To send or not to send: weighing the costs and benefits of mailing an advance letter to participants before a telephone survey

Table 1 Baseline demographic characteristics between No Letter and Letter groups

Variable	Group^a
Variable	No Letter (n = 138)	Letter (n = 137)
Age, mean years (SD)	47.5 (12.9)	48.7 (12.1)
Female sex	70 (50.7)	70 (51.1)
Married or common-law spouse	69 (50.0)	84 (61.3)
Employed full or part time	77 (56.2)	69 (50.4)
Education level
Less than high school diploma	31 (22.5)	24 (17.5)
High school diploma	63 (45.7)	66 (48.2)
Postsecondary	44 (31.9)	47 (34.3)
Household income, $
< 60,000	85 (64.4)	81 (62.3)
≥ 60,000	47 (35.6)	49 (37.7)
Cigarettes, mean (SD), days	18.3 (7.9)	18.4 (7.5)
FTND score, mean (SD)	4.8 (1.9)	5.1 (2.1)
Levels of nicotine dependence^c
Low	14 (10.4)	18 (13.4)
Low to moderate	46 (34.1)	33 (24.6)
Moderate	66 (48.9)	68 (50.7)
High	9 (6.7)	15 (11.2)
Age at first smoking, mean (SD), years	15.4 (4.8)	14.5 (4.2)
Time as smoker, mean (SD), years	23.1 (13.9)	25.0 (14.7)
No. of previous quit attempts
0	5 (3.6)	11 (8.0)
1–5	95 (68.8)	89 (65.0)
> 6	38 (27.5)	37 (27.0)
Previously used NRT (patch, gum, inhaler) in a quit attempt	70 (52.6)	86 (68.3)^b

FTND Fagerström Test for Nicotine Dependence; NRT nicotine replacement therapy
^aData are presented as number (percentage) of participants unless otherwise indicated. Sample sizes vary because of missing data on some variables
^bp < 0.05
^cLevel of nicotine dependence is based on the FTND scores. Scores range from 1 to 10, with higher scores indicating a more intense physical dependence on nicotine. Low dependence corresponds to a score of 1 or 2, low to moderate dependence a score of 3 or 4, moderate dependence a score of 5 to 7, and high dependence a score of 8 to 10

ISSN: 1756-0500