Multimorbidity

The concept of multiple long-term conditions is not clearly defined{{cite journal | vauthors = Johnston MC, Crilly M, Black C, Prescott GJ, Mercer SW | title = Defining and measuring multimorbidity: a systematic review of systematic reviews | journal = European Journal of Public Health | volume = 29 | issue = 1 | pages = 182–189 | date = February 2019 | pmid = 29878097 | doi = 10.1093/eurpub/cky098 | doi-access = free | hdl = 20.500.11820/fdedbe90-e4ec-43b8-bb78-a0f75efe6305 | hdl-access = free }}{{cite journal | vauthors = Xu X, Mishra GD, Jones M | title = Evidence on multimorbidity from definition to intervention: An overview of systematic reviews | journal = Ageing Research Reviews | volume = 37 | pages = 53–68 | date = August 2017 | pmid = 28511964 | doi = 10.1016/j.arr.2017.05.003 | s2cid = 3665446 | url = https://espace.library.uq.edu.au/view/UQ:673588/UQ673588_OA.pdf }} and may be referred to by various names.{{Cite book |url=https://acmedsci.ac.uk/file-download/82222577 |title=Multimorbidity: a priority for global health research |publisher=Academy of Medical Sciences |year=2018}}

Multimorbidity is often referred to as comorbidity even though the two are considered distinct clinical scenarios.{{cite journal | vauthors = Nicholson K, Makovski TT, Griffith LE, Raina P, Stranges S, van den Akker M | title = Multimorbidity and comorbidity revisited: refining the concepts for international health research | journal = Journal of Clinical Epidemiology | volume = 105 | pages = 142–146 | date = January 2019 | pmid = 30253215 | doi = 10.1016/j.jclinepi.2018.09.008 | s2cid = 52825086 }}{{cite journal | vauthors = Harrison C, Fortin M, van den Akker M, Mair F, Calderon-Larranaga A, Boland F, Wallace E, Jani B, Smith S | display-authors = 6 | title = Comorbidity versus multimorbidity: Why it matters | journal = Journal of Comorbidity | volume = 11 | pages = 2633556521993993 | date = 2021-01-01 | pmid = 33718251 | pmc = 7930649 | doi = 10.1177/2633556521993993 }}

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.

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. 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.

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.{{cite journal | vauthors = Chua YP, Xie Y, Lee PS, Lee ES | title = Definitions and Prevalence of Multimorbidity in Large Database Studies: A Scoping Review | journal = International Journal of Environmental Research and Public Health | volume = 18 | issue = 4 | pages = 1673 | date = February 2021 | pmid = 33572441 | pmc = 7916224 | doi = 10.3390/ijerph18041673 | doi-access = free }} 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.{{Cite web |date=21 September 2016 |title=Multimorbidity: clinical assessment and management - Recommendations |url=https://www.nice.org.uk/guidance/ng56/chapter/Recommendations |access-date=2022-05-27 |website=National Institute for Health and Care Excellence (NICE)}}

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.{{cite journal | vauthors = Almirall J, Fortin M | title = The coexistence of terms to describe the presence of multiple concurrent diseases | journal = Journal of Comorbidity | volume = 3 | issue = 1 | pages = 4–9 | date = January 2013 | pmid = 29090140 | pmc = 5636023 | doi = 10.15256/joc.2013.3.22 }}

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.{{Cite web |title=NIHR Strategic Framework for Multiple Long-Term Conditions (Multimorbidity) MLTC-M Research |url=https://www.nihr.ac.uk/documents/nihr-strategic-framework-for-multiple-long-term-conditions-multimorbidity-mltc-m-research/24639 |access-date=2022-06-27 |website=National Institute for Health and Care Research (NIHR) |language=EN}}

File:NIHR-infographic-multimorbidity.jpg

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.

One risk factor of multimorbidity in young people is being born premature.{{cite journal |last1=Heikkilä |first1=Katriina |last2=Pulakka |first2=Anna |last3=Metsälä |first3=Johanna |last4=Alenius |first4=Suvi |last5=Hovi |first5=Petteri |last6=Gissler |first6=Mika |last7=Sandin |first7=Sven |last8=Kajantie |first8=Eero |title=Preterm birth and the risk of chronic disease multimorbidity in adolescence and early adulthood: A population-based cohort study |journal=PLOS ONE |date=31 December 2021 |volume=16 |issue=12 |pages=e0261952 |doi=10.1371/journal.pone.0261952 |pmid=34972182 |pmc=8719774 |bibcode=2021PLoSO..1661952H |language=en |issn=1932-6203 |doi-access=free }}{{cite journal |last1=Heikkilä |first1=Katriina |last2=Metsälä |first2=Johanna |last3=Pulakka |first3=Anna |last4=Nilsen |first4=Sara Marie |last5=Kivimäki |first5=Mika |last6=Risnes |first6=Kari |last7=Kajantie |first7=Eero |title=Preterm birth and the risk of multimorbidity in adolescence: a multiregister-based cohort study |journal=The Lancet Public Health |date=September 2023 |volume=8 |issue=9 |pages=e680–e690 |doi=10.1016/S2468-2667(23)00145-7 |pmid=37633677 |s2cid=261187781 |url=https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(23)00145-7/fulltext|hdl=11250/3103131 |hdl-access=free }} 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.{{cite journal | vauthors = Sindi S, Pérez LM, Vetrano DL, Triolo F, Kåreholt I, Sjöberg L, Darin-Mattsson A, Kivipelto M, Inzitari M, Calderón-Larrañaga A | display-authors = 6 | title = Sleep disturbances and the speed of multimorbidity development in old age: results from a longitudinal population-based study | journal = BMC Medicine | volume = 18 | issue = 1 | pages = 382 | date = December 2020 | pmid = 33280611 | pmc = 7720467 | doi = 10.1186/s12916-020-01846-w | doi-access = free }}

