A pilot study on the effects of individually tailored education for MMR vaccine-hesitant parents on MMR vaccination intention

Figures & data

Figure 1. Participant flow through the randomized trial.

Table 1. Baseline characteristics of study population (n = 77)^a

Socio-demographic characteristic	Untailored Intervention % (n)	Tailored Intervention % (n)
Total Sample	53% (41)	47% (36)
Parent’s age
≤ 24 y   25 to 34 y   35 to 44 y   46 to 55 y	17% (7) 49% (20) 27% (11) 7% (3)	14% (5) 50% (18) 30% (11) 6% (2)
Child’s age   0 to 12 mo   13 to 23 mo   2 to 3 y   4 to < 6 y	54% (22) 12% (5) 17% (7) 17% (7)	39% (14) 6% (2) 19% (7) 36% (13)
Child’s gender (Female)	52% (21)	53% (19)
Race/ethnicity   African-American   Hispanic   Caucasian   Other	10% (4) 10% (4) 73% (30) 7% (3)	33% (12) 8% (3) 50% (18) 8% (3)
Baseline vaccination intention	% (n)	% (n)
Plan to get MMR vaccine, categorical measure^b:   Negative   Unsure/neutral   Positive	15% (6) 51% (21) 34% (14)	28% (10) 39% (14) 33% (12)
	Mean (SD)	Mean (SD)
Plan to get MMR vaccine, linear measure^c:	5.34 (1.98)	5.06 (2.59)

Abbreviations: MMR, measles-mumps-rubella. ^aThere were no statistically significant differences in socio-demographic characteristics or baseline vaccination intention between intervention groups. ^bParticipants were divided into three mutually exclusive categories based on their responses to the statement, “I plan to have my child get the MMR vaccine [at the recommended ages] if recommended by my child’s doctor.” Responses followed an 11-point scale, where higher values corresponded to greater agreement with the statement. Parents who responded with a score ≤ 4 were classified as having “negative vaccination intention,” score of 5 indicated “unsure/neutral intention,” and a score > 5 represented “positive vaccination intention.” ^cVaccination intention was also defined as a continuous variable based on participants’ responses using the same 11-point scale described above.

Table 2. Comparison of change in parental vaccination intention from baseline to post-intervention within each intervention group

Within-group comparison	Untailored Intervention (n = 41)			Tailored Intervention (n = 36)
Baseline intentions for child get MMR vaccine*:	Baseline vaccination intention % (n)	Post-intervention vaccination intention % (n)	P-value	Baseline vaccination intention % (n)	Post-intervention vaccination intention % (n)	P-value
Negative   Unsure/Neutral   Positive	15% (6) 51% (21) 34% (14)	20% (8) 34% (14) 46% (19)	0.01	28% (10) 39% (14) 33% (12)	19% (7) 22% (8) 58% (21)	0.001

Abbreviations: MMR, measles-mumps-rubella. *Participants were divided into three mutually exclusive categories based on their responses to the statement, “I plan to have my child get the MMR vaccine [at the recommended ages] if recommended by my child’s doctor.” Responses followed an 11-point scale, where higher values corresponded to greater agreement with the statement. Parents who responded with a score ≤ 4 were classified as having “negative vaccination intention,” score of 5 indicated “unsure/neutral intention,” and a score > 5 represented “positive vaccination intention.”

Table 3. Comparison of change in parental vaccination intention from baseline to post-intervention between intervention groups

Between-group comparison	Baseline vaccination intention			Post-intervention vaccination intention
Baseline intentions for child get MMR vaccine*:	Untailored Intervention % (n)	Tailored Intervention % (n)	P-value	Untailored Intervention % (n)	Tailored Intervention % (n)	P-value
Negative   Unsure/Neutral   Positive	15% (6) 51% (21) 34% (14)	28% (10) 39% (14) 33% (12)	0.327	20% (8) 34% (14) 46% (19)	19% (7) 22% (8) 58% (21)	0.476

Abbreviations: MMR, measles-mumps-rubella. *Participants were divided into three mutually exclusive categories based on their responses to the statement, “I plan to have my child get the MMR vaccine [at the recommended ages] if recommended by my child’s doctor.” Responses followed an 11-point scale, where higher values corresponded to greater agreement with the statement. Parents who responded with a score ≤ 4 were classified as having “negative vaccination intention,” score of 5 indicated “unsure/neutral intention,” and a score > 5 represented “positive vaccination intention.”

Table 4. Number in individuals in the study population who changed vaccination intention categories from before and after the intervention

Untailored Intervention (n = 41): Intentions for child get MMR vaccine*:	Post-intervention vaccination intention (n)
Baseline vaccination intention (n)	Negative	Unsure/Neutral	Positive
Negative   Unsure/Neutral   Positive	5 0 3	1 11 2	0 10 9
Tailored Intervention Arm (n = 36): Intentions for child get MMR vaccine*:	Post-intervention vaccination intention (n)
Baseline vaccination intention	Negative	Unsure/Neutral	Positive
Negative   Unsure/Neutral   Positive	5 2 0	4 4 0	1 8 12

Abbreviations: MMR, measles-mumps-rubella. *Participants were divided into three mutually exclusive categories based on their responses to the statement, “I plan to have my child get the MMR vaccine [at the recommended ages] if recommended by my child’s doctor.” Responses followed an 11-point scale, where higher values corresponded to greater agreement with the statement. Parents who responded with a score ≤ 4 were classified as having “negative vaccination intention,” score of 5 indicated “unsure/neutral intention,” and a score > 5 represented “positive vaccination intention.”

Table 5. Linear intentional change* from before and after the study intervention

Linear intentional change	Untailored Intervention (n = 41)	Tailored Intervention (n = 36)	P-value
All participants: Mean (SD)	0.49 (2.39)	1.08 (1.68)	0.22
Categorized by baseline vaccination intention
Negative: Mean (SD)	0.83 (1.72)	1.5 (1.90)	0.49
Unsure/Neutral: Mean (SD)	1.24 (1.61)	1.14 (1.99)	0.88
Positive: Mean (SD)	-0.79 (3.12)	0.67 (0.98)	0.14

Abbreviations: MMR, measles-mumps-rubella. *Linear intentional change was defined as the difference between the post-intervention and baseline vaccination intention scores (measured as a continuous variable with a scale of 0 to 10) for each participant. Higher numbers on the 11-point scale corresponded to greater vaccination intention.

Figure 2. Panel A is a screen shot of a web page discussion MMR vaccine safety viewed by a parent in the intervention group while Panel B is the web pate discussing MMR vaccine safety shown to all parents in the control group. The menu on the left in Panel A is tailored to highlight the most important concerns identified by that parent, while all parents in the control group received the standard menu shown in Panel B. Both parents from the examples were Asian-American mothers between 25–34 y old with a male child age 11–15 mo. All parents first read an introductory page about the study and proceeded to the survey, then viewed either tailored or untailored vaccine information before completing the post-survey questions (see tabs at the top of both screens). The different levels of tailored used in the intervention are shown in Panel A. green, name tailoring; blue, content tailoring; red, image tailoring; purple, experiential tailoring.