Unmask the headset effect

1 · Understand the suspicion

Beginner

Why are the authors wary of a trial that compares the headset with "no intervention"?

These trials enrol too few patients Headsets are too expensive for hospitals The headset alone may help, whatever it shows

2 · Work out the odds

The odds of a positive result are the number of positive trials divided by the number of negative ones.

Intermediate

Of the 8 trials with an active control, 3 are positive. What are their odds?

0.6 0.375 1.67

3 · Build a virtual placebo

A trial treats fear of heights: the patient crosses a virtual footbridge over a chasm.

Expert

Which virtual placebo follows the authors' recommendations?

A holiday film, watched in the headset without moving The same footbridge, laid on the ground, same movements A commercial virtual reality game, highly engaging

4 · Read the right result

A trial at last compares a therapy with a good virtual placebo. Both groups get better.

Expert

What would show that the therapy really works?

That the placebo group does not improve at all That both groups improve by more than half That it does significantly better than the placebo

Headset effect unmasked

—