care, 27(5), 1047–1053.

    Article  PubMed  Google Scholar 

  53. Heidenreich, P. A., Trogdon, J. G., Khavjou, O. A., Butler, J., Dracup, K., Ezekowitz, M. D., et al. (2011). Forecasting the future of cardiovascular disease in the United States: A policy statement from the American heart association. Circulation, 123(8), 933–944.

    Article  PubMed  Google Scholar 

  54. Perruccio, A. V., Power, J. D., & Badley, E. M. (2014). Revisiting arthritis prevalence projections—it’s more than just the aging of the population. The Journal of Rheumatology, 33(9), 1856–1862.

    Google Scholar 

  55. Maxwell, C. J., Kang, J., Walker, J. D., Zhang, J. X., Hogan, D. B., Feeny, D. H., & Wodchis, W. P. (2009). Sex differences in the relative contribution of social and clinical factors to the Health Utilities Index Mark 2 measure of health-related quality of life in older home care clients. Health and Quality of Life Outcomes, 7(1), 80.

    Article  PubMed  PubMed Central  Google Scholar 

  56. Wodchis, W. P., Maxwell, C. J., Venturini, A., Walker, J. D., Zhang, J., Hogan, D. B., & Feeny, D. F. (2007). Study of observed and self-reported HRQL in older frail adults found group-level congruence and individual-level differences. Journal of Clinical Epidemiology, 60(5), 502–511.

    Article  PubMed  Google Scholar 

  57. Thein, H.-H., Gomes, T., Krahn, M. D., & Wodchis, W. P. (2009). Health status utilities and the impact of pressure ulcers in long-term care residents in Ontario. Quality of Life Research, 19(1), 81–89.

    Article  PubMed  PubMed Central  Google Scholar 

  58. Tonelli, S. M., Rakel, B. A., Cooper, N. A., Angstom, W. L., & Sluka, K. A. (2011). Women with knee osteoarthritis have more pain and poorer function than men, but similar physical activity prior to total knee replacement. Biology of Sex Differences, 2, 12.

    Article  PubMed  PubMed Central  Google Scholar 

  59. Ahlstrand, I., Björk, M., Thyberg, I., & Falkmer, T. (2015). Pain and difficulties performing valued life activities in women and men with rheumatoid arthritis. Clinical Rheumatology, 34(8), 1353–1362.

    Article  PubMed  Google Scholar 

  60. Fortin, M., Bravo, G., Hudon, C., Lapointe, L., Almirall, J., Dubois, M.-F., & Vanasse, A. (2006). Relationship between multimorbidity and health-related quality of life of patients in primary care. Quality of Life Research, 15(1), 83–91.

    Article  PubMed  Google Scholar 

  61. Lochner, K., Goodman, R., Posner, S., & Parekh, A. (2013). Multiple chronic conditions among medicare beneficiaries: State-level variations in prevalence, utilization, and cost, 2011. Medicare & Medicaid Research Review, 3(3), E1–E19.

    Article  Google Scholar 

  62. Lochner, K. A., & Cox, C. S. (2013). Prevalence of multiple chronic conditions among medicare beneficiaries, United States, 2010. Preventing Chronic Disease, 10, 120137. http://www.cdc.gov/pcd/issues/2013/pdf/12_0137.pdf.

  63. Goodman, R. A., Posner, S. F., Huang, E. S., Parekh, A. K., & Koh, H. K. (2013). Defining and measuring chronic conditions: Imperatives for research, policy, program, and practice. Preventing Chronic Disease, 10, 120239. http://www.cdc.gov/pcd/issues/2013/pdf/12_0239.pdf.

  64. Reeve, B. B., Potosky, A. L., Smith, A. W., Han, P. K., Hays, R. D., Davis, W. W., et al. (2009). Impact of cancer on health-related quality of life of older americans. Journal of the National Cancer Institute, 101(12), 860–868.

