COST-EFFECTIVENESS OF ROUTINE MENTAL HEALTH SCREENING IN INFLAMMATORY ARTHRITIS RHEUMATOLOGY: A DISCRETE EVENT SIMULATION OF THE IMPARTS PROGRAM
Author(s)
Xiaoyu Zhang1, Sam Norton, PhD2, James Galloway, PhD2, Kang Wang, MSc2, Peizhe Yan, MSc3, Huajie Jin, PhD2.
1PhDstudent, King's College London, LONDON, United Kingdom, 2King's College London, London, United Kingdom, 3King's Health Economics, King's College London, London, United Kingdom.
1PhDstudent, King's College London, LONDON, United Kingdom, 2King's College London, London, United Kingdom, 3King's Health Economics, King's College London, London, United Kingdom.
OBJECTIVES: Comorbid depression and anxiety in inflammatory arthritis (IA) are underdiagnosed and undertreated despite high prevalence and established impact on health-related quality of life and resource use. The IMPARTS programme embeds routine PHQ-9/GAD-7 screening into NHS rheumatology outpatient clinics. This study evaluated the cost-effectiveness of IMPARTS screening versus usual care from an NHS and Personal Social Services perspective, aligned with the NICE reference case.
METHODS: A discrete event simulation (DES) was developed in Python (SimPy) to model individual patient trajectories over a lifetime horizon. The model represents five CMD severity states (aligned to PHQ-9 severity bands) as a combined depression and anxiety latent dimension, IA disease progression via the Health Assessment Questionnaire (HAQ), and NICE-concordant treatment pathways for depression (NG222, CG91) and anxiety (CG113) alongside IA pharmacological management (NG100, TA375). Model inputs were derived from the IMPARTS dataset (n=7,928; GSTT/KCL, 2013-2022), supplemented by mixed-effects HAQ modelling, MICE imputation, ALDVMM utility mapping, and PSA-ready distributional fitting. The comparator was usual care without structured screening.
RESULTS: Routine PHQ-9/GAD-7 screening increased detection of clinically significant CMD and earlier initiation of NICE-concordant treatment relative to usual care. Screening generated additional QALYs through improved CMD management and attenuation of HAQ progression in treated patients, with incremental costs partially offset by reductions in secondary care utilisation. Base-case and probabilistic results suggest screening is cost-effective at the NICE £20,000 to £30,000 per QALY threshold across a range of plausible parameter assumptions.
CONCLUSIONS: Routine CMD screening in NHS rheumatology represents good value for money under NICE reference-case conditions. This is the first economic evaluation to integrate mental and physical health trajectories in this population within a single patient-level simulation, capturing individual heterogeneity that cohort models cannot accommodate. Findings support commissioning of integrated screening programmes and provide a replicable framework for HTA of mental health identification tools in physical health settings.
METHODS: A discrete event simulation (DES) was developed in Python (SimPy) to model individual patient trajectories over a lifetime horizon. The model represents five CMD severity states (aligned to PHQ-9 severity bands) as a combined depression and anxiety latent dimension, IA disease progression via the Health Assessment Questionnaire (HAQ), and NICE-concordant treatment pathways for depression (NG222, CG91) and anxiety (CG113) alongside IA pharmacological management (NG100, TA375). Model inputs were derived from the IMPARTS dataset (n=7,928; GSTT/KCL, 2013-2022), supplemented by mixed-effects HAQ modelling, MICE imputation, ALDVMM utility mapping, and PSA-ready distributional fitting. The comparator was usual care without structured screening.
RESULTS: Routine PHQ-9/GAD-7 screening increased detection of clinically significant CMD and earlier initiation of NICE-concordant treatment relative to usual care. Screening generated additional QALYs through improved CMD management and attenuation of HAQ progression in treated patients, with incremental costs partially offset by reductions in secondary care utilisation. Base-case and probabilistic results suggest screening is cost-effective at the NICE £20,000 to £30,000 per QALY threshold across a range of plausible parameter assumptions.
CONCLUSIONS: Routine CMD screening in NHS rheumatology represents good value for money under NICE reference-case conditions. This is the first economic evaluation to integrate mental and physical health trajectories in this population within a single patient-level simulation, capturing individual heterogeneity that cohort models cannot accommodate. Findings support commissioning of integrated screening programmes and provide a replicable framework for HTA of mental health identification tools in physical health settings.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EE55
Topic
Economic Evaluation, Health Service Delivery & Process of Care, Real World Data & Information Systems
Disease
Mental Health (including addiction), Musculoskeletal Disorders (Arthritis, Bone Disorders, Osteoporosis, Other Musculoskeletal)