No pain relief by virtual reality during hysterosalpingography (HSG): results from a randomized controlled trial.

Study question: Is virtual reality (VR) an effective non-pharmacological tool to reduce procedural pain during hysterosalpingography (HSG)?

Summary answer: An HSG with VR does not reduce procedural pain scores compared to an HSG without VR.

What is known already: An HSG is often experienced as painful and uncomfortable. VR has been proven successful to reduce acute procedural pain during a variety of medical procedures and interventions.

Study design, size, duration: We performed a two-centre open-label randomized controlled trial between January 2021 and October 2022.

Participants/materials, setting, methods: Women scheduled for HSG as part of their infertility work-up were screened for participation. After informed consent, women were randomized between HSG with or without VR. Due to the nature of the intervention, the study was not blinded. VR was administered by a head-mounted device displaying nature movies and/or relaxation exercises. The primary endpoint was procedural pain measured using VAS (scale 0.0-10.0 cm). Procedural pain was divided into overall pain score and peak pain score during the procedure. It was measured immediately after HSG. Secondary endpoints included patient satisfaction, VR preferences, and adverse effects of VR.

Main results and the role of chance: We included a total of 134 women, 69 to the intervention group (HSG with VR) and 65 to the control group (HSG without VR). The mean VAS for peak pain was 6.80 cm (SD 2.25) in the intervention group versus 6.60 cm (SD 2.40) in the control group (mean difference 0.28 (95% CI -0.57, 1.12), P = 0.52). The mean VAS for overall pain was 5.00 cm (SD 2.10) in the intervention group versus 4.90 cm (SD 2.13) in the control group (mean difference 0.06 (95% CI -0.71, 0.84), P = 0.88). The expectation that VR would be a good distraction from pain during HSG was correlated with both overall and peak pain scores. When correcting for this expectation, we found that women in the intervention group reported significantly higher scores, both in peak (adjusted MD 0.58 (95% CI -0.81, 1.97), P = 0.021) and overall (adjusted MD 0.43 (95% CI -0.84, 1.71), P = 0.013) pain, compared to the control group. There were no differences in the prevalence of symptoms that were considered as adverse effects of VR.

Limitations, reasons for caution: The study was not blinded. Reasons for declining participation in the study were anxiety or wanting full control during HSG, which might have created selection bias. The distraction score possibly indicates that the level of VR immersiveness was not optimal due to the lack of sound and/or the type of VR applications. Future studies should investigate whether more immersive or interactive VR applications could decrease procedural pain scores during HSG.

Wider implications of the findings: Since VR does not reduce procedural pain, this additional tool should not be used during HSG.

Study funding/competing interest(s): There was no external funding for this study. KR and AvH report receiving a travel grant from Merck outside the scope of this study. BM is supported by a National Health and Medical Research Council (NHMRC) investigator grant (GNT1176437) and BM reports consultancy for Merck, Organon, and Norgine and travel and research funding from Merck. BM holds stock for ObsEva. CL reports receiving research grants from Merck, and Ferring. KD and VM report receiving travel and speaker's fees from Guerbet and research grants from Guerbet. VM also reports research grants from Merck and Ferring. The remaining authors have nothing to declare.

Trial registration number: The trial is registered prospectively in the Netherlands Trial Register (trialregister.nl registration number NL9203, currently accessible on trialsearch.who.int).

Trial registration date: 16-01-2021.

Date of first patient’s enrolment: The first participant was enrolled on 19 January 2021.