Table 2.

Studies Investigating the Relationship of Heaviness of Smoking Index (HSI) With Biochemical Measures of Nicotine and Tobacco Exposure

Study	Sample size	Population characteristics	HSI score (M ± SD)	TTFC in minutes (M ± SD)	CPD (M ± SD)	Questionnaire	Biochemical measure	R 2
Heatherton et al. (1989): Sample 1	168	Visitors to science centre; 52% male and 48% female; mean age was 30.7±9.6 years	N/A	43.3±56.9	22.1±9.3	HSI	Salivary cotinine	.30
							Exhaled CO	.30
Heatherton et al. (1989): Sample 2	736	Population recruited by visiting randomly selected addresses; 51% male and 49% female; mean age was 39.6±13.7 years	N/A	46.4±90.5	21.5±11.3	HSI	Salivary cotinine	.10
							Exhaled CO	.07
Heatherton et al. (1991)	254	Visitors to science center; 44% male and 56% female; mean age was 33.5±12.7 years.	N/A	47.2±86.8	20.7±10.5	HSI	Salivary cotinine	.31
							Exhaled CO	.26
Kozlowski et al. (1994)	932	Smoking cessation program participants; 35% male and 65% female. mean age was 40±11.3 years	3.9±0.05	N/A	27.0±12.2	HSI	Exhaled CO	.06
Burling (2003)	191	All male drug/alcohol dependent cigarette smokers in residential rehabilitation; mean age was 40.0±6.7 years	3.0±1.2	N/A	17.2±7.3	HSI	Urine cotinine	.10
							Exhaled CO	.17

Note. TTFC = time taken from awakening to first cigarette smoked; CPD = number of cigarettes smoked per day; R ² = coefficient of determination of linear regression; N/A = data not reported in the study; CO = carbon monoxide.