title: Validation of a telephone screening tool for spasmodic dysphonia and vocal fold tremor.
abstract: OBJECTIVE
  The objective of this study was to ascertain whether clinicians can reliably distinguish between spasmodic dysphonia (SD)/vocal tremor and other voice disorders by telephone, despite this modality's limited frequency response.
  
  
  METHODS
  Randomized, single-blinded, and prospective study.
  
  
  METHODS
  Voice-disordered patients with (n = 22) and without (n = 17) SD and/or vocal tremor recorded standardized utterances via landline telephone. A laryngologist and two speech-language pathologists blinded to the diagnoses rated each recording as "yes" or "no" to "SD or tremor present?," and if "yes" categorized into adductor, abductor, tremor only, or adductor with tremor subtypes. Twenty-one recordings were presented twice at random so intrarater reliability could be assessed. All ratings were compared with gold standard diagnosis by a second laryngologist who performed a full examination, including videostroboscopy, on each patient.
  
  
  RESULTS
  For the comparison "SD or tremor" yes versus no, sensitivity, specificity, positive predictive value, and negative predictive value are 90%, 95%, 96%, and 89%, respectively. Interrater reliability (Cohen kappa) compared with the gold standard ranged from 0.70 to 0.93 (substantial to almost perfect agreement). Cronbach alpha among three raters was 0.90 for this comparison. Intrarater reliability (number matched/number inspected) was very high, ranging from 0.97 to 1.0. Comparing gold standard and telephone rating of SD/tremor subtypes, kappa ranged from 0.48 to 0.60 (moderate agreement). Cronbach alpha among three raters was 0.88 for this comparison. Intrarater reliability ranged from 0.84 to 0.97.
  
  
  CONCLUSIONS
  SD and tremor can be reliably distinguished from other voice disorders over the telephone.
authors: Emory University School of Medicine, Atlanta, Georgia.
authors: David M
authors: DM
authors: Johnson
authors: The Emory Voice Center, Department of Otolaryngology, Emory University, Atlanta, Georgia.
authors: Edie R
authors: ER
authors: Hapner
authors: The Emory Voice Center, Department of Otolaryngology, Emory University, Atlanta, Georgia.
authors: Adam M
authors: AM
authors: Klein
authors: The Emory Voice Center, Department of Otolaryngology, Emory University, Atlanta, Georgia.
authors: Madeleine
authors: M
authors: Pethan
authors: The Emory Voice Center, Department of Otolaryngology, Emory University, Atlanta, Georgia. Electronic address: mmjohn2@emory.edu.
authors: Michael M
authors: MM
authors: Johns
mesh_terms: D003937:Diagnosis, Differential; D055154:Dysphonia / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D005260:Female; D005845:Georgia; D006801:Humans; D007821:Laryngeal Muscles / Q000503:physiopathology*; D008297:Male; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D016037:Single-Blind Method; D013035:Spasm / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D013061:Speech Acoustics; D013067:Speech Perception; D013068:Speech Production Measurement; D049489:Stroboscopy; D013689:Telephone; D014202:Tremor / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D014741:Video Recording; D014827:Vocal Cords / Q000503:physiopathology*; D014833:Voice Quality
keywords: Abductor spasmodic dysphonia; Adductor spasmodic dysphonia; Spasmodic dysphonia; Telephone screening; Vocal fold tremor