: A Case of Vaccination on Systematic Review Analysis

This study tries to provide a comparative analysis of the systematic review of economic evaluation literature available about vaccines. PubMed database were searched by using the following keywords: “vaccination/economics [MeSH]”. All articles were included if: 1) A literature or systematic review of vaccination studies; 2) primary or secondary data; 3) published in English; 4) related to human. Exclusion criteria were as followings: 1) editorial, review or methodological articles; 2) not in health sector; 3) not applied from 2009 to 2013. From 22 records found, eleven articles met selection criteria. Only 27.3 percent (3 of 11 studies) was recorded about the methodology of conducting systematic review studies based on the PRISMA, and AMSTAR guideline. Two of eleven studies (18.1 percent) in this review, the authors evaluated the quality of vaccination systematic review studies with different levels including “Moderate” to “Moderate to good” and “Moderate to good”. According to this study, it helps to understand the current situation for conducting and reporting the economic evaluation of vaccination systematic review studies. Currently, the large number of studies and systematic reviews on the effects of vaccination, high quality evidence to inform policy decisions on how best to use vaccination in health care is still lacking


INTRODUCTION
vidence-based policy making can rarely rely on single studies, so policy makers and the researchers that support them try to make best use of the various partially relevant studies already available 1 . Nowadays, economic evaluation studies is very important to ameliorate decisions about apportion of human resources in health care. Economic evaluation of drugs, medical devices, services and interventions is a useful tool for assessing important decisions regarding the optimal utilization of scarce resources 2 . Nevertheless, systematic reviews of economic studies have become a key feature of many policy making and technology assessment processes, and also a common form of published study in certain health economics journals 1 . The healthcare literature contains hundreds of thousands of studies of healthcare interventions, growing at tens of thousands per year 3 . More recently, calls have been made for 'rapid reviews' to provide decision-makers with the evidence they need in a shorter time frame, but the possible limitations of such 'rapid reviews', compared to full systematic reviews, require further research 4 .
In the last two decades, several vaccines have been developed that target a range of infectious diseases of global public health importance.
Vaccines may bring economic benefits beyond just health gains and there may be various pathways for these benefits to accrue. Unlike other health interventions, studies find that vaccines avert illness both directly through immunization and indirectly through herd immunity 5 . While all such changes can have an immense impact on a country's economy, it is difficult to get a full picture of the economic impact resulting from immunization. Understanding the full economic benefits of vaccines is vital to policy makers whose decisions to introduce new vaccines not only impact the health of a society, but also its economy. Evidence on such economic benefits is therefore critical in assessing the full return on investment in vaccines 6 . Current systematic reviews, within economic evaluation types (including cost minimization analysis (CMA), cost effectiveness analysis (CEA), cost utility analysis (CUA), cost benefit analysis (CBA). However, in some economic evaluation types, no systematic review currently exists and there may be few or even no trials. A systematic review of systematic reviews is a means of summarizing current evidence across specialties of the same or very similar intervention, to provide a synthesis of treatment effects 7,8 .
In the last two decades, several vaccines have been developed that target a range of infectious diseases of global public health importance 7 . However, the list price of these vaccines in high income countries is substantially greater than for traditional vaccines. Recently, several frameworks have been proposed by which these wider benefits of vaccination can be categorized 4,9 . Nevertheless, the extent to which these broader benefits are considered in current economic evaluations of vaccines is unclear.
This study tries to provide a comparative analysis of the literature review including: general information, the methods and the quality of systematic reviews on the economic evaluation of vaccination studies with the purpose of synthesizing evidence to date on the effectiveness of vaccination in various countries between 2000 and 2013. This study also analyses the vaccination systematic review studies including: The design, the method or guidelines (e.g. PRISMA, York and so on), keywords and searching, databases, the quality checklist of papers reviewed, presentation format (quality checklist of the review).

Literature Search
This study was designed as a systematic review that was carried out in December 2013 to identify vaccination systematic review studies conducted in many countries with a combination of key words and MeSH term. PubMed databases were used for searching with the following keywords were used in different combinations: "vaccination/economics [MeSH]" with filter criteria: Systematic review, five years ago and human.
All publications were included if: Systematic review set out to identify and include all articles that included a literature review of vaccination studies. Published articles were considered studies that used primary or secondary data. Economic evaluation studies were published in English language and were related to humans. All publications were excluded if: They were editorial, review or methodological articles and did not present both the costs and outcomes of a study. Studies were also rejected if they were not in health sector, were not implemented in humans and were not applied from 2009 to present. Figure 1 illustrates the progress of selection of articles.

