Quality appraisal
The CASP (critical appraisal skills programme, 2006) framework
was used and adapted to appraise the quality of
the research. However, relevance to the study rather than
any clinical service or organisation was a minor but necessary
adaptation of the framework. The key questions asked
when reviewing the studies are included in Table 2. The
studies were initially reviewed by one author (LRC). Subsequently
peer scrutiny of study reviews and the overall
methodological or quality issues across the body of literature,
took place in regular meetings.
The remaining 26 studies were included since they were
deemed to be sufficiently rigorous, credible and relevant to
include for full review. Some issues were identified during
the quality appraisal (see Table 3). Whilst these issues were
not sufficient to exclude the studies they did demonstrate
the great diversity in designs as well as being important
considerations when interpreting the overall synthesis in
this review. An overview of key methodological issues is
presented in Table 3. The issues are cross-referenced to
individual studies summarised in Table 4.