Effectiveness Evaluation of Social Prescribing

Social Prescribing (SP), or Social Henvisning (SH) in Denmark, integrates healthcare with social and cultural services to address social determinants of health. Internationally, SP improves patient well-being, reduces loneliness, and lowers healthcare utilization. Countries like the United Kingdom, Canada, and Australia have shown its effectiveness in reducing hospital admissions and supporting vulnerable populations.

The 'Social Prescribing Vesterbro-Sydhavnen' initiative, launched in fall 2024 as part of usual care, aims to involve general practitioners (GP) as primary prescribers to social services through a dedicated link worker, enhancing early intervention and connecting healthcare with community support.

This evaluation aims to assess the effectiveness of the 'Social Prescribing Vesterbro-Sydhavnen' project, in the following named as SP-intervention.

Information about the experimental group The participants in this evaluation are all patients participating in the SP intervention upon referral from their GP. The investigators anticipate that up to 500 patients from around 15 GPs in 10 clinics will participate in the SP-intervention, hereof a sample of 315 in the analysis of this evaluation. Participants are recruited consecutively in the GP clinics starting from summer 2025.

The target group of the SP-intervention are adults (+18) with or at risk of complex health and social challenges or with a high level of both elective and acute visits to general practice, including socially related consultations.

Research questions:

Research question 1: How does the SP intervention impact healthcare service utilization for the participating patients?

Research question 2: How does the SP intervention impact the perceived degree of loneliness and quality of life in participating patients?

All outcomes in this evaluation are presented both as a total and stratified by each GP clinic, age-group, gender, education, employment, civil status, and migration background.

Other secondary research questions:

What are the demographic and clinical characteristics of citizens utilizing the SP project, including their baseline levels of perceived loneliness and quality of life?

What characterizes the clinics that refer patients to the SP intervention? Descriptive statistics on General Practitioners regarding the clinic characteristics and population affiliated with the clinic:

• Number of patients per clinic
• Number of patients per GP
• Age distribution
• Gender distribution
• Socioeconomic distribution
• Disease burden distribution (Charlson Comorbidity Index Score, Dual Diagnosis, Triple Diagnosis)
• Type of clinic

The study will also explore the following research questions related to impact and influencing factors of the SP Intervention:

• Are the effects of the SP intervention influenced by participants' socio-economic background, pre-existing health conditions, or other variables?
• How do different types of services in the SP intervention compare in terms of their effect on participants' well-being, loneliness, and healthcare utilization over time?
• How do the frequency and duration of engagement in the SP project influence its effects on healthcare utilization and well-being?
• What factors lead to dropouts of the SP-intervention?

Project design:

This effectiveness evaluation is designed as a quasi-experimental, prospective cohort study with a real-world approach, following a per-protocol analysis. The evaluation outcomes feeds into the Implementation Programme SHINE which employs a Hybrid Type II Effectiveness-Implementation Design.

The participants in this evaluation are all patients participating in the SP intervention upon referral from their GP. Participants are recruited consecutively in the GP clinics starting in June, 2025.

The target group of the SP-intervention are adults (+18) with or at risk of complex health and social challenges or with a high level of both elective and acute visits to general practice, including socially related consultations.

Data sources:

Research Question 1 is analysed using Danish national registry data without requiring informed consent. A case-control design is applied, where cases include all patients prescribed the SP intervention by their GP in the Vesterbro-Sydhavnen area of Copenhagen. Controls are selected from the same GP clinics and matched to cases based on age group, gender, and Charlson Comorbidity Index score.

Research Question 2 is analysed using patient-reported outcomes collected after obtaining informed consent from SP intervention participants. This analysis does not include a control group.

Recruitment and informed consent After being prescribed to participate in the SP intervention by their GP, patients have an initial meeting with the link worker (in Danish: Brobygger). During this visit, the link worker introduces the evaluation, provides participant information, and explains the evaluation process in detail. Participation is voluntary. Patients who wish to consider their participation further are given a two-week reflection period and may bring a relative to a follow-up meeting before deciding.

