IODINE-SUPPORTED HIP IMPLANTS IN TOTAL HIP ARTHROPLASTY: INFECTION RISK REDUCTION ACROSS PATIENT STRATA USING ARR AND NNT
Author(s)
Amy Worden, BS, MPH.
Global Health Economics, Zimmer Biomet, Warsaw, IN, USA.
Global Health Economics, Zimmer Biomet, Warsaw, IN, USA.
OBJECTIVES: Periprosthetic joint infection (PJI) after total hip arthroplasty (THA) remains a major driver of revision. Globally, infection rates in primary THA are typically 1%-2%, although risk varies across patient populations and may approach 6%-9% in higher-risk groups. Iodine-supported titanium implants are designed to inhibit bacterial adhesion and biofilm formation. In a prospective cohort (Shirai et al., n=653), use of iodine-supported implants was associated with a 3.7% infection rate among compromised-host patients, providing a treated-risk benchmark. Given this variability, this analysis estimates absolute risk reduction (ARR) and number needed to treat (NNT) for iodine-supported hip implants across THA risk tiers.
METHODS: A deterministic sensitivity analysis was performed using baseline infection risks representative of low (1%-2%), moderate (3%-5%), and high-risk (6%-9%) populations. In high-risk patients, relative reductions were derived by comparing baseline rates with the 3.7% benchmark, corresponding to an approximate 38%-59% reduction. For moderate- and low-risk groups, relative reductions of 10%-50% were explored to account for uncertainty beyond high-risk cohorts. ARR was calculated as baseline risk multiplied by reduction, and NNT as the inverse of ARR. Global impact was estimated by applying ARR to an annual THA volume of approximately 1 million procedures.
RESULTS: For high-risk patients, ARR ranged from 2.3% to 5.3%, yielding NNT values of 19 to 43. In moderate-risk populations, ARR values of 0.3% to 2.5% translated to NNT estimates of 40 to 333. In lower-risk populations, smaller absolute reductions (0.1%-1.0%) resulted in higher NNT values (100 to 1,000). Applied globally, these effects correspond to an estimated 2,400 to 20,300 infections avoided annually (0.24%-2.03% of procedures).
CONCLUSIONS: Iodine-supported hip implants are associated with meaningful reductions in infection risk in higher-risk patients. Risk-stratified modeling suggests potential benefit across broader THA populations; however, the magnitude of effect in routine patients remains uncertain and warrants further study.
METHODS: A deterministic sensitivity analysis was performed using baseline infection risks representative of low (1%-2%), moderate (3%-5%), and high-risk (6%-9%) populations. In high-risk patients, relative reductions were derived by comparing baseline rates with the 3.7% benchmark, corresponding to an approximate 38%-59% reduction. For moderate- and low-risk groups, relative reductions of 10%-50% were explored to account for uncertainty beyond high-risk cohorts. ARR was calculated as baseline risk multiplied by reduction, and NNT as the inverse of ARR. Global impact was estimated by applying ARR to an annual THA volume of approximately 1 million procedures.
RESULTS: For high-risk patients, ARR ranged from 2.3% to 5.3%, yielding NNT values of 19 to 43. In moderate-risk populations, ARR values of 0.3% to 2.5% translated to NNT estimates of 40 to 333. In lower-risk populations, smaller absolute reductions (0.1%-1.0%) resulted in higher NNT values (100 to 1,000). Applied globally, these effects correspond to an estimated 2,400 to 20,300 infections avoided annually (0.24%-2.03% of procedures).
CONCLUSIONS: Iodine-supported hip implants are associated with meaningful reductions in infection risk in higher-risk patients. Risk-stratified modeling suggests potential benefit across broader THA populations; however, the magnitude of effect in routine patients remains uncertain and warrants further study.
Conference/Value in Health Info
2026-09, ISPOR Asia Pacific 2026, Bangkok, Thailand
Value in Health, Volume 55, Issue S1
Code
CO14
Topic
Clinical Outcomes
Topic Subcategory
Clinical Outcomes Assessment, Comparative Effectiveness or Efficacy
Disease
SDC: Injury & Trauma, SDC: Musculoskeletal Disorders (Arthritis, Bone Disorders, Osteoporosis, Other Musculoskeletal)