Economic evaluation of a vision-based patient monitoring and management system in an acute adult and an older adult mental health hospital in England

Figures & data

Table 1. Scaling inputs for application of model results.

Parameter	Adults on acute wards				Older adults
	Study- specific input	Average ward size input	NHS input	Source	Study specific input	Average ward size input	NHS input	Source
Average length of stay per patient (days)	48	48	48	Average length of stay for adult mental illness. Hospital Episodes Statistics^7.	82	82	82	Average length of stay for older age psychiatry. Hospital Episodes Statistics^7.
Number of wards	2	1	N/A	Unpublished VBPMM study was used for the study-specific input^8. Average ward size and NHS inputs were based on an assumption. Average occupancy derived from a report from Midlands and Lancashire NHS commissioning support unit^9.	2	1	N/A	VBPMM study was used for the study-specific input^10^,^11. Average ward size and NHS inputs were based on an assumption. Average occupancy derived from a report from Midlands and Lancashire NHS commissioning support unit^9.
Average beds per ward	21	16	16		12	16	16
Average occupancy	95%	90%	90%		88%	90%	90%
Total occupied bed days per year	14,572	6,903	3,931,551	Calculated based on the data above, assuming a year is 365.25 days. NHS input calculated using Midlands and Lancashire NHS commissioning support unit data^9 which reports 18,400 beds in mental health hospitals. It is also assumed 65% of inpatients at acute wards are adults.	7,708	5,260	1,131,077	Calculated based on the data above, assuming a year is 365.25 days. NHS input calculated using Midlands and Lancashire NHS commissioning support unit data^12 which reports 18,400 beds in mental health hospitals. 18.7% of patients taken to be older adults based on the proportion of consultant bed days corresponding to older psychiatry from Hospital Episodes Statistics^7.

Abbreviations. N/A, not applicable; NHS, National Health Service; VBPMM, vision-based patient monitoring and management.

Figure 1. Model structure.

Table 2. Clinical inputs.

Parameter	Adults on acute wards		Older adults
	Reported value (95% CI)	Source/comment	Reported value (95% CI)	Source/comment
Night-time observation hours
Number of night-time observations per occupied bed day	11.52	Unpublished VBPMM study^8	18	VBPMM study^10^,^11^,^17
Night-time observation time per patient (seconds)	23		23
Reduction in observation time from VBPMM	41% (25% to 53%)		41% (25% to 53%)
One-to-one observation hours
Number of one-to-one observation hours per occupied bed day per year	1.25	Unpublished VBPMM study^8	1.44	VBPMM study^10^,^11^,^17
Reduction in one-to-one observation hours from VBPMM	20% (–13% to 36%)		71% (50%, one-sided test)
Proportion of one-to-one observation hours that is cash releasing^a	40%		22%
Self-harm incidents
Average number of self-harm incidents per occupied bed day per year	0.0094	Unpublished VBPMM study^8	Not applicable to this population
Reduction in self-harm incidents from VBPMM	44% (13% to 100%)	Unpublished VBPMM study^8
Staff hours per incident	9.3	Primary data collection from mental health hospital staff interviews. See Supplementary Material.
Proportion visiting A&E	8%	James et al.^12
Night-time falls
Average number of night-time bedroom falls per occupied bed day per year	Not applicable to this population		0.014	VBPMM study^10^,^11^,^17
Reduction in night-time bedroom falls from VBPMM			48% (16% to 88%)	VBPMM study^10^,^11^,^17
Staff hours per night-time bedroom fall			7.1	Primary data collection from mental health hospital staff interviews. See Supplementary Material.
Proportion visiting a GP because of a night-time bedroom fall			60%
Proportion of night-time bedroom falls leading to litigation			0.2%	NHS Improvement.^18
Average A&E visits from night-time bedroom falls per occupied bed day per year			0.0019	VBPMM study^10^,^11^,^17
Reduction in A&E visits from night-time bedroom falls with VBPMM			68% (45% one-sided test)
Proportion of patients requiring a hospital stay who visited A&E			6%	NHS Improvement.^18
Proportion of patients requiring surgery who visited A&E			3%
Average emergency service visits from night-time bedroom falls per occupied bed day per year			0.005	VBPMM study^10^,^11^,^17
Reduction in emergency service visits from night-time bedroom falls with VBPMM			49% (17% one-sided test)

Abbreviations. A&E, accidents and emergency; GP, general practitioner; NHS, National Health Service; VBPMM, vision-based patient monitoring and management.

^aCash-releasing savings refers to savings that bring an in-year monetary return without changing safe staffing levels (e.g. through reduction in agency staff while maintaining safe staffing levels). This is in contrast to opportunity cost savings, where resources are released for other clinical tasks, but with no resulting monetary savings. This distinction is particularly relevant for one-to-one observation time which is very resource-intensive and may require additional staff beyond the core personnel of the ward.

Table 3. Costs inputs.

