Jorien Veldwijk

Preferences for Vaccination : Does Health Literacy Make a Difference?

Purpose. The purpose of this study is to examine to what extent health literacy is associated with parental preferences concerning childhood vaccination. Methods. A cross-sectional study was conducted among 467 Dutch parents of newborns aged 6 weeks (response rate of 37%). A self-reported questionnaire was used to measure health literacy by means of Chew’s Set of Brief Screening Questions, as well as parental preferences for rotavirus vaccination by means of a discrete choice experiment. Five rotavirus-related characteristics were included (i.e., vaccine effectiveness, frequency of severe side effects, location of vaccination, protection duration, and out-of-pocket costs). Panel latent class models were conducted, and health literacy and educational level were added to the class probability model to determine the association between health literacy and study outcomes. Results. Lower educated and lower health literate respondents considered protection duration to be more important and vaccine effectiveness and frequency of severe side effects to be less important compared with higher educated and higher health literate respondents. While all respondents were willing to vaccinate against rotavirus when the vaccine was offered as part of the National Immunization Program, only lower educated and lower health literate parents were willing to vaccinate when the vaccine was offered on the free market. Conclusion: Health literacy is associated with parents’ preferences for rotavirus vaccination. Whether differences in vaccination decisions are actually due to varying preferences or might be better explained by varying levels of understanding should be further investigated. To contribute to more accurate interpretation of study results, it may be advisable that researchers measure and report health literacy when they study vaccination decision behavior.

Consistency between stated and revealed preferences: a discrete choice experiment and a behavioural experiment on vaccination behaviour compared

BackgroundDiscrete Choice Experiments (DCEs) are increasingly used in studies in healthcare research but there is still little empirical evidence for the predictive value of these hypothetical situations in similar real life circumstances. The aim of this paper is to compare the stated preferences in a DCE and the accompanying questionnaire with the revealed preferences of young parents who have to decide whether to vaccinate their new born child against hepatitis B.MethodsA DCE asking parents to decide in which scenario they would be more inclined to vaccinate their child against hepatitis B. The stated preference was estimated by comparing the per respondent utility of the most realistic scenario in which parents could choose to vaccinate their child against hepatitis B, with the utility of the opt-out, based on the mixed logit model from the DCE. This stated preference was compared with the actual behaviour of the parents concerning the vaccination of their new born child.ResultsIn 80% of the respondents the stated and revealed preferences corresponded. The positive predictive value is 85% but the negative predictive value is 26%.ConclusionsThe predictive value of the DCE in this study is satisfactory for predicting the positive choice but not for predicting the negative choice. However, the behaviour in this study is exceptional in the sense that most people chose to vaccinate. Future studies should focus on behaviours with a larger variance in the population.

Parental preferences for rotavirus vaccination in young children: a discrete choice experiment.

OBJECTIVE This study aimed to identify characteristics that affect parental decisions about rotavirus vaccination, to determine the relative importance of those characteristics and subsequently to estimate vaccination coverage for different implementation strategies. METHODS A Discrete choice experiment (DCE) questionnaire was sent to the parents of 1250 newborns aged 6 weeks (response rate 37.3%). Mixed-logit models were used to estimate the relative importance of the five included rotavirus vaccine and implementation characteristics; vaccine effectiveness, frequency of severe side effects, protection duration, the healthcare facility that administrates vaccination and out-of-pocket costs. Based on the utility functions of the mixed-logit model, the potential vaccination coverage was estimated for different vaccine scenarios and implementation strategies. RESULTS All characteristics, except for healthcare facility that administrates vaccination, influenced parental willingness to vaccinate their newborn against rotavirus. Parents were willing to trade 20.2 percentage points vaccine effectiveness for the lowest frequency of severe side effects (i.e., 1 in 1,000,000) or 20.8 percentage points for a higher protection duration. Potential vaccination coverage ranged between 22.7 and 86.2%, depending on vaccine scenario (i.e., vaccine effectiveness and protection duration) and implementation strategy (i.e., out-of-pocket costs and healthcare facility that administrates vaccination). CONCLUSIONS When deciding about vaccination against rotavirus, parents are mostly driven by the out-of-pocket costs, vaccine effectiveness, protection duration, and frequency of severe side effects. The highest vaccination coverage is expected for a vaccine with high effectiveness and protection duration that is implemented within the current National Immunization Program context. Implementation of the same rotavirus vaccine in the free market will result in lowest coverage.

