External Validation

The gap

Consensus across the literature

Supporting evidence — 3 representative gaps

• Interaction between high-sensitivity C-reactive protein and mean platelet volume for 1-year major adverse cardiovascular events in stable coronary artery disease (2026) · doi

  The study population consisted entirely of Chinese patients, and MPV measurement is susceptible to methodological variations (e.g., timing of analysis and anticoagulant choice); inter-laboratory systematic errors may exist, and external validity requires further verification in other ethnic populations.

  Keywords: population consisted entirely chinese patients measurement susceptible methodological variations timing anticoagulant choice inter laboratory systematic
• Clinical features and prognostic factors of Chlamydia psittaci pneumonia: a retrospective study (2026) · doi

  The study analyzed only 74 CPP patients (21 severe cases) diagnosed via NGS from a single center. The mortality rate of 19% in severe cases and the predictive model's generalizability remain uncertain; external validation using prospectively collected data from multiple centers with larger severe CPP cohorts is required to confirm the prognostic utility of the D-dimer and L% thresholds.

  Keywords: Chlamydia psittaci pneumonia severity prediction multivariate logistic regression external validation sample size
• Association between corticosteroid dosage and symptoms of depression and anxiety in patients with systemic lupus erythematosus (2025) · doi

  The sample size of 73 patients may limit external validity, so a larger and more diverse sample is needed for a more comprehensive understanding.

  Keywords: sample size patients limit external validity larger diverse needed comprehensive understanding