Normative values for singing voice handicap index - systematic review and meta-analysis.

INTRODUCTION: There are no official diagnostic protocols for singing voice assessment. In this publication, on the basis of a literature review, standards for the singing voice handicap index exclusively dedicated to voice disorders in singing have been given. OBJECTIVE: The study aims to determine the normative values for the singing voice handicap index. METHODS: The study is a systematic review and a meta-analysis. A systematic literature search was performed using PubMed to access relevant databases and to locate outcome studies. The "inclusion" criteria were as follows: English language, original papers and human studies retrospective and prospective papers, cross-sectional and case-control studies. RESULTS: Eight articles were included for the final analysis. The normative value for the singing voice handicap index was 20.35 with a confidential range of 10.6-30.1 for a group of 729 healthy subjects whose voices were judged as normal, with an age range of 16-64 years. CONCLUSION: The mean normative value of the singing voice handicap index was 20.35 with the confidence levels between 10.6 and 30.1.