Overweight and School Performance Among Primary School Children: The PIAMA Birth Cohort Study

The aim of this study was to assess the association between overweight and school performance among primary school children prospectively and including a broad range of potential confounding factors. In addition it was investigated what factors mediate this association. For this purpose, data of 2,159 12‐year‐old children who participated in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study were used. Two indicators of school performance were parental reported when children were 12 years of age and included (i): the score on a standardized achievement test that Dutch children have to complete at the end of their primary education (Cito)‐test and (ii): the teachers advice regarding a childs potential performance level in secondary education. Childrens height and weight were measured by a trained research assistant at the age of 8 and by their parents at the age of 12. Overweight was defined using age and gender specific cut‐off points. Multivariate regression analyses were performed to assess the association between overweight and school performance. Besides, both confounder and mediation analyses were conducted. Results showed lower Cito‐test scores and lower teachers school‐level advice among overweight children. These associations were no longer significant when adjusting for parental educational level, skipping breakfast, and screen time. This study found no independent association between overweight and school performance among primary school children. Results showed strong confounding by parental educational level.

The prevalence of physical, sexual and mental abuse among adolescents and the association with BMI status

BackgroundStudies among adults show an association between abuse and Body Mass Index (BMI) status. When an aberrant BMI status as a consequence of abuse is already prevalent in adolescence, early detection and treatment of abuse might prevent these adolescents from developing serious weight problems and other long-term social, emotional and physical problems in adulthood. Therefore, this study investigated the prevalence of physical, sexual and mental abuse among adolescents and examined the association of these abuse subtypes with BMI status.MethodsIn total, data of 51,856 secondary school students aged 13–16 who had completed a questionnaire on health, well-being and lifestyle were used. BMI was classified into four categories, underweight, normal weight, overweight and obesity. Adolescents reported if they had ever been physically, sexually or mentally abused. Crude and adjusted General Estimation Equation (GEE) analyses were performed to investigate the association between abuse subtypes and BMI status. Analyses were adjusted for ethnicity and parental communication, and stratified for gender and educational level.ResultsEighteen percent of the adolescents reported mental abuse, 7% reported sexual abuse, and 6% reported physical abuse. For underweight, overweight and obese adolescents these percentages were 17%, 25%, and 44%; 7%, 8%, and 16%; and 6%, 8%, 18% respectively. For the entire population, all these subtypes of abuse were associated with being overweight and obese (OR=3.67, 1.79 and 1.50) and all but sexual abuse were associated with underweight (OR=1.21 and 1.12). Stratified analyses showed that physical and sexual abuse were significantly associated with obesity among boys (OR=1.77 and 2.49) and among vocational school students (OR=1.60 and 1.69), and with underweight among girls (OR=1.26 and 0.83).ConclusionMental abuse was reported by almost half of the obese adolescents and associated with underweight, overweight and obesity. Longitudinal analyses are recommended to explore the causality of and the mechanisms explaining this association between abuse and overweight.

The preferences of users of electronic medical records in hospitals: quantifying the relative importance of barriers and facilitators of an innovation

BackgroundCurrently electronic medical records (EMRs) are implemented in hospitals, because of expected benefits for quality and safety of care. However the implementation processes are not unproblematic and are slower than needed. Many of the barriers and facilitators of the adoption of EMRs are identified, but the relative importance of these factors is still undetermined. This paper quantifies the relative importance of known barriers and facilitators of EMR, experienced by the users (i.e., nurses and physicians in hospitals).MethodsA discrete choice experiment (DCE) was conducted among physicians and nurses. Participants answered ten choice sets containing two scenarios. Each scenario included attributes that were based on previously identified barriers in the literature: data entry hardware, technical support, attitude head of department, performance feedback, flexibility of interface, and decision support. Mixed Multinomial Logit analysis was used to determine the relative importance of the attributes.ResultsData on 148 nurses and 150 physicians showed that high flexibility of the interface was the factor with highest relative importance in their preference to use an EMR. For nurses this attribute was followed by support from the head of department, presence of performance feedback from the EMR and presence of decisions support. While for physicians this ordering was different: presence of decision support was relatively more important than performance feedback and support from the head of department.ConclusionConsidering the prominent wish of all the intended users for a flexible interface, currently used EMRs only partially comply with the needs of the users, indicating the need for closer incorporation of user needs during development stages of EMRs. The differences in priorities amongst nurses and physicians show that different users have different needs during the implementation of innovations. Hospital management may use this information to design implementation trajectories to fit the needs of various user groups.

Body mass index and cognitive ability of young children.

Objective: This study prospectively assessed the association between body mass index (BMI) and cognitive ability of young children, while accounting for confounding factors. Methods: The study included 236 children born between 1990 and 1994 participating in a Dutch birth cohort study. Anthropometric data of the children at birth, 4, and 7 years of age were collected from growth records or measured at the Academic Hospital of Maastricht. The Kaufman Assessment Battery for Children (K-ABC) was used to assess cognitive ability at 7 years of age. The association between BMI and cognitive ability was investigated using univariate and multivariate linear regression analyses, including various covariates. Results: Although the results suggest that cognitive ability at 7 years of age decreased with increasing BMI at 4 years and 7 years of age, this association was not significant in any performed analysis. Multivariate analyses showed that maternal intelligence was strongly associated with all scales of the K-ABC as a significant covariate. Adjusting analyses for physical fitness of the child, maternal education, maternal pre-pregnancy BMI, maternal smoking during pregnancy, and birth weight did not change the results. Conclusion: This study found no evidence for an association between BMI and cognitive ability of school-aged children.

