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A systematic review and meta-analysis on acoustic voice parameters after uncomplicated thyroidectomy

Lang BH, Wong CK, Ma EP

The Laryngoscope, 2016

896 participants

Abstract

BACKGROUND: Postthyroidectomy voice changes are common even without apparent laryngeal nerve injury. Our study evaluated the impact of open cervical thyroidectomy on five acoustic voice parameters in the early (< 3 months) and late (≥ 3 months) postoperative periods.

METHODS: A systematic review was performed to identify studies that quantitatively assessed voice quality by acoustic voice analysis before and after thyroidectomy. Parameters included average fundamental frequency (F0 , Hz), jitter (%), shimmer (%), noise-to-harmonic ratio (NHR), and maximum phonation time (MPT) (in secs). Meta-analysis was performed using both fixed- and random-effects models.

RESULTS: A total of 896 patients were analyzed. Relative to baseline, F0 significantly worsened in the early period (from 194.9 ± 34.9 Hz to 188.0 ± 34.0 Hz, P = 0.001). This was equivalent to a quarter-tone loss (P = 0.004). Shimmer (from 3.15 ± 1.59% to 3.19 ± 1.70%, P = 0.040) and MPT (from 17.9 secs to 16.7 secs, P = 0.046) also worsened in the early period, whereas jitter and NHR remained unchanged in the early and late periods. Males suffered greater deterioration in F0 (from 120.6 ± 18.8 Hz to 111.0 ± 18.5 Hz, P = 0.048) and in NHR (from 0.12 ± 0.02 to 0.16 ± 0.03, P = 0.019) than females in the early period. Four of the five acoustic parameters (F0 , jitter, shimmer, and NHR) significantly worsened after total thyroidectomy (TT) and not after lesser resection.

CONCLUSION: F0 , shimmer, and MPT significantly…

How strong is the evidence?

Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 896 participants or records.

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