Preferences of healthcare providers in Switzerland for attributes of pediatric hexavalent vaccines: a discrete-choice experiment

Figures & data

Table 1. Attributes and levels used in the discrete-choice experiment.

Attribute label	Attribute description	Attribute levels
Type of device	The hexavalent vaccine can come in the form of a prefilled syringe that is ready to use or with a separate vial that requires reconstitution before administration. The two types of device are linked to different preparation time as well as different risk of errors during preparation.	Prefilled syringe—ready to use
		Syringe and vial with components that require reconstitution
Protective antibody levels against Haemophilus influenzae type b (Hib) at time of booster dose (11–12 months) after receiving the first 2 doses (primary series)	The level of protection of all hexavalent pediatric vaccines in the market is approximately the same for all 6 pathogens. However, hexavalent pediatric vaccines given at 2 and 4 months might induce different levels of antibodies against Haemophilus influenzae type b (Hib). The percentage of infants with protective levels of antibodies against Hib at the time of the booster dose (11–12 months), after receiving the first 2 doses (primary series), may differ across hexavalent pediatric vaccines.	5 out of 10 vaccinated (50%) have protective antibody levels
		7 out of 10 vaccinated (70%) have protective antibody levels
		9 out of 10 vaccinated (90%) have protective antibody levels
Packaging size (box of 10 vaccines)	Some hexavalent vaccine boxes are smaller than others even if they contain the same number of vaccine doses. Smaller boxes occupy less space and may allow for more vaccines to be stored in the refrigerator.	Smaller (500 cm^3) box of 10 vaccines. Similar in size to 4 packets of tissues together
		Larger (1,000 cm^3) box of 10 vaccines. Similar in size to 8 packets of tissues together
Years that the vaccine has been available on the market	The individual vaccine components in hexavalent pediatric vaccines have been available for many years. However, some hexavalent pediatric vaccines have been available on the market for more time than others. This means that healthcare providers may have different years of experience using a hexavalent vaccine.	Less than 1 year
		1–3 years
		More than 3 years
Time that the vaccine can stay safely at room temperature (25^0 C)	Some vaccines can be kept safely at room temperature (up to 25 degrees Celsius) for a longer time than others.	3 days
		6 days

Note: Respondents were presented with either the French- or German-translated version of the survey instrument.

Figure 1. Example of a Discrete-Choice Experiment Question. Hib: Haemophilus influenzae type b.

Note: Respondents were presented with either the French- or German-translated version of the survey instrument; the example included here is the original English version used for translation.

Table 2. Respondent experience and demographic characteristics and other questions.