The effect of out-of-pocket costs and financial rewards in a discrete choice experiment: an application to lifestyle programs

BackgroundBoth out-of-pocket costs and financial rewards can be used to influence health related behavior. However, it is unclear which of these two has a larger effect on health related behavior. The aim of this study was to explore the possible difference in effect size between out-of-pocket costs and financial rewards on the willingness of diabetes mellitus type 2 (DM2) patients to participate in a lifestyle program.MethodsA discrete choice experiment (DCE) questionnaire was sent to 767 DM2 patients in a geographically defined area (De Leidsche Rijn, Utrecht) in The Netherlands and completed by 206 of them. The questionnaire comprised of 18 choice tasks of which 9 contained a financial reward for lifestyle program completion, while the other 9 included out-of-pocket costs for program participation. In a second version of the questionnaire, the order of out-of-pocket cost and financial reward choice tasks was counterbalanced to reduce bias with respect to the position (first or second) of the two types of choice tasks. Panel-mixed-multinomial-logit models were used for data analysis.ResultsIncreasing out-of-pocket costs were associated with a decreasing willingness to participate in a lifestyle program and, contrary to our expectations, increasing financial rewards were also associated with a decreasing willingness to participate in a lifestyle program. In addition, this willingness to participate changed to the same extent for both increasing out-of-pocket costs and increasing financial rewards.ConclusionsAs expected, increasing out-of-pocket costs may prevent people from deciding to participate in a lifestyle program. However, offering a financial reward to persuade people to participate in a lifestyle program, may result in decreasing willingness to participate in a lifestyle program as well.

Preferences for genetic testing for colorectal cancer within a population-based screening program: a discrete choice experiment

This study explored individuals’ preferences for genetic testing for colorectal cancer (CRC) in a screening situation and their willingness to participate in genetic testing for Lynch syndrome, familial adenomatous polyposis (FAP), and familial colorectal cancer (FCC). For that purpose, 532 respondents aged 55–65 years completed a Discrete Choice Experiment. Using panel latent class models, the preferences for two screening situation characteristics (the probability of being genetically predisposed and the probability of developing CRC) and screening test characteristics (the frequency of preventive colonoscopies and CRC survival) were estimated. Based on these preferences, respondents’ willingness to participate in the three screening initiatives was estimated. Lower-educated respondents and respondents who express serious anxiety and worries found colonoscopy frequency and the probability of developing CRC relatively more important and survival relatively less important compared with higher-educated respondents and respondents who express no anxiety and worries. These differences in preferences resulted in opposite preferences for participation in FCC and FAP screening. In conclusion, the general population is willing to participate in genetic screening for CRC. If individuals are suspected of genetic or familial CRC, they should at least be informed about their increased risk of being genetically predisposed and about the importance of participating in all preventive follow-up colonoscopies in order to maximize survival.

Vaccine preferences and acceptance of older adults

BACKGROUND Expanding vaccination programs for the older population might be important as older adults are becoming a larger proportion of the general population. The aim of this study is to determine the relative importance of vaccine and disease specific characteristics and acceptance for Dutch older adults, including pneumococcal disease, herpes zoster, pertussis vaccination, and influenza vaccination. METHODS A discrete choice experiment was conducted to generate choice data that was analyzed using a mixed multinomial logit statistical model. RESULTS Important factors that were associated with vaccination acceptance in older adults are high mortality risk of the infectious disease, high susceptibility of getting the infectious disease, and high vaccine effectiveness. Age, influenza vaccination in 2013 and self-perceived health score were identified as personal factors that affect vaccine preference. Potential vaccination rates of older adults were estimated at 68.1% for pneumococcal vaccination, 58.1% for herpes zoster vaccination, 53.9% for pertussis vaccination and 54.3% for influenza vaccination. For persons aged 50-65, potential vaccination rates were estimated at 58.1% for pneumococcal vaccination, 49.5% for herpes zoster vaccination, 43.9% for pertussis vaccination and 42.2% for influenza vaccination. For persons aged 65 and older, these were respectively 76.2%, 67.5%, 57.5% and 65.5%. DISCUSSION Our results suggest that older adults are most likely to accept pneumococcal vaccination of the four vaccines. Information provision accompanied with the implementation of a new vaccine has to be tailored for the individual and the vaccine it concerns. Special attention is needed to ensure high uptake among persons aged 50-65years.