Cohort study A defined group of participants is followed over time and comparison is made between those who did and did not receive an intervention.
Before-and-after study Comparison of outcomes in study participants before and after the introduction of an intervention. Cluster randomised trials A cluster randomised trial is a trial where clusters of people rather than single individuals are randomised to different interventions.
However, in the absence of individual patient data IPDor very detailed reporting of data broken down by participant characteristics, it is unlikely that inclusion can be restricted to particular types of participant or that detailed subgroup analyses will be possible.
More usually inclusion criteria will require that included studies report the main outcome. Details are given in Section 1. As analyses will depend on what data are available, and because it is difficult to anticipate all of the statistical issues that may arise, it can be difficult to pre-specify full details of the planned synthesis.
Publication bias occurs when the publication of a study is influenced by its results, hence inclusion of only published studies may overestimate the intervention effect. Studies of adults where childhood retinoblastoma was followed up into adulthood.
Case series Description of a number of cases of an intervention and the outcome without comparison with a control group. They may provide a useful starting point for subsequent reviews and updates; they may also improve the quality of conclusions about future research by indicating where new research has already commenced.
The protocol should also specify the methods which will be used to: Therefore researchers need to be clear about their own definitions and what elements are acceptable. The review may also consider the timing of outcome assessment and possible adverse effects of the intervention.
Where this results from a clearer understanding of the review question, it can be appropriate to carry out documented and justified amendments to the protocol. For reviews in some topic areas, these may be the only types of study available. The use of PICOS in the context of reviews incorporating different study designs is discussed in the relevant chapters.
In the example in Box 1. Example review objective and PICOS elements for a review protocol Review objective The objective of this review is to assess the clinical effectiveness of treatments for childhood retinoblastoma.
In reviews of one year or more duration, or reviews in rapidly evolving fields, provision for repeating the searches towards the end of the review process should also be considered.
Although titles and abstracts are translated in many databases, full papers are usually only available in their primary language. Further information is given in Section 1.
Interventions Any intervention or combination of interventions given for the treatment of retinoblastoma, including but not restricted to enucleation, external beam radiotherapy, chemotherapy, brachytherapy, cryotherapy, thermotherapy and photocoagulation.
In addition it may be useful to carry out current awareness searches to identify relevant papers as they are published. Study design Randomised controlled trials RCTs and controlled trials. If the review is considering cost-effectiveness or economic issues as well as clinical effectiveness, the relevant economic outcomes should also be specified.
However, it is not anticipated that many studies of these designs will be available. However, the protocol should outline how heterogeneity will be explored and quantified, under what circumstances a meta-analysis would be considered appropriate and whether a fixed or random-effects model or both would be used.
The potential biases from the inclusion of a range of study designs are discussed in Section 1. It should state whether a meta-analysis is planned, although whether a planned meta-analysis will ultimately prove possible will depend on the studies and data that are available.
The protocol should also specify the outcomes of interest and what effect measures will be used. Study design The types of study included in the review will play a major role in determining the reliability of the results and the validity of estimates of effect is linked to the study design.
Protocol amendments should be documented in a protocol addendum and in the final report of the review.
Where analysis of participant subgroups is planned, this should be specified in the protocol. The study design inclusion criteria given as an example in Box 1. While some study designs are clearly more robust than others, this should not be the only factor in determining which types of study are eligible for inclusion.
The approach taken will depend on the question and the topic, and also on the available time and resources. If foreign language papers are to be included, it may be necessary to specify translation arrangements.
For a detailed discussion of these issues see Section 1. Sensitivity analyses may be carried out to examine the effect of including data from conference abstracts. These elements of the review question, together with study design, will then be refined in order to determine the specific inclusion criteria that will be used when selecting studies for the review.
Randomised controlled trials The simplest form of RCT is known as the parallel group trial which randomises eligible participants to two or more groups, treats according to assignment, and compares the groups with respect to outcomes of interest.
Outcomes Any clinical outcome, including but not restricted to survival, progression-free survival, tumour response, preservation of the eye, visual acuity, disease remission and adverse effects.Systematic Review Protocol & Support Template This template is primarily intended to help you plan your review in a systematic way.
A copy of this completed form will be available via the intranet to help others carrying out reviews in the future and to avoid duplicating work already undertaken in the Centre. About this module.
Part of the Cochrane Interactive Learning course on Conducting an Intervention Review, this module explains why a review protocol is a crucial step in planning and delivering a systematic review.
A systematic review protocol describes the rationale, hypothesis, and planned methods of the review. It should be prepared before a review is started and used as a guide to carry out the review.
systematic review. However, since the outcomes of interest in this systematic review are the quantity, quality and relevance of health graduates and health practitioners the.
The PRISMA statement is essential reading before starting a systematic literature review. Editors increasingly expect authors of systematic reviews to use PRISMA or similar guidelines. The PRISMA checklist will guide you on HOW to develop a systematic review protocol and WHAT to include when writing up your review.
Template for a Systematic Literature Review Protocol 1. Change Record This should be a list or table summarizing the main updates and changes embodied in each version of the protocol and (where appropriate), the reasons for these.
Background a) explain why there is a need for a study on this topic.Download