Article Text
PDF
Abstract
Objectives To assess the evidence for active group-based performing arts interventions for people with Parkinson’s disease (PD).
Setting Scholarly literature (published in English) from any country or countries (last search February 2025). This systematic review was not registered and received no funding.
Data sources Five bibliographic databases: AMED (Ebsco), APA PsycINFO (Ovid), CINAHL (Ebsco), EMBASE (Ovid) and MEDLINE (Ovid), plus supplementary searches.
Primary and secondary outcome measures Eligible studies used a quantitative design to assess the benefit of active group-based performing arts interventions on quality of life, functional communication, speech, motor function and cognitive status in PD. The risk of bias was assessed using the SURE, University of York Centre for Reviews and Dissemination and Newcastle-Ottawa Scale checklists. Data were synthesised using narrative synthesis and random-effects meta-analysis.
Results A total of 94 studies were included: 2453 people with PD (mean age 68 years, 55% male) from 18 countries. Narrative synthesis supported nine combinations of performing arts modalities and outcome domains, including a benefit for dance on motor function (supported by 50 out of 54 studies), dance on quality of life (supported by 24 out of 37 studies) and singing on speech (supported by 17 out of 20 studies). Meta-analysis supported five combinations of performing art modalities, comparators and outcomes, including a clinically significant benefit for PD-specific dance versus usual care PDQ-39, MD −7.81, 95% CI −11.87 to −3.75 and tango-based dance versus usual care on UPDRS-III, MD −9.89, 95% CI −16.65 to −3.13.
Conclusions Evidence from both the narrative synthesis and the meta-analysis supports a benefit for some combinations of performing arts modalities and outcomes. Limitations of the evidence base included differences in comparators and outcomes, heterogeneity, lack of control arms and male underrepresentation. Future studies should compare the effectiveness of different performing arts modalities, assess functional communication and consider clinical significance.
- PUBLIC HEALTH
- Community-Based Participatory Research
- Systematic Review
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information. All data relevant to the study are included in the article or uploaded as online supplemental material. The presented work is a systematic review. All relevant information is provided in the manuscript and appendices. This includes the data extraction form completed with the data from all included studies and analytical code for the meta-analyses.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
Statistics from Altmetric.com
STRENGTHS AND LIMITATIONS OF THIS STUDY
Systematic review methods minimised subjectivity and bias.
A standardised outcome set was used.
An independent dual review was conducted.
It was not possible to conduct patient and public involvement.
Only English-language studies could be included.
Introduction
Parkinson’s disease
Parkinson’s disease (PD) is among the most common age-related neurodegenerative conditions, and its societal burden is increasing internationally.1 PD has a widespread and diverse range of motor and non-motor symptoms.2 It typically exerts a significant impact on the quality of life of people with PD3 and their caregivers.4 Quality of life, functional communication, speech, motor function and cognitive status have been identified as a set of five key outcomes in PD.5
Treatment options for PD
Levodopa-based pharmacotherapy has been the mainstay of treatment for PD for several decades and is generally effective in controlling motor symptoms.6 However, a relative lack of evidence for a benefit on speech and non-motor symptoms has stimulated interest in other therapeutic mediums, including lifestyle interventions, that can be used alongside pharmacotherapy. Group-based performing arts have been identified as one potentially beneficial approach.7 8
Evidence for the performing arts in PD
Systematic reviews on the performing arts in PD prior to 2020 typically focused on dance.5 Barnish and Barran5 (search date February 2020) published the first systematic review to take a comparative perspective across all available active, group-based performing arts interventions. They included 56 studies of which 38 were on dance, 12 were on singing, 4 were on music therapy and 2 were on theatre. Some evidence of benefit of each of these intervention modalities was observed on at least some of the eligible outcomes: quality of life, speech, functional communication, cognitive status and motor function. Key uncertainties in the evidence base included: (1) no studies comparing different artistic modalities (eg, dance vs singing), (2) lack of a control arm in 16 (42%) dance studies and 10 (83%) singing studies, (3) a relative lack of evidence on functional communication (only two studies, both on singing), (4) under-representation of men in studies compared with the population with PD and (5) lack of standardisation of outcome measures. We have identified nine9–17 further systematic reviews or comprehensive reviews (table 1) on the performing arts in PD since the Barnish and Barran5 review. None of these reviews, except Li et al,14 included more than one performing arts modality (eg, dance and singing). As such, they did not offer a broad evaluation of the potential benefits of the arts for PD comparable with Barnish and Barran.5 While Li et al’s study,14 which was not pre-registered and was published after our April 2024 searches, addresses a range of arts modalities, it is a comprehensive review, not a systematic review, does not include a meta-analysis and did not structure the narrative synthesis in a way that included all the Barnish and Barran5 outcome domains.
