Multimorbidity, also known as multiple long-term conditions (MLTC), means living with two or more chronic illnesses.[1] For example, a person could have diabetes, heart disease and depression at the same time. Multimorbidity can have a significant impact on people's health and wellbeing. It also poses a complex challenge to healthcare systems which are traditionally focused on individual diseases.[1] Multiple long-term conditions are much more common in older people, affecting more than half of those over 65,[2] however, they can also be found in young people.[3]

Definition

The concept of multiple long-term conditions is not clearly defined[1][4][5] and may be referred to by various names.[6]

Difference from comorbidity

Multimorbidity is often referred to as comorbidity even though the two are considered distinct clinical scenarios.[6][7][8]

Comorbidity means that one 'index' condition is the focus of attention, and others are viewed in relation to this. In contrast, multimorbidity describes someone having two or more long-term (chronic) conditions without any of them holding priority over the others. This distinction is important in how the healthcare system treats people and helps making clear the specific settings in which the use of one or the other term can be preferred. Multimorbidity offers a more general and person-centered concept that allows focusing on all of the patient's symptoms and providing a more holistic care. In other settings, for example in pharmaceutical research, comorbidity might often be the more useful term to use.[2][8]

Definitions

The broad definition of multimorbidity, consistent with what is used by most researchers, the WHO and the UK's Academy of Medical Sciences is the "co-existence of two or more chronic conditions". These can be physical non-communicable diseases, infectious and mental health conditions in any possible combinations and they may or may not interact with each other.[6] When the co-existing conditions have similar origins or treatments the terms used is concordant multimorbidity, while discordant multimorbidity is used to refer to conditions that appear to be unrelated to each other.[6]

Definitions of multimorbidity usually differ in the minimum number of concurrent conditions they require (most often this is two or more) and in the types of conditions they consider.[9] For example the UK's National Institute for Health and Care Excellence (NICE) includes alcohol and substance misuse in their list of conditions considered to constitute multimorbidity.[10]

Naming

The most commonly used term to describe the concept is multimorbidity. However, scientific literature shows a diverse range of terms used with the same meaning. These include comorbidity, polymorbidity, polypathology, pluripathology, multipathology, multicondition.[11]

The UK's National Institute for Health and Care Research (NIHR) uses the term multiple long-term conditions (MLTC) as it is more accepted and understood by patients and the public.[12]

Causes

Risk factors

A range of biological, psychological, behavioural, socioeconomic and environmental factors affect the likelihood of having multimorbidity. How these risk factors interact to trigger multiple long-term conditions is complex and still not fully understood.[1]

Lifestyle factors that may increase the risk of multiple long-term conditions include obesity, poor diet, poor sleep, smoking, air pollution, alcohol; and lifestyles factors that may reduce the risk of MLTC includes eating a healthy diet, physical activity, and strong social networks.[1][13]

Lower socioeconomic status, measured by a combination of education, occupation and literacy indicators, seems to increase the risk of developing multimorbidity.[14] For instance, based on the Whitehall II Study, people in lower employment positions seem to have a 66% higher risk of developing multiple long-term conditions than people in higher positions. However, socioeconomic status does not appear to influence the risk of dying after the onset of multiple long-term conditions.[14] Another study showed an increase of almost 50% in the odds of multimorbidity occurring in those with the least wealth compared to those with the most wealth.[15] Therefore, reducing socioeconomic inequalities by improving working and living conditions and education to everyone is important to reduce the burden of multiple long-term conditions on population health.[14]

Diagnosis and impact

Multimorbidity is associated with reduced quality of life[16] and increased risk of death.[17] The risk of death is positively associated with individuals with greater number of chronic conditions and reversely associated with socioeconomic status.[17] People with multiple long-term conditions may have a four-fold increase in the risk of death in comparison with people without MLTC irrespective of their socioeconomic status.[14]

In some cases, specific combinations of diseases are associated with higher mortality.[18] For example, people with long-term conditions affecting the heart, lung, and urinary systems have strong effects on mortality.[18]

