Rater methodology for stroboscopy: A systematic review

Objectives Laryngeal endoscopy with stroboscopy (LES) remains the clinical gold standard for assessing vocal fold function. LES is used to evaluate the efficacy of voice treatments in research studies and clinical practice. LES as a voice treatment outcome tool is only as good as the clinician interpreting the recordings. Research using LES as a treatment outcome measure should be evaluated based on rater methodology and reliability. The purpose of this literature review was to evaluate the rater-related methodology from studies that use stroboscopic findings as voice treatment outcome measures. Study Design Systematic literature review. Methods Computerized journal databases were searched for relevant articles using terms: stroboscopy and treatment. Eligible articles were categorized and evaluated for the use of rater-related methodology, reporting of number of raters, types of raters, blinding, and rater reliability. Results Of the 738 articles reviewed, 80 articles met inclusion criteria. More than one-third of the studies included in the review did not report the number of raters who participated in the study. Eleven studies reported results of rater reliability analysis with only two studies reporting good inter- and intrarater reliability. Conclusion The comparability and use of results from treatment studies that use LES are limited by a lack of rigor in rater methodology and variable, mostly poor, inter- and intrarater reliability. To improve our ability to evaluate and use the findings from voice treatment studies that use LES features as outcome measures, greater consistency of reporting rater methodology characteristics across studies and improved rater reliability is needed.