HSI Dependence Assessment
The Heaviness of Smoking Index is a two-item score derived from the Fagerström Test. It predicts nicotine dependence and guides pharmacotherapy selection.
How soon after you wake do you smoke your first cigarette?
How many cigarettes per day do you smoke?
HSI score
0
Range 0–6
Dependence assessment
Very low nicotine dependence
How to Use This Calculator
Ask two targeted questions
Time to first cigarette and cigarettes per day predict nicotine dependence quickly in busy clinical settings.
Score and interpret
High scores (≥4) indicate strong physical dependence and predict the need for pharmacotherapy.
Tailor cessation plans
Use HSI alongside Fagerström Test, carbon monoxide readings, and motivational interviewing to plan treatment intensity.
Formula
HSI score = Time-to-first-cigarette score + Cigarettes-per-day score
Scoring:
- Time to first cigarette: 0–3
- Cigarettes per day: 0–3
- Total range: 0–6
Full Description
The Heaviness of Smoking Index streamlines nicotine dependence assessment by focusing on two predictive behaviours. It correlates with cotinine levels and withdrawal severity, allowing clinicians to triage smokers rapidly. Pair the HSI with readiness-to-change assessments and deliver evidence-based cessation support—nicotine replacement therapy, varenicline, bupropion, or behavioural programmes—to maximise quit success.
Frequently Asked Questions
How does HSI differ from Fagerström?
HSI uses only two Fagerström items. It’s faster but slightly less granular. Use Fagerström for full assessment when time allows.
Is HSI valid for vaping?
Not directly. Adapt by considering nicotine strength and frequency, but use dedicated vaping dependence tools when possible.
Do I need objective measures?
Exhaled carbon monoxide or cotinine testing increases accuracy and helps motivate patients by showing toxic exposure.
What if the patient smokes roll-ups?
Estimate cigarette equivalents (1 hand-rolled ≈ 0.75 manufactured cigarette) to score accurately.