The economic evaluation departed significantly from that outlined in the original protocol. In this section, we explain what necessitated this change.
Delays due to waiting for Health Research Authority approval
The economic literature review was not planned in the original protocol. However, this study, and many others, experienced significant delays at commencement due to the launch of the Health Research Authority and changes to the procedures for securing ethics approvals. It was agreed with NIHR that to make good use of this time we would undertake a review of the published economic evidence for the effectiveness and cost-effectiveness of the 52 HHDSs (and other schemes). As noted earlier, there was an extensive ‘grey literature’, comprising many local evaluations, some of which included economic evidence.
Enabling interrogation of an additional mechanism resource
In the original protocol, we set out to compare the effectiveness and cost-effectiveness of:
Having completed the main literature synthesis (some 6 months after the study began), we developed our original realist hypothesis to capture new evidence about the importance of HHDSs having direct access to ‘step-down’ intermediate care. To enable us to interrogate this revised theory, we introduced a further comparative element across the evaluation to establish the effectiveness and cost-effectiveness of:
Compensating for the lack of EQ-5D completions
In the original protocol, we planned to collect (unconsented) information on patients from 20 HHDSs and to link this to HES data. As described in Chapter 4, this data linkage worked well. Although only 17 HHDSs were recruited, the overall sample size was large enough to compensate for this. We used these data to feed into the economic evaluation, employing a single modelling technique, as planned in the original protocol. The findings from the economic analysis of linked HES data for 17 HHDSs were described in Chapter 5.
However, in addition to collecting the linked HES data from 17 HHDSs, we also planned more in-depth economic analysis in four of the HHDS case study sites recruited for the qualitative fieldwork. The plan was that staff in the HHDSs in these sites would complete a questionnaire (encompassing EQ-5D data) with every patient at the point of discharge from hospital (T1) and then again at the 3-month follow-up (T2) (copies of the T1 and T2 questionnaires are provided in Appendix 7). However, the HHDSs did not have the capacity to incorporate this research work as part of their routine monitoring (as we had anticipated), with the consequence that only one HHDS delivered sufficient questionnaires at T1 and T2. This left us significantly short of the target (n = 372) that was needed for statistical significance. To compensate for this, we introduced a new focus for economic study (part 3).
In part 3, we shifted the ‘lens’ or ‘evaluative gaze’ from scheme typology to the study of three ‘out-of-hospital’ care configurations. That is, moving beyond a binary comparative analysis (e.g. clinically led vs. housing led) to explore the interplay between different mechanism–resource combinations in different local (geographical) contexts, each with differential access to housing and services.
Configuration 1
A multidisciplinary ‘clinically led’ (homeless health-care team) scheme that offers patient in-reach and specialist discharge co-ordination, with no direct access to ‘step-down’ intermediate care. Here, support for the patient usually ends at the point of exit from the acute sector (hospital). Two examples of this configuration were considered, one situated in a city and one in a seaside resort in the south of England.
Data source
A research team member had recently completed a RCT of two homeless health-care teams, employing EQ-5D data at two time points. We were able to draw on these EQ-5D data, which conferred access to 206 T1 completions and 56 T2 completions (at 6 weeks post discharge).
Configuration 2
In this site, two HHDSs work together in an integrated way. The configuration studied here comprised a clinically led (homeless health-care) team that offered patient in-reach and discharge co-ordination. This site had access to a 14-bed residential facility that offered step-down intermediate care. The hospital-based homeless health-care team provided ‘clinical in-reach’ into the residential intermediate care facility, ensuring continuity of multidisciplinary support for patients. The HHDSs are based in an old industrial city in the north of England.
Data source
In this fieldwork site, we were able to meet the target for EQ-5D questionnaire completions. Here, we were able to access 64 completions at T1 and 54 at T2 (at 3 months post discharge).
Configuration 3
This site contained a single housing-led HHDS in which a small team of housing support workers visited the hospital to provide patient in-reach and discharge co-ordination. The housing workers then continued to support patients in the community (offering floating support) until longer-term services were in place and working well (i.e. community ‘step-down’ intermediate care). Although a uniprofessional scheme, it had access to a multidisciplinary clinically led homeless health-care team based at the hospital. The HHDS is based in an old industrial city in the Midlands.
Data source
This site worked with the research team in the pilot phase of the study and was collecting EQ-5Ds as part of its own routine monitoring and review procedures. From this site, we were able to access 84 completions at T1 and 84 at T2 (at 3 months post discharge).
In total, drawing on these different data sources, we were able to access a total of 354 EQ-5D completions at T1 and 248 at T2. This was sufficient to enable us to carry out a range of modelling techniques.
We acknowledge, however, that it was by chance (rather than purposeful selection) that the HHDSs conferring access to the EQ-5D data were such that they enabled the comparative study of three very different out-of-hospital care systems. On the one hand, by moving beyond binary comparisons (clinically led vs. housing led) to consider the interplay between multiple resource mechanisms in different contexts, this pragmatic approach afforded, what we believe to be, a more in-depth and nuanced interrogation of the realist hypothesis than was originally planned. On the other hand, there are limitations in making comparisons where the data source is not uniform across all sites and where (geographical) contexts are very different and cannot be controlled for.
More details of the protocol changes are presented in Appendix 10.
