The study noted that many studies used small

The gap

Evidence profile

Stated in the limitations and conclusions and cells limitations sections of the source papers, classified as general, spanning 4 journals.

Supporting evidence — 4 representative gaps

• Development and internal validation of a nomogram for predicting short-term functional improvement after pharmacological treatment in severe symptomatic lumbar disk herniation (2026) · Frontiers in Medicine · doi

  This study has several limitations. First, the analysis was based on a relatively small sample from a parent randomized trial designed for treatment comparison, not for prediction modeling, so overfitting and predictor instability cannot be excluded. Variable selection was guided by clinical rationale and the EPV principle, using stepwise regression to reduce model complexity; however, some optimism bias may remain, and the model should be considered hypothesis-generating, requiring validation in larger, multicenter cohorts. Second, only internal bootstrap validation was performed, and no external cohort was available, limiting generalizability.

  generalstated in limitationsevidence 5/5
  Keywords: model validation several limitations first based relatively small sample parent randomized trial designed treatment comparison
• Thromboelastography combined with conventional coagulation parameters for developing a nomogram model to predict postpartum hemorrhage risk: A retrospective analysis (2026) · Pakistan Journal of Medical Sciences · doi

  Second, Recommendations: Future multicenter, prospective studies with larger and more diverse populations are warranted to further validate and refine the applicability of this study performed only internal validation using bootstrap to resampling, necessitating confirm the predictive accuracy of this model across different clinical settings and populations.

  generalstated in conclusionsevidence 5/5
  Keywords: populations second recommendations future multicenter prospective larger diverse warranted further validate refine applicability performed internal
• Median Arcuate Ligament Syndrome: Diagnostic Challenges and Outcomes Following Laparoscopic Decompression (2026) · Cureus · doi

  Although limited by its retrospective design and small sample size, this study contributes valuable clinicoradiological and outcome data from a region where published experience remains scarce. Prospective multicenter studies incorporating standardized symptom assessment, quality-of-life measures, and long-term follow-up are warranted to refine patient selection and establish evidence-based management strategies.

  generalstated in conclusionsevidence 5/5
  Keywords: limited retrospective design small sample size contributes valuable clinicoradiological outcome region published experience remains scarce
• Deep Learning and Machine Learning for Early Detection of Alzheimer's Disease: A Systematic Review and Meta-Analysis (2026) · medRxiv · doi

  The study noted that many studies used small or internally validated cohorts, which may risk overfitting and optimism bias. - The study highlighted the need for standardized evaluation protocols and external validation. - The study noted that the results may be limited by the quality of the included studies and the heterogeneity of the datasets and methods used.

  generalstated in cells limitationsevidence 5/5
  Keywords: study noted many studies used small internally validated

Questions about this gap