Active virtual reality increases pain tolerance compared to passive virtual reality: a randomized crossover study of healthy volunteers

Background: Virtual reality (VR) reduces pain and anxiety, but influencing factors remain ambiguous. This study evaluated the effect of interactivity within a VR experience on heat pain threshold (HPT), pressure pain threshold (PPT), and immediate and recalled pain and anxiety.Methods: The Stanford Chariot Program conducted this prospective, randomized, crossover clinical trial at Stanford Children’s Hospital Stanford, Stanford Hospital, and Stanford Medical School. Healthy adult participants meeting inclusion criteria were randomized by hand dominance and condition sequence and underwent standardized pain threshold tests with a heat thermode or pressure algometer during active and passive VR conditions. The primary outcome was the impact of active VR on HPT. Secondary outcomes evaluated its effects on PPT, immediate and recalled pain, and immediate and recalled anxiety.Results: 163 total participants were included, 81 who underwent HPT testing and 82 who underwent PPT testing. Active VR increased pain thresholds for both HPT (P = 0.0001) and PPT (P ≤ 0.0001). There was no difference in initial pain scores between VR conditions for HPT (P = 0.63), though there was for PPT (P = 0.006). There was no difference in recalled pain scores for HPT (P = 0.13) or PPT (P = 0.39). Active VR reduced initial and recalled anxiety scores for HPT (P = 0.012, P = 0.002; respectively) and initial anxiety scores for PPT (P = 0.04). Recalled anxiety scores for PPT did not differ (P = 0.32).Conclusions: Active VR improved pain tolerance and anxiety more than passive VR.