Table 1.
Overview of social-psychological scale measures1
| Measure | Item | Answer options | Scale (minimum to maximum value) | Number of items | Cronbach’s alpha (α) | Reference |
|---|---|---|---|---|---|---|
| Knowledge about the HPV vaccinationa |
־ HPV is sexually transmittable; |
−1 = incorrect |
−8 = incorrect |
8 |
n/a |
|
| ־ HPV is a virus; |
0 = don’t know |
8 = correct |
||||
| ־ The HPV vaccination in the Netherlands consists of three injections; |
1 = correct |
|||||
| ־ My daughter is/I am obliged to get the HPV vaccination when she is/I am invited; | ||||||
| ־ You will always notice when you are infected by HPV; | ||||||
| ־ Only women can get infected by HPV; | ||||||
| ־ Women who received the HPV vaccination are still advised to participate in the cervical cancer screening in the Netherlands; | ||||||
| ־ The HPV vaccination fully protects against cervical cancer. | ||||||
| Risk perception (having received no HPV vaccination) |
Imagine that your daughter was/you were not vaccinated against HPV. The chance that my daughter will get/I will get cervical cancer is… |
−3 = very small to 3 = very large |
n/a |
1 |
n/a |
[20,31] |
| Risk perception (having received the HPV vaccination) |
Imagine that your daughter was/you were vaccinated against HPV. The chance that my daughter will get/I will get cervical cancer is… |
−3 = very small to 3 = very large |
n/a |
1 |
n/a |
[20,31] |
| Attitude towards the HPV vaccination |
Vaccinating my daughter/myself against HPV is… |
−3 = very undesirable to 3 = very desirable; |
−12 = negative to 12 = positive |
4 |
M = .98 |
[31] |
| D = .94 | ||||||
| −3 = very bad to 3 = very good; | ||||||
| −3 = very negative to 3 = very positive; | ||||||
| −3 = very unimportant to 3 = very important | ||||||
| Negative outcome expectations of the HPV vaccination |
If my daughter gets/I get the HPV vaccination… |
−3 = completely agree to 3 = completely disagree |
−15 = completely agree to 15 = completely disagree |
5 |
M = .60 |
[20,27,32] |
| D = .49 | ||||||
| ־ she/I will become infertile; | ||||||
| ־ she/I will get unpleasant side effects shortly after the injection, such as head ache, fever or pain at the injection spot; | ||||||
| ־ she/I will be afraid of the injection with a needle; | ||||||
| ־ she/I will have unsafe sex in the future; | ||||||
| ־ her/my natural immune system against illnesses will be disturbed. | ||||||
| Positive outcome expectations of the HPV vaccination |
If my daughter gets/I get the HPV vaccination… |
−3 = completely disagree to 3 = completely agree |
−9 = completely disagree to 9 = completely agree |
3 |
M = .76 |
[33,34] |
| D = .77 | ||||||
| ־ she/I will not contract cervical cancer; | ||||||
| ־ she/I will not have to worry about cervical cancer; | ||||||
| ־ she/I will not be infected with HPV. | ||||||
| Anticipated regret about rejecting the HPV vaccination |
Imagine your daughter has not received the HPV vaccination and she gets cervical cancer in the future. How much would you regret your decision to let her receive no vaccination? |
1 = no regret and 5 = very much regret |
n/a |
1 |
n/a |
|
| Anticipated regret about receiving the HPV vaccination |
Imagine your daughter has received the HPV vaccination and she gets a serious illness as a result of the vaccine. How much would you regret your decision to let her receive the vaccination? |
1 = no regret and 5 = very much regret |
n/a |
1 |
n/a |
|
| Beliefs about the HPV vaccination |
־ If the government offers the vaccination, I assume it will be safe; |
−3 = completely disagree to 3 = completely agree |
−18 = negative to 18 = positive |
9 |
M = .80 |
[19,20] |
| D = .70 | ||||||
| ־ Our government shows responsibility for the health of the Dutch population by introducing the HPV vaccination; |
−3 = completely agree to 3 = completely disagree |
