Observed life jacket use in Washington State, 2010, by individual boater, boat and environmental factors*
| Category | Life jacket use No. (%) | Bivariate model | Multivariable model | ||
|---|---|---|---|---|---|
| Risk ratio (RR) | 95% CI | Risk ratio (RR) | 95% CI | ||
| Age (years) | |||||
| 0–5 | 89 (89.0) | 4.1 | (3.2 to 5.2) | 5.0 | (4.4 to 5.7) |
| 6–12 | 340 (80.0) | 3.7 | (3.3 to 4.1) | 4.2 | (3.9 to 4.6) |
| 13–17 | 221 (49.5) | 2.3 | (2.0 to 2.6) | 2.1 | (1.8 to 2.3) |
| 18–64 | 854 (21.8) | – | – | – | |
| >65 | 23 (18.3) | 0.8 | (0.69 to 1.0) | 1.1 | (0.84 to 1.5) |
| Sex | |||||
| Male | 899 (27.8) | – | |||
| Female | 618 (33.8) | 1.3 | (1.1 to 1.5) | ||
| Boat type | |||||
| Motorised boat | 877 (21.1) | – | – | ||
| PWC | 333 (96.8) | 4.6 | (2.7 to 7.9) | 3.7 | (2.9 to 4.7) |
| Kayak | 166 (79.8) | 3.8 | (2.5 to 5.7) | 4.4 | (4.0 to 4.9) |
| Canoe | 88 (59.9) | 2.8 | (1.6 to 4.9) | 2.3 | (2.1 to 2.4) |
| Rowboat/dinghy | 23 (45.1) | 2.1 | (0.93 to4.9) | 1.8 | (1.5 to 2.2) |
| Paddleboard/sailboard | 31 (62.0) | 2.9 | (1.9 to 4.6) | 2.2 | (2.1 to 2.3) |
| Sailboat | 39 (31.7) | 1.5 | (1.4 to 1.6) | 2.3 | (2.3 to 2.3) |
| Inflatable/raft | 26 (43.3) | 2.1 | (1.5 to 2.7) | 1.2 | (0.57 to 2.4) |
| Boat length | |||||
| <16 ft | 762 (56.8) | – | – | ||
| 16–20 ft | 556 (22.9) | 0.40 | (0.18 to 0.91) | 0.73 | (0.48 to 1.1) |
| 21–25 ft | 194 (19.7) | 0.35 | (0.16 to 0.73) | 0.65 | (0.37 to 1.1) |
| >25 ft | 58 (15.4) | 0.27 | (0.11 to 0.65) | 0.46 | (0.26 to 0.80) |
| Boating activity | |||||
| Fishing/intent to fish | 191 (21.2) | – | – | ||
| Water-skiing (all persons in boat with water-ski) | 214 (44.3) | 2.1 | (1.4 to 3.1) | 1.5 | (1.1 to 2.0) |
| Racing/high speed | 111 (56.9) | 2.7 | (2.6 to 2.8) | 1.0 | (0.81 to 1.3) |
| Swimming | 8 (50.0) | 2.4 | (1.5 to 3.8) | 2.1 | (0.88 to 5.2) |
| Pleasure | 1038 (29.8) | 1.4 | (1.0 to 2.0) | 0.87 | 0.68 to 1.1) |
| Other activity | 16 (72.7) | 1.3 | (0.3 to 5.7) | 0.95 | (0.27 to 3.4) |
| Weather | |||||
| Sunny | 765 (32.7) | – | – | ||
| Partly cloudy | 591 (29.3) | 0.9 | (0.84 to 0.96) | 0.95 | (0.94 to 0.97) |
| Cloudy | 219 (32.7) | 1.0 | (0.97 to 1.0) | 1.0 | (0.90 to 1.1) |
| Raining | 10 (7.8) | 0.2 | (0.15 to 0.38) | 0.39 | (0.33 to 0.46) |
| Water | |||||
| Not choppy | 1405 (29.9) | – | – | ||
| Choppy (waves >6″) | 180 (38.4) | 1.3 | (0.7 to 2.4) | 1.3 | (1.0 to 1.7) |
Bolded figures indicate statistical significance at p≤0.05.
*Multivariable risk ratios adjusted for age group, boat type, boat length, activity, weather, water conditions. Total numbers in each factor vary because of missing data for any of the variables included in the multivariable analysis.
PWC, personal watercraft.