Collaborative care: required resources and associated costs
Case managers were psychological well-being practitioners (PWPs) employed at NHS band 5. Case managers each received training to provide collaborative care as part of the CASPER plus trial. In total, three training events were held covering four regions of the study (York, Leeds, Durham and Newcastle upon Tyne), each consisting of 2 consecutive days of training. The number of attendees per training event varied and efforts were made to provide training in a manner that ensured that the overall costs of travel and accommodation were minimal.
During the training, PWPs were orientated to the case managers’manual, which outlined the overall principles of collaborative care and a‘session-by-session overview’of what case managers aimed to achieve with patients. The training courses for case managers were predominantly provided by two trainers; subsequently, these trainers also supervised case managers during implantation of the collaborative care programme implementation.
The manual stipulated that the programme of treatment should consist of‘8–10 mainly telephone contacts with occasional face-to-face contacts over a period of 12 weeks’. In terms of the expectation for each session, it further stated that‘contacts last 45 minutes for session one and 20–30 minutes for each subsequent contact’. The first session was generally held face to face and took place at participants’ homes, GP surgeries or other community venues.
Case managers received weekly supervision from a designated supervisor. The schedule of supervision followed a standardised agenda whereby for each patient there was a weekly discussion and case managers would prepare feedback to discuss each case with their supervisor. Supervisors were responsible for providing support to case managers on the process of collaborative care and medication management and on specific psychological interventions. On average, each patient contact was discussed between the case manager and supervisor for approximately 5 minutes.
Case managers provided participant-specific feedback to GPs. In the first instance, case managers worked with and advised participants’GPs on their care. During treatment, case managers would provide a letter to update the GP on participants’progress and, when appropriate, whether or not GPs might consider further treatment. At the end of the programme, case managers also sent a participant-specific summary report to the GP. Supervisors were available to advise case managers on next steps and consultation with GPs. Three letters were prepared and sent over the 12 weeks, requiring approximately 30 minutes of administration per letter. Case managers would also speak to GPs directly if they had any concerns about a participant’s medication or overall well-being.
Case managers were also charged with a duty of care to engage outside agencies (such as social services or in response to safeguarding issues) in situations in which they became aware of safety or risk (including abuse). However, the client group had a generally low level of clinical need in this respect, and this additional responsibility was not generally required.
To estimate the personnel costs required to provide collaborative care (as intended within the manual), estimates of NHS unit costs were derived from national reference costs56(Table 41).
Table 42summarises the resources required over the 12-week programme of collaborative care and indicates our estimate of the direct cost for base-case analysis. The direct cost of collaborative care (based on the prior estimation within the manual) was calculated to be £494.73. This cost is adopted for the base-case cost as, ex ante, there is insufficient information to anticipate actual levels of required care; however, deviation that did occur will be explored within our sensitivity analyses.
Consequences for health care by trial arm
Patient contacts over the duration of the trial are presented inTable 43, which compares the summary statistics for those who accessed collaborative care with the summary statistics for those who accessed usual care. Initial observation suggests that collaborative care in depression results in a small marginal increase in contacts with most services (except GP home visits). However, the mean contact rate with any service is dependent on access to the service and the subsequent level of utilisation.
To test whether or not differences in service use may be attributed to collaborative care, statistical tests must accommodate highly skewed distributions with significant numbers of zero service users and, therefore, specific analytical procedures are required.60Applying zero-inflated negative binomial regression61allows
inference on the effect of collaborative care on two factors: access (using the logistic model) and overall change in the contact rate (using the full model). For full regression outputs seeAppendix 12.
Having any access to services is indicated by outputs of the logistic models. Across all five resource use categories we may conclude that participants are generally unlikely to access any services. Examining logistic regression outputs related to nurse appointment (seeAppendix 12,Table 55) suggest that collaborative care may increase the likelihood of access (log odd=14.1944;p=0.01). However, small sample numbers available from this trial mean that inferences regarding the effect of collaborative care should be made with caution.
TABLE 41 Personnel costs required to provide collaborative care
Item Unit cost (£) Referencea
PWP (band 5) Per hourb
39 Nurse (mental health) Patient-related workb 52 Nurse (mental health)
Face-to-face contactb
74 Nurse (mental health) PWP (band 6)
Supervisionb
49 Nurse team leader GP
Appointment 45 ‘Per patient contact lasting 11.7 minutes’
Home visit 114 ‘Per out of surgery visit lasting 23.4 minutes’
Telephone consultation 27 ‘Per telephone consultation lasting 7.1 minutes’
Practice nurse
Appointment 13.43 ‘£52 per hour of face-to-face contact, duration of contact 15.5 minutes’
Telephone consultation 6.15 ‘£52 per hour of face-to-face contact, assumed similar time as GP: 7.1 minutes’
a From Curtis.56
b In the absence of specific unit costs for PWPs and supervisors, proxy values of roles at the same NHS band are taken. All price years were 2012/13.
The full model specification accounts for access and subsequent use to test any overall change in the contact rate. Over resource use categories, there is generally no significant difference between groups. However, inference of the effect of collaborative care on nurse telephone consultations suggests an overall increase in the contact rate of 2.25 (95% CI 0.9285 to 5.4403;p=0.073). Again, given the sample size, inferences on the effect of collaborative care should be made with caution.
Cost–consequences and total costs
Unit costs (as presented inTable 41) were multiplied by resource utilisation to derive patient-level costs of health care (Table 44). Health-care costs of treatment therefore extend beyond the cost of the collaborative care programme (£494.73), increasing wider costs by a mean of £682.27. Overall, the mean total cost in the collaborative care group was £1171.45 (95% CI £1166.99 to £1175.92,n=226), compared with £654.14 (95% CI £650.78 to £657.52,n=221) in the usual-care group.
TABLE 42 Summary of the health-care resource required to train and provide collaborative care as an associated base-case cost of the programme
Item Frequency Duration
Total
quantity Cost (£) Description
Training case managers
Case managers attending 16 case managers 13 hours 208 8112a
2 days, 6.5 hours each
Supervision of course Two trainers, three sessions
13 hours 96 hours 4704b
2 days, 6.5 hours each
Manual One manual/case manager
– 16 80 Printing
Travel and accommodation For two trainers × two sessions
1 night 4 nights 600 Sessions in Durham and Leeds
Subtotal (total cost of training) 13,496 Cost to train all case mangers
Subtotal (total cost of training per participant) 39.23 249 allocated to the programme Collaborative care
Session 1 One per patient 45 minutes 45 minutes 55.50 Assumed by home visitc
Sessions 2–10 Median of nine sessions per patient
30 minutes 4.5 hours 234 Assumed by telephoned
Supervisions One per week (12) 5 minutes 1 hour 88 1 hour over 12 weeksa,b
GP communication Three letters 30 minutes 1.5 hours 78 Patient-related work4
Engaging outside agencies 0 0 0 0 Not required in CASPER Subtotal (total cost of intervention per participant) 455.50
Total cost (training+intervention) 494.73 Cost for base-case
analysis
PSSRU, Personal Social Services Research Unit.
a For different tasks performed by the PWP, different costs were associated. For example, for work not requiring any patient contact, a general total staff hourly rate was applied for band 5 (£39 per hour).
b This was also the case for case manager supervision: for work not requiring any patient contact, a general total staff hourly rate was applied for band 6 (£49 per hour).
c For contact in person, the PSSRU unit cost for‘face-to-face time’was applied (£74 per hour).