There are many additional issues associated with living with multiple long term conditions. One study from the US found that having more than 3 conditions significantly increased the chance of reduced quality of life and physical functioning. The researchers called for the holistic treatment of multimorbidities due to the complexities of multiple long-term conditions.[19]

Due to the higher prevalence of multimorbidity (55 - 98%),[2] a new concept of "complex multimorbidity (CMM)" has been proposed.[20] CMM differs from the definition of conventional multimorbidity in that CMM is defined by the number of body systems affected by the diseases rather than the number of diseases. CMM is associated is mortality and long-term care needs in older adults.[21][22][23]

Mental health

Physical and mental health conditions can adversely impact the other through a number of pathways, and have significant impact on health and wellbeing.[24] For people whose long-term conditions include severe mental illness, the lifespan can be 10–20 years less than the general population.[25] For them, addressing the underlying risk factors for physical health problems is critical to good outcomes.[24]

There is considerable evidence that having multiple long-term physical conditions can lead to the development of both depression and anxiety.[26] There are many factors which might explain why physical multimorbidity affects mental health including chronic pain,[27] frailty,[28][29] symptom burden,[30] functional impairment,[31] reduced quality of life,[16] increased levels of inflammation,[32] and polypharmacy.[33] Evidence from large population studies from the United Kingdom and China suggests that specific combinations of physical conditions increase the risk of developing depression and anxiety more than others, such as co-occurring respiratory disorders and co-occurring painful and gastrointestinal disorders.[34][35]

Healthcare

People with multimorbidity face many challenges because of the way health systems are organised. Most health systems are designed to cater for people with a single chronic condition.[36] Some of the difficulties experienced by people with multiple long-term conditions include: poor coordination of medical care, managing multiple medications (polypharmacy), high costs associated with treatment,[37] increases in their time spent managing illness,[38] difficulty managing multiple illness management regimes,[39] and aggravation of one condition by symptoms or treatment of another.[40]

There is growing recognition that living with multiple long-term conditions leads to complex and challenging burdens for people living with MLTC themselves but also health care professionals working in the health system looking after those with long-term conditions. Living with multiple-long term conditions can be burdensome in terms of managing the illness, particularly if the diagnoses results in polypharmacy (taking multiple medicines).[1] The MEMORABLE study sought to understand how to improve medication management for people with MLTC. They identified five burdens that make managing medicines challenging: when the purpose of reviewing medicines is not clear to the person; when a lack of information prevents the person contributing to decisions about their health; when people with MLTC don't see the same health care professional consistently; when people are seen by lots of different professionals working across different services; and when the health service does not recognise the experiences of people living with MLTC.[41]

Prevention

There are well-evidenced prevention strategies for many of the component diseases of multiple condition clusters. For example:

An increased understanding of which conditions most commonly cluster, along with  their underlying risk factors, would help prioritise strategies for early diagnosis, screening and prevention.[1]

Epidemiology

Multimorbidity is common in older adults, estimated to affect over half of those aged 65 and over. This increased prevalence has been explained by older adults' "longer exposure and increased vulnerability to risk factors for chronic health problems".[2]

The prevalence of multimorbidity has been increasing in recent decades.[43][44][45] The high prevalence of multimorbidity has led to some describing it as "The most common chronic condition".[46] Multimorbidity is also more common among people from lower socioeconomic statuses.[2][47][48] Multimorbidity is a significant issue in low‐ and middle‐income countries, although prevalence is not as high as in high income countries.[49]

Research directions

Research funders in the UK, including the Medical Research Council (MRC), the Wellcome Trust and the National Institute for Health and Care Research (NIHR) have published the "Cross-funder multimorbidity research framework" which sets out a vision for the research agenda of multiple long-term conditions. The framework aims to drive advances in the understanding of multiple long-term conditions and promote a change in research culture to tackle multimorbidity.[50][51] The NIHR also published its own strategic framework regarding MLTC which aligns with the cross-funder framework.[12]

