JCPSLP Vol 18 No. 1Mar 2016

explored widely in the field of psychotherapy (Constantino, Arnkoff, Glass, Ametrano, & Smith, 2011). Although not as extensive, there has also been research in the fields of occupational and physical rehabilitation examining patient expectations and treatment credibility. In the area of pain treatment, a study by Goossens, Vlaeyen, Hidding, Kole-Snijders, and Evers (2005) explored how patients’ initial beliefs about the success of a provided treatment was linked to their outcomes. Findings suggested that those who believed the treatment would assist them in managing pain reported better pain coping and control, less catastrophising thoughts and negative emotions, and an overall higher health-related quality of life. Harvey, Adams, Chu, Batty, and Barratt (2012) discussed the importance of having similar therapist and patient expectations, in the context of physiotherapy for spinal cord injuries. Unreasonably high patient expectations were more likely to be associated with depression and a lower quality of life when their expectations were not met (Harvey et al., 2012). Another physiotherapy study found that higher expectations and larger changes in shoulder function were able to significantly predict expectancy fulfilment (O’Malley, Roddey, Gartsman, & Karon, 2004). Patient expectations overall (across the domains of pain, physical functioning, and social function) have been shown to positively correlate (although with borderline significance) with improved global functioning for patients post-surgery for spinal lumbar stenosis (Iversen, Daltroy, Fossel, & Katz, 1998). Patients with higher pre-operative expectations improved more than those with moderate to low expectations. However, some literature has been unable to establish convincing evidence for the association between patient expectations and treatment outcomes. This includes studies from exercise physiology (Perkins, Waters, Baum, & Basen-Engquist, 2009) and an occupational therapy study which examined upper-extremity motor function (Prager, Birkenmeier, & Lang, 2011). Treatment credibility has been found to play less of a role in predicting outcomes (Borkovec & Costello, 1993). In a study exploring chronic back pain treatment, the relationships between both patient expectations and credibility of three different treatment groups were considered (Smeets et al., 2008). It was found that only expectations were associated with patients’ self-reported disability and global perceived effect post-treatment. However, relationships were found between patients’ treatment satisfaction and both patient expectations and treatment credibility. Current research findings in this topic area remain inconclusive with respect to how patient perceptions of treatment credibility relate to the outcomes of therapies. To date, the association between patient expectations and treatment credibility, and clinical outcomes has not been investigated in the field of speech-language pathology. Research into such factors has the potential to further inform the rehabilitation process for clients with communication disorders. The primary aim of this study was to determine if patient expectations and treatment credibility were associated with the outcomes of an intensive treatment (LSVT ® LOUD) for hypokinetic dysarthria associated with PD. This study is of particular interest as LSVT ® LOUD is evidence based and well recognised for its efficacy in the treatment of the speech disorder in PD, and so treatment credibility and patient expectations may be high. It was hypothesised that treatment credibility and patient expectations would predict treatment outcomes.

The secondary aim considered other participant variables such as age, time post onset of PD, severity of dysarthria, and stage of PD, and their association with both patient expectations and treatment credibility. Participant variables were hypothesised to be associated with treatment credibility and patient expectations. Method Study design The current study used a subset of data from a non- inferiority randomised controlled trial involving three groups of participants. The non-inferiority randomised controlled trial was conducted between one group of participants who received the LSVT ® LOUD program face-to-face at the University of Queensland and another group who received the same treatment delivered via telerehabilitation in their homes within the Brisbane City Council boundary. A third group of participants residing outside this boundary, but within a 2-hour drive of Brisbane, received LSVT ® LOUD via telerehabilitation. Ethical clearance was obtained from the Behavioural and Social Sciences Ethical Review Committee of The University of Queensland, Australia and all participants provided informed consent prior to their involvement in the study. Participants Forty-nine people with PD and hypokinetic dysarthria provided data on treatment credibility and expectancy. The average age of the participants was 70.55 years and included 34 males (mean age 71.47 years; age range 55.92–87.58 years) and 15 females (mean age 68.48 years; age range 50.5–84.7 years). Participants presented with hypokinetic dysarthria of which 38 were rated as mild, 9 were rated as moderate, and 2 were rated as severe. The level of speech severity was rated by a SLP with 20 years’ experience in the management of people with PD. Ratings were based on the sound pressure level (SPL) of voice during conversation prior to treatment and a perceptual rating of speech intelligibility during a monologue task prior to treatment (Mild = > 65dB in conversation and/or mildly reduced speech intelligibility; Moderate = 60–65dB in conversation and/or mild to moderate reduction in speech intelligibility; Severe = < 65dB in conversation and moderate to severe reduction in speech intelligibility).The mean stage of PD according to the Hoehn and Yahr Scale (Hoehn & Yahr, 1967) was 1.96 (range 1 to 5). The mean time post onset of PD for the cohort was 4.36 years (range 6 months to 15 years). See Table 1 for further participant characteristics. Participants were included in the study if they were English speaking, demonstrated features of hypokinetic dysarthria, presented with a cognitive status that was adequate to participate in assessment tasks as judged by the researcher, and the participants reported that they were on a stable drug regimen. Participants were excluded if there was a co-existing neurological disorder other than PD, a co-existing speech disturbance other than that associated with PD, previous participation in a LSVT ® LOUD program, a respiratory dysfunction unrelated to PD, a positive history of alcohol abuse and/or dementia, and/or poorly aided vision or hearing. Outcome measures The assessment battery included perceptual, acoustic, and quality-of-life measures together with participants’ expectancy and perceived credibility ratings of the speech

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JCPSLP Volume 18, Number 1 2016

Journal of Clinical Practice in Speech-Language Pathology