Postpartum Mothers’ Attitudes, Knowledge, and Trust Regarding Vaccination

Abstract

Objective

To examine attitudes and knowledge about vaccinations in postpartum mothers.

Methods

This cross-sectional study collected data via written survey to postpartum mothers in a large teaching hospital in Connecticut. We used multivariable analysis to identify mothers who were less trusting with regard to vaccines.

Results

Of 228 mothers who participated in the study, 29% of mothers worried about vaccinating their infants: 23% were worried the vaccines would not work, 11% were worried the doctor would give the wrong vaccine, and 8% worried that “they” are experimenting when they give vaccines. Mothers reported that the most important reasons to vaccinate were to prevent disease in the baby (74%) and in society (11%). Knowledge about vaccination was poor; e.g., 33% correctly matched chicken pox with varicella vaccine. Mothers who were planning to breastfeed (P = .01), were primiparous (P = .01), or had an income <$40,000 but did not receive support from the women, infants, and children (WIC) program were less trusting with regard to vaccines (P = .03). Although 70% wanted information about vaccines during pregnancy, only 18% reported receiving such information during prenatal care.

Conclusion

Although the majority of infants receive vaccines, their mothers have concerns and would like to receive immunization information earlier. Mothers who are primiparous, have low family incomes but do not qualify for the WIC program, or are breastfeeding may need special attention to develop a trusting relationship around vaccination. Mothers would benefit from additional knowledge regarding the risks and benefits of vaccines particularly during prenatal care.

Introduction

Many parents have significant concerns about vaccination [1–4]. Adverse publicity such as the suspension of the rotavirus vaccine [5] and discontinuation of thimerosal-containing vaccines for infants [6] as well as reports (albeit unproven) linking autism and measles–mumps–rubella (MMR) vaccine can cause parents to be concerned about vaccination of their infants [7]. Such concerns about the side effects of vaccination are not new and were prevalent as long ago as the “Vaccination Act of 1853” which made vaccination against smallpox compulsory [8]. Today, however, the rapid spread of information and disinformation by means of internet technology and mass media can create an environment in which parents have a high likelihood of encountering antivaccination material [9, 10].

If infants are not vaccinated, diseases that have been dramatically reduced may increase in prevalence. Studies have demonstrated that the risks of measles and of pertussis are elevated in persons who choose exemption from vaccination [11–14]. Children who are underimmunized are more likely to have parents who have attitudes, beliefs, and behaviors indicative of concerns of safety of vaccines [2, 15]. At the same time, concerns about the safety of vaccination are also prominent in parents who immunize [16]. In one national telephone survey of parents, most parents understood the benefits of vaccination, but many had significant misconceptions that acted to decrease their confidence in vaccines [17]. One of the objectives of healthy people 2,010 is for 90% of young children to have full vaccination coverage; [18] thus, understanding parental concerns about vaccination is important.

Pediatric providers are frequently faced with explaining the importance of vaccination to parents who are exposed to television, newspaper, radio, and internet stories about vaccines. Despite the fact that these providers have the ability to influence a child’s immunization status, [15, 19–21] and that many parents rely on immunization information from their physicians, pediatricians spend only 1.9 min per visit discussing vaccinations and only 5% of families read vaccine information materials that are provided [22, 23]. It is not surprising that only 67% of parents report they have access to enough information to make a decision about immunizing their children [24].

Previously, we performed a qualitative study exploring decision-making about vaccinations for infants [4]. In this qualitative work, we found that the theme of trust in the medical establishment was a central concept. Comments associated with more favorable views toward vaccines included trusting the pediatrician, feeling satisfied by the pediatrician’s discussion about vaccines, not wanting to diverge from the cultural norm, and wanting to adhere to the social contract. Inhibitors, or reasons that mothers rejected vaccination, included feeling alienated by or unable to trust the pediatrician, having a trusting relationship with an influential homeopath/naturopath or other person who did not believe in vaccinating, worrying about permanent side effects, believing that vaccine-preventable diseases are not serious, and feeling that since other children are vaccinated their children are not at risk. While the qualitative study established the importance of trust in providers when making decisions on vaccination, its methodology did not allow assessment of how common lack of trust is and what factors determine lack of trust.

