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 can affect people of any age, but they are more common in older age, affecting more than half of people over 65 years old. [2] [3]
The concept of multiple long-term conditions is not clearly defined [1] [4] [5] and may be referred to by various names. [6]
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]
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]
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]
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]
One risk factor of multimorbidity in young people is being born premature. [13] [14] 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] [15]
Lower socioeconomic status, measured by a combination of education, occupation and literacy indicators, seems to increase the risk of developing multimorbidity. [16] 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. [16] 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. [17] 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. [16]
Multimorbidity is associated with reduced quality of life [18] and increased risk of death. [19] The risk of death is positively associated with individuals with greater number of chronic conditions and reversely associated with socioeconomic status. [19] 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. [16]
In some cases, specific combinations of diseases are associated with higher mortality. [20] For example, people with long-term conditions affecting the heart, lung, and urinary systems have strong effects on mortality. [20]
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. [21]
Due to the higher prevalence of multimorbidity (55 - 98%), [2] a new concept of "complex multimorbidity (CMM)" has been proposed [22] 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. [23] [24] [25]
Physical and mental health conditions can adversely impact the other through a number of pathways, and have significant impact on health and wellbeing. [26] For people whose long-term conditions include severe mental illness, the lifespan can be 10–20 years less than the general population. [27] For them, addressing the underlying risk factors for physical health problems is critical to good outcomes. [26]
There is considerable evidence that having multiple long-term physical conditions can lead to the development of both depression and anxiety. [28] There are many factors which might explain why physical multi-morbidity affects mental health including chronic pain, [29] frailty, [30] [31] symptom burden, [32] functional impairment, [33] reduced quality of life, [18] increased levels of inflammation, [34] and polypharmacy. [35] 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. [36] [37] 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. [38] However, such evaluations are currently lacking in low-income and middle-income countries.[ citation needed ]
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. [39]
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. [40] 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, [41] increases in their time spent managing illness, [42] difficulty managing multiple illness management regimes, [43] and aggravation of one condition by symptoms or treatment of another. [44]
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]
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. [45] [46] For example, the burden, on the family carer, may increase if the older person is suffering from confusion or dementia. [47] 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. [48] [45]
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. [49] [50]
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]
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. [52] [53] [54] The high prevalence of multimorbidity has led to some describing it as "The most common chronic condition". [55] Multimorbidity is also more common among people from lower socioeconomic statuses. [2] [56] [57] Multimorbidity is a significant issue in low‐ and middle‐income countries, although prevalence is not as high as in high income countries. [58]
Multimorbidity is "a growing public health problem worldwide", "likely driven by the ageing population but also by factors such as high body-mass index, urbanisation, and the growing burden of NCDs (such as type 2 diabetes) and tuberculosis in low- and middle-income countries (LMICs)". [59] [60] [61] Around the world, many people do not die from one isolated condition but from a multitude of factors and conditions. A study suggested there is a paucity of multimorbidity and comorbidity data globally and mapped comorbidity patterns. [62]
With aging populations, there is a rise of age-related diseases which puts major burdens on healthcare systems as well as contemporary economies or contemporary economics and their appendant societal systems. Healthspan extension and anti-aging research seek to extend the span of health in the old as well as slow aging or its negative impacts such as physical and mental decline. Modern anti-senescent and regenerative technology with augmented decision making could help "responsibly bridge the healthspan-lifespan gap for a future of equitable global wellbeing". [63] Aging is "the most prevalent risk factor for chronic disease, frailty and disability, and it is estimated that there will be over 2 billion persons age > 60 by the year 2050", making it a large global health challenge that demands substantial (and well-orchestrated or efficient) efforts, including interventions that alter and target the inborn aging process. [64]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. [65] Multimorbidity is also associated with factors that are related to socioeconomic disadvantage such as food insecurity, [66] low level of education, living in deprived areas and having unhealthy lifestyles. [67]
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. [65] [68]
Living in poverty or deprived areas is associated with higher rates of multimorbidity. [65] [69] Those with the lowest income have a 4 times higher chance of having multiple long-term conditions than those with the highest income. [70] 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. [71]
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. [72] In England, according to research, people from deprived neighborhoods had complex multimorbidity (3 or more conditions) 7 years earlier than the least deprived. [73] People living in deprived areas also have a higher risk of dying because of multimorbidity. [74]
Ethnic inequalities also affect who acquires multimorbidity. [75] [76] [77] 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. [65] [78] 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. [79]
Belonging to a sexual minority also means being disproportionately affected by multimorbidity, especially mental health conditions. [80] [81] [82]
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. [83] [84] The NIHR also published its own strategic framework regarding MLTC which aligns with the cross-funder framework. [12]
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. [85] [86] 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. [87] 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. [88]
Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Introduced by a group of US clinicians in the mid-1970s, the term was adopted by the American Psychiatric Association for this symptom cluster under mood disorders in the 1980 version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), and has become widely used since. The disorder causes the second-most years lived with disability, after lower back pain.
