Background We investigated the effectiveness of an Interdisciplinary Home-bAsed Reablement Programme (I-HARP) on improving functional independence, health and well-being of people with dementia, family carer outcomes and costs.

Method A multicentre pragmatic parallel-arm randomised controlled trial compared I-HARP to usual care in community-dwelling people with mild to moderate dementia and their family carers in Sydney, Australia (2018–2022). I-HARP is a 4-month, home-based, dementia rehabilitation model delivered by an interdisciplinary team. Assessments were conducted at baseline (time-1), 4-month (time-2) and 12-month (time-3) follow-up. The primary outcome measure was the client’s functional independence using the Disability Assessment for Dementia (DAD) scale at time-2, based on intention-to-treat analyses.

Result Of 130 recruited client-carer dyads, 116 dyads (58/group) completed the trial. The I-HARP group were not significantly better in most outcome measures than usual care at both time-2 and time-3; with the only statistically significant difference being a reduction in home environment hazards at time-2. Post hoc subgroup analysis of 66 clients with mild dementia found significantly better functional independence in the intervention group compared with those in usual care: difference 8.99 on DAD (95% CI 1.21, 16.79) at time-2 and difference 12.16 (95% CI 1.93, 22.38) at time-3. Economic evaluation suggests potentially lower resource use in I-HARP compared with usual care, but the cost-effectiveness is uncertain.

Conclusion Primary outcomes were not met for a population of people with dementia, with severity ranging from mild to moderate and severe. The I-HARP model appeared to benefit functional independence of participants with mild dementia, with potential cost savings.