Objectives: This paper aims to compare changes over 2 years in patients' healthrelated quality of life (HRQL) with the health and social care costs of diagnosis and treatment of people newly referred to memory assessment services (MAS).
Methods:We analysed observational data from 1318 patients referred to 69 MAS who completed resource use and HRQL questionnaires at baseline 3, 6, 12, and 24 months. We reported mean differences in HRQL (disease-specific DEMQOL and generic EQ-5D-3 L), quality-adjusted life years (QALYs), costs and costeffectiveness between baseline, and 2-year follow-up.Results: Two years after referral to MAS, patients reported a higher DEMQOL score (mean gain 4.47, 95% confidence interval, 3.08-5.90) and EQ-5D-3 L (0.014, −0.011 to 0.039). Mean total costs and QALYs over 24 months was £2411 (£1721-£2873) and 0.027 (0.003-0.051), respectively. Assuming that patients' HRQL would not have altered over the 2 years had they not attended MAS, these outcomes suggest an incremental cost-effectiveness ratio of £89 546 (£38 123-£145 864) based on changes in EQ-5D-3 L. If we assumed that patients' HRQL would have declined by about 10% over this period had they not attended MAS, the cost-effectiveness ratio would be £25 056. The largest MAS (N = 32; 46%) with over 50 new patients a month were more likely to be cost-effective than smaller ones (P < 0.01).Conclusions: MAS are effective and can be cost-effective for diagnosing and treating people with suspected dementia. Large variations in costs between clinics suggest that many MAS could improve their cost-effectiveness. KEYWORDS cost-effectiveness analysis, dementia, England, memory assessment services 1 | INTRODUCTION The number of people living with dementia worldwide has increased in the last two decades mainly driven by population ageing. 1 In 2017, there were an estimated 50 million people with dementia, with nearly 10 million new cases expected now every year. 1 Dementia is a major cause of disability and burden of care in elderly people and is associated with rising health care costs. The costs associated with dementia worldwide are expected to rise above $1 trillion in 2018, which represents over 1% of the global GDP. 2 These rising costs are mostly due to the increased need for social and health care and family support (informal care). 2There is considerable evidence that early diagnosis and support for those with dementia enables them to live well for longer and helps reduce long-term costs. 3,4 To encourage this, referral of people with