If they agree to participate, they provide informed consent digitally on a tablet. Consent forms and responses are securely uploaded to REDCap, a GDPR-compliant data capture system hosted by the Capital Region of Denmark. Data is stored securely, and only authorized project staff have access. Participants can withdraw their consent at any time without consequences for their future treatment.

Data collection:

Following consent, the link worker or designated project staff administers Patient Reported Outcome (PRO) questionnaires, assessing Health-Related Quality of Life (HRQoL) and loneliness, on a tablet. The PRO data after 3 and 9 months is collected by a link to REDCap sent to the participants by SMS message or email. In the event of participant dropout, the link worker or other project staff will attempt to collect PRO data at the time of dropout.

If participants do not respond to the 3- or 9-month follow-up via SMS or email, project staff will follow up by telephone to attempt contact. Registry data will be retrieved after the final patient has completed the 9-month assessment - see data sources in detail below.

Data sources:

The description of the baseline profile and assess outcome measures, this evaluation uses registry data from Statistics Denmark, the Register of Healthcare Providers, the National Health Insurance Service Register, the National Prescription Registry, the Danish National Patient Register (LPR), and the Danish Register of Causes of Death, utilizing the Personal Identification Number (CPR) on all SP-intervention participants provided by the GPs/brobygger.

Statistical considerations:

Baseline characteristics of participants and controls will be summarized using means (SD) or medians (IQR) for continuous variables and frequencies (%) for categorical variables.

Primary Analysis - Healthcare Utilization Outcomes Unadjusted rates of GP contacts, unplanned hospital contacts, and emergency calls (1813) will be calculated for intervention and control groups.

Multivariable Poisson or negative binomial regression models will estimate rate ratios (RRs) for changes in healthcare contacts, adjusting for age and other relevant covariates (e.g. education).

Changes in medication prescriptions will be compared between intervention and control group (assessed by dosage/number of prescriptions 6 months prior and 9 months after intervention).

Primary Analysis - Patient-Reported Outcomes (Loneliness \& HRQoL) Changes in loneliness (T-ILS and De Jong Gierveld Loneliness Scale) and HRQoL (EQ-5D-5L and EQ-VAS) from baseline to 3 and 9 months follow-up will be analysed using linear mixed-effect models, adjusting for baseline scores and covariates (e.g. age, use of psychotropic medication and civil status).

Secondary Analysis Participation and non-attendance in the SP intervention will be modelled using logistic regression, including demographic and clinical factors.

Other analysis

All primary analyses will be stratified by GP clinic (stratification analysis) Alternative definitions of multimorbidity (e.g., number of chronic conditions, dual diagnosis, triple diagnosis vs. Charlson Comorbidity Index) (sensitivity analysis)

Interactions between mental health and socioeconomic status to explore effect modification of intervention and control group. (interaction/sub analysis).

If missing data can be assumed to be missing at random, multiple imputation will be used to account for missing data.

Sample size:

The power calculation is based on the outcome measures of change in GP visits. Since GP visit rates for the study population under investigation are unknown, the investigators have based the calculation on the GP rate from a UK study with a similar intervention, which reported a median annual rate of 8.3. This is rescaled to 9 months, equalling a rate of 6.225 visits per 9 months (Carnes m.fl. 2017). With a power of 0.8, a significance level of 0.05, and a minimal rate reduction of 10%, a sample of 315 cases is required. To account for confounder adjustments, additional cases are included, resulting in a final sample of 350 cases.

Ethics:

This non-interventional evaluation of usual care in the primary healthcare sector, integrates data from Danish registers with participant-reported information collected through questionnaires administered at three time points over the course of the SP intervention. The investigators do not consider this study to pose any harm or cause discomfort to the participants.

The project will adhere to the ethical guidelines set by the Danish Council for Independent Research. The data collected will be stored and processed in accordance with the Danish Data Protection Agency and the EU General Data Protection Regulation and registered in the records of the Capital Region of Denmark. The investigators will obtain written informed consent from all participants following approval and recommendations from the Regional Research Ethics Committee.

The study will be conducted adhering to the ethical principles of the Helsinki Declaration, ensuring ethically responsible research, including informed consent, protection of participants' rights, risk assessment, and transparency in the study's purpose and methodology. Additionally, the project is registered with the Capital Region of Denmark's data registry P-2024-17318.