|||||
| ־ The HPV vaccination was only introduced because the pharmaceutical industry will earn a lot of money from it; | ||||||
| ־ There is too little known about whether |
|
|
|
|
|
|
| the HPV vaccination effectively protects against cervical cancer; |
|
|||||
| ־ There is too little known about the detrimental side effects of the HPV vaccination; | ||||||
| ־ My daughter is/I am too young to receive the HPV vaccination; | ||||||
| ־ My daughter does/I do not need to get the HPV vaccination if she is/I am already sexually active; | ||||||
| ־ My daughter does/I do not need the vaccination because she is/I am not yet sexually active; | ||||||
| ־ It is inappropriate that my daughter has/I have to pay for the HPV vaccination if she decides/I decide to get the vaccination at a higher age. | ||||||
| Relative effectiveness of the HPV vaccinationb |
How would you rate the effectiveness of the following methods of preventing cervical cancer: |
1 = not at all effective to 10 = very effective |
n/a |
5 |
n/a |
|
| | ||||||
| ־ having safe sex |
|
|||||
| ־ having sex with only one person in a lifetime | ||||||
| ־ participating in the cervical cancer screening | ||||||
| ־ having a healthy lifestyle (e.g. not smoking) | ||||||
| ־ the HPV vaccination | ||||||
| Participants rated the effectiveness of each method | ||||||
| Ambivalence towards the HPV vaccination decision |
During my decision making about my daughter’s/my HPV vaccination… |
−3 = completely disagree to 3 = completely agree |
−9 = completely disagree to 9 = completely agree |
3 |
M = .93 |
|
| D = .85 | ||||||
| ־ I felt torn between the pros and cons of vaccination; |
|
|||||
| ־ I experienced positive as well as negative feelings; | ||||||
| ־ I was torn between the pros and cons of vaccination. | ||||||
| Confidence in authorities involved in the HPV vaccination |
As regards the HPV vaccination, how much confidence do you have in… |
−3 = very little to 3 = very much confidence |
−9 = very little to 9 = very much confidence |
3 |
M = .91 |
|
| D = .88 | ||||||
| ־ science | ||||||
| ־ health care | ||||||
| ־ the Ministry of Public Health | ||||||
| Participants rated their confidence in each authority | ||||||
| Subjective norms towards the HPV vaccinationc |
Normative beliefs |
−2 = certainly not vaccinating to 2 = certainly vaccinating, |
−70 =negative to 70 = positive (M); |
M = 7 |
M = .85 |
[31] |
| What is your expectation on the opinion of … about the HPV vaccination of your daughter? |
D = 6 |
D = .77 |
||||
| 3 = not applicable; |
−60 =negative to 60 = positive (D) |
|||||
| Not applicable was recoded into ‘0’ | ||||||
| Social referents: partner (M), parents (M), daughter (M), father (D), mother (D), best friends (M/D), general practitioner (M/D), doctor/nurse from the municipal health service (M/D), the Ministry of Public Health (M/D) | ||||||
| |
Motivation to comply |
1 = not at all to 5 = very much |
M = 7 |
|
[31] |
|
| How motivated are you to comply with the opinion of …? |
D = 6 |
|||||
| Descriptive norms towards the HPV vaccination |
How many parents/girls do you know who will decide to let their daughter/themselves be vaccinated against HPV if they receive the invitation? |
1 = none of the parents/girls I know, to 7 = all the parents/girls I know |
n/a |
1 |
n/a |
[31] |
| Self-efficacy expectations towards the HPV vaccination |
To what extent would you succeed in dealing with the following situations: |
−3 = I would certainly not succeed to 3 = I would certainly succeed |
−18 = I would certainly not succeed to 18 = I would certainly succeed |
6 |
M = .82 |
|
| D = .66 | ||||||
| ־ Finding reliable information about the HPV vaccination; | ||||||
| ־ Understanding information about the HPV vaccination; |
|
|
|
|
|
|
| ־ Making a different decision about the HPV vaccination of my daughter/myself than most parents/girls among my acquaintances; | ||||||
