Physiotherapist-delivered stress inoculation training integrated with exercise is cost-effective from a health system perspective compared with exercise alone for acute whiplash injury: an economic evaluation.

QUESTION: Is a physiotherapist-delivered integrated psychological and exercise intervention cost-effective compared with exercise alone for acute whiplash-associated disorders (WAD)?

DESIGN

Economic evaluation using randomised controlled trial data, from health system (direct costs) and societal (direct and indirect costs) perspectives.

PARTICIPANTS

Adults recruited from physiotherapy clinics, with acute WAD (< 4 weeks) and at least moderate neck pain-related disability and stress-related symptoms.

INTERVENTION: Integrated stress inoculation training and exercise (StressModex) compared with exercise alone, both delivered by physiotherapists (10 sessions over 6 weeks). Both groups received an education booklet.

OUTCOME MEASURES: Quality-adjusted life years (QALYs) and Neck Disability Index (NDI; 0 to 100) over 12 months. Direct costs comprised physiotherapist training and patient healthcare utilisation; indirect costs were estimated from lost work productivity.

RESULTS

Per participant, health system costs were AUD -290 (95% CI -1,168 to 570), with greater health gains for StressModex versus exercise alone (QALYs 0.07, 95% CI 0.00 to 0.15; NDI -8.7, 95% CI -14.3 to -3.1). From a health system perspective there was high probability of cost-effectiveness (90% at a willingness-to-pay of ∼ AUD 6,000 per QALY), with StressModex saving AUD 4,143 per QALY and AUD 330 per 10-point mean improvement in NDI. Societal costs were AUD 3,489 (95% CI -6,222 to 14,242) higher per participant for StressModex. The point-estimate ICERs (AUD 49,843 per QALY gained; AUD 4,200 per 10-point mean improvement in NDI) were within common Australian willingness-to-pay thresholds, but the probability of cost-effectiveness was modest (53% at AUD 60,000 per QALY).

CONCLUSION

Compared with exercise alone, StressModex was cost-effective with high probability from a health system perspective. From a societal perspective, the point-estimate ICER fell within commonly used Australian willingness-to-pay thresholds, but with considerable uncertainty. Findings provide evidence to inform clinicians, insurers and policymakers on early intervention for acute WAD.

TRIAL REGISTRATION: ACTRN12614001036606.