As meta-interventions may fuel multiple, simultaneous changes in organisational processes and structures, studying such interventions requires recognition of the context at multiple levels of healthcare delivery [ 13].
As such, the NQRs may be defined as meta-interventions, signifying numerous features that possibly affect quality, and an almost infinite number of possible combinations of these features, particularly in relation to the local contextual conditions [ 12].
Taking these studies into account, there are aspects of the interplay between the politico-administrative and clinical levels within the regions which could constitute barriers and facilitators for quality improvement in relation to the meta-intervention NQRs.
In fact, summative and interactive component models are conceptually equivalent between meta-regression and multiple interventions meta-analysis, though multiple interventions meta-analysis offers additional benefits in terms of flexibility of the modelling approach.
According to meta-analysis, intervention group participants were slightly less likely to have suicidal and self-harm events than control group participants.
Statistical heterogeneity reflects the between trial variance of meta-analytic intervention effect estimates rather than the play of chance [ 76].
Another approach using combinations of components is, as Welton and colleagues [ 30] propose, to treat the multiple interventions meta-analysis as a meta-regression where individual components are entered as meta-regressors.
The use of clinically meaningful units in the construction of the network of evidence has clear parallels in the first applications of multiple interventions meta-analysis for the meta-analysis of trials of pharmacological interventions.
Though the standard assumptions concerning multiple interventions meta-analysis apply in this context (for a full discussion, see [ 1]), meta-analysis of multiple complex heterogeneous interventions may require additional assumptions.
Varying methods for evaluating the outcomes of single case research designs (SCD) are currently used in reviews and meta-analyses of interventions.
Finally, a 2010 meta-analysis on interventions trials to reduce falls after stroke has called for consistent and accurate methods of reporting and analyzing falls [12].