Systematic reviews and comprehensive reviews on the performing arts and PD since 2020
Aims and rationale
The key rationale for this work is that there is no available systematic review comparable with Barnish and Barran,5 whose searches (February 2020) are now 5 years old and cannot be seen to reflect an up-to-date view of the literature on the potential benefit of performing arts for PD. The present work offers an updated systematic review of evidence up to February 2025 that assessed the potential benefit of active group-based performing arts interventions on quality of life, functional communication, speech, motor function or cognitive status in people with PD. Additionally, we assess the extent to which key uncertainties identified in Barnish and Barran5 have been resolved.
Methods
Design
A systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines.18 Completed PRISMA 2020 and PRISMA for Abstracts checklists are provided in online supplemental files 1 and 2. A prespecified protocol was used (online supplemental file 3) and includes a log of protocol changes. While the review was not pre-registered, it followed the methods of the Barnish and Barran5 review as closely as feasible. Any changes are detailed in online supplemental file 4. In summary, one search database was rebranded without impact on underlying content, and the meta-analysis was expanded to include sensitivity and subgroup analysis. We used the search, screening, data extraction and risk of bias assessment from Barnish and Barran5 for studies published up to February 2020 and conducted these steps afresh for studies published after the Barnish and Barran5 search in February 2020 until February 2025.
Supplemental material
Data sources
Searches were conducted in February 2020, February 2024 and February 2025 using five pivotal bibliographic databases: AMED (Ebsco), APA PsycINFO (Ovid), CINAHL (Ebsco), EMBASE (Ovid) and MEDLINE (Ovid). The same search strategy was used for each search time point. As databases do not always index publication month, all update searches started at the start of a year, with any overlap in search periods addressed through deduplication. Supplementary searches were conducted on Google Scholar and through forward and backward citation chasing on studies identified for full-text review. Searches were designed to retrieve articles on PD and the performing arts (strategies for all databases are shown in online supplemental file 5 and were designed and conducted by the lead author MSB.
Inclusion criteria
Screening was initially conducted based on the title and abstract. Potentially relevant articles were screened at the full-text stage to determine inclusion (online supplemental file 6) or exclusion (online supplemental file 7) in the systematic review. Screening was conducted independently by two reviewers MSB and RVN-H or SER, and any disagreements were resolved through discussion. Eligibility criteria are shown in box 1. No automation tools were used.
Inclusion criteria
Eligible studies assessed:
Participants: people with a diagnosis of Parkinson’s disease.
Intervention: active group-based singing, dance or music therapy interventions (active in this context excludes passive arts activities such as listening to music).
Comparator: studies with and without control arms were eligible. There were no specific requirements for what control arms could involve.
Outcomes: quality of life, functional communication, speech, motor function and cognitive status.
Other: quantitative studies published in an English-language peer-reviewed journal or alternatively published as an English-language conference abstract in the 2 years before each search.
Studies were included in the meta-analysis if they provided sufficient quantitative information on outcomes and contributed to a comparison for which there were at least two studies for a given combination of intervention, comparator and outcome.
Data extraction
Information extracted is shown in box 2. All data extraction processes were conducted independently by two reviewers (MSB and RVN-H or SER), and any disagreements were resolved through discussion. No automation tools were used. The appendix provides additional information on study characteristics (online supplemental file 8), interventions (online supplemental file 9), controls (online supplemental file 10) and narrative results (online supplemental file 11).
Data extracted
The following information was extracted for each included study:
Bibliographic details (authors, year and citation).
Country of study.
Study design.
Participants (sample size, gender profile and mean age).
Inclusion criteria.
Outcomes.
Content of intervention.
Professional background of intervention leader.
Location of intervention (eg, community centre and outpatient clinic).
Frequency and duration of intervention.
Content of control arm.
Professional background of control arm leader.
Location of control arm.
Frequency and duration of control arm.
Study results for narrative synthesis for all eligible reported outcomes.
Study results for meta-analysis (for studies included in the meta-analysis—sample size, mean (SD) in change score—or follow-up score if change score not reported—for each arm).
Risk of bias assessment
The Specialist Unit for Review Evidence (SURE) Experimental Studies Critical Appraisal Checklist15 (online supplemental file 12) was used for the assessment of all randomised and nonrandomised trials. The SURE Cohort Studies Critical Appraisal Checklist15 (online supplemental file 13) was used for the assessment of observational longitudinal designs. Additionally, the University of York Centre for Reviews and Dissemination tool19 (online supplemental file 14) was used for all randomised controlled trials (RCTs) included in the meta-analysis, and the Newcastle-Ottawa Scale20 (online supplemental file 15) was used for all nonrandomised trials and observational studies in the meta-analysis. Risk of bias assessment was conducted independently by two reviewers (MSB and RVN-H or SER) and any disagreements were resolved through discussion. No automation tools were used. RVN-H was involved in all screening, data extraction and risk of bias, except for the February 2025 search update, where due to maternity leave, she was replaced by SER.
