efficacy

English

From Old French efficace, from Late Latin efficācia (“efficacy”), from efficāx (“efficacious”); see efficacious.

efficacy (usually uncountable, plural efficacies)

Ability to produce a desired effect under ideal testing conditions.
- 1642, Sir Thomas Browne, “Religio Medici [The Religion of a Doctor]”, in The Works Of the Learned Sr Thomas Brown, Kt., London: Tho. Basset et al., published 1686, page 15:
  […] and this hath even made me ſuſpect the efficacy of reliques, to examine the bones, queſtion the habits and appurtenances of Saints, and even of Chriſt himſelf.
- 2005, Flay et al. Standards of Evidence: Criteria for Efficacy, Effectiveness and Dissemination DOI: 10.1007/s11121-005-5553-y
  Efficacy refers to the beneficial effects of a program or policy under optimal conditions of delivery, whereas effectiveness refers to effects of a program or policy under more real-world conditions.
Degree of ability to produce a desired effect.
- 1996, Moskovich, Patent application PCT/US1996/003658
  Toothbrush with improved efficacy
- Wikipedia entry for "vaccine efficacy", as of 2016
  Vaccine efficacy is the percentage reduction of disease in a vaccinated group of people compared to an unvaccinated group, using the most favorable conditions.

ability to produce effect

Arabic: please add this translation if you can
Bulgarian: де́йственост (bg) f (déjstvenost)
Catalan: eficàcia (ca) f
Chinese:
Mandarin: 功效 (zh) (gōngxiào), 效力 (zh) (xiàolì), 效能 (zh) (xiàonéng), 效驗／效验 (zh) (xiàoyàn), 效验 (zh) (xiàoyàn), (of medicine) 藥效／药效 (yàoxiào), 药效 (yàoxiào), (of therapy or treatment) 療效／疗效 (zh) (liáoxiào), 疗效 (zh) (liáoxiào)
Czech: efektivnost f, účinnost (cs) f
Dutch: doeltreffendheid (nl)
Esperanto: efikeco
Finnish: tehokkuus (fi)
French: efficience (fr) f, efficacité (fr) f
German: Wirksamkeit (de) f
Indonesian: khasiat (id), kemanjuran (id), keampuhan (id)
(deprecated template usage) {{trans-mid}}
Interlingua: efficacia
Italian: efficacia (it) f
Japanese: 有効性 (ゆうこうせい, yūkōsei)
Latin: efficacitas f
Polish: efektywność (pl) f, skuteczność (pl) f
Portuguese: eficácia (pt) f
Romanian: eficacitate (ro) f
Russian: эффекти́вность (ru) f (effektívnostʹ), де́йственность (ru) f (déjstvennostʹ)
Slovak: efektívnosť (sk) f
Spanish: eficacia (es) f
Swedish: effektivitet (sv) f