| ־ Having a good talk with my daughter about the HPV vaccination (M); | ||||||
| ־ Having a good talk with my partner about the HPV vaccination (M); | ||||||
| ־ Having a good talk with my father about the HPV vaccination (D); | ||||||
| ־ Having a good talk with my mother about the HPV vaccination (D); | ||||||
| ־ Having a good talk with my general practitioner about the HPV vaccination. | ||||||
| HPV vaccination information processing |
Before I finally decided about my (daughter’s) vaccination, I… |
|
−6 = completely disagree to 6 = completely agree |
2 |
M = .84 |
[31] |
| D = .75 | ||||||
| ־ gathered a lot of information about the HPV vaccine |
||||||
| ־ thoroughly considered the HPV vaccination |
−3 = completely disagree to 3 = completely agree |
|||||
| Participants rated their agreement on both items separately | ||||||
| Habit strength towards the HPV vaccination |
Letting my daughter receive the HPV vaccination/Receiving the HPV vaccination is something I do… |
−3 = completely disagree to 3 = completely agree |
−6 = completely disagree to 6 = completely agree |
2 |
M = .78 |
[35] |
| D = .65 | ||||||
| ־ automatically | ||||||
| ־ without thinking | ||||||
| Participants rated their agreement on both items separately | ||||||
| Decisional conflict about the HPV vaccination - value clarity |
As regards the HPV vaccination… |
−3 = completely disagree to 3 = completely agree |
−9 = completely disagree to 9 = completely agree |
3 |
M = .89 |
[36] |
| | ||||||
| ־ I was clear about which benefits were most important to me; |
D = .85 |
|||||
| ־ I was clear about which risks were most important to me; | ||||||
| ־ I was clear about which was more important to me, the benefits or the risks. | ||||||
| Decisional conflict about the HPV vaccination - certainty |
As regards the HPV vaccination… |
−3 = completely disagree to 3 = completely agree |
−9 = completely disagree to 9 = completely agree |
3 |
M = .89 |
[36] |
| D = .87 | ||||||
| ־ I felt sure about what to choose; | ||||||
| ־ the decision was relatively easy to make; | ||||||
| ־ I was clear about the best choice for me/my daughter. | ||||||
| Opinion about alternative medicine |
In what way do you agree with the view of… |
−3 = completely disagree to 3 = completely agree |
−9 = completely disagree to 9 = completely agree |
3 |
M = .81 |
|
| ־ anthroposophy |
D = .76 |
|||||
| ־ homeopathy | ||||||
| ־ other alternative medicine | ||||||
| Past cancer experienced | Have you/has your mother had experience with… |
1 = no, 2 = yes, 3 = I do not want to answer this question | n/a | 6 | n/a | [19,27] |
| Do you know someone from your close environment who has/has had… | ||||||
| ־ cervical cancer | ||||||
| ־ other cancers | ||||||
| ־ abnormal pap smear |
Notes M = Mother; D = Daughter; n/a = not applicable; 1Scores on scaled item that showed sufficient internal consistency were summed into one scale; Mothers received questions about the HPV vaccination of their daughter, whereas daughters answered questions about the HPV vaccination of themselves; a) Knowledge is not a scale because the answer on one item does not predict the answer on the other items; the items were summed up to present a sum score of knowledge; b) The difference between the rated effectiveness of the HPV vaccination and the most effective alternative represented the relative effectiveness score (−9 = HPV vaccination least effective to 9 = HPV vaccination most effective); c) The subjective norms score was first computed by multiplying normative beliefs and motivation to comply for each social referent, and then by summing up the multiplications of the social referents; d) Past cancer experience is not a scale because the answer on one item does not predict the answer on the other items.