Explore patterns in scoring of mood subscales of the GHQ-28 for those with communication difficulty compared to those with normal communication

Previous analysis of the data from the MI trial indicated that there was a difference in mood outcome at three-months for those participating in MI compared to those receiving usual care.

This effect was shown to be greater for those with communication difficulties participating in MI. However, while there was a difference in mood outcome (GHQ-28), it is unknown where these differences lie within the mood scale. Previous research of patients with aphasia after stroke have suggested that these patients may suffer difficulty with social functioning (Darrigrand et al. 2011) and may be more likely to experience depression than those with normal communication (Kauhanen et al. 2000), suggesting there may be specific areas where changes in mood may be detected more than others. With this in mind, it was felt appropriate to compare the subscales of the GHQ-28 for participants with both normal and abnormal communication.

Aim

To explore the scoring patterns across the GHQ-28 subscales for participants with normal and abnormal communication receiving MI.

Methods

Measures

The GHQ-28 measure of mood consists of four subscales including ‘Somatic Symptoms’, ‘Social Dysfunction’, ‘Anxiety and Insomnia’, and ‘Severe Depression’. Each GHQ-28 subscale is scored from a minimum of 0 to a maximum of 7, with a higher score demonstrating a greater presence of low mood symptoms. A score of -1 indicates a missing value.

Communication was measured using the full FAST. With a total score of 30 and scores below 27 (aged up to 60) or 25 (aged 61 and above) indicating abnormal communication.

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In order to compare whether there was a difference in mean scores of GHQ-28 subscales at three months post-stroke based on communication ability, line graphs were created comparing those in the MI group with normal communication to those with abnormal communication using the full FAST. Scores of each of the mood subscales taken at three-months for both communication groups were plotted against one another. Comparisons were carried out through visual inspection of the graphs, as well as through comparison of median GHQ-28 subscale scores.

Results

At three-months, there were a total of 375 participants who completed the GHQ-28. A breakdown of each of the four GHQ-28 subscale results will be presented in turn.

Somatic Symptom Subscale

In terms of somatic symptoms, the mean scores indicate no clear difference between the two groups, with participants with abnormal communication scoring a median=0, and those with normal communication scoring median=1. The percentage of participants scoring -1 to 7 on the GHQ subscale for Somatic Symptoms for each communication group can be seen below in Figure 3.1.

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Figure 3.1: Somatic Symptom subscale scores at three-months for normal and abnormal communication ability

Social Dysfunction Subscale

Figure 3.2: Social Dysfunction subscale scores at three-months for communication groups receiving MI

In relation to social dysfunction, the median score for those with abnormal and normal communication was 1.

There appears to be only a slight difference between the GHQ-28 subscale scoring for social dysfunction between the two communication groups, with those with normal communication scoring higher at the fourth point, but this is counter balanced with those with abnormal communication scoring slightly higher at the top end of the scale (7), indicating a higher presence of low mood symptoms. This is demonstrated in Figure 3.2.

Anxiety and Insomnia Subscale

Similarly there was no difference in the median scores on the Anxiety and Insomnia subscale.

Those with normal and abnormal communication scoring a median of 0.

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Figure 3.3: Anxiety and Insomnia subscale scores at three-months for communication groups receiving MI

Figure 3.3 demonstrates the close similarity of scoring the GHQ-28 Anxiety and Insomnia subscale for those with either normal or abnormal communication. The same low median score for both groups indicates that both groups were very similar in this aspect.

Severe Depression Subscale

The final GHQ-28 subscale Severe Depression indicates that those with normal communication score marginally higher, but overall both groups had the same median score for this subscale (median=0). The scores are shown in the Figure 3.4 below.

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Figure 3.4: Severe Depression subscale scores at three-months for communication groups

A visual comparison of the two groups from Figure 3.4 reflects the similar scoring patterns of the two communication groups. The median score for both groups is 0.

Summary

The four mood subscales within the GHQ-28 were examined comparing those with normal communication to those with abnormal communication who participated in MI. The previous logistic regressions indicated a difference in the mood (based on GHQ-28 scores) between those with abnormal and normal communication receiving MI. In addition, previous research found that those with communication difficulties after stroke can have severely impaired interaction in their social life (Darrigrand et al. 2011), it was felt that there may be differences in scoring of social functioning. Due to this, the four subscales of the GHQ-28 were examined to explore whether one subscale in particular could account for this change, however no major differences in the subscales were detected. While minimal differences in scores were

identified, there appears to be little difference between communication groups scoring of the GHQ-28 subscales. Therefore no individual GHQ-28 subscale could account for a change in mood at three-months between those with abnormal or normal communication.

