Table 1. Mean (SD) scores for key voice and psychological variables at each visit for treatment and no treatment groups (patients with complete data)

Test or questionnaire Treatment
No treatment
F value Treatment effect (points (95% CI))

No of patients Visit 1 (baseline) Visit 2 or 3 No of patients Visit 1 (baseline) Visit 2 or 3

At completion of treatment (visit 2)

  Psychological distress:

  HADS anxiety 67 6.3 (4.0) 5.9 (4.5) 63 8.1 (4.3) 7.7 (3.9) 0.71 (P=0.402) 0.39 ( $-$ 0.53 to 1.31)

  HADS depression 67 3.7 (3.5) 3.6 (3.7) 63 4.2 (3.3) 4.2 (3.1) 0.38 (P=0.540) 0.25 ( $-$ 0.55 to 1.05)

  CIS total score 67 7.0 (6.9) 62 8.6 (8.2)

Voice:

  Buffalo overall rating^* 74 2.9 (1.1) 2.3 (0.93) 69 2.9 (1.0) 2.5 (0.93) 2.33 (P=0.130) 0.21 ( $-$ 0.01 to 0.49)

  Pitch perturbation 67 3.2 (2.4) 2.8 (1.5) 57 2.4 (1.4) 2.8 (1.5) 0.97 (P=0.326) 0.25 ( $-$ 0.25 to 0.74)

  Amplitude perturbation 67 6.0 (4.2) 4.5 (2.6) 57 5.0 (3.3) 5.7 (3.8) 8.03 (P=0.005) 1.6 (0.47 to 2.63)

  VPQ total 67 27.6 (8.0) 22.4 (5.8) 65 27.9 (7.5) 25.4 (8.1) 6.12 (P=0.015) 2.6 (0.51 to 4.63)

At completion of follow up (visit 3)

  Psychological distress:

  HADS anxiety 62 6.6 (4.0) 5.9 (3.8) 56 8.1 (4.0) 6.7 (4.1) 0.00 (P=0.969) 0.02 ( $-$ 1.21 to 1.25)

  HADS depression 62 4.2 (3.6) 3.8 (3.5) 56 4.2 (3.3) 4.3 (3.6) 1.08 (P=0.300) 0.4 ( $-$ 1.3 to 0.39)

  CIS total score 67 7.0 (6.9) 7.3 (8.1) 62 8.6 (8.2) 7.6 (8.8) 0.64 (P=0.424) 0.89 ( $-$ 1.3 to 3.06)

Voice:

  Buffalo overall rating^* 70 2.9 (1.1) 2.2 (1.0) 63 2.8 (1.0) 3.0 (1.0) 26.50 (P<0.001) 0.82 (0.5 to 1.13)

  Pitch perturbation 65 3.1 (2.4) 2.7 (1.5) 54 2.4 (1.4) 2.2 (1.5) 1.58 (P=0.212) 0.35 ( $-$ 0.20 to 0.89)

  Amplitude perturbation 65 5.8 (3.9) 4.1 (3.0) 54 5.1 (3.2) 4.5 (3.6) 0.90 (P=0.345) 0.57 ( $-$ 0.62 to 1.77)

  Score on VPQ 61 28.8 (8.2) 21.6 (6.3) 57 28.0 (7.5) 25.4 (8.5) 10.96 (P=0.001) 4.14 (1.67 to 6.61)

HADS=hospital anxiety and depression scale; CIS=clinical interview schedule; VPQ=vocal performance questionnaire.

^* Buffalo voice profile analysis has an "overall rating" as 1 of 10 items scored 0-5.

The higher the score the more dysphonic the voice.

Maximum score=60; the higher the score the more dysphonic the voice.