    Article  PubMed  PubMed Central  Google Scholar 

  65. Huguet, N., Kaplan, M. S., & Feeny, D. (2008). Socioeconomic status and health-related quality of life among elderly people: Results from the Joint Canada/United States survey of health. Social Science and Medicine, 66(4), 803–810.

    Article  PubMed  Google Scholar 

  66. Robert, S. A., Cherepanov, D., Palta, M., Dunham, N. C., Feeny, D., & Fryback, D. G. (2009). Socioeconomic status and age variations in health-related quality of life: Results from the national health measurement study. The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 64B(3), 378–389.

    Article  PubMed Central  Google Scholar 

  67. Lix, L., Yogendram, M., Burchill, C., Metge, C., McKeen, N., Moore, D., et al. (2006). Defining and Validating Chronic Diseases: An Administrative Data Approach (pp. 1–217). [Cited 2016 Mar 17] http://mchp-appserv.cpe.umanitoba.ca/reference/chronic.disease.pdf.

  68. Muggah, E., Graves, E., Bennett, C., & Manuel, D. G. (2013). Ascertainment of chronic diseases using population health data: A comparison of health administrative data and patient self-report. BMC Public Health, 13, 16.

    Article  PubMed  PubMed Central  Google Scholar 

  69. Kane, R. A. (2003). Definition, measurement, and correlates of quality of life in nursing homes: Toward a reasonable practice, research, and policy agenda. The Gerontologist, 43(Suppl. 2), 28–36.

    Article  PubMed  Google Scholar 

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Acknowledgments

This study was supported by the Institute for Clinical Evaluative Sciences (ICES), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement by ICES or the MOHLTC is intended or should be inferred. Further, parts of this material are based on data and information compiled and provided by the Canadian Institute for Health Information (CIHI). However, the analyses, conclusions, opinions and statements expressed herein are those of the author, and not necessarily those of CIHI.

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Authors and Affiliations

  1. Institute for Clinical Evaluative Sciences (ICES), Toronto, ON, Canada

    Luke Mondor, Colleen J. Maxwell, Susan E. Bronskill, Andrea Gruneir & Walter P. Wodchis

  2. Health System Performance Research Network (HSPRN), Toronto, ON, Canada

    Luke Mondor, Colleen J. Maxwell, Susan E. Bronskill, Andrea Gruneir & Walter P. Wodchis

  3. Schools of Pharmacy and Public Health and Health Systems, University of Waterloo, Waterloo, ON, Canada

    Colleen J. Maxwell

  4. Institute of Health Policy, Management and Evaluation, University of Toronto, 155 College Street, Toronto, ON, M5T 3MS, Canada

    Susan E. Bronskill, Andrea Gruneir & Walter P. Wodchis

  5. Department of Family Medicine, University of Alberta, Edmonton, AB, Canada

    Andrea Gruneir

  6. Toronto Rehabilitation Institute, Toronto, ON, Canada

    Walter P. Wodchis

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Appendix

Appendix

See Tables 5, 6, 7, 8 and 9.

Table 5 Results (effect sizes/beta coefficients) for all covariates included in the final multivariate linear regression model examining the relative impact of 16 chronic conditions on health-related quality of life, Ontario long-stay home care population
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Table 6 Results of multivariable linear regression analyses comparing the relative impact of having (vs. not having) a chronic diagnosis on health-related quality of life, by age and sex
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Table 7 Results of multivariable linear regression analyses comparing the relative impact of increasing morbidity on health-related quality of life, by age and sex
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Table 8 Distribution of select characteristics of long-stay home care clients in Ontario (aged 18–105 years) diagnosed with one or more of 16 chronic conditions, stratified by sex
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Table 9 Distribution of select characteristics of long-stay home care clients in Ontario (aged 18–105 years) diagnosed with one or more of 16 chronic conditions
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Mondor, L., Maxwell, C.J., Bronskill, S.E. et al. The relative impact of chronic conditions and multimorbidity on health-related quality of life in Ontario long-stay home care clients. Qual Life Res 25, 2619–2632 (2016). https://doi.org/10.1007/s11136-016-1281-y

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