The goal of the study was to develop recommendations for guiding the parent–physician discussion on vaccines by quantifying the results of the qualitative study. The objectives of the study were to assess (1) the frequency that mothers have beliefs that are consistent with the promoters or inhibitors of vaccination, (2) the frequency that mothers do not trust their providers and what determines trust or lack of trust, and (3) maternal knowledge regarding vaccination. We hypothesized that a significant proportion of mothers would have beliefs that are consistent with inhibitors of vaccination and would have lack of trust in relationships with their providers because of the adverse publicity that vaccines have received. Furthermore, we thought that a high proportion of mothers would have concerns about vaccination and that maternal knowledge would be poor. Focusing on the attitudes of postpartum mothers is particularly relevant as their children are about to receive their first vaccinations. In the most recent recommendation, the centers for disease control and prevention emphasized the importance of receiving the hepatitis B vaccine birth dose [25]. To our knowledge, this is the first study to evaluate attitudes and knowledge of mothers during the immediate postpartum time period.

Methods

Study Design

This was a cross-sectional survey of postpartum mothers. A self-administered survey of postpartum mothers was conducted on the postpartum ward of a large teaching hospital that serves a diverse population with 4,700 births per year. Subjects were consecutive postpartum mothers who were present in the hospital on a weekday between June 2003 and August 2003. Eligible subjects included all mothers who had given birth 1–5 days previously, were English- or Spanish-speaking, and had delivered healthy newborns. The research assistant approached all mothers on the postpartum wards to determine eligibility. Mothers who had newborns who stayed in the neonatal intensive care unit for more than 24 h were excluded. The study was approved by the Yale University School of Medicine’s Institutional Review Board.

Survey Questions

The survey-tool was based on the results of our earlier qualitative study that assessed mothers’ decision making about vaccinations for their infants; [27] the major themes that were identified in the qualitative study [27] were the basis of the questions used in our survey. The tool, which took mothers approximately 30 min to complete, included 56 questions that used seven-point Likert scales, were multiple choice, matching, or ranking questions. Questions fell into the domains of knowledge about vaccines, promoters and inhibitors to accepting vaccination, and trust. We pre-tested the survey-tool both during our previous qualitative study as well as with nine postpartum pilot-participants in order to refine the questions and avoid socially desirable responses.

Questions addressing promoters of vaccination asked if mothers agreed that reasons to vaccinate were that: the benefits outweigh the risks, the pediatrician recommends vaccination, mothers have not experienced problems in past, mothers wanted to avoid feeling regret if their babies became ill because they were not vaccinated, and they felt that everyone gets their baby vaccinated. Questions regarding inhibitors of vaccination asked if mothers were worried about vaccinating their babies, were worried that the vaccine will not work, were afraid the doctor will give wrong vaccine, were afraid “they” are experimenting when “they” give vaccines, were not trusting of information doctors give about vaccines, felt diseases that vaccines prevent are not very bad, and felt if everyone else’s children are vaccinated, then their babies do not need to be vaccinated. To further assess inhibitors and promoters of accepting vaccination, mothers were asked to rank lists of inhibitors and promoters.

Because our qualitative work suggested that mothers who see homeopaths, naturopaths, herbalists, or chiropractors may decline immunizations for their children and have a low degree of trust in traditional pediatric providers, we included a question to assess use of alternative medicine providers. Also based on our previous qualitative work, [27] we developed nine questions to assess trust in the relationships with providers.

Analysis

Responses to the questionnaires were entered into a Microsoft Access database (Seattle, WA), and statistical analysis was performed using SAS statistical software (v 8.1 SAS Institute Inc, Cary, NC). Responses based on Likert scales were compressed into three categories of agree/neutral/disagree for analysis. We examined frequency distributions and univariate statistics of all of the questions. Associations between categorical variables were tested by the chi-square test (for proportions) or the Wilcoxon rank sum test (for distributions or medians) as appropriate.