See also

References

  1. ^ a b c d e f g "Multiple long-term conditions (multimorbidity): making sense of the evidence". NIHR Evidence. National Institute for Health and Care Research. 30 March 2021. doi:10.3310/collection_45881. S2CID 243406561.
  2. ^ a b c d e Marengoni A, Angleman S, Melis R, Mangialasche F, Karp A, Garmen A, et al. (September 2011). "Aging with multimorbidity: a systematic review of the literature". Ageing Research Reviews. 10 (4): 430–439. doi:10.1016/j.arr.2011.03.003. PMID 21402176. S2CID 40912813.
  3. ^ Nguyen H, Manolova G, Daskalopoulou C, Vitoratou S, Prince M, Prina AM (1 January 2019). "Prevalence of multimorbidity in community settings: A systematic review and meta-analysis of observational studies". Journal of Comorbidity. 9: 2235042X19870934. doi:10.1177/2235042X19870934. PMC 6710708. PMID 31489279.
  4. ^ Johnston MC, Crilly M, Black C, Prescott GJ, Mercer SW (February 2019). "Defining and measuring multimorbidity: a systematic review of systematic reviews". European Journal of Public Health. 29 (1): 182–189. doi:10.1093/eurpub/cky098. PMID 29878097.
  5. ^ Xu X, Mishra GD, Jones M (August 2017). "Evidence on multimorbidity from definition to intervention: An overview of systematic reviews" (PDF). Ageing Research Reviews. 37: 53–68. doi:10.1016/j.arr.2017.05.003. PMID 28511964. S2CID 3665446.
  6. ^ a b c d Multimorbidity: a priority for global health research. Academy of Medical Sciences. 2018.
  7. ^ Nicholson K, Makovski TT, Griffith LE, Raina P, Stranges S, van den Akker M (January 2019). "Multimorbidity and comorbidity revisited: refining the concepts for international health research". Journal of Clinical Epidemiology. 105: 142–146. doi:10.1016/j.jclinepi.2018.09.008. PMID 30253215. S2CID 52825086.
  8. ^ a b Harrison C, Fortin M, van den Akker M, Mair F, Calderon-Larranaga A, Boland F, et al. (1 January 2021). "Comorbidity versus multimorbidity: Why it matters". Journal of Comorbidity. 11: 2633556521993993. doi:10.1177/2633556521993993. PMC 7930649. PMID 33718251.
  9. ^ Chua YP, Xie Y, Lee PS, Lee ES (February 2021). "Definitions and Prevalence of Multimorbidity in Large Database Studies: A Scoping Review". International Journal of Environmental Research and Public Health. 18 (4): 1673. doi:10.3390/ijerph18041673. PMC 7916224. PMID 33572441.
  10. ^ "Multimorbidity: clinical assessment and management - Recommendations". National Institute for Health and Care Excellence (NICE). 21 September 2016. Retrieved 27 May 2022.
  11. ^ Almirall J, Fortin M (January 2013). "The coexistence of terms to describe the presence of multiple concurrent diseases". Journal of Comorbidity. 3 (1): 4–9. doi:10.15256/joc.2013.3.22. PMC 5636023. PMID 29090140.
  12. ^ a b "NIHR Strategic Framework for Multiple Long-Term Conditions (Multimorbidity) MLTC-M Research". National Institute for Health and Care Research (NIHR). Retrieved 27 June 2022.
  13. ^ Sindi S, Pérez LM, Vetrano DL, Triolo F, Kåreholt I, Sjöberg L, et al. (December 2020). "Sleep disturbances and the speed of multimorbidity development in old age: results from a longitudinal population-based study". BMC Medicine. 18 (1): 382. doi:10.1186/s12916-020-01846-w. PMC 7720467. PMID 33280611.
