Herd et al. (2012)

SECONDARY REVIEW CRITIQUE

 

 

KEY:

 

C = clinician

CI = confidence interval

LSVT = Lee Silverman Voice Treatment

NA = not applicable

P = patient or participant

pmh = Patricia Hargrove, blog developer

SLP = speech-language pathologist

SR = Systematic Review

 

 

Source: Herd, C. .P, Tomlinson, C. L., Deane, K. HO., Brady, M. C., Smith, C. H., Sackley, C., Clarke, C. E. (2012) Speech and language therapy versus placebo or no intervention for speech problems in Parkinson’s disease. Cochrane Database of Systematic Reviews, 2001, Issue 2. Art. No.: CD002812. DOI: 10.1002/14651858.CD002812. Update 2012

 

Reviewer(s): pmh

 

Date: April 4, 2016

 

Overall Assigned Grade: B (NOTE: The highest possible grade is A+ because this is a Systematic Review or SR. The Overall Assigned Grade is concerned with the quality of the design, the execution of the research, and the potential effectiveness of the intervention. For this SR, the grade was lowered because of the SR authors’ rating of the quality of the research supporting the interventions, not due to the quality of SR.)

 

Level of Evidence: A+ (Systematic Review with Narrow Criteria)

 

Take Away: This well-executed SR is a revision/update of a previously published SR. The authors of the SR identified 3 new investigations that met their narrow criteria and described the overall methodological quality of the 3 investigations as “poor.” The authors provided thorough analyses of the investigations and clearly justified their ratings. However, considering the scope of intervention research in Communication Sciences and Disorders, a speech-language pathologist (SLP) might be more generous with respect to grading of the 3 new investigations described in this SR. Each of the 3 interventions resulted in improvement in one or more of the following outcomes: loudness, monotonicity, pitch, and ratings of speech impairment. In addition, one of the interventions explored maintenance and determined that progress was maintained.

 

 

What type of secondary review? Meta Analysis

 

 

  • Were the results valid? Yes

 

– Was the review based on a clinically sound clinical question? Yes

 

– Did the reviewers clearly describe reasonable criteria for inclusion and exclusion of literature in the review (i.e., sources)? Yes

 

– The authors of the secondary research noted that they reviewed the following resources:

  • abstracts from conferences
  • conference proceedings/abstracts
  • hand searches
  • internet based databases
  • references from identified literature
  • theses/dissertations
  • Controlled Trial Registers
  • Internal reports

 

– Did the sources involve only English language publications? Unclear

 

– Did the sources include unpublished studies? Yes

 

– Was the time frame for the publication of the sources sufficient? Yes

 

– Did the authors of the secondary research identify the level of evidence of the sources? Yes, the authors described the methodology as poor; they also provided a critique for each of the sources.

 

– Did the authors of the secondary research describe procedures used to evaluate the validity of each of the sources? Yes

 

Was there evidence that a specific, predetermined strategy was used to evaluate the sources? Yes

 

– Did the authors of the secondary research or review teams rate the sources independently? Yes

 

– Were interrater reliability data provided? No

 

– If there were no interrater reliability data, was an alternate means to insure reliability described? Yes, the authors reported that they rated the sources independently, discussed disagreements, and came to consensus regarding the disagreements.

 

– Were assessments of sources sufficiently reliable? Yes

 

– Was the information provided sufficient for the reader to undertake a replication? Yes

 

– Did the sources that were evaluated involve a sufficient number of participants? Variable. Although the authors of the SR were not impressed by the total number of Ps, it was respectable for the Communication Sciences and Disorders literature.

 

– Were there a sufficient number of sources? No.

 

  1. Description of outcome measures:

 

  • Outcome #1: Improved measures of loudness
  • Outcome #2: Improved measures of monotonicity
  • Outcome #3: Improved measures of pitch
  • Outcome #4: Improved ratings of speech impairment

 

 

  1. Description of results:

 

  • What measures were used to represent the magnitude of the treatment/effect size? Mean difference and effect

 

  • Summarize overall findings of the secondary research:

 

NOTE: The authors of the SR reworked the data from the 3 investigations/ sources to compare the outcomes of the treatment and no treatment groups because this was not provided in the original sources. Rather, the original sources/investigations had compared the pre and post intervention scores of the treatment and no treatment groups individually.

