Defining and measuring complex multimorbidity: a critical analysis

In their timely critical analysis of “complex multimorbidity” Pati et al.¹ highlight that multimorbidity is the norm rather than the exception in care. Moving beyond single-disease-based treatments is therefore vital. However, they question the value of measuring "complex multimorbidity" for clinical practice as definitions encompass varied phenomena and patient experiences.

We concur with the concerns expressed by Pati et al. and would go even further in questioning the value of current efforts in quantifying multimorbidity. Insights into the needs of patients are hard to quantify, and often ultimately a matter best judged in the specifics of each clinical encounter. Targeting efforts and resources towards managing multimorbidity through seeking more precise definitions and metrics may miss the mark.

The conceptual value of multimorbidity resides precisely in its capacity to prompt a shift beyond single-disease based understandings of illness. The ‘problem’ of multimorbidity emerges specifically in a context of care systems which have, over the past century, become increasingly specialized, standardised, and incentivised around single-disease-based approaches. This leads to high treatment burdens and polypharmacy for patients with multimorbidity. Multimorbidity requires a generalist understanding of illness, recognition of the role of social adversity and the treatment of illness as a unified experience.

We propose a novel understanding of multimorbidity. Instead of focusing on measuring and defining multimorbidity as a problem inside patients’ bodies, we argue it is more fruitful to embrace multimorbidity as a concept that highlights problems in care systems. The key challenge of multimorbidity lies in the increasing difficulties contemporary care systems encounter in coping with complexity^2,3. Multimorbidity is an experience that manifests through the discrepancy between medical policy and life-as-lived, brought to the fore by people’s attempts to bridge fissured care systems⁴.

The difficulties experienced by patients (and arguably clinicians) as they grapple with multimorbidity serve as a motivation to advocate for increased funding for general practice, improved continuity of care, and heightened attention to issues of overtreatment and polypharmacy⁵. We suggest that these steps, more than refined definitions – are what really matter when it comes to improving the care of patients ‘with multimorbidity’.

References

1. Pati S, MacRae C, Henderson D, Weller D, Guthrie B, Mercer S. Defining and measuring complex multimorbidity: a critical analysis. Br J Gen Pract 2023; 73(733):373-6. DOI: https://doi.org/10.3399/bjgp23X734661.
2. Treadwell J. Coping with complexity: working beyond the guidelines for patients with multimorbidities. J Comorb. 2015;5(1):11-4. DOI: https://doi.org/10.15256/joc.2015.5.49.
3. Treadwell J, McCartney M. Overdiagnosis and overtreatment: generalists—it’s time for a grassroots revolution. Br J Gen Pract 2016; 66(644):116-7. DOI: https://doi.org/10.3399/bjgp16X683881.
4. van Blarikom E, Fudge N, Swinglehurst D. The emergence of multimorbidity as a matter of concern: a critical review. Biosocieties 2023; 18:614-631. DOI: https://doi.org/10.1057/s41292-022-00285-5.
5. Swinglehurst D, Fudge N. The polypharmacy challenge: time for a new script? Br J Gen Pract 2017; 67(662):388-9. DOI: https://doi.org/10.3399/bjgp17X692189.