# Strengthening Primary Care for Recognising and Treating Depression (SPiRiT-D): a study protocol for a cluster randomised controlled effectiveness-implementation trial of collaborative care for depression

## TL;DR

This study tests a collaborative care model for depression in primary care clinics in Pakistan to see if it's effective and cost-efficient in real-world conditions.

## Contribution

The study introduces a contextually adapted collaborative care model for depression in resource-limited primary care settings in low- and middle-income countries.

## Key findings

- The trial will assess clinical and cost-effectiveness of collaborative care for depression in Pakistan.
- A mixed-methods process evaluation will explore factors influencing the implementation of collaborative care.
- The study will use a hybrid trial design to evaluate both effectiveness and implementation outcomes.

## Abstract

The effectiveness of collaborative care for treating depression in primary care has been well-established in high-income countries and, more recently, in a few trials in low- and middle-income countries (LMICs). However, evidence for its effectiveness, costs and how it can be implemented in ‘real-world’ settings within resource-constrained health systems in LMICs is currently limited. We aim to investigate the implementation, clinical and cost-effectiveness of a contextually adapted collaborative care model for depression in primary care clinics in Pakistan.

A hybrid type-II effectiveness-implementation cluster randomised controlled trial with embedded process and economic evaluations will be conducted. Twenty-four primary care clinics located in socioeconomically disadvantaged areas of Karachi will be randomly allocated (1:1) using minimisation to either (i) a contextually adapted collaborative care model for depression supported by co-designed implementation strategies or (ii) optimised usual care (routine practice with additional depression screening and provision of information leaflets about depression for those screening positive). Participants aged 18 years or above, scoring ≥ 10 on the 9-item Patient Health Questionnaire (PHQ-9) and not under any active treatment for depression, will be recruited. The Reach, Effectiveness, Adoption, Implementation and Maintenance framework will guide our outcome evaluation. The primary clinical outcome will be depression severity, assessed using the PHQ-9 at 6 months after participant recruitment. The primary implementation outcome will be ‘reach’ (proportion calculated as the number of people who participated in depression treatment divided by those eligible for such treatment) using routine, clinic-level aggregated data at 6 months. The process evaluation will explore factors such as fidelity, acceptability and sustainability of collaborative care using a mixed-methods approach guided by the Consolidated Framework for Implementation Research. A within-trial economic evaluation will explore the cost-effectiveness of both collaborative care and implementation activities. Individual-level effectiveness outcomes will be analysed using mixed-effect linear regression; and clinic-level implementation outcomes using generalised linear regression. Trial data analysis will be based on an intention to treat principle.

If collaborative care is shown to be successfully implemented, clinically, and cost-effective, it will provide health and economic benefits for people with depression presenting in primary care. It will also be a means to strengthen primary care services through a trained workforce that can recognise and manage depression, improve information management systems, and promote evidence-based care.

ISRCTN13462277 prospectively registered on 07 October 2024 10.1186/ISRCTN13462277.

The online version contains supplementary material available at 10.1186/s13063-026-09453-5.