Qualities of potential future outcome measures under investigation in CARiAD
TABLE 27
Qualities of potential future outcome measures under investigation in CARiAD
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| Outcome measure | Description | Method(s) of assessment |
|---|
| Family MSAS-GDI | The Family MSAS-GDI has established validity and reliability when used to provide a measure of overall symptom burden/distress in the last 7 days of life. It has in-built averages: it is the average of the frequency of four prevalent psychological symptoms (feeling sad, worrying, feeling irritable and feeling nervous) and the average of the distress associated with six prevalent physical symptoms (lack of appetite, lack of energy, pain, feeling drowsy, constipation and dry mouth) in the last 7 days of life This measure is less likely to differ systematically between the two groups, as it covers a wider range of experiences and a longer time range than ‘time to symptom relief’ per episode It is designed for proxy completion by carers and HCPs. It can be administered either face to face or over the telephone
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| QOLLTI-F | QOLLTI-F has established psychometric properties (reported validity and reliability, demonstrated responsiveness, no floor and ceiling effects), is relatively brief (16 items) and can be administered every 2 days (rather than daily, reducing the risk of overburdening carers) It is broadly aimed at carer quality of life, and incorporates issues of control (reported as paramount by carers) and self-efficacy (conceptualised as ‘a person’s belief about her or his ability to organise and execute courses of action to manage given situations’) This measure is also less likely than ‘time to symptom relief’ to differ systematically between study groups
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| Time to symptom relief | This measure will be calculated using data items from the carer diary. We will minimise bias by using strict definitions of episode timings:the start of an episode is defined as the point at which the patient has a breakthrough symptom that triggers perceived need for a SC injection, as per the view of either the patient or the carer symptoms are defined as ‘resolved’ (indicating the end of an episode) at the point that the patient (or the carer if the patient is unable to) feels that the symptom is felt to be controlled or reduced to an acceptable level and when more additional SC medication is not needed if a patient needs a further dose of SC medication for the same symptom within 2 hours of the first injection, the episode will be classed as ‘not resolved’
As the onset of an episode, as well as the judgement when it is resolved, is subjective, fidelity can be interrogated using objective data. We will assess bias by interrogating:the percentage of ‘resolved within 30 mins of injection’ episodes between both groups (i.e. at that point the measure between the two groups should not differ significantly as the injection has already been given) rather than from time of onset of the symptom the number of repeat SC injections (for the same symptom/indication) within 2 hours the symptom score recorded in relation to ‘resolution’ the time to symptom relief minus travel time by HCPs (i.e. not taking HCP travel time into account)
| The carer diary is designed for completion by the carer and will be collected from the carer after the patient had died Blinded assessment is not possible as symptoms occur at random times and symptom scores are assessed when symptoms occur rather than at fixed time points, and no assessor (HCP or RN) can be in attendance 24/7. (Even if someone, e.g. another family carer/member, were able to be there at all times, they will not be blinded as treatment allocation will be obvious, as the carer is administering SC medication or not)
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Rationale for choice of Family MSAS-GDI and QOLLTI-F
The Memorial Symptom Assessment Scale (32 items) is a valid and reliable patient self-report instrument.10 The MSAS-GDI has demonstrated reliability and validity in measuring global symptom distress from the patient perspective. Although the scale was designed to produce one single score, the individual items can also be used as single item indicators of burdensome symptoms at the end of life, identifying which symptoms are getting better or worse over time in different patient populations.59
Hickman et al.59 showed that the MSAS-GDI is amenable to modification for use in research with recently bereaved family respondents whose family members died from a wide range of causes. Items were modified so that the questions focused on the symptoms experienced by decedents in the last week of their life, as observed by family respondents. The Family MSAS-GDI has good face validity for use in understanding symptoms experienced by patients in the last week of life, regardless of cause of death or role in relation to the patient (carer or HCP).61
In the Hickman et al.59 study, in the 103 family members the mean Family MSAS-GDI score was 1.14 (SD 0.87), with a range from 0 to 3.73. The scale demonstrated good internal consistency (α = 0.82). The average item-total correlation was r = 0.49 and the average inter-item correlation was r = 0.30, which suggests that items were moderately correlated with the overall total scale and with each other. They concluded that the Family MSAS-GDI could prove to be a useful tool in assessing and tracking global symptom distress in dying patients.59
Lobchuk’s work60 corroborates these findings, showing good to excellent intraclass correlations with patients’ ordinal ratings to support the concurrent validity and utility of the MSAS-GDI subscales in family carer populations who care for cancer patients in the home setting.
Rationale for the choice of QOLLTI-F41 is that it has established psychometric properties (reported validity and reliability, demonstrated responsiveness, no floor and ceiling effects), is relatively brief (16 items) and can be administered every 2 days (rather than daily, reducing the risk of overburdening carers). It is broadly aimed at carer quality of life, and incorporates issues of control (reported as paramount by carers) and self-efficacy (conceptualised as ‘a person’s belief about her or his ability to organise and execute courses of action to manage given situations’).
