---
title: Effectiveness
description: "One of the 3 E's from the hugely influential monograph: Cochrane, A. L. (1972). Effectiveness and efficiency. Random reflections on health services. Nuffield Provincial Hospitals Trust. #### Details In Cochrane's terms effectiveness of an intervention was what you needed assuming…"
url: "https://www.psyctc.org/psyctc/glossary2/effectiveness-2/"
updated: "2026-06-01"
category: All OM book glossary entries
---

# Effectiveness

One of the 3 E's from the hugely influential monograph: Cochrane, A. L. (1972). Effectiveness and efficiency. Random reflections on health services. Nuffield Provincial Hospitals Trust.

#### Details

In Cochrane's terms effectiveness of an intervention was what you needed assuming you had shown efficacy (q.v.!) It is the practicality of the intervention: can it be delivered realistically in routine practice and does it continue to work well in those conditions as opposed to the rather unrealistic conditions of efficacy studies.

To a large extent this was the driver behind my involvement in developing [the CORE system](https://www.coresystemtrust.org.uk) and the broad idea of Practice Based Evidence (PBE) for psychosocial interventions.

#### Try also

- [The 3 E's](https://www.psyctc.org/psyctc/glossary2/the-3-es-efficacy-effectiveness-efficiency/)
- [Efficacy](https://www.psyctc.org/psyctc/glossary2/efficacy/)
- [Efficiency](https://www.psyctc.org/psyctc/glossary2/efficiency/)
- [Practice Based Evidence](https://www.psyctc.org/psyctc/glossary2/pbe-practice-based-evidence/)

#### Chapters

Not covered specifically in the OMbook but the idea runs through it.

#### Online resources

None likely from me.

#### Dates

First created 2.iv.25.