We developed a trust rating for each mother by summing responses to the nine questions that assessed trust (Cronbach alpha = .74). Scores of 1–7 based on responses to Likert scales were given for each question, with “1” representing a low degree of trust and “7” representing a high degree of trust; the range of possible results for the trust rating was 7–63.

Because children who are white, [28] have higher household income, [29] receive WIC, [30] or have mothers who are older, [31] more educated, [31] and intend to breastfeed [30] are more likely to be vaccinated and first-born children are more likely to receive vaccinations on time, [32] we focused our analysis on these variables. We used multivariable linear regression to identify predictors of mothers who were less trustful with regard to vaccines. Variables with P < .2 were entered into the model in a stepwise manner and those with P ≤ .05 were retained. Variables that were included in the final model included race/ethnicity, parity, family income<$40,000, planning to breastfeed, and support from WIC. For all analyses two-tailed P values ≤ .05 were considered significant.

Results

Of 296 mothers approached, 228 (77%) completed questionnaires. Respondents and nonrespondents did not differ with respect to whether the newborn was in the NICU for less than 24 h or the date of birth of the baby. Of the nonrespondents, 6% reported that they could not read English or Spanish. Table 1 shows the characteristics of the mothers who participated in the study. The survey was completed in English by 93% of the mothers and in Spanish by the remaining 7%. For 39%, this newborn was their first-born, for 38% this was their second-born child. Seventy percent of mothers and 92% of the fathers were employed. Fifty-five percent of mothers and 53% of fathers had a college or higher education. Ninety-six percent of mothers planned to have their baby get vaccines, while 1% planned for baby to not get vaccines, .5% were not sure, and 2% reported that their baby will receive some vaccines. Of 216 mothers responding to the question, 2% reported that the family sees a homeopath, 3% naturopath, 1% herbalist, and 6% chiropractor.

Table 1.

Characteristics of mothers

Characteristic (N = 228)	%
Race/ethnicitya
White	67%
Black	11%
Latina	17%
First childb	39%
Maternal age, median	31 years (IQR: 26–35)
Plans to breastfeedb	75%
WICc	23%
Incomed
< $20,000	14%
$20,001–$4,000	12%
$40,001–$60,000	17%
>$60,001	57%
Baby to get none or only some vaccinese	4%
Child or mother sees homeopath, naturopath, herbalist, or chiropractorf	9%

^aN = 219

^bN = 222

^cN = 218

^dN = 166

^eN = 223

^fN = 216

Mothers were asked to rank reasons to vaccinate their babies. Seventy-four percent of mothers felt that preventing disease in their babies was the most important reason to vaccinate and 11% felt that preventing disease was the most important reason. Thirty-seven percent of mothers felt the second most important reason to vaccinate was to prevent disease in society and 20% felt their trust in the pediatrician or pediatric care-provider was the second most important reason to vaccinate. Table 2 shows the proportion of mothers who agreed with each reason to vaccinate. Seventy-eight percent felt that a reason to vaccinate is the pediatrician’s recommendation and 75% agreed that a reason to vaccinate was that they had no problems in the past. Sixty-nine percent of mothers stated their opinions about vaccines were most influenced by their pediatrician, while 5% were most influenced by another doctor or obstetrician.

Table 2.

Attitudes towards vaccination, N = 195

	All mothers (N = 195)	First-time mothers (N = 76)
Reasons to vaccinate
Benefits outweigh risks	89%	88%
Pediatrician recommends it	78%	76%
No problems in the past	75%	69%
Avoid feeling regret if baby became ill because not vaccinated	62%	61%
Everyone does it	13%	13%
Concerns about vaccination
Worried about vaccinating	29%	31%
Worried vaccine will not work	23%	26%
Afraid doctor will give wrong vaccine	11%	12%
Afraid “they” are experimenting when they give vaccines	8%	6%
Do not trust information from the doctor	7%	7%
Diseases that vaccines prevent are not very bad	5%	2%
If everyone else’s baby is vaccinated then mine does not need to be	3%	2%

Concerns about vaccinating are listed in Table 2. Twenty-nine percent of mothers reported that they were worried about vaccinating their babies in general. The entire study population of mothers were asked questions about specific concerns, 31% of all mothers worried about death from vaccination, 24% worried about immune problems, autism, or SIDS from vaccination, 23% worried about pain, and 22% worried about fever. Primiparous mothers did not differ in their responses significantly compared to multiparous mothers.

