Klaske van Sluis

Objective and subjective voice outcomes: a systematic review 21 and/or the EORTC QLQ-C30 questionnaire, which include questions about speech functioning [10, 11]. PROs, such as the Voice Handicap Index (VHI) and Voice-Related Quality of Life (V-RQOL) provide more detailed evalua- tions of speech rehabilitation results [12–14]. At present, a comprehensive literature review on the advantages and disad- vantages of the current speech rehabilitation options has not been performed. Collecting the best evidence available on the three speech rehabilitation meth- ods will likely help to build consensus about which speech rehabilitation after TL is optimal, and could aid in clinicians’ decision-making, patients’ counsel- ing and reimbursement issues. In this systematic review, we focus on obtaining comparative acoustic, perceptual, and PROs for the three speech rehabilitation methods after TL. We aim to identify how outcomes of the various speech reha- bilitation methods relate to those of normal laryngeal speech (healthy speakers), and what outcomes are favorable for each rehabilitation method. 2.2 Materials and methods The literature on speech outcomes after total laryngectomy (TL) was reviewed by means of a systematic search strategy. This search strategy was conducted with specific attention to the primary and secondary outcomes of interest (Table 2.1). The most suitable primary and secondary outcomes were selected based on the literature. With the acoustic outcomes, we aimed to obtain objective infor- mation about the speech rehabilitation options. We aimed to obtain subjective information of the voices though perceptual ratings and PROs. We have chosen to indicate fundamental frequency (F0), Harmonics to Noise Ratio (HNR), and percentage of voicedness (%voiced) as primary acoustic outcomes. These out- comes are indicated by several authors to obtain information about the pitch, stability and the amount of noise components [7, 15–17]. Secondary acoustic outcomes of interest were jitter, shimmer, intensity, spectral tilt and maximum phonation time (MPT). These outcome variables are frequently used in the lit- erature although some are known to be less reliable in substitute voicing [16, 17]. Primary perceptual outcomes of interest were overall impression of voice quality and intelligibility, derived from the IINFVo scale, where impression, intelligibil- ity, noise, fluency and voicing is evaluated [18]. Secondary perceptual outcomes of interest were chosen from well-established perceptual assessment tools, such as the Grade Roughness Breathiness Asthenia Strain scale assessment (GR- BAS [19], and other recommended perceptual parameters in TL-speech such as unintended additive noise, fluency, and voicing [8, 18]. Primary PROs were the widely used VHI [13] and V-RQOL[14]. As secondary PROs we included voice specific outcomes on the EORTC QLQ-H&N35 [11] and the EORTC QLQ- C30 [10], where general quality of life is evaluated including a specific subset of questions on communication. The literature search was performed by the medical information specialist. The search was conducted in PubMed, Embase (ovid), Scopus and PsychInfo. Terms searched for were “laryngectomy”, “voice”,