About 70% of all NHS expenditure goes on the treatment and care of people with long-term conditions (LTCs) such as diabetes, asthma, arthritis, dementia and chronic cardiovascular disease (Department of Health 2010). More than 15 million people in England have one or more such conditions (Department of Health 2011) and multi-morbidity, i.e. the co-existence of two or health problems at the same time, is very common, particularly among older people. For example, multi-morbidity has an estimated prevalence of 60% among all people aged 55 to 74 (Fortin et al. 2005), rising to 83% among those aged 75+, including 58% with three or more conditions at the same time and 33% with four or more (Britt et al. 2008).
It is thus no exaggeration to say that multi-morbidity is the rule rather than the exception among people with poor health, but despite this the problem is given relatively little attention, whether in policy and service design or in published research. For example, it has been estimated that for every one article in the medical literature on multi-morbidity, there are 74 on asthma, 94 on hypertension and 38 on diabetes (Fortin et al. 2005).
The most common form of multi-morbidity is the co-existence of mental and physical ill health. Research evidence consistently shows that people with long-term physical conditions are two to three times more likely than the general population to experience mental health problems such as depression or anxiety, and a recent study jointly produced by the King’s Fund, the Centre for the Mental Health and the LSE has conservatively estimated that some 4.6 million people suffer from co-morbid mental and physical health conditions – about 30% of all those with LTCs (Naylor et al. 2012).
The mechanisms underlying the relationship between mental and physical health are complex and lines of causation undoubtedly run in both directions. Notwithstanding this complexity, two things are abundantly clear from the available evidence: co-morbid mental health problems lead to much poorer health outcomes for people with long-term physical conditions and they add significantly to NHS costs. To give a couple of examples of the adverse impact on health outcomes: mortality rates for individuals with co-morbid asthma and depression are twice as high as among people with asthma on its own (Walters et al. 2011); and patients with chronic heart failure are eight times more likely to die within 30 months if they also have depression (Junger et al. 2005).
Concerning the impact on NHS costs, evidence reviewed in the joint study mentioned above found that co-morbid mental health problems are typically associated with increases of 45-75% in the costs of physical health care for long-term conditions (Naylor et al. 2012). Increases of this order are observed across a wide range of LTCs and are based on costs measured after adjustment for the severity of physical disease. Much of the excess is associated with higher rates of acute hospital bed use.
Taking a mid-point of 60% for this cost mark-up, it may be estimated that at the aggregate level mental health co-morbidities cost the health service around £10.6 billion a year in additional spending on physical health care, or 10% of the total NHS budget. At the individual patient level, average cost per case is about £6,170 a year for a patient with a long-term physical condition and co-morbid mental health problem, compared with £3,855 a year for someone with a long-term physical condition on its own – a difference of £2,315 a year.
Much of this huge excess cost could be avoided by better management of the mental health needs of people with long-term physical conditions. Two key requirements are:
- First, better identification of co-morbid mental health problems. At present the great majority of cases of depression and anxiety among people with physical illnesses go untreated for the simple reason that they are not detected. One reason for this is that both patients and practitioners tend to focus on physical symptoms during consultations (“diagnostic overshadowing”). Even in acute hospital settings, most mental health problems go undetected, particularly in older patients.
- Second, greater availability of evidence-based interventions for mental health problems, such as cognitive behavioural therapy (CBT), and the integration of these interventions within chronic disease management frameworks or rehabilitation programmes designed to support people in managing their physical condition. As an example of current provision, only 42% of cardiac patients are provided with rehabilitation and only 16% of these programmes have a psychological component, even though about half of all these patients suffer from anxiety or depression (British Heart Foundation 2011).
To attempt a very rough estimate of the overall scope for cost savings, a meta-analysis has found that psychological interventions for patients with physical conditions being treated in acute hospitals and other settings reduce health care costs per patient by about 20% on average (Chiles et al. 1999). As noted above, the average cost of care for a patient with co-morbid mental and physical illness is currently about £6,170 a year. A reduction of 20% in this cost thus implies an annual saving of £1,235 per patient, or – if applied to all 4.6 million patients with co-existing mental and physical health problems – a total potential saving of some £5.7 billion a year.
A separation of mental and physical health is hard-wired into the NHS as presently constituted. The evidence briefly reviewed above demonstrates that one consequence of this separation – namely, a common failure to identify and address mental health problems among people with long-term physical conditions – is not only leading to poorer clinical outcomes and lower quality of life but is also imposing a very large burden on the NHS in avoidable healthcare costs. Improved integration of services offers the prospect of better health at lower cost on a significant scale.