efficacy
/ˈefɪkəsi/ (bre, ipa) · /ˈefɪkəsi/ (ame, ipa) · /ˈe-fi-kə-sē/ (ame, mw)
efficacy — noun
1. the degree to which a method, product, or approach succeeds at doing what it was
the degree to which a method, product, or approach succeeds at doing what it was designed or expected to do
The new teaching method's efficacy was clear when test scores rose across the school.
collocation: efficacy of [method/system/program]
Diya questioned the recycling system's efficacy after learning most waste went to landfill.
collocation: question the efficacy of
The committee reviewed the efficacy of current safety rules after the factory accident.
Noor was pleased with the new software's efficacy, which cut her team's workload in half.
A new study examined the efficacy of exercise programs for older adults with back pain.
- effectiveness
the most common, everyday equivalent; 'efficacy' is more formal
- utility
focuses more on practical usefulness than ability to produce results
- potency
usually refers to strength of a chemical, drug, or argument; narrower scope
- ineffectiveness
the opposite in everyday language
- inefficacy
the direct antonym but very rare in use
文法句型
the efficacy of [something]
用法筆記
Typically uncountable and used in formal or academic writing rather than everyday conversation. Often paired with a prepositional phrase beginning with 'of' to specify what is being evaluated.
常見錯誤
2. a measure of how successfully a medical treatment, drug, or therapy performs whe
a measure of how successfully a medical treatment, drug, or therapy performs when tested in a controlled research setting, before or after it reaches patients
Clinical trials test the efficacy of new vaccines before they reach the public.
collocation: clinical efficacy
The drug showed high efficacy in treating the disease during the initial lab tests.
collocation: show high efficacy in treating
Researchers compared the efficacy of the two treatments by monitoring patient recovery over six months.
The Ministry of Health approved the therapy after reviewing its safety and efficacy data.
Haruto's team published a paper on a new drug's efficacy for childhood asthma.
- effectiveness
used more broadly in everyday medical talk; 'efficacy' is the technical research term
- potency
emphasises the strength or power of a drug at a given dose, rather than overall success rate
文法句型
the efficacy of [drug/treatment/vaccine]
safety and efficacy
用法筆記
Frequently appears alongside 'safety' in the fixed phrase 'safety and efficacy'. Subject of evaluation is typically a treatment, drug, vaccine, or therapy. Common in regulatory and pharmaceutical contexts.