Incidence rate ratio

Researchers evaluated whether a community falls prevention service reduced the rate of falls in older people. They used a randomised controlled trial design. Participants were recruited if they were aged over 60 years, had experienced a fall while living at home or in residential care, and an emergency ambulance had been called but had not taken them to hospital. Participants were randomised to the community falls prevention service or standard medical and social care (control treatment).1

The primary outcome was rate of falls in one year of follow-up, as recorded in monthly diaries. Analysis was by intention to treat. After randomisation, 99 participants were offered the community falls prevention service and 102 participants were offered the control treatment. Diaries for the intervention group contributed 88.6 person years and those for the control group contributed 84.5 person years. The incidence rates of falls per year were 3.46 in the intervention group and 7.68 in the control group, with an incidence rate ratio equal …