Lower socioeconomic status, measured by a combination of education, occupation and literacy indicators, seems to increase the risk of developing multimorbidity.{{cite journal | vauthors = Dugravot A, Fayosse A, Dumurgier J, Bouillon K, Rayana TB, Schnitzler A, Kivimaki M, Sabia S, Singh-Manoux A | display-authors = 6 | title = Social inequalities in multimorbidity, frailty, disability, and transitions to mortality: a 24-year follow-up of the Whitehall II cohort study | journal = The Lancet. Public Health | volume = 5 | issue = 1 | pages = e42–e50 | date = January 2020 | pmid = 31837974 | pmc = 7098476 | doi = 10.1016/S2468-2667(19)30226-9 }} 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. 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.{{cite journal | vauthors = Singer L, Green M, Rowe F, Ben-Shlomo Y, Morrissey K | title = Social determinants of multimorbidity and multiple functional limitations among the ageing population of England, 2002-2015 | journal = SSM - Population Health | volume = 8 | pages = 100413 | date = August 2019 | pmid = 31194123 | pmc = 6551564 | doi = 10.1016/j.ssmph.2019.100413 }} 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.

Multimorbidity is associated with reduced quality of life{{cite journal | vauthors = Makovski TT, Schmitz S, Zeegers MP, Stranges S, van den Akker M | title = Multimorbidity and quality of life: Systematic literature review and meta-analysis | journal = Ageing Research Reviews | volume = 53 | pages = 100903 | date = August 2019 | pmid = 31048032 | doi = 10.1016/j.arr.2019.04.005 | s2cid = 139101266 | url = https://cris.maastrichtuniversity.nl/ws/files/87879047/Zeegers_2019_Multimorbidity_and_quality_of_life.pdf }} and increased risk of death.{{cite journal | vauthors = Nunes BP, Flores TR, Mielke GI, Thumé E, Facchini LA | title = Multimorbidity and mortality in older adults: A systematic review and meta-analysis | journal = Archives of Gerontology and Geriatrics | volume = 67 | pages = 130–138 | date = November 2016 | pmid = 27500661 | doi = 10.1016/j.archger.2016.07.008 | url = https://zenodo.org/record/2673076 }} The risk of death is positively associated with individuals with greater number of chronic conditions and reversely associated with socioeconomic status. 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.

In some cases, specific combinations of diseases are associated with higher mortality.{{cite journal | vauthors = Gijsen R, Hoeymans N, Schellevis FG, Ruwaard D, Satariano WA, van den Bos GA | title = Causes and consequences of comorbidity: a review | journal = Journal of Clinical Epidemiology | volume = 54 | issue = 7 | pages = 661–674 | date = July 2001 | pmid = 11438406 | doi = 10.1016/s0895-4356(00)00363-2 }} For example, people with long-term conditions affecting the heart, lung, and urinary systems have strong effects on mortality.

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.{{cite journal | vauthors = Williams JS, Egede LE | title = The Association Between Multimorbidity and Quality of Life, Health Status and Functional Disability | journal = The American Journal of the Medical Sciences | volume = 352 | issue = 1 | pages = 45–52 | date = July 2016 | pmid = 27432034 | doi = 10.1016/j.amjms.2016.03.004 | s2cid = 3455192 }}

Due to the higher prevalence of multimorbidity (55 - 98%), a new concept of "complex multimorbidity (CMM)" has been proposed{{cite journal | vauthors = Harrison C, Britt H, Miller G, Henderson J | title = Examining different measures of multimorbidity, using a large prospective cross-sectional study in Australian general practice | journal = BMJ Open | volume = 4 | issue = 7 | pages = e004694 | date = July 2014 | pmid = 25015470 | pmc = 4120329 | doi = 10.1136/bmjopen-2013-004694 }} 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.{{cite journal | vauthors = Storeng SH, Vinjerui KH, Sund ER, Krokstad S | title = Associations between complex multimorbidity, activities of daily living and mortality among older Norwegians. A prospective cohort study: the HUNT Study, Norway | journal = BMC Geriatrics | volume = 20 | issue = 1 | pages = 21 | date = January 2020 | pmid = 31964341 | pmc = 6974981 | doi = 10.1186/s12877-020-1425-3 | doi-access = free }}{{cite journal | vauthors = Kato D, Kawachi I, Saito J, Kondo N | title = Complex multimorbidity and mortality in Japan: a prospective propensity-matched cohort study | journal = BMJ Open | volume = 11 | issue = 8 | pages = e046749 | date = August 2021 | pmid = 34341044 | pmc = 8330573 | doi = 10.1136/bmjopen-2020-046749 }}{{cite journal | vauthors = Kato D, Kawachi I, Saito J, Kondo N | title = Complex Multimorbidity and Incidence of Long-Term Care Needs in Japan: A Prospective Cohort Study | journal = International Journal of Environmental Research and Public Health | volume = 18 | issue = 19 | date = October 2021 | page = 10523 | pmid = 34639825 | pmc = 8508235 | doi = 10.3390/ijerph181910523 | doi-access = free }}