  14. ^ a b c d Dugravot A, Fayosse A, Dumurgier J, Bouillon K, Rayana TB, Schnitzler A, et al. (January 2020). "Social inequalities in multimorbidity, frailty, disability, and transitions to mortality: a 24-year follow-up of the Whitehall II cohort study". The Lancet. Public Health. 5 (1): e42–e50. doi:10.1016/S2468-2667(19)30226-9. PMC 7098476. PMID 31837974.
  15. ^ Singer L, Green M, Rowe F, Ben-Shlomo Y, Morrissey K (August 2019). "Social determinants of multimorbidity and multiple functional limitations among the ageing population of England, 2002-2015". SSM - Population Health. 8: 100413. doi:10.1016/j.ssmph.2019.100413. PMC 6551564. PMID 31194123.
  16. ^ a b Makovski TT, Schmitz S, Zeegers MP, Stranges S, van den Akker M (August 2019). "Multimorbidity and quality of life: Systematic literature review and meta-analysis" (PDF). Ageing Research Reviews. 53: 100903. doi:10.1016/j.arr.2019.04.005. PMID 31048032. S2CID 139101266.
  17. ^ a b Nunes BP, Flores TR, Mielke GI, Thumé E, Facchini LA (November 2016). "Multimorbidity and mortality in older adults: A systematic review and meta-analysis". Archives of Gerontology and Geriatrics. 67: 130–138. doi:10.1016/j.archger.2016.07.008. PMID 27500661.
  18. ^ a b Gijsen R, Hoeymans N, Schellevis FG, Ruwaard D, Satariano WA, van den Bos GA (July 2001). "Causes and consequences of comorbidity: a review". Journal of Clinical Epidemiology. 54 (7): 661–674. doi:10.1016/s0895-4356(00)00363-2. PMID 11438406.
  19. ^ Williams JS, Egede LE (July 2016). "The Association Between Multimorbidity and Quality of Life, Health Status and Functional Disability". The American Journal of the Medical Sciences. 352 (1): 45–52. doi:10.1016/j.amjms.2016.03.004. PMID 27432034. S2CID 3455192.
  20. ^ Harrison C, Britt H, Miller G, Henderson J. Examining different measures of multimorbidity, using a large prospective cross-sectional study in Australian general practice. BMJ Open. 2014;4(7):4694.
  21. ^ Storeng SH, Vinjerui KH, Sund ER, Krokstad S (January 2020). "Associations between complex multimorbidity, activities of daily living and mortality among older Norwegians. A prospective cohort study: the HUNT Study, Norway". BMC Geriatrics. 20 (1): 21. doi:10.1186/s12877-020-1425-3. PMC 6974981. PMID 31964341.
  22. ^ Kato D, Kawachi I, Saito J, Kondo N (August 2021). "Complex multimorbidity and mortality in Japan: a prospective propensity-matched cohort study". BMJ Open. 11 (8): e046749. doi:10.1136/bmjopen-2020-046749. PMC 8330573. PMID 34341044.
  23. ^ Kato D, Kawachi I, Saito J, Kondo N (October 2021). "Complex Multimorbidity and Incidence of Long-Term Care Needs in Japan: A Prospective Cohort Study". International Journal of Environmental Research and Public Health. 18 (19): 10523. doi:10.3390/ijerph181910523. PMC 8508235. PMID 34639825.
  24. ^ a b Firth J, Siddiqi N, Koyanagi A, Siskind D, Rosenbaum S, Galletly C, et al. (August 2019). "The Lancet Psychiatry Commission: a blueprint for protecting physical health in people with mental illness". The Lancet. Psychiatry. 6 (8): 675–712. doi:10.1016/S2215-0366(19)30132-4. hdl:10072/391717. PMID 31324560. S2CID 198134221.
  25. ^ World Health Organization, issuing body (14 August 2018). Management of physical health conditions in adults with severe mental disorders : WHO guidelines. ISBN 978-92-4-155038-3. OCLC 1089879045.
  26. ^ Triolo F, Harber-Aschan L, Belvederi Murri M, Calderón-Larrañaga A, Vetrano DL, Sjöberg L, et al. (December 2020). "The complex interplay between depression and multimorbidity in late life: risks and pathways". Mechanisms of Ageing and Development. 192: 111383. doi:10.1016/j.mad.2020.111383. PMID 33045250. S2CID 222233540.
