A methodological analysis of systematic reviews of cost-effectiveness in screening, diagnosis, and treatment of colorectal cancer.

Abstract

INTRODUCTION: Economic evaluations are essential for informing decisions on colorectal cancer screening, diagnosis, and treatment. However, substantial methodological variability across studies challenges the comparability and interpretation of cost-effectiveness evidence. OBJECTIVE: To identify, characterize, and critically analyze systematic reviews of economic evaluations in colorectal cancer, emphasizing their methodological characteristics and reporting practices. METHODS: We conducted a thorough search across multiple databases to identify systematic reviews published until 2025 that synthesized comprehensive economic evaluations (cost-effectiveness and cost-utility analyses) of colorectal interventions. We extracted data on intervention type (screening, diagnosis, treatment), model structure, time horizon, analytical perspective, discounting, handling of uncertainty, and model validation. We applied an integrated framework based on established methodological and reporting criteria. Findings were synthesized narratively. RESULTS: We included 20 systematic reviews, covering screening, diagnostic, and treatment strategies. Most economic evaluations used Markov or microsimulation models with lifetime horizons and discount rates ranging from 3% to 5%. The healthcare system perspective predominated, while societal perspectives were less frequently applied. Across domains, substantial heterogeneity was observed in comparators, modeling assumptions, cost inputs, and outcome measures. Screening studies showed the greatest variability, particularly in comparator selection and adherence assumptions. Although sensitivity analyses were commonly reported, formal model validation was infrequent. These findings are consistent with previous reviews, which have shown that colorectal cancer interventions are generally cost-effective but that variability in model assumptions limits the identification of optimal strategies. CONCLUSIONS: Systematic reviews of economic evaluations in colorectal cancer report widespread use of advanced modeling techniques and sensitivity analyses; however, significant limitations remain regarding validation, transparency, and methodological standardization. Improving reporting practices and enhancing model validation are essential to improve the reliability and policy relevance of economic evidence in colorectal cancer.