Physical and mental health conditions can adversely impact the other through a number of pathways, and have significant impact on health and wellbeing.{{cite journal | vauthors = Firth J, Siddiqi N, Koyanagi A, Siskind D, Rosenbaum S, Galletly C, Allan S, Caneo C, Carney R, Carvalho AF, Chatterton ML, Correll CU, Curtis J, Gaughran F, Heald A, Hoare E, Jackson SE, Kisely S, Lovell K, Maj M, McGorry PD, Mihalopoulos C, Myles H, O'Donoghue B, Pillinger T, Sarris J, Schuch FB, Shiers D, Smith L, Solmi M, Suetani S, Taylor J, Teasdale SB, Thornicroft G, Torous J, Usherwood T, Vancampfort D, Veronese N, Ward PB, Yung AR, Killackey E, Stubbs B | display-authors = 6 | title = The Lancet Psychiatry Commission: a blueprint for protecting physical health in people with mental illness | journal = The Lancet. Psychiatry | volume = 6 | issue = 8 | pages = 675–712 | date = August 2019 | pmid = 31324560 | doi = 10.1016/S2215-0366(19)30132-4 | hdl = 10072/391717 | s2cid = 198134221 | hdl-access = free }} For people whose long-term conditions include severe mental illness, the lifespan can be 10–20 years less than the general population.{{Cite book | author = World Health Organization, issuing body |url=http://worldcat.org/oclc/1089879045 |title=Management of physical health conditions in adults with severe mental disorders : WHO guidelines. |date=14 August 2018 |publisher=World Health Organization |isbn=978-92-4-155038-3 |oclc=1089879045}} For them, addressing the underlying risk factors for physical health problems is critical to good outcomes.

There is considerable evidence that having multiple long-term physical conditions can lead to the development of both depression and anxiety.{{cite journal | vauthors = Triolo F, Harber-Aschan L, Belvederi Murri M, Calderón-Larrañaga A, Vetrano DL, Sjöberg L, Marengoni A, Dekhtyar S | display-authors = 6 | title = The complex interplay between depression and multimorbidity in late life: risks and pathways | journal = Mechanisms of Ageing and Development | volume = 192 | pages = 111383 | date = December 2020 | pmid = 33045250 | doi = 10.1016/j.mad.2020.111383 | s2cid = 222233540 | doi-access = free | hdl = 11392/2437730 | hdl-access = free }} There are many factors which might explain why physical multi-morbidity affects mental health including chronic pain,{{cite journal | vauthors = Sharpe L, McDonald S, Correia H, Raue PJ, Meade T, Nicholas M, Arean P | title = Pain severity predicts depressive symptoms over and above individual illnesses and multimorbidity in older adults | journal = BMC Psychiatry | volume = 17 | issue = 1 | pages = 166 | date = May 2017 | pmid = 28472936 | doi = 10.1186/s12888-017-1334-y | pmc = 5418685 | doi-access = free }} frailty,{{cite journal | vauthors = Vetrano DL, Palmer K, Marengoni A, Marzetti E, Lattanzio F, Roller-Wirnsberger R, Lopez Samaniego L, Rodríguez-Mañas L, Bernabei R, Onder G | display-authors = 6 | title = Frailty and Multimorbidity: A Systematic Review and Meta-analysis | journal = The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences | volume = 74 | issue = 5 | pages = 659–666 | date = April 2019 | pmid = 29726918 | doi = 10.1093/gerona/gly110 | doi-access = free }}{{cite journal | vauthors = Soysal P, Veronese N, Thompson T, Kahl KG, Fernandes BS, Prina AM, Solmi M, Schofield P, Koyanagi A, Tseng PT, Lin PY, Chu CS, Cosco TD, Cesari M, Carvalho AF, Stubbs B | display-authors = 6 | title = Relationship between depression and frailty in older adults: A systematic review and meta-analysis | journal = Ageing Research Reviews | volume = 36 | pages = 78–87 | date = July 2017 | pmid = 28366616 | doi = 10.1016/j.arr.2017.03.005 | s2cid = 205668529 | url = http://www.repositorio.ufc.br/handle/riufc/25064 }} symptom burden,{{cite journal | vauthors = Katon W, Lin EH, Kroenke K | title = The association of depression and anxiety with medical symptom burden in patients with chronic medical illness | journal = General Hospital Psychiatry | volume = 29 | issue = 2 | pages = 147–155 | date = 2007-03-01 | pmid = 17336664 | doi = 10.1016/j.genhosppsych.2006.11.005 }} functional impairment,{{cite journal | vauthors = Calderón-Larrañaga A, Vetrano DL, Ferrucci L, Mercer SW, Marengoni A, Onder G, Eriksdotter M, Fratiglioni L | display-authors = 6 | title = Multimorbidity and functional impairment-bidirectional interplay, synergistic effects and common pathways | journal = Journal of Internal Medicine | volume = 285 | issue = 3 | pages = 255–271 | date = March 2019 | pmid = 30357990 | pmc = 6446236 | doi = 10.1111/joim.12843 }} reduced quality of life, increased levels of inflammation,{{cite journal | vauthors = Miller AH, Raison CL | title = The role of inflammation in depression: from evolutionary imperative to modern treatment target | journal = Nature Reviews. Immunology | volume = 16 | issue = 1 | pages = 22–34 | date = January 2016 | pmid = 26711676 | pmc = 5542678 | doi = 10.1038/nri.2015.5 }} and polypharmacy.{{cite journal | vauthors = Holvast F, van Hattem BA, Sinnige J, Schellevis F, Taxis K, Burger H, Verhaak PF | title = Late-life depression and the association with multimorbidity and polypharmacy: a cross-sectional study | journal = Family Practice | volume = 34 | issue = 5 | pages = 539–545 | date = September 2017 | pmid = 28369380 | doi = 10.1093/fampra/cmx018 | doi-access = free }} 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.{{cite journal | vauthors = Yao SS, Cao GY, Han L, Huang ZT, Chen ZS, Su HX, Hu Y, Xu B | display-authors = 6 | title = Associations Between Somatic Multimorbidity Patterns and Depression in a Longitudinal Cohort of Middle-Aged and Older Chinese | journal = Journal of the American Medical Directors Association | volume = 21 | issue = 9 | pages = 1282–1287.e2 | date = September 2020 | pmid = 31928934 | doi = 10.1016/j.jamda.2019.11.028 | s2cid = 210191651 }}{{cite journal | vauthors = Ronaldson A, Arias de la Torre J, Prina M, Armstrong D, Das-Munshi J, Hatch S, Stewart R, Hotopf M, Dregan A | display-authors = 6 | title = Associations between physical multimorbidity patterns and common mental health disorders in middle-aged adults: A prospective analysis using data from the UK Biobank | journal = The Lancet Regional Health. Europe | volume = 8 | pages = 100149 | date = September 2021 | pmid = 34557851 | pmc = 8447568 | doi = 10.1016/j.lanepe.2021.100149 }} There has been a scarcity of economic evaluations concerning interventions for managing individuals with mental-physical multimorbidity, including depression. A recent systematic review identified four intervention types (collaborative care, self-management, telephone-based, and antidepressant treatment)) that were assessed for cost-effectiveness in high-income countries.{{cite journal | vauthors = Banstola A, Pokhrel S, Hayhoe B, Nicholls D, Harris M, Anokye N | title = Economic evaluations of interventional opportunities for the management of mental-physical multimorbidity: a systematic review | journal = BMJ Open | volume = 13 | issue = 2 | pages = e069270 | date = February 2023 | pmid = 36854591 | pmc = 9980364 | doi = 10.1136/bmjopen-2022-069270 }} However, such evaluations are currently absent in low-income and middle-income countries as no studies have been identified in these regions.

