Five RCTs (1,544 participants) were included in the review. Four out of five studies had adequate randomisation and allocation concealment. Four of the five studies had high drop-out rates (16% to 77%). Only one study reported blinding during outcome assessment.
None of the studies found a significant difference in reassurance levels between intervention and control groups at the end of follow-up; one study found an interim benefit at three months which disappeared at one year follow-up.
Four studies assessed symptom levels and none found a significant difference between intervention and control groups at the end of follow-up. One study found significantly fewer headaches after magnetic resonance imaging in a subgroup of patients with high baseline anxiety and depression scores.
Three studies assessed disability levels and none found a significant difference between intervention and control groups at the end of follow-up.
Three trials assessed patient satisfaction. One trial found that patients who received radiographic investigations of the lumbar spine for lower back pain were significantly more satisfied with their care at the end of nine months follow-up than those who had not. Two studies found no significant difference in patient satisfaction at the end of follow-up.