Question	Pediatricians (n = 150)	Nursing staff (n = 40)	Full sample (N = 190)
What gender identity best describes you?
Female	102 (68.0%)	38 (95.0%)	140 (73.7%)
Male	47 (31.3%)	2 (5.0%)	49 (25.8%)
Prefer not to answer	1 (0.7%)	0 (0.0%)	1 (0.5%)
How old are you?
Younger than 21^a	–	–
21-30 years	2 (1.3%)	15 (37.5%)	17 (8.9%)
31-40 years	37 (24.7%)	12 (30.0%)	49 (25.8%)
41-50 years	55 (36.7%)	7 (17.5%)	62 (32.6%)
51-60 years	42 (28.0%)	5 (12.5%)	47 (24.7%)
61-70 years	11 (7.3%)	1 (2.5%)	12 (6.3%)
71-80 years	3 (2.0%)	0 (0.0%)	3 (1.6%)
Older than 80 years	–	–
Which of the following best describes the geographic area in which you practice?
Urban	97 (64.7%)	26 (65.0%)	123 (64.7%)
Rural	53 (35.3%)	14 (35.0%)	67 (35.3%)
Which of the following best describes your practice?
Individual practice	37 (24.7%)	14 (35.0%)	51 (36.8%)
Group practice	110 (73.3%)	24 (60.0%)	134 (70.5%)
Regional hospital	1 (0.7%)	0 (0.0%)	1 (0.5%)
University hospital	1 (0.7%)	0 (0.0%)	1 (0.5%)
Other	1 (0.7%)	2 (5.0%)	3 (1.6%)
How many years have you practiced?
Less than 10 years	33 (22.0%)	17 (42.5%)	50 (36.3%)
10-20 years	62 (41.3%)	16 (40.0%)	78 (41.1%)
More than 20 years	55 (36.7%)	7 (17.5%)	62 (32.6%)
Prefer not to answer	–	–	–
In which canton do you mainly practice?
Bern	22 (14.7%)	12 (30.0%)	34 (17.9%)
Vaud	12 (8.0%)	5 (12.5%)	17 (8.9%)
Zurich	40 (26.7%)	12 (30.0%)	52 (27.4%)
Other	76 (50.7%)	11 (27.5%)	87 (45.8%)
Which hexavalent pediatric vaccine(s) have you prescribed or administered in the past year?
DTaP3-IPV-HepB/Hib	54 (36.0%)	14 (35.0%)	68 (35.8%)
DTaP5-IPV-HepB-Hib	26 (17.3%)	18 (45.0%)	44 (23.2%)
Both	70 (46.7%)	8 (20.0%)	78 (41.1%)
Prefer not to answer	–	–
How many infants are vaccinated with a hexavalent pediatric vaccine in your office or practice per month, on average?
Less than 10^a	–	–
10–50	89 (59.3%)	29 (72.5%)	118 (62.1%)
51–100	40 (26.7%)	9 (22.5%)	49 (25.8%)
101–200	17 (11.3%)	2 (5.0%)	19 (10.0%)
More than 200	4 (2.7%)	0 (0.0%)	4 (2.1%)
Which of the following activities are you responsible for regarding hexavalent pediatric vaccines? (Please select all that apply.)
Decide which vaccines to buy	118 (78.7%)	5 (12.5%)	123 (64.7%)
Order vaccines	47 (31.3%)	31 (77.5%)	78 (41.1%)
Store vaccines	71 (43.3%)	35 (87.5%)	106 (55.8%)
Prescribe vaccines	111 (74.0%)	6 (15.0%)	117 (61.6%)
Prepare vaccines	85 (56.7%)	32 (80.0%)	117 (61.6%)
Administer vaccines	142 (94.7%)	31 (77.5%)	173 (91.1%)
Prefer not to answer	0 (0.0%)	2 (5.0%)	2 (1.1%)
Are you concerned about how much space you have in your practice’s refrigerator when ordering hexavalent vaccines?
Yes	79 (52.7%)	29 (72.5%)	108 (56.8%)
No	61 (40.7%)	9 (22.5%)	70 (36.8%)
Don’t know or not sure	10 (6.7%)	2 (5.0%)	12 (6.3%)
How often are hexavalent vaccines kept outside the refrigerator at your clinic for more than 30 min (e.g. unused vaccine, left outside the refrigerator by accident)?
Never	54 (36.0%)	26 (65.0%)	80 (42.1%)
Rarely (once or twice a year)	64 (42.7%)	11 (27.5%)	75 (39.5%)
Occasionally (once or twice a month)	25 (16.7%)	1 (2.5%)	26 (13.7%)
Often (once a week or more often)	4 (2.7%)	2 (5.0%)	6 (3.2%)
Don’t know or not sure	3 (2.0%)	0 (0.0%)	3 (1.6%)

Note: Percentages are provided to 1 decimal place, and as such, rounding may mean totals do not equal 100.0%.

^aRespondents selecting those options were ineligible; therefore, none of the respondents who completed the survey selected these options.

Table 3. Random-parameters logit model odds ratios: full sample (N = 190).

Variable	OR	95% CIs
Type of device^a
Prefilled syringe—ready to use	2.77*	(1.39–4.15)
Syringe and vial with components that require reconstitution	Reference
Protective antibody levels
5 out of 10 vaccinated (50%) have protective antibody levels	0.00*	(0.00–0.00)
7 out of 10 vaccinated (70%) have protective antibody levels	0.01*	(0.00–0.01)
9 out of 10 vaccinated (90%) have protective antibody levels	Reference
Package size
Smaller (500 cm^3) box of 10 vaccines. Similar in size to 4 packets of tissues together	1.89*	(1.23–2.55)
Larger (1,000 cm^3) box of 10 vaccines. Similar in size to 8 packets of tissues together	Reference
Years that the vaccine has been available on the market
More than 3 years	4.76*	(1.87–7.65)
1-3 years	2.83*	(1.57–4.08)
Less than 1 year	Reference
Time that the vaccine can stay safely at room temperature
6 days	1.07	(0.73–1.42)
3 days	Reference

*statistically significant

CI, confidence interval; OR, odds ratio.

^aWith their respective associated preparation time and risk of errors.

^bOdds ratio (95% CI) for more than 3 years versus 1–3 years on the market was not significant: 1.68 (0.83–2.54).