Strategies to prevent the onset of depression or depressive episodes in people with long-term physical conditions include psychological interventions and pharmacological interventions, however the long-term effectiveness and benefits of these approaches is very uncertain.{{cite journal | vauthors = Kampling H, Baumeister H, Bengel J, Mittag O | title = Prevention of depression in adults with long-term physical conditions | journal = The Cochrane Database of Systematic Reviews | volume = 2021 | issue = 3 | pages = CD011246 | date = March 2021 | pmid = 33667319 | pmc = 8092431 | doi = 10.1002/14651858.CD011246.pub2 }}

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.{{cite journal |vauthors=Salisbury C |date=July 2012 |title=Multimorbidity: redesigning health care for people who use it |journal=Lancet |volume=380 |issue=9836 |pages=7–9 |doi=10.1016/S0140-6736(12)60482-6 |pmid=22579042 |s2cid=12325320}} 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,{{cite journal |vauthors=Wang L, Si L, Cocker F, Palmer AJ, Sanderson K |date=February 2018 |title=A Systematic Review of Cost-of-Illness Studies of Multimorbidity |url=https://ueaeprints.uea.ac.uk/id/eprint/64861/1/Accepted_manuscript.pdf |journal=Applied Health Economics and Health Policy |volume=16 |issue=1 |pages=15–29 |doi=10.1007/s40258-017-0346-6 |pmid=28856585 |s2cid=21008606}} increases in their time spent managing illness,{{cite journal |display-authors=6 |vauthors=Jowsey T, McRae IS, Valderas JM, Dugdale P, Phillips R, Bunton R, Gillespie J, Banfield M, Jones L, Kljakovic M, Yen L |date=2013 |title=Time's up. descriptive epidemiology of multi-morbidity and time spent on health related activity by older Australians: a time use survey |journal=PLOS ONE |volume=8 |issue=4 |pages=e59379 |bibcode=2013PLoSO...859379J |doi=10.1371/journal.pone.0059379 |pmc=3613388 |pmid=23560046 |doi-access=free}} difficulty managing multiple illness management regimes,{{cite journal |vauthors=Jowsey T, Dennis S, Yen L, Mofizul Islam M, Parkinson A, Dawda P |date=July 2016 |title=Time to manage: patient strategies for coping with an absence of care coordination and continuity |journal=Sociology of Health & Illness |volume=38 |issue=6 |pages=854–873 |doi=10.1111/1467-9566.12404 |pmid=26871716|doi-access=free |hdl=2292/29920 |hdl-access=free }} and aggravation of one condition by symptoms or treatment of another.{{cite journal |vauthors=Bayliss EA, Steiner JF, Fernald DH, Crane LA, Main DS |date=2003 |title=Descriptions of barriers to self-care by persons with comorbid chronic diseases |journal=Annals of Family Medicine |volume=1 |issue=1 |pages=15–21 |doi=10.1370/afm.4 |pmc=1466563 |pmid=15043175}}

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).

Older people and their family carers frequently find medication management a burden. This burden fluctuates and is often hidden from health and social care practitioners.{{cite journal | title = Medication management in older people: the MEMORABLE realist synthesis | journal = Health Services and Delivery Research | volume = 8 | issue = 26 | pages = 1–128 | date = June 2020 | pmid = 32579319 | doi = 10.3310/hsdr08260 | last1 = Maidment | first1 = Ian D. | last2 = Lawson | first2 = Sally | last3 = Wong | first3 = Geoff | last4 = Booth | first4 = Andrew | last5 = Watson | first5 = Anne | last6 = McKeown | first6 = Jane | last7 = Zaman | first7 = Hadar | last8 = Mullan | first8 = Judy | last9 = Bailey | first9 = Sylvia | s2cid = 225671789 | doi-access = free }}{{cite journal | vauthors = Lawson S, Mullan J, Wong G, Zaman H, Booth A, Watson A, Maidment I | title = Family carers' experiences of managing older relative's medications: Insights from the MEMORABLE study | journal = Patient Education and Counseling | volume = 105 | issue = 7 | pages = 2573–2580 | date = July 2022 | pmid = 35016779 | doi = 10.1016/j.pec.2021.12.017 | s2cid = 245620865 | url = https://publications.aston.ac.uk/id/eprint/43490/1/Family_Carers.pdf }} For example, the burden, on the family carer, may increase if the older person is suffering from confusion or dementia.{{cite journal | vauthors = Maidment ID, Aston L, Moutela T, Fox CG, Hilton A | title = A qualitative study exploring medication management in people with dementia living in the community and the potential role of the community pharmacist | journal = Health Expectations | volume = 20 | issue = 5 | pages = 929–942 | date = October 2017 | pmid = 28105781 | pmc = 5600213 | doi = 10.1111/hex.12534 }} In general there are five burdens that make managing medicines challenging for older people: 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. To help older people and their family carers experiencing medication-related burden, medical professionals can consider this burden when changing or amending a medication.{{Cite journal |date=2020-11-24 |title=Managing medication: older people and their families need support to deal with the hidden burden of medication |url=https://evidence.nihr.ac.uk/alert/managing-medication-older-people-need-support-hidden-burden/ |journal=NIHR Evidence |type=Plain English summary |language=en |doi=10.3310/alert_42757|s2cid=240496292 |url-access=subscription }}