For the nine questions that related to trust regarding vaccination, the median score for the trust rating was 19 (range 9–40), on a scale from 7 to 63 with lower values representing lower degree of trust. Table 3 shows the percentage of mothers who agreed with each statement. The median response for each of the 9 trust questions was 4 (scale of 1–7) for mothers not planning to vaccinate and 5.9 for mothers planning to vaccinate (P = .005). On multivariable analysis, when controlling for race and ethnicity, mothers who were planning to breastfeed (P = .01), having their first baby (P = .01), or had an income <$40,000 but did not receive WIC (P = .03) were less trusting with regard to vaccines than were the other mothers.

Table 3.

Indicators of trust regarding vaccination

Question/statement	%Agreea
	All mothers (N = 223)	First-time mothers (N = 86)
Indicators of lack of trusta
1. Afraid doctor will give wrong vaccine	11%b	12%
2. Afraid “they” are experimenting when they give vaccines	8%b	6%
3. Do not trust information that the doctors give about vaccines	7%c	7%
4. Pediatrician is only allowed to tell me information about vaccines in a way that makes risks of vaccines seem low	6%d	4%
5. Pediatrician does not have time to talk with me about vaccines	3%e	0%
6. Pediatrician does not want me to ask a lot of questions about vaccines	3%b	2%
Indicators of positive trust
7. Comfortable talking to pediatrician about vaccines	94%b	91%
8. Reason to vaccinate is that the pediatrician recommends it	78%f	77%
9. Doctors are supportive of my worries about vaccination	73%c	69%

^aResponses to the seven-point Likert scale questions were grouped so that mothers who “strongly agreed,” “agreed,” or “somewhat agreed” with each statement about trust were included, i.e. 11% of all mothers “strongly agreed,” “agreed,” or “somewhat agreed” with the statement that they were afraid that their doctor will give the wrong vaccine

^bN = 220

^cN = 221

^dN = 217

^eN = 219

^fN = 223

Both first-time and experienced mothers scored poorly with regard to knowledge about vaccination (Table 4). When asked to match a vaccine with a disease that it prevents, 33% correctly matched chicken pox with varicella, 29% matched whooping cough with DTaP, and 16% matched liver cancer with hepatitis B. Ten percent responded that autism is a proven side effect of MMR, 8% believed vaccines cause immunological problems. When provided a list of common side effects of specific vaccines (fever, redness, soreness), 16% of mothers reported they were not sure which were the side effects associated with the specific vaccines.

Table 4.

Proportion of mothers who correctly matched disease with vaccine

Disease–vaccine match	All mothers (n = 188)	First time mothers (n = 74)
Measles with MMR	72%	70%
Chicken pox with varicella	33%	28%
Whooping cough with DTaP	29%	26%
Paralysis with polio	27%	30%
Meningitis with Hib or prevnar	17%	11%
Liver cancer with Hep B	16%	16%

Note: Differences between first-time mothers and experienced mothers were not statistically different. MMR was spelled as “MMR (measles, mumps, rubella)”

Seventy percent of mothers preferred receiving information about vaccination before or during pregnancy and 20% preferred to receive information during the first month of their baby’s life. Ninety-eight percent wanted information on diseases vaccines prevent, names of vaccines, and side effects. Only 18% had received information during their prenatal care.

Discussion

The strength of this study stems from its timing at the point when mothers are making their first decisions about vaccinating their infants. Our previous qualitative work had identified the prominent theme of trust in mothers’ attitudes regarding vaccination for their infants and categorized attitudes held by mothers. This quantitative work builds on and extends those findings in order to develop an approach to understanding which mothers are likely to have concerns about vaccinating.