 

  • Outcome #1: Improved measures of loudness

Two of the 3 sources reported significant improvements for treatment groups compared to nontreatment groups in a variety of measures of loudness following intervention

 

  • Outcome #2: Improved measures of monotonicity

– Only 1 of the sources/investigations explored measures of monotonicity.

     – One measure of monotonicity (counting to 5 with their softest to their loudest volume) improved significantly with treatment; the other (singing up and down to the lowest to highest pitch) did not.

    

  • Outcome #3: Improved measures of pitch

–   Only 1 of the sources/investigations explored measures of pitch.

   –   The investigators of the source did not find a significant difference in measures comparing treatment and nontreatment groups

 

  • Outcome #4: Improved ratings of speech impairment

Two of the 3 sources/investigations reported that measures of overall speech impairment were significantly better for the treatment group compared to the nontreatment group.

 

– Were the results precise? Yes

 

– If confidence intervals (CI) were provided in the sources, did the reviewers consider whether evaluations would have varied if the “true” value of metrics were at the upper or lower boundary of the confidence interval? Unclear, CI were reported but not discussed thoroughly.

 

– Were the results of individual studies clearly displayed/presented? Yes

 

– Were the results in the same direction? Yes

 

– Did a forest plot indicate homogeneity? Yes

 

– Was heterogeneity of results explored? Yes, heterogeneity reported but it was not discussed.

 

– Were the findings reasonable in view of the current literature? Yes

– Were negative outcomes noted? Yes

                                                                                                                   

 

  • Were maintenance data reported? Yes. Only one of the investigations reported maintenance data (for loudness measures.) In all cases progress was maintained.

 

 

  • Were generalization data reported?  Unclear

 

 

 

SUMMARY OF INTERVENTION

 

 

Population: Parkinson’s Disease; Adults

 

Prosodic Targets: loudness, intonation (monotonicity), pitch

 

Nonprosodic Targets: speech impairment

 

Aspects of Prosody Used in Treatment of Nonprosodic Targets: loudness (for all 3 sources) and pitch (for 2 of the sources)

 

===================================

 

Description of Procedure/Source #1— Johnson & Pring (1990)

 

  • Group treatment focused on pitch and loudness.

 

  • The clinician (C) developed individual programs for the Ps and provided visual feedback.

 

Evidence Supporting Procedure/Source #1— Johnson & Pring (1990)

 

  • Compared to the no treatment group, Ps receiving this invention improved significantly more on measures of speech impairment, loudness, and maximum volume range (a measure of monotonocity.)

 

Evidence Contraindicating Procedure/Source #1— Johnson & Pring (1990)

 

  • It is not clear that the significant improvement in the measure of speech impairment is clinically significant.

 

  • There was not a significant improvement in maximum pitch range (a measure of monotonocity) or fundamental frequency.

 

 

Description of Procedure/Source #2—Robertson & Thomson (1984)

 

  • Group treatment focused on pitch and loudness as well as respiration, voice, and intelligibility. If needed, C provided individual therapy.

 

  • C provided visual feedback to the P using a video.

 

Evidence Supporting Procedure/Source #2— Robertson & Thomson (1984)

 

  • Compared to the no treatment group, Ps receiving this invention improved significantly more on a measure of speech impairment

 

 

Description of Procedure/Source #3—Ramig et al. (2001)

 

  • C administered Lee Silverman Voice Treatment (LSVT) which used healthy phonatory effort to increase loudness.

 

  • The sessions were individual sessions.

 

Evidence Supporting Procedure/Source #3— Ramig et al. (2001)

 

  • The results of statistical analyses of several measures of loudness reveal that loudness consistently improved significantly more after LVST treatment compared to no treatment.

 

  • The improvement was maintained 6 months after the termination of therapy.
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