Multimorbidity often results in taking 5 or more medicines (polypharmacy) which can represent a burden and might come with potential harm. When the medications are not effective enough or the risks outweigh the benefits, stopping medicines (deprescribing) might be necessary. In people with multiple long-term conditions and polypharmacy this represents a complex challenge as clinical guidelines are usually developed for single conditions. In these cases tools and guidelines like the Beers Criteria and STOPP/START could be used safely by clinicians but not all patients might benefit from stopping their medication. Clarity about how much clinicians can do beyond the guidelines and the responsibility they need to take could help them prescribing and deprescribing for complex cases. Further factors that can help clinicians tailor their decisions to the individual are: access to detailed data on the people in their care (including their backgrounds and personal medical goals), discussing plans to stop a medicine already when it is first prescribed, and a good relationship that involves mutual trust and regular discussions on progress. Furthermore, longer appointments for prescribing and deprescribing would allow time explain the process of deprescribing, explore related concerns, and support making the right decisions.{{Cite journal |date=2023-05-18 |title=How to reduce medications for people with multiple long-term conditions |url=https://evidence.nihr.ac.uk/alert/how-to-safely-deprescribe-medications-for-people-with-multiple-long-term-conditions/ |journal=NIHR Evidence |language=en |doi=10.3310/nihrevidence_57904|s2cid=258801327 |url-access=subscription }}{{cite journal | vauthors = Reeve J, Maden M, Hill R, Turk A, Mahtani K, Wong G, Lasserson D, Krska J, Mangin D, Byng R, Wallace E, Ranson E | display-authors = 6 | title = Deprescribing medicines in older people living with multimorbidity and polypharmacy: the TAILOR evidence synthesis | journal = Health Technology Assessment | volume = 26 | issue = 32 | pages = 1–148 | date = July 2022 | pmid = 35894932 | pmc = 9376985 | doi = 10.3310/AAFO2475 }}

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

• quitting smoking - to prevent cardiovascular, respiratory and several neoplastic diseases
• a reduction in blood pressure - to prevent coronary disease, ischaemic stroke, cerebral haemorrhage, congestive heart failure and chronic kidney disease, and
• LDL-cholesterol lowering - to prevent coronary heart disease and ischaemic stroke.{{cite journal | vauthors = Head A, Fleming K, Kypridemos C, Pearson-Stuttard J, O'Flaherty M | title = Multimorbidity: the case for prevention | journal = Journal of Epidemiology and Community Health | volume = 75 | issue = 3 | pages = 242–244 | date = March 2021 | pmid = 33020144 | pmc = 7892394 | doi = 10.1136/jech-2020-214301 }}

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.

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".

The prevalence of multimorbidity has been increasing in recent decades.{{cite journal | vauthors = King DE, Xiang J, Pilkerton CS | title = Multimorbidity Trends in United States Adults, 1988-2014 | journal = Journal of the American Board of Family Medicine | volume = 31 | issue = 4 | pages = 503–513 | date = 2018 | pmid = 29986975 | pmc = 6368177 | doi = 10.3122/jabfm.2018.04.180008 }}{{cite journal | vauthors = Pefoyo AJ, Bronskill SE, Gruneir A, Calzavara A, Thavorn K, Petrosyan Y, Maxwell CJ, Bai Y, Wodchis WP | display-authors = 6 | title = The increasing burden and complexity of multimorbidity | journal = BMC Public Health | volume = 15 | issue = | pages = 415 | date = April 2015 | pmid = 25903064 | pmc = 4415224 | doi = 10.1186/s12889-015-1733-2 | doi-access = free }}{{cite journal | vauthors = Uijen AA, van de Lisdonk EH | title = Multimorbidity in primary care: prevalence and trend over the last 20 years | journal = The European Journal of General Practice | volume = 14 | issue = sup1 | pages = 28–32 | date = 2008 | pmid = 18949641 | doi = 10.1080/13814780802436093 | s2cid = 34601052 | doi-access = free | hdl = 11250/2487933 | hdl-access = free }} The high prevalence of multimorbidity has led to some describing it as "The most common chronic condition".{{cite journal | vauthors = Tinetti ME, Fried TR, Boyd CM | title = Designing health care for the most common chronic condition--multimorbidity | journal = JAMA | volume = 307 | issue = 23 | pages = 2493–2494 | date = June 2012 | pmid = 22797447 | pmc = 4083627 | doi = 10.1001/jama.2012.5265 }} Multimorbidity is also more common among people from lower socioeconomic statuses.{{cite journal | vauthors = Barnett K, Mercer SW, Norbury M, Watt G, Wyke S, Guthrie B | title = Epidemiology of multimorbidity and implications for health care, research, and medical education: a cross-sectional study | journal = Lancet | volume = 380 | issue = 9836 | pages = 37–43 | date = July 2012 | pmid = 22579043 | doi = 10.1016/S0140-6736(12)60240-2 | s2cid = 8212325 | doi-access = free }}{{cite journal | vauthors = Pathirana TI, Jackson CA | title = Socioeconomic status and multimorbidity: a systematic review and meta-analysis | journal = Australian and New Zealand Journal of Public Health | volume = 42 | issue = 2 | pages = 186–194 | date = April 2018 | pmid = 29442409 | doi = 10.1111/1753-6405.12762 | s2cid = 4754463 | doi-access = free | hdl = 10072/384397 | hdl-access = free }} Multimorbidity is a significant issue in low‐ and middle‐income countries, although prevalence is not as high as in high income countries.{{cite journal | vauthors = Afshar S, Roderick PJ, Kowal P, Dimitrov BD, Hill AG | title = Multimorbidity and the inequalities of global ageing: a cross-sectional study of 28 countries using the World Health Surveys | journal = BMC Public Health | volume = 15 | issue = | pages = 776 | date = August 2015 | pmid = 26268536 | pmc = 4534141 | doi = 10.1186/s12889-015-2008-7 | doi-access = free }}

