Almost one in four of us has two or more health conditions. With each additional disease, morbidity, mortality and poly pharmacy increases. Some think multiple health problems can be cured by minimizing the uncoordinated care that comes with trying to deal with a number of health problems sequentially and that the focus should be on the whole patient and not on the individual health problems. Patients should be involved in discussions about treatment options, the benefits and harms of each therapy, and patients and their families’ preferences to achieve a workable outcome.

Shared decision making has become the simplistic solution to a complex problem.

It is a noble objective, which has now turned into a new industry for the instrument makers. There is a plethora of patient decision aids now under evaluation. Typically, they contain summarised information, based on available evidence, on the options, the benefits and harms, and sometimes questions that prompt patients to think about preferences and values.

Whilst initially they look good, they may be no more than a simplistic solution in an increasingly complex health care world. They are fraught with problems. A recent review of more than 50 shared decision-making instruments found that more than half, whilst technically sound, failed to produce consistent results, including effective decisions between clinicians and patients.

Secondly, they are usually designed around guidelines that have been developed for one particular condition and where concomitant conditions have already been deprioritised by the instrument or by clinicians. They are not designed for people with multi morbidity.

Thirdly, consider decision-making about multiple medical conditions from the patients’ point of view. They are already anxious about interacting with health care professionals and unsure about what to do. Shared decision making may mean that patients with little or no medical knowledge are not even given a reasoned recommendation from their doctors.

Unfortunately, adequate treatment of well described constellations of conditions is in the minority. Most care of coexistent morbidity is difficult, especially when sequencing and severity is unknown or waxes and wanes. For example, what comes first – obesity or osteoarthritis of the knees? Do patients get fat because it is too painful to walk/exercise or does the excess weight cause the knee joints to disintegrate. What should be dealt with first and as a priority? Painkillers or diet? When should these priorities change?  Even more difficult is making these decisions in real time where no link can be made between coexisting diseases, such as with multiple sclerosis and diabetes.

Competing disease priorities that are subject to flux require difficult decisions about priorities and even tolerance of less than optimal outcomes. Clinicians are still grappling with these issues. It is important that this burden is not added to patients.