Horowitz index

noun

An assessment of lung function; the ratio of partial pressure of oxygen in blood (PaO2), and the fraction of oxygen in the inhaled air (FiO2).

Meanings

nounHorowitz index (plural Horowitz indexes or Horowitz indices)

plural Horowitz indexes · plural Horowitz indices

  1. medicineAn assessment of lung function; the ratio of partial pressure of oxygen in blood (PaO2), and the fraction of oxygen in the inhaled air (FiO2).

    Synonyms: Horowitz, Horowitz ratio, Horowitz quotient, Horowitz number, P/F ratio, PaO2/FiO2 ratio, Carrico index

Synonyms & antonyms

nounAn assessment of lung function; the ratio of partial pressure of oxygen in blood (PaO2), and the fraction of oxygen in the inhaled air (FiO2).

Origin

The ratio was first suggested in a 1974 paper by Joel H. Horovitz et al. The reason for the spelling with w is unclear.

Full word history & related roots →
Cite this entry
APA

Horowitz index. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Horowitz%20index

MLA

“Horowitz index.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Horowitz%20index. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “Horowitz index,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Horowitz%20index.

Source: Horowitz index on Wiktionary, CC BY-SA 4.0.