439: Physiotherapist-led integrated psychological and physical care is cost-effective for acute whiplash

Topic: Clinical Science
Subtopic: Pain category (ICD-11), Acute posttraumatic pain, Physiotherapy (e.g. exercise, rehab), Physiotherapy, Treatment/management

Background and Aims: Road traffic crashes cause 20-50-million non-fatal injuries annually[1]. Whiplash-associated disorders (WAD) are the most common non-hospitalised injury and although labelled “minor”, 50% of people develop persistent pain resulting in significant societal costs [>1-billion Australian Dollars (AUD) annually][2,3]. A randomized trial showed StressModex (physiotherapist-led integrated stress inoculation training and exercise) was clinically effective for neck pain-related disability in adults with acute WAD and elevated pain-related disability and stress symptoms[4]. While clinically effective, evidence on its cost-effectiveness is required to inform decision making, policy, and clinical guidelines. Using trial data, we aimed to evaluate cost-effectiveness of StressModex compared to guideline-based exercise.

Methods: 108 adults with acute WAD (<4 weeks post-crash; at risk of poor recovery) were recruited from physiotherapy clinics and randomized to StressModex or guideline-based exercise alone; both physiotherapist-delivered (10-sessions/6-weeks). Economic outcomes comprised quality-adjusted life years (QALYs) and Neck Disability Index (NDI; 0–100) over 12-months. Incremental cost-effectiveness ratios were calculated for QALYs and NDI per 10‑point difference (clinically relevant difference) from health system (physiotherapist training and participant healthcare use costs) and societal perspectives (health system costs plus lost work productivity costs). Missing data (16%) were handled and uncertainty assessed using multiple imputation nested within bootstrapping, with adjustment for baseline differences[5].

Results: Per participant, health system costs were AUD290 lower for StressModex versus guideline-based exercise (95%CI -1168, 570), alongside greater health benefits (QALYs 0.07[95%CI 0.00, 0.15]; NDI -8.7[95%CI -14.3, -3.1]. From the health system perspective, StressModex had a high probability of cost-effectiveness, saving AUD4143 per QALY gained and AUD330 per 10-point improvement in NDI. Although societal costs were AUD3489 higher per participant (95%CI -6222, 14242), StressModex remained cost-effective, with costs of AUD49843 per QALY gained and AUD4200 per 10-point NDI improvement, consistent with Australian willingness-to-pay thresholds per QALY gained (AUD45000-60000); 53% probability of cost-effectiveness at willingness-to-pay AUD60000.

Conclusions: StressModex, a physiotherapist‑led program combining stress inoculation training and exercise, was a cost‑effective treatment in terms of QALY gains, compared with guideline‑based exercise alone. Evidence of cost‑effectiveness was more robust for reductions in neck‑related disability, an outcome of particular importance for people with acute WAD[6]. Together with the demonstrated clinical effectiveness[4], economic benefits of StressModex provide evidence for patients, clinicians, insurers, and policy makers when considering early intervention and funding decisions for people with acute WAD.

References: 1. World Health Organization. Road Traffic Injuries. https://www.who.int/news-room/fact-sheets/detail/road-traffic-injuries. Published 13 December 2023. Accessed February 9, 2026.
2. Sterling M, Hendrikz J, Kenardy J. Compensation claim lodgement and health outcome developmental trajectories following whiplash injury: a prospective study. Pain. 2010;150(1):22-28.
3. Connelly LB, Supangan R. The economic costs of road traffic crashes: Australia, states and territories. Accident Analysis & Prevention. 2006;38(6):1087-1093. doi:10.1016/j.aap.2006.04.015
4. Sterling M, Smeets R, Keijzers G, Warren J, Kenardy J. Physiotherapist-delivered stress inoculation training integrated with exercise versus physiotherapy exercise alone for acute whiplash-associated disorder (StressModex): a randomised controlled trial of a combined psychological/physical intervention. British Journal of Sports Medicine. 2019;53(19):1240-1247. doi:10.1136/bjsports-2018-100139
5. Mutubuki EN, El Alili M, Bosmans JE, et al. The statistical approach in trial-based economic evaluations matters: get your statistics together! BMC Health Services Research. 2021/05/19 2021;21(1):475. doi:10.1186/s12913-021-06513-1
6. Sterling M, Andersen T, Carroll L, et al. Recommendations for a core outcome measurement set for clinical trials in whiplash associated disorders. Pain. 2023;164(10):2265-2272.

Presenting Author: Christopher Papic
Submitting Author: Christopher Papic

Senior Author: Michele Sterling

IASP 2026 Global Year theme of Neuropathic Pain: No

• Nigel Armfield: PhD - RECOVER Injury Research Centre, The University of Queensland, Australia
• Rachel Elphinston: PhD - RECOVER Injury Research Centre, The University of Queensland, Australia
• Michele Sterling: PhD - RECOVER Injury Research Centre, The University of Queensland, Australia