{'fraction_non_alphanumeric': 0.02059266700150678, 'fraction_numerical': 0.0055248618784530384, 'mean_word_length': 5.244514106583072, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The subversive challenges of multimorbidity.

Epidemiology often reveals important insights by applying simple definitions and measurements to large numbers of people so that they can be studied in groups. A common approach is to define multimorbidity as having two or more conditions. A landmark study that used this approach showed multimorbidity increased with age, with an onset 10–15 years earlier in socioeconomically deprived areas.1 In this Scottish population, although prevalence rose with age, the demographic shape of the population determined that most people with multimorbidity were <65 years of age.

Such observations are useful but in clinical practice a definition based on two or more conditions can be of little consequence. The commonest comorbidity in older people is hypertension, so that only one other condition is required to meet the definition of multimorbidity. This case definition offers little new challenge to clinicians or to services.

On the other hand, the commonest comorbidity in deprived areas is a mental health problem,1 whose combination with another condition is likely to complicate the care that patients need and receive.

More demanding case definitions — such as five or more conditions, the combination of a physical and psychological health problem, or three or more chronic conditions from three or more body systems — have smaller prevalences but steeper social gradients, and present a significantly greater clinical challenge.2,3

Even so, many patients with multiple conditions are not ‘complex’, whereas some patients with single conditions are very ‘complex’. Such distinctions draw on a wider body of knowledge concerning not only the individual but also their circumstances.

For example, in the Care Plus Study, involving a randomised controlled trial of increased consultation time with a GP for patients ‘with complex problems’ in very deprived areas, it was impossible to agree on an operational definition of ‘complexity’.4 …