Authors' objectives: Link worker social prescribing enables health-care professionals to address patients’ non-medical needs by linking patients into various services. Evidence for its effectiveness and how it is experienced by link workers and clients is lacking. To evaluate the impact and costs of a link worker social prescribing intervention on health and health-care costs and utilisation and to observe link worker delivery and patient engagement. Link worker social prescribing enables health-care professionals (HCPs) to address patients’ non-medical needs by linking patients to various services, and is key to the personalisation agenda in the 2019 The NHS Long Term Plan (NHS England. The NHS Long Term Plan. 2019. URL: www.longtermplan.nhs.uk/wp-content/uploads/2019/08/nhs-long-term-plan-version-1.2.pdf; accessed 3 December 2020). Evidence for its effectiveness and how it is experienced is lacking. To measure the impact of the social prescribing intervention for adults with T2DM on glycated haemoglobin levels (HbA1c; primary outcome), body mass index (BMI), blood pressure (BP), cholesterol level, smoking and health-care utilisation. To examine differential intervention effects in subgroups by gender, age, ethnicity, multimorbidity, BMI and deprivation level. To measure self-reported health-related quality of life (HRQoL) as a change in EuroQol-5 Dimensions, five-level version (EQ-5D-5L), scores at the 12-month follow-up. To establish the cost-effectiveness of the social prescribing intervention for health-care utilisation and outcomes. To examine the delivery of social prescribing by exploring link workers’ daily practices. To examine patients’ engagement with the social prescribing intervention. To examine the role of social prescribing during the early stages of lockdown.

Authors' results and conclusions: Intention-to-treat analysis of approximately 8400 patients in 13 intervention and 11 control general practices demonstrated a statistically significant, although not clinically significant, difference in HbA1c level (–1.11 mmol/mol) and a non-statistically significant 1.5-percentage-point reduction in the probability of having high blood pressure, but no statistically significant effects on other outcomes. Health-care cost estimates ranged from £18.22 (individuals with one extra comorbidity) to –£50.35 (individuals with no extra comorbidity). A statistically non-significant shift from unplanned (non-elective and accident and emergency admissions) to planned care (elective and outpatient care) was observed. Subgroup analysis showed more benefit for individuals living in more deprived areas, for the ethnically white and those with fewer comorbidities. The mean cost of the intervention itself was £1345 per participant; the incremental mean health gain was 0.004 quality-adjusted life-years (95% confidence interval –0.022 to 0.029 quality-adjusted life-years); and the incremental cost-effectiveness ratio was £327,250 per quality-adjusted life-year gained. Ethnographic data showed that successfully embedded, holistic social prescribing providing supported linking to navigate social determinants of health was challenging to deliver, but could offer opportunities for improving health and well-being. However, the intervention was heterogeneous and was shaped in unanticipated ways by the delivery context. Pressures to generate referrals and meet targets detracted from face-to-face contact and capacity to address setbacks among those with complex health and social problems. This social prescribing model resulted in a small improvement in glycaemic control. Outcome effects varied across different groups and the experience of social prescribing differed depending on client circumstances. Health outcomes and health-care costs Consistently, the intervention was found to impact on levels of HbA1c and blood pressure. The size of the impact varied depending on the treatment and control groups. ITT analysis estimated that the overall impact on HbA1c levels was small and clinically non-significant, but statistically significant (i.e. –1.11 mmol/mol); when accounting for the time-varying nature on the treated, statistically significant reductions in levels of HbA1c of –4.57 mmol/mol were observed. These represent reductions of between 2% and 8% compared with the control group. Similar trends were observed for BP, with a decrease of 1.5 percentage points (not statistically significant) in the ITT analysis, rising to a seven-point reduction for individuals 3 years post treatment compared with the controls. There was little evidence of an effect on levels of cholesterol level, BMI or smoking status. Subgroup analysis showed that improvements in levels of HbA1c were higher among those living in areas of higher socioeconomic deprivation. Improvements in BP were greater for the ethnically non-white and, marginally, for people living in areas of higher socioeconomic deprivation. Health-care cost estimates ranged from £18.22 (for individuals with one extra comorbidity) to –£50.35 (for individuals with no extra comorbidity), the latter being approximately 16% of the pre-treatment mean inpatient non-elective costs. For the treatment group, there was a shift from unplanned care (non-elective and accident and emergency admissions) to planned care (elective and outpatient care). Although not statistically significant, these may be economically significant changes.