Figure 2. Conditional relative importance of attributes: full sample (N = 190). Hib: Haemophilus influenzae type b; vs. = versus.

Note: Conditional relative attribute importance is the proportion of total utility gained by switching from the least-to the most-preferred levels of attributes, rescaled to sum to 100% across all attributes.

^a With their respective associated preparation time and risk of errors.

Figure 3. Conditional relative importance of attributes: subgroup analyses. A. Type of healthcare provider B. Experience with vaccine in the past year. Hib, Haemophilus influenzae type b; vs., versus.

^a With their respective associated preparation time and risk of errors.

Table 4. Random-parameters logit model odds ratios, subgroup analysis: type of healthcare provider (N = 190).

Variable	Pediatricians (n = 150)		Nursing staff (n = 40)
	OR	95% CI	OR	95% CI
Type of device^a
Prefilled syringe—ready to use	2.99*	(1.12–4.86)	2.35	(0.36–4.33)
Syringe and vial with components that require reconstitution	Reference		Reference
Protective antibody levels
5 out of 10 vaccinated (50%) have protective antibody levels	0.00*	(0.00-0.00)	0.00*	(0.00–0.00)
7 out of 10 vaccinated (70%) have protective antibody levels	0.01*	(0.00–0.01)	0.03*	(−0.00, 0.07)
9 out of 10 vaccinated (90%) have protective antibody levels	Reference		Reference
Package size
Smaller (500 cm^3) box of 10 vaccines. Similar in size to 4 packets of tissues together	1.92*	(1.17–2.67)	1.53	(0.70–2.36)
Larger (1,000 cm^3) box of 10 vaccines. Similar in size to 8 packets of tissues together	Reference		Reference
Years that the vaccine has been available on the market^b
More than 3 years	5.22*	(1.62–8.81)	3.84	(−0.01, 7.70)
1–3 years	2.32*	(1.18–3.46)	3.40	(0.90–5.90)
Less than 1 year	Reference		Reference
Time that the vaccine can stay safely at room temperature
6 days	1.12	(0.68–1.56)	1.01	(0.51–1.51)
3 days	Reference		Reference

*statistically significant.

CI, confidence interval; OR, odds ratio.

^aWith their respective associated preparation time and risk of errors.

^bOdds ratio (95% CI) for more than 3 years versus 1–3 years on the market was not significant for either subgroup: 2.25 (0.92–3.57) for pediatricians and 1.13 (0.20–2.06) for nursing staff.

Table 5. Random-parameters logit model odds ratios, subgroup analysis: experience with vaccine (N = 190).

Variable	DTaP5-IPV-HepB-Hib and both (n = 122)		DTaP3-IPV-HepB/Hib only (n = 68)
	OR	95% CI	OR	95% CI
Type of device^a
Prefilled syringe—ready to use	4.73*	(1.65–7.81)	1.10	(0.37–1.82)
Syringe and vial with components that require reconstitution	Reference		Reference
Protective antibody levels
5 out of 10 vaccinated (50%) have protective antibody levels	0.00*	(0.00–0.00)	0.00*	(0.00–0.00)
7 out of 10 vaccinated (70%) have protective antibody levels	0.01*	(0.00–0.01)	0.00*	(0.00–0.01)
9 out of 10 vaccinated (90%) have protective antibody levels	Reference		Reference
Package size
Smaller (500 cm^3) box of 10 vaccines. Similar in size to 4 packets of tissues together	1.38	(0.80–1.95)	2.81*	(1.31–4.31)
Larger (1,000 cm^3) box of 10 vaccines. Similar in size to 8 packets of tissues together	Reference		Reference
Years that the vaccine has been available on the market^b
More than 3 years	4.22*	(1.10–7.34)	10.95*	(1.07–20.82)
1-3 years	2.23*	(1.07–3.38)	4.12*	(1.22-7.02)
Less than 1 year	Reference		Reference
Time that the vaccine can stay safely at room temperature
6 days	1.07	(0.66–1.50)	1.12	(0.55–1.68)
3 days	Reference		Reference

*Statistically significant.

CI, confidence interval; OR, odds ratio.

^aWith their respective associated preparation time and risk of errors.

^bOdds ratio (95% CI) for more than 3 years versus 1–3 years on the market was not significant for either subgroup: 1.90 (0.68–3.11) for DTaP5-IPV-HepB-Hib and both vaccine users; and 2.66 (0.67–4.64) for DTaP3-IPV-HepB/Hib only.