# Cost-effectiveness analysis of depression case finding followed by alerting patients and their GPs among older adults in northern England: results from a regression discontinuity study

## TL;DR

A study in northern England found that a depression screening and alert strategy for older adults was not cost-effective overall but might work better with more balanced patient groups.

## Contribution

The study provides new evidence on the cost-effectiveness of depression screening and GP alerting in older adults using a regression discontinuity design.

## Key findings

- Screening + GP incurred higher costs and fewer quality-adjusted life years compared to standard care.
- Subgroup analyses showed potential cost-effectiveness for patients with specific baseline depression scores.
- Sensitivity analyses confirmed the overall findings, suggesting screening + GP was dominated by standard care.

## Abstract

In the UK, around 1 in 4 adults over 65 years suffers from depression. Depression case finding followed by alerting patients and their general practioners (GPs) (screening + GP) is a promising strategy to facilitate depression management, but its cost-effectiveness remains unclear.

To investigate the cost-effectiveness of screening + GP compared with standard of care (SoC) in northern England.

Conducted alongside the CASCADE study, 1020 adults aged 65+ years were recruited. Participants with baseline Geriatric Depression Scale (GDS) ≥5 were allocated to the intervention arm and those >5 to SoC. Resource use and EQ-5D-5L data were collected at baseline and 6 months. Incremental cost-effectiveness ratio was calculated. Non-parametric bootstrapping was performed to capture sampling uncertainty. The results are presented using cost-effectiveness acceptability curves. Sensitivity analyses were conducted to assess the robustness of primary findings. Subgroup analyses were undertaken to examine the cost-effectiveness among participants with more comparable baseline characteristics across treatment groups.

Screening + GP incurred £37 more costs and 0.006 fewer quality-adjusted life years than SoC; the probability of the former being cost-effective was <5% at a £30 000 cost-effectiveness threshold. Sensitivity analyses confirmed the base-case findings. Subgroup analyses indicated that screening + GP was cost-effective when patients with baseline GDS 2–7, 3–6 and 4–5, respectively, were analysed.

Screening + GP was dominated by SoC in northern England. However, subgroup analyses suggested it could be cost-effective if patients with more balanced baseline characteristics were analysed. Economic evaluations alongside randomised controlled trials are warranted to validate these findings.