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Speech and language therapy for Parkinson’s disease. Clare Herd Research Associate. Contents. The importance of reviewing the literature prior to undertaking new research & the value of systematic reviews
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Speech and language therapy for Parkinson’s disease. Clare Herd Research Associate
Contents • The importance of reviewing the literature prior to undertaking new research & the value of systematic reviews • The steps involved in conducting a systematic review of available evidence on the topic ‘Speech and language therapy for people with Parkinson’s disease’.
Definitions • Review (narrative): all attempts to synthesise the results & conclusions of two or more publications on a given topic • Systematic review: when a review strives to comprehensively identify & track down all the literature on a given topic • Meta-analysis: an overview incorporating a specific statistical strategy for assembling the results of several studies into a single estimate
Why carry out systematic reviews / meta-analyses Provide totality of the evidence • SRs / MAs: summarise existing evidence base by providing manageable information on which decisions on health policy and individual treatment can be based Assist the practice of evidence-based health care • SRs / MAs minimise bias and present a clearer picture of the current state of evidence • Improve the reliability and accuracy of any recommendations
Objective Update two Cochrane systematic reviews published in 2001 • Speech and language therapy versus placebo or no intervention for Parkinson’s disease • Comparison of speech and language therapy techniques for Parkinson’s disease • Deane K et al. Speech and language therapy for dysarthria in Parkinson's disease. Cochrane Database of Systematic Reviews 2001, Issue 2 • Deane K et al. A comparison of speech and language therapy techniques for dysarthria in Parkinson's disease. Cochrane Database of Systematic Reviews 2001, Issue 2
Methods Inclusion criteria: • Randomised or quasi randomised controlled trials • SLT vs. placebo or no intervention, and SLT A vs. B • Participants with a diagnosis of PD, any duration of PD, all ages, any duration of treatment. P – People with diagnosis of PD I – SLT C – Placebo/ no intervention/ 2nd SLT technique O – Speech S – RCT’s
Search strategy The following MeSH and free terms were used combined with RCT study design filter: a. Dysarthria OR speech OR speak OR intelligibility OR dysprosody OR hypophonia OR monotonicity OR phonate b. ((Speech OR speak OR language OR voice OR vocal OR articulate OR sing) near (task OR therapy OR treatment OR train OR counsel OR intervention OR exercise OR drill OR rehabilitation)) OR silverman OR LSVT c. Parkinson OR Parkinson's disease OR Parkinsonism d. (#a AND #b AND #c) OR (#a and #c)
Methods Literature search (to April 2011) for RCTs of SLT interventions using: • Electronic databases (e.g. MEDLINE, EMBASE) • Trials registers (e.g. Cochrane Controlled Trials Register, metaRegister of Controlled Trials, ClinicalTrials.gov) • Conference proceedings • Reference lists
Methods • Data extracted independently by two people, with any discrepancies resolved by consensus or discussion with a third person. • Standard meta-analysis methods for continuous data • Mean difference between arms • Forest plots of change from baseline to end of the treatment period or follow-up.
Outcome measures • Total impairments • Objective and subjective acoustic measures of speech samples • Level of communication participation • Activities of daily living • Handicap and quality of life measures • Depression rating scales • Adverse effects • Carer outcomes • Economic analysis
Methods Search Abstract screening (1054) In/Out (35) Data Extraction (3) Data Extraction (6) Preparation of manuscript Preparation of manuscript SLT vs no intervention SLT A vs B
Speech and language therapy versus placebo or no intervention for speech problems in Parkinson’s disease. Herd C et al. Cochrane Database of Systematic Reviews 2012, Issue 2.
Methodological quality - SLT vs no intervention • Insufficient numbers of participants to avoid reaching false negative conclusions and to reduce the possibility of selection bias. • All three trials failed to clearly define their disease of interest or state their inclusion and exclusion criteria. • Blinding of assessors could not be confirmed for any of the included trials.
Results – SLT vs no intervention • The trials used a variety of treatment methods and outcome measures. • This heterogeneity meant that meta-analysis was possible in only a couple of instances.
Results – SLT vs no intervention SPL of monologue speech / dB
Results – SLT vs no intervention SPL of reading a passage / dB
Results – SLT vs no intervention • The objective loudness of the patients’ speech improved, with all types of speech modality measured, after therapy. • Primary outcome of interest is improved intelligibility, none of the trials reviewed used QOL or intelligibility scales. • Adverse events were not reported by any of the trials included in this review. • Economic analyses were not carried out for any of the studies.
Conclusions - SLT vs no intervention • Improvements in speech impairments were noted in the 41 participants evaluable from these studies, though it cannot be stated whether or not these changes were clinically significant. • Considering the methodological flaws in many of the studies, the small number of patients examined, and the possibility of publication bias, there is insufficient evidence to support or refute the efficacy of speech and language therapy for speech problems in Parkinson's disease.
Comparison of speech and language therapy techniques for speech problems in Parkinson’s disease. Herd C et al. Cochrane Database of Systematic Reviews 2012, Issue 2.
Results – SLT A vs B • All included trials assessed intelligibility and almost all results were not statistically significant. • All three trials for LSVT recorded loudness measures. Patients showed a greater improvement from LSVT than alternative therapies for this outcome. • Objective measures of monotonicity of a monologue also favoured the LSVT method.
Results – SLT A vs B • Outcome measures from two trials could not be analysed for statistical significance due to missing data. • Constantinescu et al (2011) reported no significant difference between online LSVT and face-to-face delivery in reading and monologue loudness, intelligibility and monotonicity.
Conclusions - SLT A vs B • The small number of patients examined, the low methodological quality of the trials evaluated and the possibility of publication bias resulted in an inability to determine the superiority of any one type of SLT over another.
Implications of results • Further large scale RCTs are needed, with longer follow up periods and should utilise outcome measures that are meaningful to patients. • More evidence to support the efficacy of SLT for speech problems in PD is required before meaningful comparisons between various techniques can be made.
Acknowledgements • Carl Clarke • Claire Smith • Katherine Deane • Christina Smith • Marian Brady • Catherine Sackley • UK Cochrane centre