Table 1 Full list of objectives

Primary objective

To compare the effect of the online vestibular rehabilitation tool with standard written instructions after acute onset vertigo on vestibular symptoms.

Secondary objectives

1. Compare the impact of the online vestibular rehabilitation tool with standard written instructions after acute onset vertigo on different aspects of everyday living.

2. Compare how the online vestibular rehabilitation tool influences the walking ability compared with standard written instructions after acute onset vertigo.

3. Compare how the online vestibular rehabilitation tool influences the lateral canal vestibulo-ocular reflex (VOR) recovery compared with standard written instructions after acute onset vertigo.

4. Compare the long-term effects of early vs. delayed online vestibular rehabilitation on vestibular symptoms and mobility.

5. Compare the effects of online vestibular rehabilitation with standard written instructions on vestibular rehabilitation compliance.

6. Compare the health economic effects of online vestibular rehabilitation with standard written instructions.

7. Compare the multi-joint kinematic output data from a portable multi-sensor movement analysis system, with the hip kinematic output data received from the mobile phone app.

8. Translate and validate the VSS-SF scale from English to Swedish.

9. Investigate the frequency of benign positional paroxysmal vertigo (BPPV) after AVS at different time points and using different evaluation methods; investigate the correlation between BPPV the DHI, VSS-SF, steps, and safety endpoints; and investigate the effect of treatment arm allocation on the risk for BPPV.

Safety endpoint:

The proportion of participants who have experienced falls/fractures since study start up until 6 weeks, 3 months, and 12 months; and the number of falls/fractures in each study arm at the same time points.