---
title: "The 3 E’s: Efficacy, Effectiveness & Efficiency"
description: "From the hugely influential monograph: Cochrane, A. L. (1972). Effectiveness and efficiency. Random reflections on health services. Nuffield Provincial Hospitals Trust. #### Details See next: links! #### Try also - [Effectiveness](https://www.psyctc.org/psyctc/glossary2/effectiveness-2/) - [Efficacy](https://www.psyctc.org/psyctc/glossary2/efficacy/) - [Efficiency](https://www.psyctc.org/psyctc/glossary2/efficiency/) #### Chapters Not covered specifically…"
url: "https://www.psyctc.org/psyctc/glossary2/the-3-es-efficacy-effectiveness-efficiency/"
updated: "2026-06-01"
category: All OM book glossary entries
---

# The 3 E’s: Efficacy, Effectiveness & Efficiency

From the hugely influential monograph: Cochrane, A. L. (1972). Effectiveness and efficiency. Random reflections on health services. Nuffield Provincial Hospitals Trust.

#### Details

See next: links!

#### Try also

- [Effectiveness](https://www.psyctc.org/psyctc/glossary2/effectiveness-2/)
- [Efficacy](https://www.psyctc.org/psyctc/glossary2/efficacy/)
- [Efficiency](https://www.psyctc.org/psyctc/glossary2/efficiency/)

#### Chapters

Not covered specifically in the OMbook but the broad ideas run through it.

#### Online resources

None likely from me.

#### Dates

First created 2.iv.25, links completed 18.v.25.