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Introduction  – RCT
a background

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Randomised controlled trials (RCTs) are largely considered
the “gold standard” within evidence-based research (Grossman and Mackenzie 2005).

They have been seen as
holding the highest ranking in the ‘evidence hierarchy’ (blackwood). However, even the most zealous advocates of RCTs will
admit there are certain problematic elements of RCTs (Ibid). Michael Rawlins, Chairman of the
National Institute for Health and Clinical Excellence (NICE) calls the attempt
to place evidence in hierarchies ‘illusory’ and the placement of RCTs at the
top as ‘an undeserved pedestal’ (Rawlins, 2008). Often they can be
ethically questionable, due to the existence of the control group (Meldrum
2000). Logistically carrying out a trial with real-world constrictions of cost
and time is not always feasible (O). Furthermore, the absence of external validity is often the most common criticism of RCTs
(Rothwell 2006). To what extent can the results of a given study applied
to other groups is perhaps the greatest weakness of RCT’s (Rothwell 2005). RCT’s can be considered to have
another weakness depending where you stand as a researcher, positivist or
social constructivist. There are those who considered the positivistic nature
of RCT’s prevents it from unpacking complex causal mechanisms, which can help
explain why a given intervention has an effect (reference). This essay hopes
to address to what extent qualitative research methods used in conjunction with RCTs can help shed light
upon the causal mechanism and therefore is this the only way that RCTs should
be used by policy makers. 


This essay will focus upon that debate about around RCT’s
ability to “unpack” complex interventions. There can be little debate around
RCTs strength when dealing with pharmaceutical trails or certain medical trails
(Feneck, 2009). However, the current RCT debate that rages is it possible for
an RCT, which is aware of its potential shortcomings has the ability to explain
the causal mechanisms of complex interventions (Porter and O’Halloran, 2012).


Complex interventions – a MRC framework


There is now perhaps a conesus and awareness about the
limitations of RCT’s when it comes to understanding complex interventions (reference). As a result, the Medical Research
Council (MRC) produced a framework that would attempt to address the complexity
of developing and evaluating complex healthcare interventions, in an attempt to
overcome some of the limitations of the RCT (Medical Research Council,
2000, 2008).


The framework provided a step-by-step guide as how to
approach and RCT addressing a complex intervention. There are 5 different
phases that the MRC guidelines suggest. Firstly, a sound hypothesis should be
formed embedded in theory and evidence. Following this step the researchers
must identify the components of the intervention. Determining how these
component’s mechanisms will work. Both these first two stages may integrate
qualitative methods to describe component and their mechanisms. The third stage
is the exploratory trial and the conduction of the RCT. There are a final two
stages proposed by the MRC. Firstly, a definitive RCT is central step in
evaluating the effectiveness of the complex intervention. Finally, a process evaluation,
aiming to understand how local context influenced outcomes. This final stage
hopes the address some of the external validity issues often associated with
RCTs. So the MRC is grappling with the issue of complexity in health services
research by declaring that there is value to be achieved through using other
research methods, including qualitative strategies, to inform the development
and evaluation of complex interventions.


Critique of the MRC framework


The question that we wish to address here is how
successfully does the MRC framework address the limitations of the RCT’s when
dealing with complex interventions. The supplement RCTs with various qualitative
methods appears to be a neat solution to the epistemological difficulties presented
by complex interventions (Porter and O’Halloran, 2012). Nonetheless, there a
potential issues with this MRC framework.


One of the core challenges is that the MRC framework is the
bridging the divide of positivism and realism (Denzin and Lincoln, 2000).

Undoubtedly, there may be some difficulty in integrating qualitative methods
within an RCT experimental design. It could be argued that the schism of
positivism and social constructivism are mutually exclusive. However, this
dichotomous viewpoint hides more than it illuminates (reference). Though there a core epistemological differences
in the theory that has developed these different methodological research
methods moving past that divide will undoubtedly benefit research (reference).


Though the MRC framework attempted to address the lack of
the RCT’s ability to address the causal mechanisms of complex innervations
there are those who still argue it was unsuccessful. The MRC framework could
perhaps benefit form the incorporation of what has been coined the ‘realist
RCT’ (Bonnel et al 2012)   


Realism to Realist RCTs


Realism has been argued as to be the panacea of RCT’s
problems in relation to complex interventions (Boneell etal 2008)(Pawson and Tilly ???). A realist
RCT would look at the how multiple components interact, by looking at these components
alone and together (Ibid). Factorial trials (Montgomery et al., 2003) could be used
to do this and there are a number of of this research projects that conducted
this (Dangour et al., 2007; Flay et al., 2004).


Secondly, a realist RCT advocates the use of additional strategic and synchronized
approaches to test the effects of interventions. They also seek to understand
how the components of the RCT work in different contexts using consistent
measures where possible eg (Breitenstein et al., 2010). Perhaps there
are already elements of this in cluster RCT’s. Realist argued that it should be
a core component of all RCT’s (Strange et al., 2002). Examples of RCTs attempts
to do this, are characterised and by the inconsistent measures of contexts (Armstrong
et al., 2011). More consistent measurement of context is recommended in
theorization of hypotheses. The aspects of the context may be significant for the
interventions so that projects can be designed to examine these possibilities.

(Bonnel et al 2012)


Thirdly, realist RCTs should utilise both qualitative and
quantitative research methods (Palinkas et al., 2010). Qualitative research can
cultivate hypotheses around defining the most important intervention components,
how they work and the context impact on implementation and effect.


Furthmore, realist RCTs would aim to explain the interaction
of context and an intervention’s fundamental mechanisms produce outcomes. They
also should pay more attention to interaction of mechanisms with context (Patton,
2002: Weiss, 1995). Therefore, it is critical that interventions are a clearly enunciated
within the theory of change (Connell & Kubisch, 1998). Incorporating
contextual factors within theories of change, would explicitly consider the circumstances
in which an intervention can be enhanced or fail. Optimising the targeting, application
and structural support.

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