Parameter	Value	Source/comment
Night-time observation hours
Weighted staff cost for observation time per hour	£30	PSSRU^16^,^19 Hospital-based nurses. Assumed 70% band 3 nurse (HCA), 30% band 5 Nurse.
One-to-one observation hours
Weighted staff cost for observation time per hour	£30	PSSRU^16^,^19 Hospital-based nurses. Assumed 70% band 3 nurse (HCA), 30% band 5 Nurse.
Self-harm incidents (adults on acute mental health ward only)
Weighted staff cost per hour	£37	PSSRU^16^,^19 Hospital-based staff. Psychiatric consultant, Band 7 Nurse, Band 5 Nurse, Band 3 Nurse (HCA). See Supplementary Material for more details.
Cost of A&E (non-surgery)	£2,134	NHS Reference costs 2018/29^15 Weighted average of fractures codes (HE71B- HE11H) without interventions.
Tariff cost of A&E (non-surgery)	£1,604	NHS improvement, National tariff payment system^20 Weighted average of fractures codes (HE71B- HE11H) fractures without interventions.
Bedroom falls at night (older adult population only)
Weighted staff cost per hour	£58	PSSRU^16^,^19 Hospital-based staff. Psychiatric consultant, Band 7 Nurse, Band 5 Nurse, Band 3 Nurse (HCA). See supplementary material for more details.
Increased length of stay cost from the resulting fall	£3,215	Average length of additional stay estimated to be 8.4 days in the VBPMM study in older adults^11. This was multiplied by the cost per day of stay in a mental health hospital from NHS improvement^18 and inflated to current prices using PSSRU^16.
Cost of GP review	£118	PSSRU^16 Low or moderate harm falls were assumed to require on average 3 GP appointments at a cost of £39.23 each.
Litigation cost	£14,117	NHS Improvement^18 Inflated to current prices using PSSRU^16.
Staff cost per hour for A&E visits	£26	PSSRU^16^,^19 Hospital-based nurses. Band 3 nurse (HCA).
A&E cost (non-surgery treatment)	£2,134	NHS Reference Costs 2018/19^15 Weighted average of fractures codes (HE71B- HE11H) without interventions.
Tariff cost of A&E (non-surgery treatment)	£1,604	NHS Improvement, National tariff payment system^20 Weighted average of fractures codes (HE71B- HE11H) fractures without interventions.
Hospital stay without surgery cost	£317	NHS Improvement^18 Assumed only 1 night stay needed when surgery is not required. Cost per day of stay taken from acute patient. Inflated to current prices using PSSRU^16.
Hospital stay with surgery cost	£2,535	NHS Improvement^18 Assumed 8-night stay when surgery is required. Cost per day of stay taken from acute patient. Inflated to current prices using PSSRU^16.
Surgery cost	£4,527	NHS Improvement^18 Inflated to current prices using PSSRU^16.
Cost of emergency service callout	£265	NHS reference costs^15 Includes codes ASC1 and ASS02.
VBPMM
Cost of VBPMM: adults on acute mental health wards (average sized ward)	£26,542	Annual license fees and annuitized installation and cabling costs provided by the manufacturer (Oxehealth). Staff training costs were calculated by combining staff costs from PSSRU^16^,^19 with estimated training requirements provided by the VBPMM manufacturer. This input is higher in the older adult population due to more staff requiring the training.
Cost of VBPMM: older adult mental health inpatients (average sized ward)	£26,555

Abbreviations. A&E, accidents and emergency; GP, general practitioner; HCA, healthcare assistant; NHS, National Health Service; PSSRU, Personal Social Services Research Unit; VBPMM, vision-based patient monitoring and management.

Table 4. Confidence intervals for the population of adults on acute mental health wards.

Parameter	Base Case	Lower bound	Upper bound
Reduction in night-time observation time from VBPMM	41%	25%	53%
Reduction in one-to-one observation hours from VBPMM	20%	–13%	36%
Reduction in self-harm incidents from VBPMM	44%	13%	100%

Table 5. Base case results.

	Adults on acute wards			Older adults
	Standard care	VBPMM +  standard care	Incremental	Standard care	VBPMM +  standard care	Incremental
Cost of observations (£ per patient)	107	63	–44	286	169	–117
Cost of one-to-one observations (£ per patient)	1,813	1,444	–369	3,571	1,040	–2,531
Cost of bedroom falls at night (£ per patient)	N/A	N/A	N/A	4,238	2,190	–2,048
Cost of A&E visits from night time falls (£ per patient)	N/A	N/A	N/A	378	121	–257
Cost of change in emergency services (£ per patient)	N/A	N/A	N/A	108	55	–53
Cost of self-harm incidents (£ per patient)	231	129	–101	N/A	N/A	N/A
Cost of VBPMM (£ per patient)	0	242	242	0	414	414
Total cost per patient (£)	2,151	1,879	–272	8,581	3,990	–4,591
Total cost per occupied bed day (£)	45	39	–6	105	49	–56
Total cost per average sized ward per year (£)	235,676	£205,849	–29,827	550,402	255,901	–294,501
Total cost to the NHS per year (£)	176,167,573	153,872,139	–22,295,434	118,363,899	55,031,472	–63,332,427

Figures are rounded to the nearest integer, resulting in potential discrepancies in the incremental estimates.

Abbreviations: NHS, National Health Service; ROI, return on investment; VBPMM, vision-based patient monitoring and management.

Table 6. Clinical events per patient per year.

	Standard care	VBPMM + standard care	Incremental
Adults on acute wards
Total staff hours per patient	68.16	52.68	–15.48
Assaults or self-harms per year	0.53	0.34	–0.20
A&E visits per patient	0.04	0.02	–0.02
Older adults
Staff hours per patient	135.29	44.05	–91.24
Night time bedroom falls per patient	1.14	0.59	–0.55
A&E visits per patient	0.16	0.05	–0.11
Emergency services calls per patient	0.41	0.21	–0.20

Table 7. Scenario analysis for adults on acute wards excluding one-to-one observations.

	Standard care	VBPMM + standard care	Difference
Total cost per occupied bed day (£)	45	47	2
Total cost per patient (£)	2,151	2,248	97
Total cost per average sized ward per year (£)	235,676	246,309	10,633
Total cost to the NHS per year (£)	176,167,573	184,115,799	7,948,226

Figures are rounded to the nearest integer, resulting in potential discrepancies in the incremental estimates.

Abbreviations. NHS, National Health Service; ROI, return on investment; VBPMM, vision-based patient monitoring and management.

Figure 2. Tornado plots.

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Data availability statement

To request the original data regarding Oxevision please contact [email protected]

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.