Efficacy of a Self-Hypnotic Relaxation App on Pain and Anxiety in a Randomized Clinical Trial: Results and Considerations on the Design of Active and Control Apps

Abstract

Despite an explosion of mobile app offerings for management of pain and anxiety, the evidence for effectiveness is scarce. Placebo-controlled trials are the most desirable but designing inactive placebo apps can be challenging. For a prospective randomized clinical trial with 72 patients in a craniofacial pain center, we created an app with self-hypnotic relaxation (SHR) for use with iOS and Android systems. A placebo background audio (BA) app was built with the same look and functionality. Both iOS and Android SHR apps alone and in comparison to the BA group significantly reduced pain and anxiety during the waiting-room time. The Android BA app significantly reduced anxiety but not pain. The iOS BA app affected neither pain nor anxiety, functioning as an ideal placebo. Usage analysis revealed that different default approaches of the iOS and Android devices accounted for the difference in results.

Conflict of interest statement

Declaration of Interest Statement

Author EVL is owner of the company that designed the app; authors PS, TC, and GC were/are employees of the company. The other authors do not have conflict of interest.

Figures

Fig. 1a

iPad (iOS) version of the SHR-app with the opening screen (left top), selection menu of main themes (right top), choice of voice, listening time, and addition of extras (bottom left), which are spelled out on the extra screen (bottom right).

Fig. 1b

iPad version of the BA-app which was designed to resemble the SHR-app showing the opening screen (left top), selection menu of main themes (right top), choice of voice, listening time, and addition of extras (bottom left), which are spelled out on the extra screen (bottom right). Exterior A refers to nature sounds, Exterior B to urban sounds, Exterior C to sounds from the waterfront and interior to indoor sounds. Note that on the Android BA the sequence of themes from top to bottom was Exterior A, B, C, Interior, not as on the iOS Interior, Exterior A, C, B.

Fig. 2

Participant Flow Chart. * One participant who was withdrawn after consent by the research assistant when the participant realized that she did not actually have a smartphone (part of inclusion criteria) or knew how to use a tablet. ** Two participants who withdrew after consent before listening.

Fig. 3

Change (Delta) in anxiety and pain from start of the waiting room time to the end of the waiting room time. Scale 0–10 with 0=no anxiety/no pain at all and 10=worst anxiety/pain possible. P-values based on Wilcoxon Signed Rank tests. ★ Significant difference of the delta pain or anxiety respectively.