History of the Prognosis Methods Group. Exploratory meetings were held at the Dublin (2006), Melbourne (2005) and Ottawa (2004) Cochrane Colloquia. It was evident from these meetings that systematic reviews of prognosis are currently being undertaken and the majority of those who attended expressed strong interest in pursuing further discussions around the methodology of systematic reviews of prognostic studies. As a result, a Prognosis Review Network was established in 2004/5. Through the Network, members were provided information about recent published work in prognosis, potential collaborations were identified, and methodological questions related to prognosis reviews were answered. At the Dublin Cochrane Colloquium (2006), participants attending an open meeting agreed unanimously to work toward the establishment of a Prognosis Methods Group. Six convenors were identified to move the application forward. That application resulted in this group being established in 2008. Most of the activities of the Prognosis Review Network will now be undertaken by this Methods Group. However, the Prognosis Review Network will continue activities that are outside the scope of this group.
What is prognosis research? Prognosis research provides information about the long-term health and well-being of individuals with specific diseases or conditions. Prognosis studies can provide information on the likelihood of a particular outcome or disease recurrence; they can identify target groups for treatment, or suggest intervention strategies to modify factors associated with poor outcomes. Such information is required for health care decision- making and is not always available from clinical trials. Prognostic information may also inform diagnosis. Clinical decision models or tools that help clinicians make decisions following diagnostic testing require information about prognosis before thresholds for investigation or treatment can be calculated. Also, clinical course (i.e. prognosis) may be used to validate a diagnostic test in the absence of a 'gold standard' or reference test.
Individual prognosis studies often present inconsistent conclusions. Systematic review methods are increasingly being used in many topic areas to synthesize prognosis study findings. However, application of systematic review methods in the area of prognosis is in its infancy. Although basic principles to reduce bias and random error are similar to those used for intervention reviews, there are several challenges unique to systematic reviews of prognosis: lack of clarity in the indexing of these studies for bibliographic searches; low quality of primary studies; poor reporting; and difficulties in combining results across different research designs, analyses, and presentations of results.
What is its role in evidence review? Prognostic information is important for clinicians, health service providers and consumers. Prognosis systematic reviews will help provide best evidence for healthcare decision-making relevant to diagnosis, therapy and service delivery. The Prognosis Methods Group will have two primary roles: