Objective:The Interdisciplinary Home-bAsed Reablement Program (I-HARP) integrates evidence-based rehabilitation strategies into a dementia-specific person-centred, time-limited, home-based, interdisciplinary rehabilitation package. I-HARP was a 4-month model of care, incorporated into community aged care services and hospital-based community geriatric services. I-HARP involved: 8-10 individually tailored home visits by occupational therapist and registered nurse; 2-4 optional other allied health sessions; up to A$1,000 minor home modifications and/or assistive devices; and three individual carer support sessions. The aim of the study was to determine the effectiveness of I-HARP on the health and wellbeing of people living with dementia and their family carers.Methods:A multi-centre pragmatic parallel-arm randomised controlled trial compared I-HARP to usual care in community-dwelling people with mild to moderate dementia and family carers in Sydney, Australia (2018-22). Assessments of the client’s daily activities, mobility and health-related quality of life, caregiver burden and quality of life were conducted at baseline, 4- and 12-month follow-up. Changes from baseline were compared between groups.Results:Of 260 recruited, 232 (116 dyads of clients and their carers, 58 dyads per group) completed the trial to 4-month follow-up (89% retention). Clients were: aged 60-97 years, 63% female, 57% with mild dementia and 43% with moderate dementia. The I-HARP group had somewhat better mean results for most outcome measures than usual care at both 4 and 12 months, but the only statistically significant difference was a reduction in home environment hazards at 4 months (reduction: 2.29 on Home Safety Self-Assessment Tool, 95% CI: 0.52, 4.08; p=.01, effect size [ES] 0.53). Post-hoc sub-group analysis of 66 clients with mild dementia found significantly better functional independence in the intervention group: 11.2 on Disability Assessment for Dementia (95% CI: 3.4, 19.1; p=.005; ES 0.69) at 4 months and 13.7 (95% CI: 3.7, 23.7; p=.007; ES 0.69) at 12 months.Conclusion:The I-HARP model enhanced functional independence of people with mild dementia only but not significantly in people with moderate dementia, so did not result in better outcomes in the group overall. A different type of rehabilitation model or strategies may be required as dementia becomes more severe.