OBJECTIVE

To examine whether change in cognitive performance during dual task condition compared with a task in isolation, known as dual task cost, is related to fall risk of patients with multiple sclerosis.

DESIGN

Prospective cohort. During baseline assessment, data about balance, walking and cognitive performance of patients with multiple sclerosis were collected under a single and dual task condition. The dual task cost was calculated as a percentage of change in parameters from single to dual task conditions. Falls were recorded prospectively for six months and participants were classified as none/one time fallers and recurrent fallers (⩾2 falls). The association between dual task costs and fall status was evaluated by logistic regression.

SETTING

Balance research lab of university hospital.

PARTICIPANTS

A total of 60 patients with relapsing-remitting multiple sclerosis.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The dual task cost of the center of pressure sway area, walking velocity and correct response rate were outcome measures for balance, walking and cognitive performance, respectively.

RESULTS

A total of 79 falls were reported by 38 of the participants who experienced one or more falls; 26 (43.3%) of them had recurrent falls. Dual tasking resulted in increased sway area and decreased walking velocity and correct response rate during walking (all p values <0.05). Logistic regressions showed that the dual task cost of the correct response rate during walking and walking velocity were associated with increased risk of recurrent falls ( P = 0.02, odds ratio = 1.34; confidence interval (CI) 1.04-3.74; P =  0.05, odds ratio = 1.23, CI = 1.02-4.45, respectively).

CONCLUSIONS

The dual task cost of cognition was related to fall, which should be considered as a target for falls evaluation and prevention strategies.