Assessing Prognostic Studies of Tubularized Incised Plate Urethroplasty in Hypospadias: A Systematic Review of Methodological Rigor

Introduction: Hypospadias is a congenital anomaly of male genitalia that requires surgical correction to achieve normal anatomy and function. Tubularized incised plate urethroplasty (TIP) is a common repair method, but prognostic studies of TIP outcomes are limited by their methodological quality. This systematic review evaluates the methodological rigor of prognostic studies on TIP urethroplasty in hypospadias cases, employing the Quality in Prognosis Studies (QUIPS) Cochrane tool. Methods: Following PRISMA guidelines, a systematic review of single-arm prognostic studies of TIP was conducted. Inclusion criteria were primary studies (first attempt of surgery), evaluating prognostic factors and outcomes, with the QUIPS tool used for quality assessment. Review studies and reports without full text were excluded. Inter-rater agreement was then evaluated using Cohen's kappa analysis. Results: Among 14 included studies, most exhibited low risk of bias (RoB). Inter-rater agreement varied across domains, being strongest for statistical analysis (κ = 0.89) and weakest for prognostic factor measurement (κ = 0.42). Nevertheless, overall assessment showed minimal agreement (κ = 0.49), indicating poor reliability of the included studies. Our findings highlight biases inherent in existing literature, particularly with respect to outcome measurement domains, underscoring the need for standardized methods and validated patient-reported outcomes. Selection bias and lack of standardized outcome measures pose significant challenges in interpreting study findings. Conclusion: Low inter-rater agreement indicates methodological shortcomings in prognostic studies of TIP in the context of hypospadias. Future research should prioritize methodological rigor to enhance the reliability and generalizability of findings, thus improving clinical practice and future patient outcomes.