Background: People with Parkinson's disease are twice as likely to experience a fall as a healthy older person, often leading to debilitating effects on confidence, activity levels and quality of life.

Objective: To estimate the effect of a physiotherapy programme for fall prevention among people with Parkinson's disease.

Design: A multicentre, pragmatic, investigator-masked, individually randomised controlled trial (RCT) with prespecified subgroup analyses.

Setting: Recruitment from NHS hospitals and clinics and community and social services in eight English regions with home-based interventions.

Participants: A total of 474 people with Parkinson's disease (i.e. Hoehn and Yahr scale stages 1-4) were recruited: 238 were assigned to a physiotherapy programme and 236 were assigned to usual care. Random allocation was 50 : 50.

Interventions: All participants received routine care; the usual-care group received an information digital versatile disc (DVD) and a single advice session at trial completion. The intervention group had an individually tailored, progressive, home-based fall avoidance strategy training programme with balance and strengthening exercises: PDSAFE.

Main outcome measures: The primary outcome was the risk of repeat falling, collected by self-report monthly diaries between 0 and 6 months after randomisation. Secondary outcomes included near-falls, falls efficacy, freezing of gait (FoG), health-related quality of life, and measurements taken using the Mini-Balance Evaluation Systems Test (Mini-BESTest), the Chair Stand Test (CST), the Geriatric Depression Scale, the Physical Activity Scale for the Elderly and the Parkinson's Disease Questionnaire.

Results: PDSAFE is the largest RCT of falls management among people with Parkinson's disease: 541 patients were screened for eligibility. The average age was 72 years, and 266 out of 474 (56%) participants were men. Of the 474 randomised participants, 238 were randomised to the intervention group and 236 were randomised to the control group. No difference in repeat falling within 6 months of randomisation was found [PDSAFE group to control group odds ratio (OR) 1.21, 95% confidence interval (CI) 0.74 to 1.98; p = 0.447]. An analysis of secondary outcomes demonstrated better balance (Mini-BESTest: mean difference 0.95, 95% CI 0.24 to 1.67; p = 0.009), functional strength (CST: p = 0.041) and falls efficacy (Falls Efficacy Scale - International: mean difference 1.6, 95% CI -3.0 to -0.19; p = 0.026) with near-falling significantly reduced with PDSAFE (OR 0.67, 95% CI 0.53 to 0.86; p = 0.001) at 6 months. Prespecified subgroup analysis (i.e. disease severity and FoG) revealed a PDSAFE differing effect; the intervention may be of benefit for people with moderate disease but may increase falling for those in the more severe category, especially those with FoG.

Limitations: All participants were assessed at primary outcome; only 73% were assessed at 12 months owing to restricted funding.

Conclusions: PDSAFE was not effective in reducing repeat falling across the range of people with Parkinson's disease in the trial. Secondary analysis demonstrated that other functional tasks and self-efficacy improved and demonstrated differential patterns of intervention impact in accordance with disease severity and FoG, which supports previous secondary research findings and merits further primary evaluation.

Future work: Further trials of falls prevention on targeted groups of people with Parkinson's disease are recommended.

Trial registration: Current Controlled Trials ISRCTN48152791.

Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 36. See the NIHR Journals Library website for further project information. Sarah E Lamb is funded by the NIHR Collaboration for Leadership in Applied Health Research and Care (CLAHRC) at Oxford Health NHS Foundation Trust, the NIHR Oxford Biomedical Research Centre at the Oxford University Hospitals NHS Foundation Trust and CLAHRC Oxford. Victoria A Goodwin is supported by the NIHR Collaborations for Leadership in Applied Health Research and Care in the South West Peninsula (PenCLAHRC). Lynn Rochester is supported by the NIHR Newcastle Biomedical Research Centre based at Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University. The research was also supported by the NIHR Newcastle Clinical Research Facility Infrastructure funding. Helen C Roberts is supported by CLAHRC Wessex and the NIHR Southampton Biomedical Research Centre.