File:Number of conditions ever recorded per individual (from 308 health conditions), stratified by age, sex, and ethnicity.jpg

File:Comparison of comorbidities for primary breast cancer by ethnicity (A), and asthma by sex (B).jpg

{{Excerpt|Global health|Multimorbidity, age-related diseases and aging}}

The likelihood of having multiple long-term conditions is increased by socioeconomic inequalities. Certain groups of disadvantaged or discriminated people are more likely to struggle with earlier and more severe multimorbidity.{{Cite report |url=https://evidence.nihr.ac.uk/collection/multiple-long-term-conditions-multimorbidity-and-inequality-addressing-the-challenge-insights-from-research/ |title=Multiple long-term conditions (multimorbidity) and inequality- addressing the challenge: insights from research |date=2023-09-20 |publisher=National Institute for Health Research |doi=10.3310/nihrevidence_59977 |language=en|url-access=subscription }} Multimorbidity is also associated with factors that are related to socioeconomic disadvantage such as food insecurity,{{Cite journal |last1=Kantilafti |first1=Maria |last2=Giannakou |first2=Konstantinos |last3=Chrysostomou |first3=Stavri |date=2023-07-06 |editor-last=Alahdab |editor-first=Fares |title=Multimorbidity and food insecurity in adults: A systematic review and meta-analysis |journal=PLOS ONE |language=en |volume=18 |issue=7 |pages=e0288063 |doi=10.1371/journal.pone.0288063 |issn=1932-6203 |pmc=10325088 |pmid=37410753 |bibcode=2023PLoSO..1888063K |doi-access=free }} low level of education, living in deprived areas and having unhealthy lifestyles.{{Cite journal |last1=Álvarez-Gálvez |first1=Javier |last2=Ortega-Martín |first2=Esther |last3=Carretero-Bravo |first3=Jesús |last4=Pérez-Muñoz |first4=Celia |last5=Suárez-Lledó |first5=Víctor |last6=Ramos-Fiol |first6=Begoña |date=2023-03-27 |title=Social determinants of multimorbidity patterns: A systematic review |journal=Frontiers in Public Health |volume=11 |doi=10.3389/fpubh.2023.1081518 |issn=2296-2565 |pmc=10084932 |pmid=37050950 |doi-access=free |bibcode=2023FrPH...1181518A }}

There are multiple theories on how socioeconomic inequality leads to multimorbidity but so far there is a lack of scientific evidence about the exact mechanism. Some of the potential links between the two are health-related behaviours (smoking, drinking, diet), lack of access to financial resources and housing, and the psychological response to living in difficult circumstances. Knowing the exact pathway would allow designing effective interventions that prevent or mitigate inequalities in multimorbidity.{{Cite journal |last1=Fleitas Alfonzo |first1=Ludmila |last2=King |first2=Tania |last3=You |first3=Emily |last4=Contreras-Suarez |first4=Diana |last5=Zulkelfi |first5=Syafiqah |last6=Singh |first6=Ankur |date=23 February 2022 |title=Theoretical explanations for socioeconomic inequalities in multimorbidity: a scoping review |journal=BMJ Open |language=en |volume=12 |issue=2 |pages=e055264 |doi=10.1136/bmjopen-2021-055264 |issn=2044-6055 |pmc=8882654 |pmid=35197348}}

