Understanding the impact of single disease resolution in Multiple Long-Term Conditions (MLTC) on long-term trajectories towards hospitalisation and all-cause mortality: A cohort study

Background: Over 15 million people in England have multiple long-term conditions (MLTC) and prevalence is projected to increase to 20 million by 2030.

People with MLTC have poorer health, reduced mobility, lower quality of life, increased risk of premature mortality, and higher health costs. Resolution of one or more of these conditions could improve health outcomes. However, there is a lack of research exploring the potential of condition resolution in people with MLTC.

Aims: To use a novel methodological approach to examine: (1) how commonly (and which) conditions resolve among people with MLTC, (2) which groups of people achieve resolution of these conditions, and (3) the impact of this on long-term outcomes including hospitalisation and all-cause mortality.

Objectives: To describe the epidemiology of one or more condition resolution over the life course of MLTC including the condition/s most commonly resolving using a large MLTC cohort from primary care health records.

To describe the usage of condition resolution codes in primary care electronic records and compare this to the persistence of condition codes over time in people with MLTC.

To describe sociodemographic characteristics of people with MLTC who achieve one or more condition resolution for >6 months.

To quantify the impact of condition resolution on trajectories towards hospitalisation and all-cause mortality in people with MLTC.

Methods: We will analyse data from the Clinical Practice Research Datalink primary care database (CPRD) to identify the conditions with a resolved (or remission) code and describe rates of resolution for these conditions.

We will compare baseline sociodemographic characteristics of people who achieve condition resolution (for > 6 months), those who do not achieve resolution, those who have permanent condition resolution, and those who die.

Illness-death multistate models will be used to assess the probability of resolution and association with hospitalisation and all-cause mortality. Models will adjust for age, sex and total number of medications and length of time on medication, where possible.

Anticipated impact and dissemination: The project will take 12 months to be completed, with dissemination continuing after the end of the study period.

We will publish our findings in open-access journals, present at conferences and produce a lay summary, animation, and policy brief of findings.

The study will provide a list of high interest conditions that are most likely to be resolved among people with MLTC to be shared with clinicians and policymakers.

These may inform the NHS Major Conditions Strategy by identifying which conditions and which groups of people, may be prioritised for treatment to achieve improvements in long-term health outcomes.

The study findings will feed into an NIHR programme development grant in 2025 to develop an intervention aimed at promoting resolution in these target groups. This would be followed by a full trial of the intervention within 3-years of completion of this grant.