JCPSLP Vol 18 No. 1Mar 2016

JCPSLP

Volume 18, Number 1 2016

Journal of Clinical Practice in Speech-Language Pathology

treatment credibility would predict treatment outcomes;

however, the findings did not support the hypothesis. The

study revealed that for LSVT

LOUD, treatment credibility

and patient expectations did not correlate with outcomes.

The results also refuted the secondary hypothesis, that

there would be a relationship between participant variables

and treatment credibility and patient expectations.

Research suggests that patient expectations and

treatment credibility are more often associated with

quality-of-life outcomes measured by self-report (Smeets

et al., 2008). This association is reflected in the results of

the current study in that treatment credibility ratings were

associated to a fair degree with the quality-of-life outcome,

but not the clinical acoustic outcome measure. The quality-

of-life measure (DIP total score difference) was subjective

and based on self-report, whereas the acoustic measure

(difference in dB level in monologue) was an objective

measure. A possible explanation for this association

between self-reported quality-of-life measures and

treatment credibility and expectation may be that patients

with better coping skills are more optimistic and score

themselves well on personal achievement (Carver, Scheier,

& Kumari Weintraub, 1989).

Although the majority of the research in psychotherapy

and rehabilitation has been able to establish some

relationship between patient expectations and treatment

outcomes (Linde et al., 2007; Smeets et al., 2008), other

research has been unable to demonstrate this correlation

(Perkins et al., 2009; Sanderson et al., 2012). Sanderson

et al. attributed their lack of correlation to the particularly

chronic nature of the back pain the study sample suffered

from which resulted in a lack of significant outcomes

from the treatment. In the current sample, the severity of

the condition was not a major factor as the group was

comprised predominately of people with mild dysarthria.

The three participants in advanced stages of PD, however,

did demonstrate significant improvements on both outcome

measures. Research has shown that those in the later

stages of PD can still make significant gains in outcomes

with some adjustment to functional goals in LSVT

LOUD

(Trail et al., 2005).

In another study, Perkins and colleagues (2009)

attributed their nil correlation between patient expectations

Results

Normality of the independent variables (expectancy and

credibility) was investigated and it was confirmed that the

data were normally distributed. The mean treatment

credibility score for the entire sample was 6.82 (1.40 SD)

and the mean participant expectation score was 59.59%

(22.19 SD). For the pooled data, the mean group

monologue dB level pre-treatment was 70.41 (4.38 SD),

while post-treatment the group mean was 76.88 (4.86 SD).

Thus, the group mean difference in dB between pre- and

post-treatment monologue was 6.47dB (3.78 SD). The

mean DIP total score pre-treatment was 148.67 (19.26 SD),

while post-treatment the mean was 161.02 (19.78 SD). The

mean difference in DIP total score, pre- and post-treatment

was 12.35 (12.78 SD). This difference indicated an

improvement in quality of life as a result of a reduced

impact of dysarthria. A paired t-test revealed a significant

difference pre- to post-treatment for dB level in monologue

(t = –11.98; p < .001) and DIP total score (t = –6.76; p < .001).

Spearman’s rank correlation coefficients found no

significant relationship between difference in dB level

in monologue and patient expectations (r

= –.066, p =

.652) or treatment credibility (r

= .103, p = .483). Analysis

revealed a correlation between treatment credibility and

DIP total score difference. This finding was statistically

significant with a fair positive correlation (r

= .388, p =

.006). There was no correlation found between DIP total

score difference and patient expectations (r

= .182, p =

.211). No significant correlations were identified between

any of the independent variables and participant variables;

age, time post onset of PD, severity of dysarthria, stage of

PD. All correlation coefficients are shown in Table 2.

Discussion

Treatment credibility and patient expectations have not

been explored widely in the rehabilitation disciplines, and

are particularly lacking in the field of speech-language

pathology. Therefore, this study is an important addition to

the literature as it explored how treatment credibility and

patient expectations may relate to treatment outcomes for

people with PD participating in LSVT

LOUD. The primary

hypothesis of this study was that patient expectations and

Table 2. Descriptive statistics and relationships between average credibility and expectancy, and

participant variables

Descriptive statistics

Average credibility

Average expectancy

Mean

Range

Correlation

coefficient

Significance

(2-tailed)

Correlation

coefficient

Significance

(2-tailed)

Credibility

6.81

4–9

1.40

Expectancy

59.59

10–100

22.19

Diff. mono. dB

6.47 –5.74–15.81

3.78

.103

.483

–.066

.652

DIP total diff.

12.34

–13–48

12.78

.388

.006*

.182

.211

Age

70.55 50.50– 87.58

8.69

.091

.533

–.019

.897

Timepostonset

4.35

.50–15

3.21

–.025

.862

.212

.144

Severity

1.22

1–3

.421

.073

.619

.076

.602

Stage PD

1.95

1–5

.923

.116

.274

.177

.223

*p < .05