Background and Aims: This systematic review and meta-analysis aimed to determine whether the use of therapeutic drug monitoring (TDM) in inflammatory bowel disease (IBD) patients on anti-tumour necrosis factor (anti-TNF) therapy results in improved rates of clinical and endoscopic remission, surgery, corticosteroid-free remission and hospitalisation.
Methods: MEDLINE, EMBASE, EMBASE classic, PubMed, Cochrane central databases register of controlled trials and Cochrane Specialised Trials Register were searched between 01 Janurary 1946 and 08 April 2022. Randomised controlled trials (RCTs) and prospective and retrospective observational studies were included, comparing TDM to standard of care (SOC) or reactive vs proactive TDM. Results were reported as pooled relative risks (RR) with 95% confidence intervals (95% CI).Results: Twenty-six studies, including 9 RCTs, were included. Compared to SOC, proactive TDM was associated with a significantly decreased risk of treatment failure (RR 0.64, 95% CI 0.48-0.85 p<0.01), and a non-significant decrease in need for surgery (RR 0.51, 95% CI 0.25-1.02) and hospitalisation (RR 0.64, 95% CI 0.40-1.00).Furthermore compared to SOC, Proactive TDM was associated with higher rates of endoscopic remission (RR 1.19,) and clinical remission (RR 1.07, 95% CI 0.97-1.18). Compared to reactive TDM, proactive TDM was associated with significant decreased risk of treatment failure (RR 0.46, 95% CI 0.21 = 0.98, p = 0.04) and significant reduction in hospitalisation (RR 0.33, 95% CI 0.21-0.54, p < 0.01).Conclusions: Compared to SOC, proactive TDM was associated with significant benefit in reducing treatment failure. Compared to reactive TDM, proactive TDM led to a significant reduction in hospitalisation and treatment failure. More studies with larger RCTs and standardised assays are needed to substantiate these results and validate the cost-effectiveness of TDM.