Introduction

PRISMA guidelines (1) and the Cochrane collaboration (2) provide systematic reviewers with clear instructions as to how such reviews should be conducted and reported.  However,  while the guidance in relation to search strategies and data extraction are generic, most of the rest of the guidance, particularly in relation to interpretation, are aimed at informing approaches to analysis of quantitative data.  Despite its importance, there has been no such similar universal agreement about how the analysis of qualitative data should be handled.  Researchers have been exploring a number of methods as outlined earlier ranging from realist synthesis to narrative summary and meta-ethnography (3,4,5) but no clear consensus has yet been reached on the best approach to adopt.  Thus how best to analyse qualitative data that describes processes as opposed to quantitative data focusing on outcomes remains uncertain.   The NPT offers new ways to approach the analysis of qualitative data gathered as part of a systematic review.  First, NPT can be used directly as a coding framework, either coding data within each of the four main propositions: coherence, cognitive participation, collective action and reflexive monitoring; or coding to a greater level of detail including the four main propositions and each of the four constructs relating to the main proposition, such as interactional workability within collective action or individual appraisal within reflexive monitoring.  Alternatively, one could undertake thematic coding and then look at how the newly emerging themes fit within the NPT framework, again coding to the level of the main propositions or to the level of the propositions and accompanying constructs.  NPT provides a consistent framework with which to describe work processes and has the capacity to highlight gaps, that might be missed through, for example, thematic coding alone (6).

Things to consider

• NPT is not a theory of everything.  If one decides to use NPT as a coding framework, it is inevitable that some data will not fit into the framework.  This does not mean that use of NPT is inappropriate.  However, it will be important to note what kind of data falls outside of the framework and whether such data raises issues that seem likely to be important or not.
• Using NPT as a coding framework can be a good method of identifying gaps in the literature.  It is possible to code using the framework and then to look at the distribution of such codes pictorially using radar plots.  Such an approach can prove to be a powerful means of highlighting gaps or deficiencies in the existing literature.  This does not imply that using NPT allows quantitative claims to be made but merely that these kinds of methods can serve as a valuable way to illustrate the distribution of comments relating to constructs of NPT and identify those issues that have been addressed to a greater extent than others.
• We would recommend getting two researchers independently to analyse the content of the included papers using NPT to ensure consistency in approach and thereby to increase the robustness and reliability of coding, in particular to ensure that the approach to coding is clearly defined and transparent.

EXAMPLE - e-HEALTH IMPLEMENTATION & INTEGRATION

In this study (6) a review of systematic reviews of implementation of e-Health interventions into health care systems was undertaken.  There were clear systematic search strategies with clear inclusion and exclusion criteria and papers were reviewed independently by two reviewers.  NPT was used as a tool to facilitate data analysis with data extracted from eligible papers being coded by two reviewers using NPT as a coding framework. Any areas of disagreement, which were minimal, were resolved through discussion.

A couple of coding examples are illustrated.

Coherence could be used to relate to the work needing to be undertaken with staff intended as implementers and users of the new e-Health service, to identify and explore beliefs about the system to be implemented as the following extract shows:

'Prior to implementation it may be beneficial to assess expectations and concerns regarding EMR system implementation' (Studer 2005)

In the example above coding was simply undertaken at the level of the main construct, coherence.  Coding could also be undertaken to the level of the components of constructs, as illustrated by the next example which shows coding of data within the interactional workability component of collective action:

'a common theme among all four features is that they make it easier for clinicians to use a decision support system….as  a general principle then our findings suggest that an effective clinical decision support system must minimise the effort required by clinicians to receive and act on system recommendations.'(Kawamoto 2005)

The above quotation illustrated how ease of use of new technologies, that is, whether new systems helped or hindered professionals in carrying out tasks, was a major barrier or facilitator of implementation.

EXAMPLE - IMPLEMENTING TELECARE

In this study (7) a systematic review of qualitative studies examining telecare implementation was undertaken.  Once again, explicit search strategies were adopted with predefined inclusion and exclusion criteria.  The data was analysed thematically and then these themes were mapped onto the constructs of the NPT as illustrated by the following table.

Themes	Papers			Area of Normalisation Process Model Evident
	Stroke	Asthma	Multiple conditions	Stroke	Asthma	Multiple conditions
Technical factors	Transmission Problems			Interactional Workability - Disposal
	Ease of use	Ease of Use Difficulty using system	Technology appears invisible	Interactional Workability - Disposal	Interactional Workability -Disposal	Interactional Workability - Disposal
			Lack of technical support			Contextual Integration
	Security and Privacy Issues		Security and Privacy	Relational Integration -Accountability		Relational Integration -Accountability
	Restricted availability of health professionals			Contextual Integration - Execution
Personal traits Type	User type				outside model

References

1. Moher D, Liberati A, Tetzlaff J, Altman DG, for the PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. BMJ 2009;339:b2535. Back to text
2. Green S, Higgins J (2005) Glossary. Cochrane handbook for systematic reviews of interventions 4.2.5. The Cochrane Collaboration. Available: http://www.cochrane.org/resources/glossa​ry.htm . Accessed 19 May 2009.  Back to text
3. Dixon-Woods M, Agarwal S, Jones D, Young B, Sutton S.  Synthesising qualitative and quantitative evidence: a review of possible methods.  J Health Serv Res Policy 2005; 10 (1): 45-53. Back to text
4. Greenhalgh T, Kristjansson E, Robinson V. School feeding programmes Realist review to understand.  BMJ 2007;335;858-861. Back to text
5. Pawson R, Greenhalgh T, Harvey G, Walshe K. Realist review - a new method of systematic review designed for complex policy interventions.  Journal of Health Services Research Policy 2005;10-21-34. Back to text
6. Mair F, May C, Murray E, Finch T, O'Donnell C, Anderson G, Wallace P, Sullivan F.  Understanding the implementation and integration of e-Health Services.  Report for the NHS Service and Delivery Organisation R&D (NCCSDO). 2009. London. SDO. www.sdo.nihr.ac.uk Back to text Back to example
7. May C. et al. Integrating Telecare For Chronic Disease Management In The Community: What Needs To Be Done? Department of Health 2010, London. Back to example