Are We Ready for Multimorbidity?

Keywords::

• evidence-based practice
• multimorbidity
• outcomes
• patient-centered care
• shared decision-making

The aging of the population has made medical care much more complicated. Not only do older individuals suffer from chronic diseases, they often have multiple diseases [1,2,101]. Multimorbidity, in turn, is linked to frailty [3,4]. Together this makes it hard to operationalize the key concepts of evidence-based practice and patient-centered care.

Evidence is generally weak for most care questions and is virtually nonexistent for circumstances when a patient suffers from several problems simultaneously. Applying clinical guidelines for all problems could produce more harm than good [1]. It is simply not known how the presence of one problem affects the effectiveness of treating another, or even worse what happens in the context of multiple comorbidities. Moreover, the same set of comorbidities may result in different benefits and harms for different patients. Each patient represents a unique complex body system and is embedded in a complex system of social and environmental factors. Modeling may help, but new approaches are needed to tackle this complexity [5–8].

Our professional confusion equally extends to the concept of patient-centered care. The phrase is appealing and the meaning is elusive. It has been used to denote shared decision making (SDM), as well as providing a basis for defining meaningful outcomes of care.

From the perspective of SDM, multimorbidity introduces many complications. Patients, and some clinicians, typically have problems dealing even with simple concepts of risk [9,10]. Successfully negotiating the complexity of multimorbidities and the potential trade-offs involved is much less likely.

Another aspect of SDM is deciding what outcomes are most important and for whom. Multimorbidity and associated frailty encourage us to pay closer attention to the bigger issues of functioning and quality of life. In the context of these conditions, the marginal effects of specific treatments are limited and more attention must be paid to how they affect the overall life and well-being of the patient. This is not comfortable ground for many clinicians who are used to celebrating HbA1c levels and blood pressure control.

How do we value such soft outcomes as quality of life? Economists like to use utilities, some expression of an average value or importance placed on a state. But whose values count? Typically, utility weighters collect data on a sample of the general population, most of whom have never experienced the outcome of interest. Research has demonstrated that people tend to undervalue states of disability and hence may be unduly risk averse [11]. Even when they are dealing with known situations, they may not truly understand or articulate their real preferences. People report preferences that are contrary to their actual behaviors [10].

Is the idea of an average value meaningful? Utility weight distributions derived from sample populations are generally relatively flat and widely dispersed (covering the full range from 0 to 1) around the mathematical average (for an example, see [12]). If we accept the premise that measured weights and stated preferences are valid, the preferences of the large majority of people are not being met in order to satisfy a mathematical average used as a proxy for a population-level value.

How do we balance patient-centered decisions based on individual preferences with responsible use of societal resources? Using societal norms makes sense when public funds are available and allows more general analyses of benefits and harms; however, many patients may not agree with these norms. Do we want a tyranny of the majority [13]? Are we prepared to customize care to suit individual preferences? One compromise may lie in using societal norms to define the upper and lower bounds of what is politically and socially acceptable, but then allowing individual preferences to be exercised within those constraints. However, such a solution will be a challenging process to operationalize.

Decades ago, only a small band of geriatricians worried about such issues. Ironically, it seems that geriatrics is headed for extinction just when it is needed most. Years ago there was a debate over strategy. Should we train a limited number of geriatric specialists or gerontologize the variety of clinicians who come into contact with older patients? Fate seems to have settled that question.

We face a growing horde of patients seeking care with the geriatric paradigm of multiple interactive problems in both the medical (including mental health) and social sectors. They pose serious clinical and political challenges for society. Everyone needs to get involved in finding effective (and affordable) ways to address these challenges. Geriatricians, who have been struggling with these issues for decades, may be well positioned to provide some useful insights if anyone is willing to listen to them.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

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Funding

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.