Investigations
1st investigations to order
self-report of smoking status
Test
Assessing a patient’s smoking history should be done at every visit to a healthcare professional.[2][71] Use of a smoking status identification system questionnaire should be standard; however, it may be limited by lack of standard terminology and granularity for data collection, shifting cultural attitudes regarding tobacco use, and potentially frequent changes in individuals' smoking behaviour.[75] Overall, self-reported data are shown to be reliable, but some misreporting of smoking status may occur and is subject to recall bias.[91][92]
Result
if former or current smoker: details of duration of time smoked, type and amount of tobacco product used, and number of stopping attempts
Fagerström Test For Nicotine Dependence (FTND)
Test
A 6-item self-report tool assessing the intensity of physical addiction to nicotine. It assesses the quantity of cigarette consumption, the compulsion to use, and dependence.[79]
Result
test is scored from 0-10: score 8+ = high dependence; score 5-7 = moderate dependence; score 3-4 = low to moderate dependence; score 0-2 = low dependence
Heaviness of Smoking Index (HSI)
Test
A 2-item self-report tool derived from the Fagerström Test for Nicotine Dependence, with questions on time to first cigarette and number of cigarettes smoked per day.[78]
Result
test is scored from 1-6, with higher scores indicating higher degrees of nicotine dependence
Investigations to consider
carbon monoxide (CO) monitoring
Test
CO monitoring involves measurement of exhaled breath to give an indication of levels of CO in the blood, given that CO is a marker of recent smoking. CO monitoring is recommended in some locations (e.g., the UK) at each contact during smoking cessation as a motivational tool.[63] CO monitoring is also recommended routinely for all pregnant women at antenatal appointments in the UK.[63]
A CO level of 10 parts per million (ppm) or less suggests that the person is a non-smoker.[63] However, note that clinical experience indicates that any value above 5 ppm usually suggests exposure to tobacco smoking, either from personal use or from second-hand exposure, and so further questioning may be warranted for results within this range.[83] In pregnancy, a reading of 4 ppm or above is an indication to offer referral for stop-smoking support according to UK guidance.[63]
Result
CO level above 5 ppm suggests likely exposure to smoke
cotinine level
Test
Cotinine levels may be obtained from blood or saliva in scenarios where tobacco abstinence is required (e.g., prior to knee replacement or organ transplant in some centres). Provides a more accurate measurement of exposure to smoking than CO monitoring, indicative of exposure over the past few days, rather than hours.[63]
Different levels have been suggested to differentiate between total abstinence, passive tobacco exposure, and active tobacco exposure; however, the optimal cut-offs for classification vary with population characteristics or regions and over time.[80][92]
Result
negative in tobacco or nicotine product abstinence
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