Missing data

Sanchez-Fernandez et al. (2012) offered a different perspective on the success of a survey, they argued that perhaps response rate is not the most important indicator of success, but rather the quality of the responses, and the rates of missing data which should be used as an indicator of the success of a survey. Reflecting upon this, while the quality of the data is acceptable, a problem with missing data affected question 6 (the diagnosis of delirium) as no responses were logged for question 6a (appendix 5.1). The author had set up the web based survey in a way that meant that question 6 routed according to the selections respondents made. This was in an attempt to simplify the survey and reduce the burden on participants, a strategy reportedly important in increasing response rates in online surveys (Dillman and Smyth 2007). This factor was not identified in the piloting of the survey since it was not possible to carry out the pilot using the BoS tool itself: the tool is set up in such a way that once a survey is launched, the researcher cannot change the questions within. This meant that in order for the pilot to be possible, the questions had to be transcribed into paper form. This was done, making sure that the paper

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copy was as close as possible to the electronic version, however, the pilot participants were not able to comment on any aspect of the software itself, which would have been useful in flagging up unforeseen difficulties and given the researcher the opportunity to test how procedures would work in practice (Dillman et al. 2009). The result was that data were missing from the survey – a matter which would have been avoided had the survey been piloted in the web-based form rather than paper form.

5.5.4.3 Generalisability

Several issues affect the generalisability of the findings of this survey, these are largely due to decisions taken at the time of writing the study protocol in 2011.

While these decisions were taken by consensus within the team of supervisors and external advisers working with the researcher, in retrospect, some of these were misguided. The recruitment procedures were affected by sampling error as the coordinators of the 12 stroke managed clinical networks in Scotland were missed off the list of clinicians to be approached at the time of recruitment. These networks could have potentially helped disseminate the invitation to participate in the survey to clinicians who did not belong to a special interest group. A further issue affecting coverage of the survey and therefore generalisability of the findings was the importance placed on calculating response rates accurately. According to Lynn (2008) response rate is an important indicator of the success of the survey in terms of representing the target population and should therefore always be included in the outcome data for the survey. This was key in the decision to choose a convenience approach to sampling as opposed to snowballing. Streeton et al. (2004) outlined the advantages and disadvantages of snowballing recruitment in surveys, one of the disadvantages is the difficulty in verifying respondents’ eligibility to participate. An important advantage, according to Streeton et al. (2004), is in reaching populations that are difficult to approach, an issue that is clearly a concern in this survey as

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clinicians’ email addresses are not in the public domain and particularly for junior doctors who may not be registered with any professional interest groups, snowballing the recruitment may well have enabled the researcher to reach these clinicians.

5.5.4.4 Participants

The decision to exclude AHPs from participating in the survey needs to be viewed in light of the era in which this survey was conducted. The survey was designed and distributed prior to the rolling out of the multidisciplinary ‘Think Delirium’

programme in Scotland (Healthcare Improvement Scotland 2014). In the time prior to this programme being rolled out, the multidisciplinary rapid assessment tool for the detection of delirium was not yet disseminated widely among clinicians, and the literature had limited reference to AHPs taking a role in delirium identification. In hindsight, it would have been interesting to include AHPs in the mix of professionals targeted to respond to this survey since it is likely to have revealed interesting data on professional roles in delirium recognition, a matter not previously discussed in the allied health literature. A further issue related to participants was the restriction of the survey to Scottish stroke units only rather than disseminating the survey throughout the UK. It is recognised that this decision had impacted on the ability to generalise the findings of the survey to health services in other parts of the UK. However, from the outset, the second and third strands of this programme of research were conceived to be restricted to NHS Scotland. This decision was taken in recognition of the potential to triangulate some of the findings (e.g. methods of delirium identification) for the purpose of complementarity, as consistent with the integrated mixed methods designs discussed in chapter 3 (section 3.4) of the thesis.

In summary, several adaptations of this survey would have allowed for the findings to be more representative of clinical practice, as well as greater potential for

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the findings to be generalisable: less of an emphasis on calculating response rate would have freed the researcher to use snowball sampling in order to increase the sample size and potentially disseminate the survey to difficult-to-reach clinicians (Streeton et al. 2004). Including the coordinators of the stroke managed clinical networks as well as adapting the inclusion criteria to allow the inclusion of AHPs would have allowed for a more representative clinical picture to be revealed through the data gleaned from the survey. Finally, the piloting of the survey should have taken place online rather than on paper form. This would have identified the problems with the options to question 6 being routed incorrectly and potentially prevented the problem of missing data as discussed in section 5.4.3. Despite the limitations highlighted above, these data are of interest because this is, to the best of the author’s knowledge, the first survey of diagnostic and screening practice in relation to delirium in acute stroke services in Scotland or indeed the rest of the UK.

5.7 Conclusions and implications for practice

This chapter details the second strand of the doctoral programme, an online survey of practice of delirium identification in the acute stroke setting in Scotland.

Despite the limitations reflected upon in the sections above, this survey contributes to a growing body of knowledge on delirium identification in acute stroke patients. The findings of this survey suggest that in Scotland, at the time of data collection, no standardised guidelines regarding the identification of delirium in stroke patients existed. The survey also highlighted the inconsistent approach to the screening and diagnosis of delirium, echoing the results of the systematic review presented in chapter IV of this thesis, as the diagnostic processes of delirium described in the literature also seems to be inconsistent. It would therefore be beneficial for future practice guidelines in stroke care to incorporate information on delirium and perhaps

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consider establishing a standardised way of identifying the condition in this population, who clearly possess some of the important risk factors for developing the condition. Given the impact of delirium upon the patient as well as the health service (Inouye et al. 2014), it is important to ensure that staff are provided with clear guidance on how to best identify this condition in acute stroke. Practice guidelines on delirium identification are likely to lead to an increase in the amount of correctly identified delirium cases. This in turn is likely to lead to better outcomes for these patients as well as the potential for cost benefits to the health service (National Institute for Clinical Excellence 2010).

The survey highlighted that there are differences in the practice of doctors and nurses when it comes to delirium identification in this setting. Based on the literature consulted in the discussion, this finding may relate to a difference in confidence in delirium identification between doctors and nurses, although confidence in delirium identification was not explicitly explored in this survey. The differences in approach to delirium identification between doctors and nurses working in the acute stroke setting raised a question regarding the response of various members of the multidisciplinary team to delirium in patients in their care. The next chapter of this thesis attempts to address this by exploring the perspectives of a variety of health professionals working in Scottish stroke units.

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Chapter VI