Cost-effectiveness of steroid (methylprednisolone) injections versus anaesthetic alone for the treatment of Morton's neuroma: economic evaluation alongside a randomised controlled trial (MortISE trial).
BACKGROUND
Morton's neuroma is a common foot condition affecting health-related quality of life. Though its management frequently includes steroid injections, evidence of cost-effectiveness is sparse. So, we aimed to evaluate whether steroid injection is cost-effective in treating Morton's neuroma compared with anaesthetic injection alone.


METHODS
We undertook incremental cost-effectiveness and cost-utility analyses from the perspective of the National Health Service, alongside a patient-blinded pragmatic randomised trial in hospital-based orthopaedic outpatient clinics in Edinburgh, UK. Of the original randomised sample of 131 participants with Morton's neuroma (including 67 controls), economic analysis focused on 109 (including 55 controls). Both groups received injections guided by ultrasound. We estimated the incremental cost per point improvement in the area under the curve of the Foot Health Thermometer (FHT-AUC) until three months after injection. We also conducted cost-utility analyses using European Quality of life-5 Dimensions-3 Levels (EQ-5D-3L), enhanced by the Foot Health Thermometer (FHT), to estimate utility and thus quality-adjusted life years (QALYs).


RESULTS
The unit cost of an ultrasound-guided steroid injection was £149. Over the three months of follow-up, the mean cost of National Health Service resources was £280 for intervention participants and £202 for control participants - a difference of £79 [bootstrapped 95% confidence interval (CI): £18 to £152]. The corresponding estimated incremental cost-effectiveness ratio was £32 per point improvement in the FHT-AUC (bootstrapped 95% CI: £7 to £100). If decision makers value improvement of one point at £100 (the upper limit of this CI), there is 97.5% probability that steroid injection is cost-effective. As EQ-5D-3L seems unresponsive to changes in foot health, we based secondary cost-utility analysis on the FHT-enhanced EQ-5D. This estimated the corresponding incremental cost-effectiveness ratio as £6,400 per QALY. Over the recommended UK threshold, ranging from £20,000 to £30,000 per QALY, there is 80%-85% probability that steroid injection is cost-effective.


CONCLUSIONS
Steroid injections are effective and cost-effective in relieving foot pain measured by the FHT for three months. However, cost-utility analysis was initially inconclusive because the EQ-5D-3L is less responsive than the FHT to changes in foot health. By using the FHT to enhance the EQ-5D, we inferred that injections yield good value in cost per QALY.


BACKGROUND
Current Controlled Trials ISRCTN13668166.
Bangor University, Centre for Health Economics and Medicines Evaluation (CHEME), School of Healthcare Sciences, College of Health and Behavioural Sciences (CoHaBS), Ardudwy Hall, Normal Site, Bangor, LL57 2PZ, Gwynedd UK.
Rhiannon Tudor
RT
Edwards
Bangor University, Centre for Health Economics and Medicines Evaluation (CHEME), School of Healthcare Sciences, College of Health and Behavioural Sciences (CoHaBS), Ardudwy Hall, Normal Site, Bangor, LL57 2PZ, Gwynedd UK.
Seow Tien
ST
Yeo
Swansea University, Singleton Park, Institute of Life Science 2, College of Medicine, Swansea, SA2 8PP UK.
Daphne
D
Russell
Health Sciences, Queen Margaret University, Queen Margaret University Drive, Edinburgh, EH21 6UU Scotland UK.
Colin E
CE
Thomson
The Royal Infirmary of Edinburgh, 51 Little France Crescent, Department of Radiology, Old Dalkeith Road, Edinburgh, EH16 4SA Scotland UK.
Ian
I
Beggs
Musculoskeletal Directorate, The Royal Infirmary of Edinburgh, 51 Little France Crescent, Old Dalkeith Road, Edinburgh, EH16 4SA Scotland UK.
J N Alastair
JN
Gibson
Health Sciences, Queen Margaret University, Queen Margaret University Drive, Edinburgh, EH21 6UU Scotland UK.
Diane
D
McMillan
Teesside University, Health and Social Care Institute, Middlesbrough, TS1 3BA UK.
Denis J
DJ
Martin
Swansea University, Singleton Park, Institute of Life Science 2, College of Medicine, Swansea, SA2 8PP UK.
Ian T
IT
Russell
Cost-effectiveness analysis; Cost-utility analysis; Foot health; Interdigital plantar nerves; Methylprednisolone; Morton’s neuroma; Quality-adjusted life years; Steroid injection