Coding Scheme for the Cochrane Consumers and Communication Review Group (CCCRG) Specialised Register

Tags: Poster
Stoelwinder J, Hill, S, Oliver S, Broclain D, Wensing M, Brewer L

Objective: To develop a method of coding the trials in the CCCRG Specialised Register in relation to the scope of the Group, the interventions undertaken and the outcome measures used.

Methods: An alphanumeric coding scheme was developed to facilitate the coding and analysis of the 2545 trials in the Procite database. The coding scheme was pilot tested on 50 trials, revised, tested independently on another 25 trials, then re-tested on a further 50 trials, before a final version was agreed. Selection of concepts and terms to include in the coding was made from the Group's scope and the interventions and outcomes of interest to the Group, from knowledge of the subject range of the trials in the register, and from the interventions and outcomes listed in relevant systematic reviews. Whilst there are five broad areas of the Group's scope, there are a wide range of types of communication based interventions and outcome measures. This meant the various expressions for the same concepts were grouped to facilitate coding and analysis. Alphanumeric codes were allocated in a format to facilitate searching and counting the number of trials indexed by particular concepts and to allow for insertion of additional terms and adjustments to the scheme. Each trial may be coded for more than one scope area, intervention or outcome measure.

Results: Trials in the register may now be coded by the broad scope areas; by the intervention, indicating direction of the communication between health provider and consumer, by the type of communication strategy, the setting of the intervention, and the communication medium used; and by the outcomes as consumer oriented, health care provider oriented or health service delivery oriented. A further level of coding is used to provide more detailed analysis of the interventions and outcomes. For example, under the broad heading of Consumer oriented outcomes (Code:N) there are nine groupings of outcomes. One of these is Health status and wellbeing (Code: N7), with the more detailed coding to the level of Physical health (Code: N7g), Psychological health (Code: N7m) and Psychosocial outcomes (Code: N7q). Counting the number of trials in the register that are relevant to particular areas of the scope or by particular intervention or outcome is possible by searching by the alphanumeric code to the level required. This project commenced in October 2001, and as of 6 March 2002, 814 trials have been coded.

Conclusions: The coding scheme that we have developed will serve the purpose of:

* identifying and coding interventions and outcomes from studies that are relevant to our Group,

* provide a means for input to the analysis of the studies in our register,

* using the grouping of terms when searching for studies with particular types of interventions or outcome measures in addition to the usual searching by free text or thesaurus terms,

* provide a checklist of outcomes that reviewers may need to consider,

* help with gap analysis of the current reviews,

* assist with the planning and prioritizing of future reviews.