Abstract
This paper is a critical review of an article on original research about the controversies surrounding ASD vaccination. The paper is divided into five sections. In the introduction, which is the first section, the study’s research problems and their significance to nursing are stated. Other aspects covered include justification of the study and conceptual framework. The second part is the methodology section whereby the study design, sampling, data collection instruments, and ethical concerns are addressed.
Under the results section, the sample characteristics, data analysis procedures, and a summary of the findings are highlighted. The discussion section covers how the authors relate the findings to the research objective and the limitations of the study. The last part is the overall presentation and final summary.
Introduction
The research problem for this study is that some parents with children who have autism spectrum disorder (ASD) fear that vaccines are linked with the regressive-onset variant of the condition. Consequently, such parents delay or refuse to have their children vaccinated against ASD even in cases where older siblings have the condition. The research problem is clearly stated in the article. This research problem is important to nursing because when parents start questioning the role of vaccines against ASD based on unproven claims, the affected children may not get the necessary intervention measures early enough to address the condition appropriately.
Prevention is one of the strategies used in nursing to minimize disease progression where possible. In this case, establishing whether vaccines are associated with regressive-onset ASD would help nurses in educating parents on the need to embrace preventive approaches towards this health condition.
The study is justified because, in 1998, Andrew Wakefield published a fraudulent paper claiming that the MMR vaccine caused regressive-onset autism. Even though the study has since been retracted, fears about a possible link between vaccines and regressive-onset autism have persisted. Therefore, this study is justified because it will help clear the fears and doubts associated with this issue. The authors stated the study’s hypothesis and objectives clearly. The objectives were to
(a) Investigate rates of vaccine receipt in a large, well-characterized sample of North American children with confirmed ASD diagnoses and standardized assessment of regression status and (b) examine whether there are differences in parent-reported rates of vaccine receipt by the pattern of ASD onset (Goin-Kochel et al., 2016, p. 1336).
The authors hypothesized that the rate of receipt of parent-reported vaccines would be the same in all ASD-onset categories.
The authors did not state any conceptual or theoretical framework for the study. However, it is implied in the article. By proving that regressive-onset ASD is not linked to vaccines, it would be easy to educate parents to allow their affected children to be vaccinated against this health condition and thus improve care outcomes in the long term. The framework is linked to the research purpose as the two seek to address the same issue – to establish whether vaccines are associated with the occurrence of regressive-onset ASD.
The literature review section is not included in the article. However, the authors referenced earlier studies on this topic especially in the introductory section where background information is given. Both old and current literature materials have been referenced. Out of the 38 sources used, four were published in the 1990s, 14 in the 2000s, and 20 after 2010. Therefore, it suffices to argue that the reviewed literature is current because the majority of the articles were published within 10 years of the study. Additionally, the literature review is organized logically with references being used appropriately to back the claims made concerning the topic.
The literature review also supports the need for the study. For instance, through the literature review, the authors established the publication of the fraudulent article that sparked controversy about the possibility of vaccines causing regressive-onset ASD. The authors have also used the literature review to establish studies that have been carried out on this topic in the past.
Methods
The descriptive study design was used for this research, and it fits the purpose of the study. The purpose was to establish the rate of vaccine receipt among the participants and assess whether these rates were different across all the ASD-onset categories based on reports from parents of the affected children. The study design involved collecting the relevant data on ASD vaccination history from parents through an extensive Medical History Interview (MHI) to establish at what point the involved children received their vaccine.
Therefore, the design fits the purpose of the study. Additionally, the design is linked to the sampling method and statistical analysis by providing the framework through which relevant data can be collected and analyzed. For instance, the sampling involved obtaining participant data through the SSC; 27, which is “a repository of clinical and genetic data from families who have a single child diagnosed with ASD and no other first- through third-degree relatives with ASD or suspected ASD” (Goin-Kochel et al., 2016, p. 1336). Therefore, the sample would provide relevant information based on the study design.
The sample is clearly stated and adequately described in the article. In total, 2755 children were recruited as participants for the study. Their characteristics were as follows – “86.4% male; M [SD] age = 9.0 years [3.6 years], range = 4 years to 17 years, 11 months; 78.5% White; 88.8% non-Hispanic). Frequencies of children in each ASD onset group were 922 (33.5%) for early onset, 1005 (36.5%) for plateau, 272 (10%) for delays-plus-regression, and 556 (20%) for regression” (Goin-Kochel et al., 2016, p. 1337). However, the authors did not justify the size of the sample.
The sampling procedure is also discussed in detail. Individuals that qualified as participants for the study were obtained via the Simons Simplex Collection [SSC; 27]. This repository has information about families with children or relatives diagnosed with ASD. The information was collected across North America by 12 sites acting on behalf of the SSC from 2007 to 2011. The study protocol involved obtaining ASD vaccination history during an extensive MHI, which was conducted with the affected children’s parents.
