With ageing come many benefits, including freedom, wisdom, perspective, and – in many cultures – respect. Unfortunately, the downside is that ageing also brings medical ailments. Many people in wealthy countries have multiple co-existing, chronic conditions. This is known as multimorbidity. In 2016, chronic conditions accounted for over two-thirds of deaths worldwide. Many of these people had more than one condition.
The number of medical conditions that people accrue increases with age. The concept of multimorbidity is well known to healthcare providers in high-income countries where there are large numbers of older people. In poorer parts of the world, such as sub-Saharan Africa, populations are younger. The focus of healthcare has been on diseases affecting these younger populations such as infectious diseases and maternal and child ill-health.
But the world is changing. The number of older people in lower income countries is growing. These countries’ health systems are not designed to care for people with chronic conditions. They are more focused on single, acute diseases. This may need to change towards more individual-based health care for chronic conditions. This is why it’s important to establish if multimorbidity is also an issue in lower income countries.
Our work shows that the impact of multimorbidity on individuals living in lower income countries is substantial. This should inform the planning of health system development which will need different medical skills, facilities, policies and resources to care for individuals with multiple chronic conditions in addition to acute single conditions.
Multimorbidity in low-income countries
Previous investments into health challenges in lower income countries are paying off. Fewer women are dying in childbirth, more children are reaching adulthood, and people are living long lives with HIV.
These healthcare successes have conspired positively with increasing country wealth and change in lifestyle and diets to result in life expectancy increasing worldwide, especially in the lower income countries. In fact, by 2050 most of the elderly population will be living in developing countries. But an ageing population means that chronic diseases and multimorbidity will increase.
Multimorbidity in lower income countries has so far been given little attention by researchers. Most research and development funding still goes to infectious diseases and those that predominantly affect mothers and young children.
We recently did a study in Burkina Faso, one of the poorest countries in the world. We found that 20% of people over 40 years of age had multimorbidity – one or more infectious, non-infectious, or mental health conditions.
We also found that the chance of having multiple conditions increased with age, being female, or being unmarried. This is in line with other studies which have shown that increasing age is a risk factor for multimorbidity. People over 60 or 65 years are particularly vulnerable. In addition, research suggests that the combination of mental health conditions and physical conditions is more common among women then men. But more research is needed to map the extent of multimorbidity in different population groups. The evidence is especially low in low-income countries.
In our study, multimorbidity was more common among people with higher socioeconomic status (education and wealth). This differs from what is usually seen in high-income countries, where it is more common among poorer or less educated people. It may be that in lower income countries people who are wealthier can afford the unhealthy lifestyles that lead to multimorbidity.
More troubling, we found that multimorbidity is associated with increased disability, low quality of life, and poor physical performance in Burkina Faso. These are all outcomes that are very important to older people, as they capture health in a broader sense than just assessing medical conditions. We also found that the combination of non-communicable diseases and mental health conditions is particularly negative.
If we found these results in such a poor country, it is highly likely that multimorbidity is a major problem for older people in all parts of the world.
The double burden of disease and the health system
Large improvements have been made in tackling infectious diseases and those that affect younger people. But lower income countries are still struggling with these conditions, in addition to an increasing burden of chronic diseases and multimorbidity. This double burden of disease is overwhelming the health services. This is especially pertinent, given that health services in many developing countries are organised only to handle single conditions, and not to care for patients with multiple chronic conditions.
There’s a lack of health service factors – for example, follow-up systems and availability of doctors or nurses – needed to take care of patients with multimorbidity. There are also patient-side barriers to care – for example, the understanding of chronic conditions and their treatment. These factors culminate in other unpublished findings from our study that fewer than 10% of the people with the chronic conditions of hypertension or diabetes had their conditions adequately managed.
The prevalence of multimorbidity, the fact that conditions are not being adequately treated, and the association with outcomes that matter to patients (quality of life, physical function, and disability) mean that without rapid development of adequate health services to prevent and manage it, multimorbidity will be especially devastating in these settings.
The way forward
Our research from Burkina Faso adds to a growing body of evidence that highlights multimorbidity as a global health issue of major significance. Investments are needed by researchers, development agencies and national governments to prioritise understanding of this emerging global epidemic. The aim is to prevent the increasing burden that multimorbidity could put on health systems, individuals, families and societies worldwide in the years to come.
Justine Ina Davies, Professor of Global Health, Institute for Applied Research, University of Birmingham
Maria Odland, Research Fellow Global Health, University of Birmingham