CO validation Рcarbon monoxide (CO) validation is the most cost effective and least evasive method of measuring someone’s smoking status. CO validation rates are important markers of service data quality.

CO validated 4 week quitter – the national outcome measure of stop smoking services is success rates at the four week post quit date. A smoker is counted as a ‘CO validated 4 week quitter’ if s/he is a self-reported quitter and his/her expired-air CO is assessed four weeks after the designated quit date (minus three days or plus 14 days) and found to be less than 10ppm (parts per million).

Deprivation quintile – populations are divided into quintiles based on socio-economic deprivation of place of residence, with the first 20% being the least deprived and the last 20% being the most deprived. The measure of deprivation used is Index of Multiple Deprivation (IMD 2015).

Smoking prevalence (or prevalence rate) – the proportion of individuals in a population who smoke