This study has four key findings. First, although the majority of mothers hold beliefs that are consistent with promoters of vaccination, a substantial proportion of mothers have concerns about vaccines. Twenty-nine percent of mothers were worried about vaccinating, and 23% were worried that the vaccine would not be effective, even though these concerns did not keep them from vaccinating their newborns. When addressing vaccinations, providers should be aware that the proportion of mothers who have concerns is high even among mothers who choose to vaccinate their children. Other studies have shown that mothers have concerns about vaccination causing autism or other learning disabilities, [33] but it is striking that 31% of mothers in our sample were concerned about death of their children as a result of vaccination. Addressing these types of concerns for parents has the potential to improve vaccination rates as children are more likely to be vaccinated if their parents are less concerned about adverse events [2, 11, 34–37].

Second, we identified characteristics of mothers who were less trustful about vaccinations. Mothers who were planning to breastfeed, just delivered their first baby, or had an income <$40,000 but did not receive aid from WIC, were less trusting about vaccination when compared to the other mothers. Previous studies have demonstrated that children with lower household incomes are less likely to be completely immunized [16] and that mothers who prevent their newborn babies from receiving the hepatitis B vaccine are more likely to have intention to prolong breastfeeding [36]. One reason that intention to breastfeed is associated with less trust may be that mothers with higher levels of education tend to breastfeed, [38] and parents with higher education are more likely to expect to be active participants in their children’s health care decisions and are therefore less trustful [39]. Based on our results, we can suggest that some of the motivation behind such nonvaccinators refusing vaccination may be due to having a less trusting relationship with pediatric providers.

Third, both first-time and experienced mothers demonstrated poor scores with respect to knowledge about vaccination. Our results portray a situation for mothers whereby trust is a main promoter of vaccination while concomitantly knowledge about vaccination is lacking. This paradox places the vaccine program in a vulnerable situation: parents lack factual information to guide their decision-making when controversies or questions arise. Parents who feel that they lack adequate access to information about vaccination are more likely to have negative attitudes to vaccination, and improved understanding of immunization is postulated to lead parents to seek vaccinations for their children [24]. Healthcare providers and public health programs will need to provide parents with knowledge about vaccination as well as build trusting relationships.

Fourth, mothers preferred to receive information on vaccinations early, preferably before the birth of their children but only 18% had actually received such information. Because the first hepatitis B vaccination is recommended at birth, this early period is an important time to begin to generate trust with mothers about vaccination. In the future, pediatricians may want to consider partnering with obstetricians and midwives to begin the discussion on childhood immunizations before the birth of the children. The most recent US Preventive Health Service Expert Panel’s recommendations for the content of the prenatal visits includes “education to support and promote healthy behaviors, provide general knowledge about pregnancy and parenting…” [40]. We believe that “knowledge about parenting” should include knowledge about vaccinations and should be transmitted to parents during obstetrical prenatal visits or prenatal visits with pediatric providers. Our study found that primiparous mothers may be less trusting of vaccination, thus the pre-natal visit may be a particularly important time to focus on vaccination. Prenatal visits among urban, low-income mothers result in increased rates of breastfeeding, decreased emergency department visits, and improved doctor–patient relationships, [41] and have the potential to improve trust in vaccinations.

Our findings should be considered in light of their generalizability and validity. The generalizability of the study may be limited as the respondents were mostly Caucasian, English-speaking, and well-educated, and the sample size was relatively small. Despite the racial, ethnic, educational, and economic background of our population, our findings are consistent with results from a recent study showing that black and Hispanic parents, lower household income, and lower educational level were associated with high concerns about vaccination safety [42]. Thus, our study population actually provides an additional strength to our study because we examined a previously unstudied group. Validity of the results may be affected by response bias as 23% of questionnaires were not returned and some respondents purposefully or inadvertently skipped some of the questions. As with any survey of this type, the responses may be affected by social desirability bias which we attempted to preclude through our pilot testing.

The findings from this study imply that communication between pediatric providers and parents will benefit from a focus on improving knowledge and developing trusting relationships. In particular, work on developing trusting relationships and conveying information about vaccines should begin as early as possible and involve collaboration with obstetrical groups. Pediatric providers should recognize the high proportion of parents with concerns about vaccinating and may need to spend more time discussing vaccination with groups who may be more distrustful about vaccines.