  27. ^ Sharpe L, McDonald S, Correia H, Raue PJ, Meade T, Nicholas M, Arean P (May 2017). "Pain severity predicts depressive symptoms over and above individual illnesses and multimorbidity in older adults". BMC Psychiatry. 17 (1): 166. doi:10.1186/s12888-017-1334-y. PMC 5418685. PMID 28472936.
  28. ^ Vetrano DL, Palmer K, Marengoni A, Marzetti E, Lattanzio F, Roller-Wirnsberger R, et al. (April 2019). "Frailty and Multimorbidity: A Systematic Review and Meta-analysis". The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences. 74 (5): 659–666. doi:10.1093/gerona/gly110. PMID 29726918.
  29. ^ Soysal P, Veronese N, Thompson T, Kahl KG, Fernandes BS, Prina AM, et al. (July 2017). "Relationship between depression and frailty in older adults: A systematic review and meta-analysis". Ageing Research Reviews. 36: 78–87. doi:10.1016/j.arr.2017.03.005. PMID 28366616. S2CID 205668529.
  30. ^ Katon W, Lin EH, Kroenke K (1 March 2007). "The association of depression and anxiety with medical symptom burden in patients with chronic medical illness". General Hospital Psychiatry. 29 (2): 147–155. doi:10.1016/j.genhosppsych.2006.11.005. PMID 17336664.
  31. ^ Calderón-Larrañaga A, Vetrano DL, Ferrucci L, Mercer SW, Marengoni A, Onder G, et al. (March 2019). "Multimorbidity and functional impairment-bidirectional interplay, synergistic effects and common pathways". Journal of Internal Medicine. 285 (3): 255–271. doi:10.1111/joim.12843. PMC 6446236. PMID 30357990.
  32. ^ Miller AH, Raison CL (January 2016). "The role of inflammation in depression: from evolutionary imperative to modern treatment target". Nature Reviews. Immunology. 16 (1): 22–34. doi:10.1038/nri.2015.5. PMC 5542678. PMID 26711676.
  33. ^ Holvast F, van Hattem BA, Sinnige J, Schellevis F, Taxis K, Burger H, Verhaak PF (September 2017). "Late-life depression and the association with multimorbidity and polypharmacy: a cross-sectional study". Family Practice. 34 (5): 539–545. doi:10.1093/fampra/cmx018. PMID 28369380.
  34. ^ Yao SS, Cao GY, Han L, Huang ZT, Chen ZS, Su HX, et al. (September 2020). "Associations Between Somatic Multimorbidity Patterns and Depression in a Longitudinal Cohort of Middle-Aged and Older Chinese". Journal of the American Medical Directors Association. 21 (9): 1282–1287.e2. doi:10.1016/j.jamda.2019.11.028. PMID 31928934. S2CID 210191651.
  35. ^ Ronaldson A, Arias de la Torre J, Prina M, Armstrong D, Das-Munshi J, Hatch S, et al. (September 2021). "Associations between physical multimorbidity patterns and common mental health disorders in middle-aged adults: A prospective analysis using data from the UK Biobank". The Lancet Regional Health. Europe. 8: 100149. doi:10.1016/j.lanepe.2021.100149. PMC 8447568. PMID 34557851.
  36. ^ Salisbury C (July 2012). "Multimorbidity: redesigning health care for people who use it". Lancet. 380 (9836): 7–9. doi:10.1016/S0140-6736(12)60482-6. PMID 22579042. S2CID 12325320.
  37. ^ Wang L, Si L, Cocker F, Palmer AJ, Sanderson K (February 2018). "A Systematic Review of Cost-of-Illness Studies of Multimorbidity" (PDF). Applied Health Economics and Health Policy. 16 (1): 15–29. doi:10.1007/s40258-017-0346-6. PMID 28856585. S2CID 21008606.