This result contrasts with previous studies which identified that patients with communication difficulties are more likely to experience symptoms measured by the GHQ-28, such as social

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dysfunction, than patients with normal communication (Parr. 2007; Darrigrand et al. 2011).

However this results was not replicated in this analysis.

3.4 Discussion

This chapter has explored data from a previous RCT delivering MI to patients early post-stroke (Watkins et al. 2007). Examination of the FAST scores highlights that participants with

communication difficulties were included in the trial and were able to participate in MI at this early stage after stroke, with most participants completing all four sessions. However, the FAST scores were collected on admission and may have changed by the time the participant

commenced the MI sessions; although with no follow-up measure of communication this cannot be proven. The secondary analysis of this data presented in this chapter has highlighted that participants who received MI were shown to have improved mood at three-months post-stroke, and this result was more prominent in those with abnormal communication.

Features of communication were then studied to discover whether there were any specific aspects of communication which could influence mood outcome.

The analysis showed that individually, there was no subscale of communication (as measured by the FAST) that interacted on mood outcome at three-months. It may be that all aspects of communication subscales interact, providing a combined effect on mood. Previous research has indicated patients with communication difficulties may have different mood outcomes compared to patients with normal communication, including an increased risk of depression (Kauhanen et al. 2000). Furthermore, patients with communication difficulties report experiencing more psychological distress at three-months post-stroke more than those with normal communication (Hilari et al. 2010). However, there is no evidence in previous research to suggest that a deficit in a particular area of communication leads to a difference in mood outcome, and similarly no such relationship was found in this analysis.

It was felt that the ability to read and write may not affect people’s ability to participate in a talk based therapy. Therefore these subscales were removed and the shortened version of the FAST, the Mini-FAST was explored. The Mini-FAST explored if removal of the Reading and Writing subscales would increase the effect of the remaining subscales, however this was not the case. This result may be limited by the lack of validity of the Mini-FAST. While the FAST has been previously validated, there has been little validation of the mini-FAST. Until further studies confirm the validity of the Mini-FAST, future studies should continue to utilise the well validated FAST tool.

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Finally, in examining GHQ-28 scores from the original RCT, subscales of the GHQ-28 were explored to discover where a particular subscale of the GHQ-28 could account for the overall difference in mood. The results indicated that patients with communication difficulties benefitted in mood at three-months more than those with normal communication. However, further to this, when exploring the individual subscale, no single subscale could account for this overall difference in mood.

In the original MI trial, communication was measured on admission to hospital, therefore it is unknown how severe any communication deficits were prior to commencing the MI sessions, and whether these had an impact on the patient’s ability to participate. The FAST was used to measure communication in the study. While this is a validated screening tool, it is limited in the depth of information it can provide about communication ability. This necessitates further exploration to assess its suitability in this capacity.

Previous studies have explored depression in patients with communication difficulties

compared to those with normal communication (Hilari et al. 2010). Patients with various levels of communication difficulties (as assessed using the FAST) were included in this study (Hilari et al. 2010) exploring factors predicting psychological distress at three-months and six-months post-stroke as measured by the GHQ-12. Results found the presence of communication difficulties was associated with psychological distress at three-months. However, results are only reported for patients with mild to moderate communication difficulties, and not for those with severe communication difficulties. As commonly occurs in research, patients with severe communication difficulties were not reported in this study, and it is unknown whether results can be applied to this group of patients. Future studies should include patients with

communication difficulties in research, including those with severe difficulties to ensure all patients are represented in the results of such trials.

In a separate study exploring the prevalence of communication difficulties and associated deficits, patients were assessed for mood through psychiatric interview (Kauhanen et al. 2000).

In this study, communication difficulties were assessed using the aphasia quotient of the Western Aphasia Battery (Kertesz. 1982). This was administered in the first week post-stroke.

