Specific combinations of long term conditions have a major role in the additional pressures the NHS faces every winter, because they are associated with significantly higher risks of hospital admissions and death, finds research published in the open access journal BMJ Medicine.
The risk of hospital admission was 11 times higher among those with the quartet of cancer, kidney disease, cardiovascular disease, and type 2 diabetes than it was among those without any of these long term conditions, the findings show.
And people with kidney disease, cardiovascular disease, dementia, and osteoarthritis were 24 times more likely to die as those who didn't have these conditions.
Winter pressures are prompted by the worsening of health issues as a result of colder weather, seasonal viruses, increased isolation and loneliness, plus systems level difficulties caused by higher bed occupancy and staff absences, explain the researchers. These additional pressures usually cover the period from December 1 to March 31.
The number of people in England with 2 or more long term conditions is projected to include almost 70% of the population by 2035. And while previously published research has established the increased health service demand related to multiple long term conditions during the winter, it's not clear exactly which combinations might be the most critical, say the researchers.
To try and find out, they reviewed routinely collected and linked primary and secondary care health data for adults in England, during the winter pressures period of 2021-22, to identify the reasons for hospital admission. This period coincided with the COVID-19 pandemic when health and social care services were substantially disrupted.
Complete data were available for 48.3 million people, just over half of whom were women (51%). Their average age was 49, and 81% of them were White.
The researchers selected 59 long term conditions which were categorised into 19 groups, based on feedback from clinicians, patients, and policy-makers.
During the study period, 4,710,675 hospital admissions and 176,895 deaths were recorded. Overall, nearly 20 million people (40.5%) had no long term conditions; 13.5 million (28%) had one; and nearly a third (15 million; 31%) had 2 or more.
Analysis of the data showed that particular combinations of long term conditions were associated with heightened risks of hospital admission and death.
After factoring in age, sex, ethnicity, and area based socioeconomic deprivation, people with cancer, kidney disease, cardiovascular disease, and type 2 diabetes were 11 times more likely to be admitted to hospital during the winter than those who didn't have this combination.
Similarly, this risk was nearly 10 times higher for those with cancer, chronic kidney disease, cardiovascular disease, and osteoarthritis, and those with cancer, chronic kidney disease, and cardiovascular disease.
Among the 10 combinations that contributed to the highest rates of hospital admissions, cardiovascular disease featured in all but 1, chronic kidney disease in 8, and cancer in 6.
Analysis of the deaths linked to particular combinations of long term conditions showed that people with cardiovascular disease and dementia were nearly 15 times more likely to die than those with neither of these conditions.
And those with the combination of kidney disease, cardiovascular disease, dementia, and osteoarthritis were more than 24 times more likely to do so.
Cardiovascular disease featured in all 10 of the riskiest combinations, while chronic kidney disease featured in 7 of them.
Cardiovascular disease plus dementia also featured in all of the top 5 riskiest combinations, and this duo was associated with a substantially higher rate of death than many 3, 4, and 5 long term condition combinations.
This is an observational study, precluding firm conclusions to be drawn about causal factors. And the researchers acknowledge various limitations to their findings, including the lack of information about the length or severity of illness or frailty among those with long term conditions.
But they point out: "Current policy and clinical guidance consider the risk of hospital admission and death for multiple long term conditions during the winter season as one homogenous condition," when this is clearly not the case.
And they suggest that the findings could help inform more targeted planning for winter pressures, enabling resources to be allocated where they are needed the most.
"Multimorbidity patterns are a major determinant of hospital admission and mortality during winter," agree Dr Jonathan Batty and colleagues of the University of Leeds, in a linked editorial.
"In the broader context of winter pressures and increasing multimorbidity, [the study] underscores the need for methods that can identify individuals at high risk of preventable hospital admission and mortality, and strategies to mitigate the risk observed for those people with the most adverse combinations of long term conditions," they conclude.