  38. ^ Jowsey T, McRae IS, Valderas JM, Dugdale P, Phillips R, Bunton R, et al. (2013). "Time's up. descriptive epidemiology of multi-morbidity and time spent on health related activity by older Australians: a time use survey". PLOS ONE. 8 (4): e59379. Bibcode:2013PLoSO...859379J. doi:10.1371/journal.pone.0059379. PMC 3613388. PMID 23560046.
  39. ^ Jowsey T, Dennis S, Yen L, Mofizul Islam M, Parkinson A, Dawda P (July 2016). "Time to manage: patient strategies for coping with an absence of care coordination and continuity". Sociology of Health & Illness. 38 (6): 854–873. doi:10.1111/1467-9566.12404. PMID 26871716.
  40. ^ Bayliss EA, Steiner JF, Fernald DH, Crane LA, Main DS (2003). "Descriptions of barriers to self-care by persons with comorbid chronic diseases". Annals of Family Medicine. 1 (1): 15–21. doi:10.1370/afm.4. PMC 1466563. PMID 15043175.
  41. ^ Maidment I, Lawson S, Wong G, Booth A, Watson A, Zaman H, et al. (June 2020). "Towards an understanding of the burdens of medication management affecting older people: the MEMORABLE realist synthesis". BMC Geriatrics. 20 (1): 183. doi:10.1186/s12877-020-01568-x. PMC 7272211. PMID 32498672.
  42. ^ Head A, Fleming K, Kypridemos C, Pearson-Stuttard J, O'Flaherty M (March 2021). "Multimorbidity: the case for prevention". Journal of Epidemiology and Community Health. 75 (3): 242–244. doi:10.1136/jech-2020-214301. PMC 7892394. PMID 33020144.
  43. ^ King DE, Xiang J, Pilkerton CS (2018). "Multimorbidity Trends in United States Adults, 1988-2014". Journal of the American Board of Family Medicine. 31 (4): 503–513. doi:10.3122/jabfm.2018.04.180008. PMC 6368177. PMID 29986975.
  44. ^ Pefoyo AJ, Bronskill SE, Gruneir A, Calzavara A, Thavorn K, Petrosyan Y, et al. (April 2015). "The increasing burden and complexity of multimorbidity". BMC Public Health. 15: 415. doi:10.1186/s12889-015-1733-2. PMC 4415224. PMID 25903064.
  45. ^ Uijen AA, van de Lisdonk EH (2008). "Multimorbidity in primary care: prevalence and trend over the last 20 years". The European Journal of General Practice. 14 (sup1): 28–32. doi:10.1080/13814780802436093. PMID 18949641. S2CID 34601052.
  46. ^ Tinetti ME, Fried TR, Boyd CM. Designing health care for the most common chronic condition—multimorbidity. Jama. 2012 Jun 20;307(23):2493-4.
  47. ^ Barnett K, Mercer SW, Norbury M, Watt G, Wyke S, Guthrie B (July 2012). "Epidemiology of multimorbidity and implications for health care, research, and medical education: a cross-sectional study". Lancet. 380 (9836): 37–43. doi:10.1016/S0140-6736(12)60240-2. PMID 22579043. S2CID 8212325.
  48. ^ Pathirana TI, Jackson CA (April 2018). "Socioeconomic status and multimorbidity: a systematic review and meta-analysis". Australian and New Zealand Journal of Public Health. 42 (2): 186–194. doi:10.1111/1753-6405.12762. PMID 29442409. S2CID 4754463.
  49. ^ Afshar S, Roderick PJ, Kowal P, Dimitrov BD, Hill AG (August 2015). "Multimorbidity and the inequalities of global ageing: a cross-sectional study of 28 countries using the World Health Surveys". BMC Public Health. 15: 776. doi:10.1186/s12889-015-2008-7. PMC 4534141. PMID 26268536.
  50. ^ "Research funders publish framework to tackle multiple long-term conditions". The Academy of Medical Sciences. Retrieved 28 June 2022.
  51. ^ Cross-funder multimorbidity research framework (Report). The Academy of Medical Sciences. June 2020.