{{see also|Diseases of poverty}}

Living in poverty or deprived areas is associated with higher rates of multimorbidity.{{Cite journal |last1=Pathirana |first1=Thanya I. |last2=Jackson |first2=Caroline A. |date=14 February 2018 |title=Socioeconomic status and multimorbidity: a systematic review and meta-analysis |journal=Australian and New Zealand Journal of Public Health |language=en |volume=42 |issue=2 |pages=186–194 |doi=10.1111/1753-6405.12762 |pmid=29442409 |s2cid=4754463|doi-access=free |hdl=10072/384397 |hdl-access=free }} Those with the lowest income have a 4 times higher chance of having multiple long-term conditions than those with the highest income.{{Cite journal |last1=Ingram |first1=Elizabeth |last2=Ledden |first2=Sarah |last3=Beardon |first3=Sarah |last4=Gomes |first4=Manuel |last5=Hogarth |first5=Sue |last6=McDonald |first6=Helen |last7=Osborn |first7=David P. |last8=Sheringham |first8=Jessica |date=2021-03-01 |title=Household and area-level social determinants of multimorbidity: a systematic review |url=https://jech.bmj.com/content/75/3/232 |journal=J Epidemiol Community Health |language=en |volume=75 |issue=3 |pages=232–241 |doi=10.1136/jech-2020-214691 |issn=0143-005X |pmc=7892392 |pmid=33158940}} Self-management is vital in coping with multimorbidity but people living in deprivation struggle more with managing their conditions. Self-management becomes more challenging due to financial barriers, health literacy (difficulties with understanding health information) and the combined weight of multimorbidity and deprivation.{{Cite journal |last1=Woodward |first1=Abi |last2=Davies |first2=Nathan |last3=Walters |first3=Kate |last4=Nimmons |first4=Danielle |last5=Stevenson |first5=Fiona |last6=Protheroe |first6=Joanne |last7=Chew-Graham |first7=Carolyn A. |last8=Armstrong |first8=Megan |date=2023-02-21 |editor-last=Sagtani |editor-first=Reshu Agrawal |title=Self-management of multiple long-term conditions: A systematic review of the barriers and facilitators amongst people experiencing socioeconomic deprivation |journal=PLOS ONE |language=en |volume=18 |issue=2 |pages=e0282036 |doi=10.1371/journal.pone.0282036 |issn=1932-6203 |pmc=9942951 |pmid=36809286 |bibcode=2023PLoSO..1882036W |doi-access=free }}

Research shows that in Scotland residents of deprived areas are affected by multiple long-term conditions 10 to 15 years earlier than people living in affluent neighborhoods. They also have a higher chance that their long-term conditions include mental health disorders.{{Cite journal |last1=Barnett |first1=Karen |last2=Mercer |first2=Stewart W |last3=Norbury |first3=Michael |last4=Watt |first4=Graham |last5=Wyke |first5=Sally |last6=Guthrie |first6=Bruce |date=10 May 2012 |title=Epidemiology of multimorbidity and implications for health care, research, and medical education: a cross-sectional study |journal=The Lancet |language=en |volume=380 |issue=9836 |pages=37–43 |doi=10.1016/S0140-6736(12)60240-2 |pmid=22579043|doi-access=free }} In England, according to research, people from deprived neighborhoods had complex multimorbidity (3 or more conditions) 7 years earlier than the least deprived.{{Cite journal |last1=Head |first1=Anna |last2=Fleming |first2=Kate |last3=Kypridemos |first3=Chris |last4=Schofield |first4=Pieta |last5=Pearson-Stuttard |first5=Jonathan |last6=O'Flaherty |first6=Martin |date=21 July 2021 |title=Inequalities in incident and prevalent multimorbidity in England, 2004–19: a population-based, descriptive study |journal=The Lancet Healthy Longevity |language=en |volume=2 |issue=8 |pages=e489–e497 |doi=10.1016/S2666-7568(21)00146-X |pmid=36097998 |s2cid=237719820|doi-access=free }} People living in deprived areas also have a higher risk of dying because of multimorbidity.{{Cite journal |last1=Charlton |first1=Judith |last2=Rudisill |first2=Caroline |last3=Bhattarai |first3=Nawaraj |last4=Gulliford |first4=Martin |date=October 2013 |title=Impact of deprivation on occurrence, outcomes and health care costs of people with multiple morbidity |journal=Journal of Health Services Research & Policy |language=en |volume=18 |issue=4 |pages=215–223 |doi=10.1177/1355819613493772 |issn=1355-8196 |pmc=3808175 |pmid=23945679}}

Ethnic inequalities also affect who acquires multimorbidity.{{Cite journal |last1=Hayanga |first1=Brenda |last2=Stafford |first2=Mai |last3=Bécares |first3=Laia |date=2023-01-27 |title=Ethnic inequalities in multiple long-term health conditions in the United Kingdom: a systematic review and narrative synthesis |journal=BMC Public Health |language=en |volume=23 |issue=1 |page=178 |doi=10.1186/s12889-022-14940-w |issn=1471-2458 |pmc=9879746 |pmid=36703163 |doi-access=free }}{{Cite journal |last1=Verest |first1=Wim J G M |last2=Galenkamp |first2=Henrike |last3=Spek |first3=Bea |last4=Snijder |first4=Marieke B |last5=Stronks |first5=Karien |last6=van Valkengoed |first6=Irene G M |date=2019-08-01 |title=Do ethnic inequalities in multimorbidity reflect ethnic differences in socioeconomic status? The HELIUS study |url=https://academic.oup.com/eurpub/article/29/4/687/5320321 |journal=European Journal of Public Health |language=en |volume=29 |issue=4 |pages=687–693 |doi=10.1093/eurpub/ckz012 |issn=1101-1262 |pmc=6660190 |pmid=30768174}}{{Cite journal |last1=Mathur |first1=Rohini |last2=Hull |first2=Sally A |last3=Badrick |first3=Ellena |last4=Robson |first4=John |date=26 April 2011 |title=Cardiovascular multimorbidity: the effect of ethnicity on prevalence and risk factor management |journal=British Journal of General Practice |language=en |volume=61 |issue=586 |pages=e262–e270 |doi=10.3399/bjgp11X572454 |issn=0960-1643 |pmc=3080231 |pmid=21619750}} In the United Kingdom, Indian, Pakistani, Bangladeshi, Black African, Black Caribbean people and those who identify as Black other, other Asian, and mixed ethnicity have a higher risk of developing multiple long-term conditions. In England, people from Pakistani and Bangladeshi backgrounds have the highest multimorbidity rates and they are twice as likely than people from the Chinese minority to have multimorbidity.{{Cite web |title=Quantifying health inequalities in England |url=https://www.health.org.uk/news-and-comment/charts-and-infographics/quantifying-health-inequalities |access-date=2023-09-28 |website=www.health.org.uk |date=15 August 2022 |language=en}} Pakistani, Black African, Black Caribbean and other black ethnic groups in England are also significantly more likely to die due to having multiple long-term conditions.{{Cite journal |last1=Stafford |first1=Mai |last2=Knight |first2=Hannah |last3=Hughes |first3=Jay |last4=Alarilla |first4=Anne |last5=Mondor |first5=Luke |last6=Pefoyo Kone |first6=Anna |last7=Wodchis |first7=Walter P. |last8=Deeny |first8=Sarah R. |date=2022-04-01 |editor-last=Torén |editor-first=Kjell |title=Associations between multiple long-term conditions and mortality in diverse ethnic groups |journal=PLOS ONE |language=en |volume=17 |issue=4 |pages=e0266418 |doi=10.1371/journal.pone.0266418 |issn=1932-6203 |pmc=8974956 |pmid=35363804 |bibcode=2022PLoSO..1766418S |doi-access=free }}