Chronic pain or chronic pain syndrome is a type of pain that is also known by other titles such as gradual burning pain, electrical pain, throbbing pain, and nauseating pain. This type of pain is sometimes confused with acute pain and can last from three months to several years; Various diagnostic manuals such as DSM-5 and ICD-11 have proposed several definitions of chronic pain, but the accepted definition is that it is "pain that lasts longer than the expected period of recovery."
Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased crying, and poor sleep. Decreased eating and a fever may also be present. The other main type is otitis media with effusion (OME), typically not associated with symptoms, although occasionally a feeling of fullness is described; it is defined as the presence of non-infectious fluid in the middle ear which may persist for weeks or months often after an episode of acute otitis media. Chronic suppurative otitis media (CSOM) is middle ear inflammation that results in a perforated tympanic membrane with discharge from the ear for more than six weeks. It may be a complication of acute otitis media. Pain is rarely present. All three types of otitis media may be associated with hearing loss. If children with hearing loss due to OME do not learn sign language, it may affect their ability to learn.
In medicine, comorbidity refers to the simultaneous presence of two or more medical conditions in a patient; often co-occurring with a primary condition. It originates from the Latin term morbus prefixed with co- ("together") and suffixed with -ity. Comorbidity includes all additional ailments a patient may experience alongside their primary diagnosis, which can be either physiological or psychological in nature. In the context of mental health, comorbidity frequently refers to the concurrent existence of mental disorders, for example, the co-occurrence of depressive and anxiety disorders. The concept of multimorbidity is related to comorbidity but is different in its definition and approach, focusing on the presence of multiple diseases or conditions in a patient without the need to specify one as primary.
Cardiovascular disease (CVD) is any disease involving the heart or blood vessels. CVDs constitute a class of diseases that includes: coronary artery diseases, heart failure, hypertensive heart disease, rheumatic heart disease, cardiomyopathy, arrhythmia, congenital heart disease, valvular heart disease, carditis, aortic aneurysms, peripheral artery disease, thromboembolic disease, and venous thrombosis.
Polypharmacy (polypragmasia) is an umbrella term to describe the simultaneous use of multiple medicines by a patient for their conditions. The term polypharmacy is often defined as regularly taking five or more medicines but there is no standard definition and the term has also been used in the context of when a person is prescribed 2 or more medications at the same time. Polypharmacy may be the consequence of having multiple long-term conditions, also known as multimorbidity and is more common in people who are older. In some cases, an excessive number of medications at the same time is worrisome, especially for people who are older with many chronic health conditions, because this increases the risk of an adverse event in that population. In many cases, polypharmacy cannot be avoided, but 'appropriate polypharmacy' practices are encouraged to decrease the risk of adverse effects. Appropriate polypharmacy is defined as the practice of prescribing for a person who has multiple conditions or complex health needs by ensuring that medications prescribed are optimized and follow 'best evidence' practices.
Global health is the health of the populations in the worldwide context; it has been defined as "the area of study, research, and practice that places a priority on improving health and achieving equity in health for all people worldwide". Problems that transcend national borders or have a global political and economic impact are often emphasized. Thus, global health is about worldwide health improvement, reduction of disparities, and protection against global threats that disregard national borders, including the most common causes of human death and years of life lost from a global perspective.
A chronic condition is a health condition or disease that is persistent or otherwise long-lasting in its effects or a disease that comes with time. The term chronic is often applied when the course of the disease lasts for more than three months. Common chronic diseases include diabetes, functional gastrointestinal disorder, eczema, arthritis, asthma, chronic obstructive pulmonary disease, autoimmune diseases, genetic disorders and some viral diseases such as hepatitis C and acquired immunodeficiency syndrome. An illness which is lifelong because it ends in death is a terminal illness. It is possible and not unexpected for an illness to change in definition from terminal to chronic. Diabetes and HIV for example were once terminal yet are now considered chronic due to the availability of insulin for diabetics and daily drug treatment for individuals with HIV which allow these individuals to live while managing symptoms.