The participants were asked to indicate when their children had received any ASD vaccine and the timing of the same – whether it was “on schedule” or “delayed”. The instruments described in the article include interviews. The instruments measure the concept they are intended to measure. For instance, the study sought to establish the rate of ASD vaccine receipt and the timing of the same, which is what the interviews measured.
The concept definition (of vaccine receipt and the time of receipt) is consistent with the operational definition. The authors present information on the reliability and validity of the instruments. For example, one of the confounding factors of the interview question would be the phrase “given on schedule” because vaccination records for some of the participants were not available. Therefore, “given on schedule” was interpreted to mean that the parents accepted the vaccine the moment it was offered without delay or refusal.
This approach differentiated the participants based on those that received a specific vaccination, those that received it on schedule, and those that delayed their receipt. As such, the authors addressed threats to the internal and external validity of the interview as the chosen instrument for the study. The authors did not provide any evidence regarding the human subject’s review and approval by the relevant ethics committees. Similarly, there is no indication of any ethical concerns. Nevertheless, the study is described with enough detail for replication especially considering the large number of participants drawn all over from North America.
Results
The characteristics of the sample are described in detail. For example, the participant’s age, gender, race, and the number of children in each ASD-onset group are highlighted in the article. The two research questions are answered separately. The data collected indicated when the children received their ASD vaccination (on schedule or delayed) and the kind of vaccine received. The list of the vaccinations, which are considered for the study, included varicella, MMR, polio (injected or oral), Hib, HepB, and DPT/DTaP.
The authors analyzed data statistically using Stata version 12.1. For the demographic characterization and calculation of frequencies of the sample, descriptive statistics were used. A two-sided 90% confidence interval was used to compare parental reports on vaccination receipt across all ASD-onset groups. A TOST procedure was used to calculate the p-values, which were adjusted for each vaccine using the Holms step-down method. Tables and charts were used to present data. The text explains the data in the tables.
The results showed that vaccine receipt rates for each vaccine studied were significantly equivalent. In other words, parents did not delay or refuse to have their children vaccinated against ASD. These findings are contrary to previous reviews indicating that parents of children with ASD change their views and attitudes towards the vaccines, as they are associated with regressive-onset of the condition. Additionally, most vaccines are given between birth and the age of 18 months, while autism does not present until after the age of 24 months.
Therefore, parents who delayed or declined such vaccines could have done so because they were not concerned about their children having ASD in the first place. This explanation refutes the claim that parents delayed or refused ASD vaccines due to concerns associating the vaccines with the regressive-onset variant of the condition.
Discussion/Implications for Practice
The authors relate the findings to the study’s purpose by disproving the claims that parents delay or refuse ASD vaccines for their children due to concerns associated with autism induced by the vaccines. The findings are consistent with previous results from previous studies. For instance, recent surveillance studies by the CDC between 2007 and 2011 showed that the rate of receipt in the general population for DPT/DTaP, HepB, Hib, MMR, and polio was above 90% (Goin-Kochel et al., 2016).
These findings are consistent with those of the current study. The authors discussed the findings that conflict with previous work. For instance, two studies had indicated that parents with older children vaccinated against ASD are likely to refuse vaccination for their subsequent children. However, the authors of the current study noted that such works did not explain the reasons for such trends.
Limitations – the collected data was parent-reported, and thus it is subject to personal bias. Additionally, the reliability of the data depended on the parent’s capacity to recall when vaccines were given and their nature. Such information is prone to recall bias, and thus it could be unreliable. Moreover, it could be difficult to determine when vaccines were given because some records were missing. Therefore, in some cases, data indicated as “given of schedule” might be wrong.
The new research that emerged from this study is to repeat the research using vaccination records to avoid a recall and personal biases that affected the current study. The results are important to the nursing practice because nurses have a point of reference when educating and encouraging parents to have their children vaccinated against ASD without fear of the vaccines causing the delayed onset variant of the condition.
Overall Presentation and Final summary
The title accurately describes the type of the study, major variables, and the target population. For instance, from the title, it is clear that the study seeks to establish whether rates of vaccination differ by the type of ASD onset variant based on parental reports. The target population involves parents with children who have ASD. However, the abstract is not elaborate enough to represent the study accurately. While it states the research problem and the findings, the methodology and results sections are not covered clearly.
Despite this aspect, the report is logically consistent. The authors present the research problem, give background information, and carry out a structured study to prove their hypothesis. Additionally, the writing is clear and concise. The article is written in a language and style that could be understood by different readers even if they are not specialists in ASD vaccinations.
Reference
Goin-Kochel, R. P., Mire, S. S., Dempsey, A. G., Fein, R. H., Guffey, D., Minard, C. G., … Boom, J. A. (2016). Parental report of vaccine receipt in children with autism spectrum disorder: Do rates differ by pattern of ASD onset? Vaccine, 34(11), 1335-1342. Web.