Table 3.
Effects of the intervention on the outcome measures according to intention-to-treat analyses (N=8062).
| Outcome | Control (N=4067) | Intervention (N=3995) | Beta (standard error) |
Cohen ƒ2 or OR | ||||||||||
| Pretest | Posttest | Pretest | Posttest | |||||||||||
| Primary outcome |
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HPV vaccination uptake a |
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Has received no HPV injection (reference), n (%) |
|
1106 (27.19) |
|
1066 (26.67) |
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|
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Has received one or two HPV injections, n (%) |
|
2961 (72.81) |
|
2929 (73.32) | .03 (.05)b | 1.03 | ||||||
| Secondary outcomes |
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IDM: dichotomous |
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Not informed (reference), n (%) | 2689 (66.12) | 1924 (47.31) | 2689 (67.31) | 1699 (42.53) |
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Informed, n (%) | 1376 (33.83) | 2143 (52.69) | 1306 (32.69) | 2296 (57.47) | .25 (.06)c | 1.28 | ||||||
|
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IDM: continuous (0-48), mean (SD) | 18.95 (11.45) | 24.28 (11.82) | 18.69 (11.21) | 25.85 (12.30) | 1.72 (.27)c | 0.007 | |||||||
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|
Decisional conflict (1-7), mean (SD) | 4.33 (1.74) | 5.17 (1.45) | 4.33 (1.75) | 5.38 (1.36) | .21 (.04)c | 0.008 | |||||||
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Intention (1-7), mean (SD) | 5.35 (1.70) | 5.42 (1.97) | 5.35 (1.69) | 5.59 (1.87) | .18 (.03)c | 0.006 | |||||||
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Attitude (1-7), mean (SD) | 5.19 (1.46) | 5.22 (1.57) | 5.18 (1.45) | 5.37 (1.51) | .15 (.03)c | 0.006 | |||||||
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Beliefs (1-7), mean (SD) | 4.21 (.72) | 4.37 (.80) | 4.19 (.73) | 4.47 (.81) | .12 (.02)c | 0.010 | |||||||
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Risk perception not vaccinated (1-7), mean (SD) | 3.73 (.98) | 3.70 (1.05) | 3.74 (0.98) | 3.77 (1.08) | .06 (.02)d | 0.001 | |||||||
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Risk perception vaccinated (1-7), mean (SD) | 2.76 (1.06) | 2.74 (1.08) | 2.77 (1.07) | 2.64 (1.10) | −.11 (.03)c | 0.004 | |||||||
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Anticipated regret (1-5), mean (SD) | 3.68 (1.27) | 3.50 (1.33) | 3.71 (1.25) | 3.59 (1.31) | .07 (.03)d | 0.001 | |||||||
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Subjective norm (−20 to 20), mean (SD) | 5.92 (7.90) | 6.46 (9.46) | 5.88 (7.81) | 7.25 (9.20) | .82 (.20)c | 0.004 | |||||||
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Habit (1-7), mean (SD) | 4.26 (1.79) | 4.36 (1.82) | 4.28 (1.78) | 4.51 (1.83) | .14 (.04)c | 0.004 | |||||||
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Relative effectiveness (1-10), mean (SD) | −2.01 (2.24) | −1.84 (2.36) | −1.97 (2.22) | −1.35 (2.27) | .46 (.07)c | 0.015 | |||||||
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Self-efficacy (1-7), mean (SD) | 6.24 (.76) | 6.24 (.78) | 6.27 (.73) | 6.29 (.75) | .04 (.02)e | 0.001 | |||||||
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Knowledge (−8 to 8), mean (SD) | 4.42 (2.16) | 5.41 (2.09) | 4.40 (2.14) | 5.75 (2.09) | .35 (.05)c | 0.009 | |||||||
aHuman papillomavirus (HPV) vaccination uptake was not assessed at baseline.
bP=.60.
cP ≤.001, thus significant (P<.003; Bonferroni: 0.05/14 factors).
dP=.01.
eP=.03.