Table 1 Return on investment
Costs (£) | Benefits (£) | ROI | |
|---|---|---|---|
Project implementation = £4539.50 (cost of installation per house) * 2252 (# of households receiving EWI) = £10,222,954 | Adjusted monthly difference in fuel expenditure (early cladders-control) 40 | Annual adjusted difference between treatment and control group * total households £40 * 12 * 3256 = £1,562,880 | |
Maintenance = £0 (over first 4 years of installation) | Adjusted difference in EQ-5D-3L score (early cladders-control) 0.01 | Adjusted Difference in EQ-5D-3L score * NICE QALY threshold * total households 0.01 * £20,000 * 3256 = £651,200 | |
Adjusted difference in usage * cost of health care (early cladders-control): outpatient appointments/hospital visits (£4,185,665–£3,111,284) Medical procedures: (£887,609–£1,159,201) Medication: (£60,254–£4,438,493) | Sum of adjusted difference in health care costs between early cladders and control: − £695,035 | ||
Total costs = £10,222,954 | Total benefits = £1,519,045/year or £6,076,180 for 4 years | ROI (%) = (benefits-costs)/costs = − 41% | |