Evaluation of Studies
This study was analysis two parts, such as: general information section including the number of vaccination economic evaluations published per year, number of paper reviewed in economic evaluations of vaccines review studies, type of the design or the method or guidelines, number of databases, and the quality of economic evaluation.
About the quality and strength of evidence presented in the individual, included reviews should influence the conclusions drawn in the systematic review of these. Although the researchers will usually have to do this via an assessment of the quality of report, with the hope that initiatives such as design or method or guideline (e.g. PRISMA, York), keywords and techniques, databases, quality checklist of papers reviewed, presentation format (quality checklist of the review). Two reviewers were separately reviewed for all of articles. After comparison of the results, two reviewers had discussed.

The
search yielded 22 articles about vaccination/economic from PubMed database between January 2009 to December 2013. Based on inclusion and exclusion criteria, 11 remain publications related this study. Reviewers applied the inclusion and the exclusion criteria to remain 11 papers after two steps: reviewing their title and abstract, reviewing their full-text due to mentioned to Portuguese study and not researched about systematic review, not accessed to full-text. Table 1 illustrates the amount of publication year by year from 2009 to 2013. According the table, we can see that the number of papers were stable from two to three studies. However, in 2010, there is no study to review in this field. Of the 11 systematic review studies selected, 4 studies (3 studies had conducted in 2012 and one study were conducted in 2013) reviewed many different vaccination studies. Furthermore, seven of 11 studies evaluated the economic evaluation of one vaccination studies including: rubella vaccination, Herpes Zoster vaccination, Pneumococcal Conjugate vaccination, autoimmune inflammatory rheumatic diseases, influenza vaccination, pneumococcal polysaccharide vaccination and human papillomavirus (HPV) vaccine. Table 1 also shows the number of articles in economic evaluations of vaccines review studies. In above table, we can see in 11 papers, number of paper studies less than or equal to 20 is five articles (45.2 %). The number of paper studies from 21 to 100 and over 100 studies are four (36.4 percent) and two (18.2 percent) papers, respectively.

General Information Section
Of two literature reviews with over 100 studies, first study examined the cost effectiveness and economic benefits of vaccines in low-and middle-income countries and authors in this review defined 108 relevant articles from 51 countries spanning 23 vaccines from three major electronic databases (PubMed, EmBase TM , and Econlit) ( For developing search strategy and locate studies, searching is the stage where a reference librarian can be extremely helpful in terms of helping to develop and run electronic searches.

International Journal of Pharmaceutical Sciences Review and Research
Available online at www.globalresearchonline.net    (Table 3). Table 6 provides information that articles evaluated in this review (N=11).
At present, there are many instruments to evaluate quickly and accurately measure aspects of the quality health economics studies and has been used to identify evidence to enhance decision-making of quality of studies.
A high score on the quality of checklist of papers reviewed guidelines indicates a study better quality. When using the results to identify potential gaps in the evidence on the economics of vaccination as it relates to helped reduce the burden of disease and mortality from infection disease.
According to Table 4, there are five (45.5 percent) the economic evaluation of vaccination systematic review studies to evaluate the quality of checklist of papers reviewed.
Many the quality of checklist of papers reviewed guidelines were evaluated by different authors. For instances, the guidelines embrace the Quality of Health Economics Studies questionnaire (QHES), British Medical Journal guidelines (BMJ), Grades of Recommendation Assessment, Development and Evaluation (GRADE), The Consensus on Health Economic Criteria list (CHEC) and Drummond. guideline. Six studies which were not mentioned the quality of checklist guidelines are account for 54.5 percent.
We were recorded two studies of 11 (18.2 percent) which were mentioned the quality of each studies ( Table 5).
The authors in these studies evaluated the vaccination systematic review studies two results, including "Moderate" to "Moderate to good" and "Moderate to good". Nine studies (81.8 percent) were not evaluated the quality of articles reviewed. Three of nine studies had gave the quality checklist of papers reviewed, however the authors were not mentioned the results because of differences in study design and specific data elements collected, we were unable to compare studies or evaluate data quality.    n/a n/a n/a Notes: 1=Yes; 2= No; 3= Can't answer; 4= Not applicable; "Can't answer" is chosen when the item is relevant but not described by the authors; "not applicable" is used when the item is not relevant, such as when a meta-analysis has not been possible or was not attempted by the authors.