Belonging to a sexual minority also means being disproportionately affected by multimorbidity, especially mental health conditions.{{Cite journal |last1=Saunders |first1=Catherine L |last2=MacCarthy |first2=Sarah |author-link2=Sarah MacCarthy |last3=Meads |first3=Catherine |last4=Massou |first4=Efthalia |last5=Mant |first5=Jonathan |last6=Saunders |first6=Alison M |last7=Elliott |first7=Marc N |date=October 2021 |title=Long-term conditions among sexual minority adults in England: evidence from a cross-sectional analysis of responses to the English GP Patient Survey |journal=BJGP Open |language=en |volume=5 |issue=5 |pages=BJGPO.2021.0067 |doi=10.3399/BJGPO.2021.0067 |issn=2398-3795 |pmc=8596314 |pmid=34465579}}{{Cite journal |last1=Caceres |first1=Billy A. |last2=Travers |first2=Jasmine |last3=Sharma |first3=Yashika |date=June 2021 |title=Differences in Multimorbidity among Cisgender Sexual Minority and Heterosexual Adults: Investigating Differences across Age-Groups |journal=Journal of Aging and Health |language=en |volume=33 |issue=5–6 |pages=362–376 |doi=10.1177/0898264320983663 |issn=0898-2643 |pmc=8122030 |pmid=33382014}}{{Cite journal |last1=Han |first1=Benjamin H. |last2=Duncan |first2=Dustin T. |last3=Arcila-Mesa |first3=Mauricio |last4=Palamar |first4=Joseph J. |date=4 August 2020 |title=Co-occurring mental illness, drug use, and medical multimorbidity among lesbian, gay, and bisexual middle-aged and older adults in the United States: a nationally representative study |journal=BMC Public Health |language=en |volume=20 |issue=1 |page=1123 |doi=10.1186/s12889-020-09210-6 |issn=1471-2458 |pmc=7401198 |pmid=32746891 |doi-access=free}}

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.{{Cite web |title=Research funders publish framework to tackle multiple long-term conditions |url=https://acmedsci.ac.uk/more/news/research-funders-publish-framework-to-tackle-multiple-long-term-conditions |access-date=2022-06-28 |website=The Academy of Medical Sciences}}{{Cite report |date=June 2020 |title=Cross-funder multimorbidity research framework |url=https://acmedsci.ac.uk/file-download/50613213 |journal= |publisher=The Academy of Medical Sciences}} The NIHR also published its own strategic framework regarding MLTC which aligns with the cross-funder framework.

As rehabilitation usually focuses on a single disease people with multiple long-term conditions are often excluded or not all their conditions are treated during rehabilitation. Researchers are looking for new models of rehabilitation that could be applied to people with multimorbidity.{{cite journal | vauthors = Taylor RS, Singh S | title = Personalised rehabilitation for cardiac and pulmonary patients with multimorbidity: Time for implementation? | journal = European Journal of Preventive Cardiology | volume = 28 | issue = 16 | pages = e19–e23 | date = May 2020 | pmid = 33611479 | doi = 10.1177/2047487320926058 | doi-access = free }}{{cite journal | vauthors = Carlesso LC, Skou ST, Tang LH, Simonÿ C, Brooks D | title = Multimorbidity: Making the Case for an End to Disease-Specific Rehabilitation | journal = Physiotherapy Canada. Physiotherapie Canada | volume = 72 | issue = 1 | pages = 1–3 | date = February 2020 | pmid = 34385742 | doi = 10.3138/ptc-72-1-gee | pmc = 8330980 | s2cid = 214155787 }} For example the PERFORM (Personalised Exercise-Rehabilitation For people with Multiple long-term conditions) research group in the UK is developing and evaluating an exercise-based rehabilitation intervention that can be personalised for people with multiple long-term conditions.{{Cite web |title=The PERFORM trial |url=https://le.ac.uk/perform/about |access-date=2023-02-05 |website=University of Leicester |language=en}} The MOBILIZE group in Denmark are currently undertaking a randomised controlled trial of a rehabilitation intervention for people with multimorbidity co-developed with people with long-term conditions and clinicians.{{cite journal | vauthors = Bricca A, Jäger M, Dideriksen M, Rasmussen H, Nyberg M, Pedersen JR, Zangger G, Andreasson KH, Skou ST | display-authors = 6 | title = Personalised exercise therapy and self-management support for people with multimorbidity: Development of the MOBILIZE intervention | journal = Pilot and Feasibility Studies | volume = 8 | issue = 1 | pages = 244 | date = December 2022 | pmid = 36461048 | pmc = 9717541 | doi = 10.1186/s40814-022-01204-y | doi-access = free }}

{{Reflist}}

{{Medical resources}}

• Multimorbidity in Nature Reviews Disease Primers.

{{Public health}}

{{Authority control}}

Category:Diseases and disorders

Category:Public health

Category:Epidemiology