Background Care home residents with stroke-related disabilities have significant activity limitations. Phase II trial results suggested a potential benefit of occupational therapy (OT) in maintaining residents’ capacity to engage in functional activity. Objective Evaluate clinical and cost effectiveness of a targeted course of OT in maintaining functional activity and reducing further health risks from inactivity for UK care home residents living with stroke-related disabilities. Design Pragmatic, parallel-group, cluster randomised controlled trial with economic evaluation. Cluster randomisation occurred at the care home level. Homes were stratified according to trial administrative centre, and type of care provided (nursing or residential) and randomised 1:1 to either the intervention or control arm. Setting 228 care homes local to 11 trial administrative centres across England and Wales. Participants 1042 care home residents with a history of stroke or transient ischaemic attack, including residents with communication and cognitive impairments, not receiving end of life care. 114 care homes (n=568 residents) were allocated to the intervention arm; 114 homes (n=474 residents) to the control arm. Randomisation of participating homes occurred between May 2010 and March 2012. Intervention Personalised three-month course of OT delivered by qualified therapists. Care workers participated in training workshops to support personal activities of daily living. The control condition consisted of usual care for residents. Main outcome measures Primary outcome at the participant level: Barthel Index of Activities of Daily Living at three months. Secondary outcomes at the participant level: Barthel Index scores at six and twelve months post-randomisation, and the Rivermead Mobility Index, Geriatric Depression Scale-15, and EuroQol EQ-5D-3L questionnaire at all time-points. An economic evaluation examined the incremental cost per quality-adjusted life year (QALY) gain, costs were estimated from the perspective of the NHS and personal social services. Results Participants mean age= 82.9 years, 665/1042 (64%) were female. 2538 OT sessions were delivered to 498 participants in the intervention group (mean visits/participant =5.1, SD=3.0). No adverse events attributable to the intervention were recorded. The primary outcome showed no significant differences between groups. The adjusted mean difference in the Barthel Index score between groups was 0.19 points higher in the intervention arm (95% CI -0.33 to 0.70, p=0.48, adjusted ICC 0.09). Secondary outcome measures showed no significant differences at all time-points. Mean incremental cost of the OTCH intervention was £438.78 (CI £-360.89 to £1238.46), and the incremental QALY gain was 0.009 (CI -0.030 to 0.048). Conclusion A three-month individualised course of OT, showed no benefit in maintaining functional activity in an older care home population with stroke-related disabilities. Limitations A high proportion of participants with very severe activity-based limitations and cog...