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The SYSTEM initiative
University of the Witwatersrand
Systematic Review initiative for Evidence-based Minimum Intervention in Dentistry
Page last updated 20.08.13 / 08:12 by SM
Research Method

The work of SYSTEM is focused on conducting systematic reviews to interrelated aspects per clinical topic. SYSTEM champions quantitative above qualitative synthesis as it provides opportunities for detecting statistically significant treatment effects and improves precision of effect estimation by quantifying their outcomes. Thus quantitative collation of clinical information from separate trials (with or without meta-analysis) covering a particular treatment approach and comparison of materials used provides a more objective assessment of the currently available evidence.

There is still a general lack of randomised control trials (RCT) in dentistry (as compared to medical topics) and therefore SYSTEM has departed from the common approach of strictly considering RCT's for review, only. In this way lack of accepted trials for review and thus lack of information concerning the current status quo of clinical is avoided. Instead, SYSTEM has adopted a 2-way approach regarding the precision and internal validity of available clinical evidence from controlled trials:

In the judgement of internal validity of RCTs, SYSTEM's focus lies on the risk assessment of selection- performance/detection- and attrition bias. In regard to assessing selection- performance/detection bias, SYSTEM has also departed from the common practice and adopted stricter criteria. These criteria do include the common focus on

Adequacy of reported attempts for bias control but also includes focus on Adequacy of reported results of attempts for bias control.

In regard to assessment of attrition bias, the SYSTEM approach follows the quantitative method of sensitivity analysis by computation of assumed worst-case scenarios / clinical outcomes for study subject that have been lost to follow-up in the reviewed trials. This method was developed in collaboration with the help of Prof Paul Fatti from the School of Statistics & Actuarial Science, University of the Witwatersrand.

The above stated methods are novel to common systematic review methodology and have been applied successfully in SYSTEM's systematic review articles that were accepted in international peer-reviewed dental journals. Besides the adoption of these novelties, SYSTEM's methodology is based on common consensus for systematic reviews, i.e. as represented by the Cochrane collaboration and its reporting follows recommendations of the PRISMA statement.