Objectives: The evaluation of the diagnostic value of endoscopic procedures usually lacks a gold
standard when performed in cross-sectional studies. The objective is to demonstrate an easily
applicable method to assess the possible range of sensitivity, specificity, and predictive values of
endoscopic procedures in the absence of a gold standard method.
Methods: Data from a study of 328 endoscopies comparing two different methods to diagnose
superficial bladder cancer were used as a numerical example. Both endoscopic procedures
were performed in the same patients in one session. Under the assumption of a systematic
misclassification process, a model to correct sensitivity estimates is developed.
Results: The lowest possible sensitivity estimate for a new fluorescence endoscopy technique
(FE) was 78%, the maximum 97.5%. Depending on realistic assumptions made upon the
misclassification, a reasonable estimate for sensitivity was 93.4% (95% confidence interval [CI]:
90%–97.3%) for the FE technique. The sensitivity of the traditional white-light endoscopy method
ranged from 47.2% to 53%, with a reasonable estimate of 46.7% (95% CI:
39.4%–54.3%).
Conclusions: This method to determine the theoretically possible range of sensitivity estimates in
endoscopic procedures is helpful in cross-sectional studies with a missing gold standard method.
It is easily applicable for a variety of endoscopic procedures, including upper and lower
gastro-intestinal tract, urogenital tract, or diagnostic laparoscopic surgery.