This study showed that healthcare practitioners' perceptions about the risks in their system were different depending on whether they were reflecting on the risks without a process map, working with a sequential flow diagram or working with a hierarchical diagram (HTA). The results suggest that the type of representation chosen for use in quality improvement work is important because improvement efforts will be influenced by how the process is represented: variation in the safety problems that practitioners identified was related to the type of process map they used.
The results of this study suggest that improvement efforts might need to be based on more than one type of representation to ensure that all aspects of the process are captured. Using both sequential and hierarchical diagrams might yield a more comprehensive view of the process than using one alone. This is in agreement with Marsolek and Friesdorf [9] who advocated the use of both sequential and hierarchical diagrams for improving work systems and processes.
What a representation captures is clearly important. In the present study, co-ordination across organizational boundaries was not represented in the process maps. Both diagrams were focused on tasks performed by the healthcare professionals within the bounded context of the clinic, but risks often emerge just outside those boundaries in the patient's behaviour and in the liminal zone between different care services. Communication and liaison across organizations and the movement of patients between services were cited as some of the biggest problems when participants were asked open ended questions without the diagrams, and this has been confirmed by ongoing safety improvement work within the CBAC, including root cause analyses. Some of these issues were captured in a limited way by the HTA through its high-level goals, but not by the sequential flow diagram.
During the mapping process our reflective notes showed that two central questions must be decided early when constructing a process map: defining the system boundary and the granularity required. We decided to define our system by the entry and exit of a patient under care of the CBAC service. However, as noted, problems were perceived and experienced at the boundaries of the system. To ensure that the important aspects of the process are captured, the construction of a process map should therefore proceed iteratively with emerging information about where the risks in the system are located. Preliminary investigation into risks identified through incident reporting and interviewing clinicians will be necessary to determine where the boundary of the process map should be set, and this might change as the mapping process continues. If the focus of the improvement work is to be the interface between different parts of the healthcare system (in our case, with GPs, the Primary Care Trust and hospitals), mapping should involve participants with knowledge of these services.
The other key decision is the granularity of the diagram. The HTA method includes a stopping rule for formalizing how much detail is represented [16]. There is no similar guidance for flow diagrams, with the possibility that some parts of the process might be shown in more detail than others, thus biasing subsequent improvement work. A further practical difficulty is how to represent the maps as their size increases quickly. An electronic representation can, with the appropriate software, be easier to revise, particularly with a hierarchical map. Berlingieri et al. [18], for example, offer a web-based view of a process map in which sections expand or contract to ease visualisation.
Which of these methods healthcare professionals will choose to use will probably be a pragmatic choice based on the time available and how easy each method is to use. Reflecting on the experience of constructing the maps we found that the two diagrams each had advantages and disadvantages. The HTA was highly structured and thus easier to produce graphically and easier to revise as the mapping progressed. It offered flexibility in representing important goals which did not correspond to specific acts at specific times but which represented ongoing issues that could be triggered at any time, such as seeking help from a peer, patient education, or tasks that were purely cognitive. On the other hand, the timing of some parts of the work was much easier for us to handle within the flow diagram than the HTA. The flow diagram was harder to adapt because additional details have to be added within the process steps, creating branches and loops. The information gleaned from standard operating procedures was easier to represent with the HTA, but information gained from interviews and observations was easier to represent with the flow diagram.
Despite HTA being little used in healthcare compared to flow diagrams and anecdotal reports that it is hard for healthcare professionals to understand, we found it was as readily accepted as the flow diagram. The HTA was preferred by participants for discussing their work with a colleague, suggesting that the representation of goals in the HTA is important in providing context and enabling people with similar levels of expertise to improve the system. Healthcare work is driven by the need to achieve the goals of patient care despite variability in the patients, the demands on the service and the support available, both technological and social. The representation of those goals in the hierarchical structure of the HTA is therefore important, especially if communicating with others who understand those goals. The unpredictability of healthcare and the professional autonomy of healthcare practitioners are also better encompassed by the HTA with its focus on the goal to be achieved rather than the precise method used.
This study was exploratory and has suggested that the form of a process map does influence perceptions of the quality and safety problems in a service and different maps draw attention to or away from different aspects of the work. Interviewing clinicians to elicit concerns not readily captured by process maps was also found to be important, and should be regarded as an essential preliminary step to determine the boundary of the process map and to identify known risks. However, the study was limited by a number of factors. First, the size of the sample was constrained by the small number of people in the service with sufficiently detailed knowledge to participate. A difficulty of conducting such studies is that each clinical micro system is unique and is likely to contain only small numbers of experts who can contribute. Second, we asked participants to simply identify their quality and safety concerns, whereas most quality improvement work will follow a structured method to identify where improvements can be made. For example, HFMEA proceeds by asking specific questions about how a process could fail at each step [4]. The study did not evaluate whether different types of process maps are more useful for particular quality improvement methods, but this is an important question to investigate in subsequent work. Third, in order to compare the two diagrams the content had to be standardised, which meant that the maps were constructed by the researchers. The practitioners were then presented with a finished map to work with (although they were asked to review and update it). In most quality improvement work the team-based mapping process is an important part of the process of generating shared understanding about how work is carried out in reality and where risks are located [6]. We acknowledge that in this study this did not occur and this might have affected the results.
Fourth, a related issue is that the study design necessitated standardising the diagrams so that they each contained the same content, but it is possible that the diagrams are most effective at representing different parts of the process. This could be examined in further work. Finally, the clinical setting examined in this study involved tasks that were relatively well structured and well defined. This work could be extended by examining different clinical systems with different clinical demands and different professional groups. We recognise, in particular, that the differing autonomy of different healthcare professions in different roles has implications for whether a flow diagram or HTA should be preferred.