Table 1 General characteristics of study population before and after propensity score matching
From: Association between smokeless tobacco use and cigarette smoking amount by age
| Â | Smokeless tobacco use | Standardized difference after matching | |||
|---|---|---|---|---|---|
Before propensity score matching | After propensity score matching | ||||
No (n = 19,048) | Yes (n = 587) | No (n = 2,900) | Yes (n = 580) | ||
Number of cigarettes used per day | 13.9 ± 0.1 | 15.0 ± 0.5 | 14.4 ± 0.2 | 15.0 ± 0.5 | 0.07 |
Age (year) | 46.7 ± 0.2 | 37.5 ± 0.7 | 38.3 ± 0.3 | 37.5 ± 0.7 | 0.01 |
Body mass index | 29.2 ± 0.1 | 28.5 ± 0.4 | 28.4 ± 0.3 | 28.5 ± 0.4 | -0.00 |
Ln (household income) | 10.0 ± 0.0 | 10.0 ± 0.0 | 10.1 ± 0.0 | 10.0 ± 0.0 | -0.00 |
Sex | |||||
 Men | 9,163 (84.3) | 520 (15.7) | 2,543 (71.0) | 513 (29.0) | 0.02 |
 Women | 9,885 (93.3) | 67 (6.7) | 357 (63.5) | 67 (36.5) |  |
Race | |||||
 Whites | 15,219 (88.3) | 525 (11.7) | 2,590 (69.1) | 520 (30.9) | 0.03 |
 African Americans | 2,763 (94.3) | 35 (5.7) | 165 (80.6) | 34 (19.4) |  |
 Others | 1,066 (93.6) | 27 (6.4) | 145 (83.0) | 26 (17.0) |  |
Marital status | |||||
 Single | 6,597 (86.4) | 240 (13.6) | 1,276 (70.7) | 236 (29.3) | 0.08 |
 Widowed, divorced or separated | 6,409 (88.7) | 156 (11.3) | 770 (69.6) | 153 (30.4) |  |
 Married | 6,042 (86.5) | 191 (13.5) | 854 (66.2) | 191 (33.8) |  |
Education level | |||||
 Under high school | 864 (86.9) | 25 (13.1) | 102 (66.9) | 25 (33.1) | 0.04 |
 High school | 9,768 (87.8) | 337 (12.2) | 1,656 (71.3) | 333 (28.7) |  |
 Above high school | 8,416 (87.7) | 225 (12.3) | 1,142 (66.7) | 222 (33.3) |  |
Job status | |||||
 All others | 11,550 (91.2) | 220 (8.8) | 1,473 (74.8) | 217 (25.2) | 0.04 |
 Blue collar workers | 6,104 (82.0) | 316 (18) | 1,193 (60.8) | 312 (39.2) |  |
 Unemployed | 1,394 (79.5) | 51 (20.5) | 234 (66.7) | 51 (33.3) |  |
Alcohol consumption | |||||
 Never drinkers | 1,682 (89.5) | 33 (10.5) | 126 (63.5) | 32 (36.5) | 0.06 |
 Former drinkers | 3,595 (88.4) | 63 (11.6) | 289 (65.8) | 62 (34.2) |  |
 Current drinkers | 13,771 (87.4) | 491 (12.6) | 2,485 (70.6) | 486 (29.4) |  |
Physical activity | |||||
 Inactive | 8,906 (88.3) | 238 (11.7) | 1,167 (70.4) | 236 (29.6) | 0.01 |
 Insufficient | 4,617 (87.9) | 122 (12.1) | 604 (66.7) | 121 (33.3) |  |
 Active | 5,525 (86.1) | 227 (13.9) | 1,129 (70.5) | 223 (29.5) |  |
Tried to quit smoking | |||||
 Yes | 8,410 (86.6) | 287 (13.4) | 1,417 (67.9) | 285 (32.1) | 0.01 |
 No | 10,638 (88.2) | 300 (11.8) | 1,483 (69.9) | 295 (30.1) |  |
Year | |||||
 2013 | 4,548 (85.4) | 123 (14.6) | 596 (65.8) | 121 (34.2) | 0.03 |
 2014 | 3,939 (87.2) | 131 (12.8) | 683 (70.5) | 131 (29.5) |  |
 2015 | 3,726 (84.5) | 114 (15.5) | 538 (65.9) | 111 (34.1) |  |
 2016 | 3,904 (88.8) | 133 (11.2) | 658 (71.6) | 131 (28.4) |  |
 2017 | 2,931 (89.8) | 86 (10.2) | 425 (71.8) | 86 (28.2) |  |