Single Quantitative Study (e.g., Randomized Controlled Trial, Nonrandomized Controlled Trial, Case-Control Study, Cohort Study) Template | Citation (APA) | (Uchiyama, Kurosawa, & Inaba, 2006) | Title | MMR Vaccine & Regression in Autism Spectrum Disorders: Negative Results Presented from Japan | Database Source (& ID number) | PubMed (PMID: 16865547) | Type of Evidence | Non-experimental cohort study/casual comparative research | Hierarchical Evidence Rating Level | Level 4 | Your Summary of the Study/Publication (use paraphrasing, not quotes) | What was the stated research question/objective of the study? | To evaluate the correlation between the MMR Vaccine and Autism Spectrum Disorders | What research methodology was used (e.g., RCT, Case-Control, Cohort)? | Cohort StudyCasual Comparative Research | Describe the sample (including size)? | 904 patients with Autism Spectrum Disorders | How was the sample selected (e.g., randomization, inclusion/exclusion criteria)? | Inclusion Criteria: Young children born between 1976-1999 from the Yokohama Psycho-Developmental Clinic (YPDC) Regression reported from questionnaireExclusion Criteria: Young children who received the MMR Vaccine in foreign countries, reports denying regression in questionnaire, and subjects parents who provided no response or information on the questionnaire regarding regression. | What methods were used for data analysis? | The study analyzed data from clients of the Yokohama Psycho-Development Clinic. All patients diagnosed with ASD born between 1976 and 1999 were selected. A standard questionnaire was used to ask parents view of their child’s development, behavior, medical history, and present status. Patients were classified into three groups: Pre-MMR, MMR, and Post-MMR generations. These groups were classified into two further groups: regression and without regression. Analysis 1 analyzed the odds ratio for the association between regression and MMR exposure using MMR-subgroups above. Analysis 2 used all data across the three Generations and computed an odds ratio for the association between regression in ASD and exposure to MMR by combining data from three periods. All odds ratios are presented with 95% confidence intervals and categorical variables were compared by the two-sided Fisher’s exact test. The odds ratio was computed for the association between ASD and regression using the MMR Generation as the reference group. Comparison of the Pre-MMR and MMR Generations (analysis 3) Comparison of the MMR Generation and Post-MMR Generation (analysis 4) and comparison of the MMR Generation and the Pre-MMR and Post-MMR Generations combined group (analysis 5) | What were the results of the study? At what Level of Significance? | Analysis 1: Rate of regression lower in those who received MMR during the MMR era, but not statistically significantAnalysis 2: Lower rate of regression in children receiving MMR, but not statistically sifnificantAnalysis 3, 4, and 5:Rate of regression did not vary across the sub-group eras | What conclusions/implications for practice were drawn by the authors? | The rate of regression in those who received the MMR Vaccine was not higher than those who did not receive it. No statistical evidence that suggest the rate of regression in ASD was higher during the period when MMR was used compared to the “before” and “after” periods. | Your Critical Appraisal of the Study’s Appropriateness for Application to Clinical Practice | Was the research design appropriate for the research question (e.g., RCT for cause-effect questions, Case Control for harm or causation questions, Cohort for questions regarding prognosis)? Support your response. | Yes, the Cohort Study research design is appropriate. This study followed a group of subjects (MMR Vaccinated and Non-Vaccinated Children with and without regression) longitudinally over a period of time (1976 -1999) to determine the relationship (incidence of regression) across three MMR-program-related periods. | Was the sample size adequate? Was bias controlled with sample selection methods? Support your responses. | The sample size was not adequate for subjects who had received the MMR Vaccine. It was relatively small. Bias was not adequately controlled, as the study was conducted in a private clinic instead of using a population base study. This could potentiate selection bias. | Were the study results significant (level of significance)? Are the results valid and reliable? Is there a possibility of bias or of confounding variables? Support your responses. | The study results have limitations that decrease the level of significance as well as the validity and reliability. Firstly, participants were from a private clinic, thus potentiating selection bias. Secondly, the sample size of the subjects who received the MMR Vaccine was small. Thirdly, confounding variables defining regression were found. The questionnaire was the only instrument used to define regression. Information obtained on regression was reliant solely on parental report. “False Positives” of regression may have been present due to the limited questions and the fact that regression was not clinically assessed. Statistically, the data was accurate and odds ratios are presented with a 95% confidence interval. | Is the study and its findings directly applicable to your EBP question (match all selection criteria)? Support your response. | The study is directly applicable to our EBP question, “Do young children that receive immunizations have an increased risk of autism spectrum disorders than children who are not vaccinated?” The study includes the sample population (children), the intervention (receiving immunizations), the comparison (not receiving immunizations), and outcome (incidence of Autism Spectrum Disorders). However, the study focused on the rate of regression in those who received the MMR Vaccine. |