Authors' recommendations: Intention-to-treat analysis of approximately 8400 patients in 13 intervention and 11 control general practices demonstrated a statistically significant, although not clinically significant, difference in HbA1c level (–1.11 mmol/mol) and a non-statistically significant 1.5-percentage-point reduction in the probability of having high blood pressure, but no statistically significant effects on other outcomes. Health-care cost estimates ranged from £18.22 (individuals with one extra comorbidity) to –£50.35 (individuals with no extra comorbidity). A statistically non-significant shift from unplanned (non-elective and accident and emergency admissions) to planned care (elective and outpatient care) was observed. Subgroup analysis showed more benefit for individuals living in more deprived areas, for the ethnically white and those with fewer comorbidities. The mean cost of the intervention itself was £1345 per participant; the incremental mean health gain was 0.004 quality-adjusted life-years (95% confidence interval –0.022 to 0.029 quality-adjusted life-years); and the incremental cost-effectiveness ratio was £327,250 per quality-adjusted life-year gained. Ethnographic data showed that successfully embedded, holistic social prescribing providing supported linking to navigate social determinants of health was challenging to deliver, but could offer opportunities for improving health and well-being. However, the intervention was heterogeneous and was shaped in unanticipated ways by the delivery context. Pressures to generate referrals and meet targets detracted from face-to-face contact and capacity to address setbacks among those with complex health and social problems. This social prescribing model resulted in a small improvement in glycaemic control. Outcome effects varied across different groups and the experience of social prescribing differed depending on client circumstances. Health outcomes and health-care costs Consistently, the intervention was found to impact on levels of HbA1c and blood pressure. The size of the impact varied depending on the treatment and control groups. ITT analysis estimated that the overall impact on HbA1c levels was small and clinically non-significant, but statistically significant (i.e. –1.11 mmol/mol); when accounting for the time-varying nature on the treated, statistically significant reductions in levels of HbA1c of –4.57 mmol/mol were observed. These represent reductions of between 2% and 8% compared with the control group. Similar trends were observed for BP, with a decrease of 1.5 percentage points (not statistically significant) in the ITT analysis, rising to a seven-point reduction for individuals 3 years post treatment compared with the controls. There was little evidence of an effect on levels of cholesterol level, BMI or smoking status. Subgroup analysis showed that improvements in levels of HbA1c were higher among those living in areas of higher socioeconomic deprivation. Improvements in BP were greater for the ethnically non-white and, marginally, for people living in areas of higher socioeconomic deprivation. Health-care cost estimates ranged from £18.22 (for individuals with one extra comorbidity) to –£50.35 (for individuals with no extra comorbidity), the latter being approximately 16% of the pre-treatment mean inpatient non-elective costs. For the treatment group, there was a shift from unplanned care (non-elective and accident and emergency admissions) to planned care (elective and outpatient care). Although not statistically significant, these may be economically significant changes.

Authors' methods: Quality Outcomes Framework and Secondary Services Use data. Multimethods comprising (1) quasi-experimental evaluation of effects of social prescribing on health and health-care use, (2) cost-effectiveness analysis, (3) ethnographic methods to explore intervention delivery and receipt, and (4) a supplementary interview study examining intervention impact during the first UK COVID-19 lockdown (April–July 2020). (1) Health outcomes study, approximately n = 8400 patients; EuroQol-5 Dimensions, five-level version (EQ-5D-5L), study, n = 694 (baseline) and n = 474 (follow-up); (2) ethnography, n = 20 link workers and n = 19 clients; and COVID-19 interviews, n = 14 staff and n = 44 clients. The main outcome measures were glycated haemoglobin level (HbA1c; primary outcome), body mass index, blood pressure, cholesterol level, smoking status, health-care costs and utilisation, and EQ-5D-5L score. The limitations of the study include (1) a reduced sample size because of non-participation of seven general practices; (2) incompleteness and unreliability of some of the Quality and Outcomes Framework data; (3) unavailability of accurate data on intervention intensity and patient comorbidity; (4) reliance on an exploratory analysis with significant sensitivity analysis; and (5) limited perspectives from voluntary, community and social enterprise. Study design The study design was a multimethods evaluation comprising three work packages (WPs).

Project Status: Completed

URL for project: https://www.journalslibrary.nihr.ac.uk/hta/AQXC8219

Year Published: 2023

URL for published report: https://njl-admin.nihr.ac.uk/document/download/2042149

URL for additional information: English

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: England, United Kingdom

DOI: 10.3310/AQXC8219

Organisation Name: NIHR Public Health Research programme

Contact Address: NIHR Journals Library, National Institute for Health and Care Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK

Contact Name: journals.library@nihr.ac.uk

Contact Email: journals.library@nihr.ac.uk