Allostatic load is "the wear and tear on the body" which accumulates as an individual is exposed to repeated or chronic stress. The term was coined by Bruce McEwen and Eliot Stellar in 1993. It represents the physiological consequences of chronic exposure to fluctuating or heightened neural or neuroendocrine response which results from repeated or prolonged chronic stress.
Chronic care management encompasses the oversight and education activities conducted by health care professionals to help patients with chronic diseases and health conditions such as diabetes, high blood pressure, systemic lupus erythematosus, multiple sclerosis, and sleep apnea learn to understand their condition and live successfully with it. This term is equivalent to disease management for chronic conditions. The work involves motivating patients to persist in necessary therapies and interventions and helping them to achieve an ongoing, reasonable quality of life.
Obesity is a risk factor for many chronic physical and mental illnesses.
A doctor's visit, also known as a physician office visit or a consultation, or a ward round in an inpatient care context, is a meeting between a patient with a physician to get health advice or treatment plan for a symptom or condition, most often at a professional health facility such as a doctor's office, clinic or hospital. According to a survey in the United States, a physician typically sees between 50 and 100 patients per week, but it may vary with medical specialty, but differs only little by community size such as metropolitan versus rural areas.
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious long-term illness. People with ME/CFS experience a profound fatigue that does not go away with rest, sleep issues and problems with memory or concentration. They are able to do much less than before they became ill. Further common symptoms include dizziness, nausea and pain. The hallmark symptom is a worsening of the illness which starts hours to days after minor physical or mental activity. This "crash" can last less than a day to several months.
Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. GOLD 2024 defined COPD as a heterogeneous lung condition characterized by chronic respiratory symptoms due to abnormalities of the airways and/or alveoli (emphysema) that cause persistent, often progressive, airflow obstruction.
Childhood chronic illness refers to conditions in pediatric patients that are usually prolonged in duration, do not resolve on their own, and are associated with impairment or disability. The duration required for an illness to be defined as chronic is generally greater than 12 months, but this can vary, and some organizations define it by limitation of function rather than a length of time. Regardless of the exact length of duration, these types of conditions are different than acute, or short-lived, illnesses which resolve or can be cured. There are many definitions for what counts as a chronic condition. However, children with chronic illnesses will typically experience at least one of the following: limitation of functions relative to their age, disfigurement, dependency on medical technologies or medications, increased medical attention, and a need for modified educational arrangements.
Deprescribing is a process of tapering or stopping medications to achieve improved health outcomes by reducing exposure to medications that are potentially either harmful or no longer required. Deprescribing is important to consider with changing health and care goals over time, as well as polypharmacy and adverse effects. Deprescribing can improve adherence, cost, and health outcomes but may have adverse drug withdrawal effects. More specifically, deprescribing is the planned and supervised process of intentionally stopping a medication or reducing its dose to improve the person's health or reduce the risk of adverse side effects. Deprescribing is usually done because the drug may be causing harm, may no longer be helping the patient, or may be inappropriate for the individual patient's current situation. Deprescribing can help correct polypharmacy and prescription cascade.
The taxonomy of the burden of treatment is a visualization created for health care professionals to better comprehend the obstacles that interfere with a patient's health care plan. It was created as a result of a worldwide, qualitative-based study that asked adults with chronic conditions to list the personal, environmental, and financial barriers that burden a patient. The purpose of this visualization is to help health care providers develop personalized management strategies that the patient can follow through a narrative paradigm. The goal is to target interventions, achieve an interpersonal doctor-patient relationship, and improve health outcomes.
Long COVID or long-haul COVID is a group of health problems persisting or developing after an initial period of COVID-19 infection. Symptoms can last weeks, months or years and are often debilitating. The World Health Organization defines long COVID as starting three months after the initial COVID-19 infection, but other agencies define it as starting at four weeks after the initial infection.
In medicine, the Charlson Comorbidity Index (CCI) predicts the mortality for a patient who may have a range of concurrent conditions (comorbidities), such as heart disease, AIDS, or cancer. A score of zero means that no comorbidities were found; the higher the score, the higher the predicted mortality rate is. For a physician, this score is helpful in deciding how aggressively to treat a condition.