Follow up measures at three and twelve months found that those with communication difficulties were more likely to experience depressive symptoms than those with normal communication. However, this was not explored further to establish whether specific aspects of depression were experienced more than others. In addition, this study found that

communication difficulties were often improved to less severe syndromes, or had completely

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resolved, by follow up. This emphasises the changeable nature of communication difficulties for some patients and the need for regular measures to be taken to measure such change.

Patients with communication difficulties are more likely to experience depression, therefore it is important to identify and treat it. The analysis carried out in this chapter found that those with communication difficulties in the MI group may have benefitted more. However, these patients are excluded from the majority of studies; therefore there is a lack of evidence to build on. To address this lack of evidence, studies must adapt to ensure they are inclusive to all patients, including those with communication difficulties.

In order to explore the potential for including patients with communication difficulties, future studies should include patients with a lower ability of expressive communication to better understand what level of communication is required to participate in MI, and whether those with more severe expressive communication difficulties can participate in a talk-based therapy such as MI.

In a future MI trial, recruitment will specifically target patients who have communication difficulties beyond the level recruited in the original MI RCT. In a future feasibility study, recruited participants will have a range of communication difficulties from moderate to severe difficulties.

3.5 Limitations

There have been limitations to the analysis described in this chapter. Firstly, this chapter has presented a secondary analysis, and therefore data was already collected. Due to this, the nature of the data originally gathered was not specific to the questions explored in this analysis.

The FAST is a screening tool designed to detect the presence or absence of communication difficulties, not as a comprehensive assessment of communication. The analysis was therefore limited in the level of detail of communication ability which could be drawn from baseline FAST scores. Data from the original trial using the FAST may not have been comprehensive enough for this secondary analysis to detect specific communication impairments that may have impacted upon mood. Furthermore, the FAST was only administered at admission and therefore was unable to detect any changes in communication over time.

Future trials, should consider more in-depth measures of communication across a number of time points, in addition to an aphasia screening tool. This will allow for any deficits in

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communication to be detected, as well as to monitor communication over the course of the study. If a comprehensive measure of communication is used in addition to an aphasia screening tool, a more complete explanation of the areas of communication impairment can be gained, and potentially an idea of which areas of communication are required for

participation in MI. Therefore, while the analysis of the FAST used in the original MI RCT provided a crude measure of communication, in future studies, a more comprehensive measure of communication should be used to provide a more in-depth understanding of communication ability.

A further limitation to the analysis is that patients in the original MI RCT were excluded if they had severe communication difficulties. This may have been for practical reasons, such as the difficulties these patients would face in completing the study measures and communicating in sessions. Nevertheless, in excluding these patients, the benefit of MI for patients with severe communication difficulties remains unknown. The exclusion of patients with communication difficulties from research studies is not uncommon (Hackett et al. 2005), with inclusion in depression trials even poorer for patients with severe communication difficulties (Townend et al. 2007). However, results of psychological interventions will remain biased and may never be generalizable to patients with moderate to severe communication difficulties without their inclusion. This is therefore an area for a future intervention study to explore.

The GHQ-28 was used to measure mood in the original MI trial. This questionnaire requires patients to have the ability to read, comprehend and appropriately respond to questions, therefore despite its reliability and validity in stroke populations (Lincoln and Flannaghan 2003), its suitability for patients with communication difficulties may be limited. Future studies recruiting patients with more severe communication difficulties than those involved in the original MI trial may require alternative mood assessment tools to suit patient communication needs.

3.6 Summary

This chapter has described a secondary analysis of data from a motivational interviewing RCT trial for patients early after stroke. The chapter has described the original RCT, providing a context for the secondary analysis which has been completed. This study has identified that patients with communication difficulties were able to participate in MI sessions, however we are not sure how severe the communication impairment was before commencing MI, and whether this had an impact on the ability to participate. In addition, due to the exclusion of patients with moderate to severe communication difficulties in the original trial, the level of

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communication ability required for participation in MI remains unknown and therefore requires further exploration.

In addition, the original trial measured mood using the GHQ-28, a tool validated in patients with normal communication after stroke. However, this tool has not been validated in patients with communication difficulties and therefore may not be appropriate for this group of

patients. Furthermore, the suitability of assessing communication using the FAST alone has been questioned in this chapter. As a result, the next chapter will review current aphasia screening tools, comprehensive language batteries and finally mood screening tools to identify applicable tools for patients with moderate to severe communication difficulties after stroke.

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