Impact of Precision-Guided Dosing on Clinical Decision Making and Health Care Utilization in Inflammatory Bowel Disease: A 24-Month Real-World Outcome Comparison Before and After Test Implementation
Background:
Precision-guided dosing (PGD) is a personalized medicine tool to guide informed clinical decision making for the treatment of inflammatory bowel disease (IBD) with infliximab (IFX) and its biosimilars. PGD utilizes nonlinear mixed-effect models with patient-specific pharmacokinetic inputs to calculate clearance (CL) and predict the optimal IFX dose and interval. The benefits of PGD include enhanced IBD treatment outcomes, which may potentially reduce healthcare expenditures.
Methods:
We conducted a multicenter, retrospective study as a follow up to our previous clinical experience program (CEP). We aimed to evaluate the impact of PGD on clinical decision-making, patient outcomes, healthcare utilization, and expenditures. Healthcare providers (HCP) reviewed medical charts of a subset of patients included in the prior CEP. Treatment decisions based on PGD were assessed, healthcare resource utilization in the 12 months pre- and post-test were compared, and costs were calculated based on literature data. Disease activity was measured using the physician global assessment (PGA) as follows: remission (0), mild (1), moderate (2), and severe (3). Statistical analysis included Kruskal-Walli’s rank test, Fisher’s exact test, univariate logistic regression, permutation analysis, paired t-test, and Wilcoxon test, applied as appropriate.
Results:
Among 82 patients, groups were divided into reduction (18%), continuation (48%), intensification (27%), and discontinuation (7%) of IFX therapy. The study found significant associations between forecasted trough IFX levels and treatment modifications. Patients with forecasted trough IFX < 5 μg/mL were more likely to have their IFX therapy intensified (OR 15.8, 95% CI 4.95–57.0; p < 0.001) or discontinued (OR 7.50, 95% CI 1.34–57.7; <italic>P =</italic> 0.022). Patients with forecasted trough IFX > 10 μg/mL were significantly more likely to continue therapy (OR 2.59, 95% CI 1.06–6.56; <italic>P =</italic> 0.037). For those with forecasted trough IFX > 15 μg/mL, there was a significant likelihood of therapy reduction (OR 12.7, 95% CI 3.55–61.3; p < 0.001). Higher IFX clearance (>0.294 L/day) was significantly associated with therapy intensification (OR 6.22, 95% CI 2.19–19.8; p < 0.001). Twelve months post-PGD test, there was a significant improvement in disease activity compared to 12 months pre-test (observed mean difference in PGA: 0.378; p=0.008). The group with reduced IFX dosage saw the highest estimated savings of $189,343, attributed to a lower average IFX dose (558 mg weekly), 4 fewer hospitalizations, a 15-day reduction in hospital stay duration, and 12 fewer IBD-related office visits. Overall, the economic impact on IBD-related healthcare resource utilization for the entire patient cohort during the follow-up period, both before and after the PGD test, was estimated to result in total savings of $343,796 annually. This translates to an average cost reduction of approximately $4,193 per patient per year.
Conclusions:
HCPs used PGD to guide treatment decisions. Optimization of IFX therapy led to improved patient outcomes, lower healthcare utilization, and cost savings.