Narrative synthesis
Thematic narrative synthesis was used to analyse all studies that met the inclusion criteria. The inclusion of a detailed thematic narrative synthesis was prespecified in advance due to the high levels of observed methodological and clinical heterogeneity in the Barnish and Barran5 review. Synthesis was initially by outcome domain: quality of life, functional communication, speech, motor function and cognitive status. Within outcome domains, synthesis was by arts modality. The primary focus of the narrative synthesis was to assess the totality of the available evidence to assess the potential benefit of active, group-based, performing arts interventions for quality of life, functional communication, speech, motor function and cognitive status in people with PD. The secondary focus was on the extent to which the evidence has progressed over 2020–2025 and addressed key uncertainties identified in the Barnish et al5 review.
Meta-analysis
Meta-analysis was also conducted using Review Manager (RevMan) V.5.4.1 (Cochrane Collaboration) for combinations of key scale outcomes and interventions for which there were at least two studies using a common comparator. Meta-analysis included studies from the entire time period of the updated systematic review, including studies that featured in the Barnish and Barran5 meta-analyses. In addition to updating the meta-analysis sets from this review,5 new meta-analysis sets were constructed where available evidence permitted. Singing and music therapy were assessed as unitary categories in the meta-analysis. The higher number of studies on dance facilitated the creation of three dance categories: (i) Brazilian or tango-based dance, (ii) PD-specific dance and (iii) Argentine or adapted tango-based dance. Meta-analysis was conducted on mean differences (MD).
The choice of meta-analysis model was prespecified in the protocol rather than based on the results of heterogeneity tests, as recommended by Nikolakopoulou et al.21 Random-effects models were chosen, since heterogeneity was expected, based on the Barnish and Barran5 review. Random-effects meta-analysis considers heterogeneity by assuming that treatment effects differ between studies in a distribution of true effect sizes.22 Heterogeneity was quantified by Cochran Q test and I2 statistics, with values for the latter interpreted following the Cochrane guidelines.23
Where feasible (ie, at least two studies remained in the analysis set), leave-one-out sensitivity analysis and subgroup analysis only including RCTs were conducted to further explore heterogeneity. Clinical significance was considered, as well as statistical significance, in the interpretation of meta-analysis findings, using established Minimally Clinically Important Differences (MCIDs)24 for the appropriate population where available. Publication bias could not be assessed as there were fewer than 10 studies in each meta-analysis.25
Further details on the meta-analysis method are shown in online supplemental file 4, and results of sensitivity and subgroup analyses are shown in online supplemental file 16. Due to methodological and clinical heterogeneity, and the fact that, due to differences in intervention-comparator-outcome combinations, a relatively small proportion of available studies can contribute to the meta-analysis, the meta-analysis and the narrative synthesis should be seen as complementary to each other.
Certainty assessment
Certainty assessment was conducted using GRADE26 for each meta-analysis set as well as for each combination of performing arts modality and outcome domain in the narrative synthesis.
Patient and public involvement
Patient and public involvement could not be conducted for this systematic review assessing a broad range of performing arts interventions due to a lack of funding. The corresponding author will respond to any reputable media enquiries.
Results
Search results
Database searches returned a total of 7703 records (AMED 152, PsycINFO/APA PsycINFO 376, CINAHL 499, EMBASE 2880 and MEDLINE 796), plus 15 from supplementary searches. A total of 7199 records preceeded to title and abstract screening. 210 unique records were assessed at full-text screening; 109 records (94 unique studies) were included in the systematic review (figure 1) and 13 studies were included in the meta-analysis. Included studies assessed 2453 people with PD from 18 countries (mean age 68 years, 55% male). 63 studies assessed dance, 20 assessed singing, 8 assessed music therapy and 3 assessed theatre. No studies compared different performing arts modalities. Further details are explained in online supplemental file 17.
PRISMA 2020 flow diagram. PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.
Narrative synthesis
As there are 94 included studies, a summary of the narrative synthesis is provided here (further details in online supplemental file 17). A numerical summary of the evidence landscape for each combination of performing arts modality and outcome domain is provided in table 2.
Evidence landscape
There were nine combinations of performing arts modalities and outcomes that were overall supported by the evidence base.
A benefit of dance on quality of life was supported by 24 out of 37 (65%) studies, including multiple RCTs across different dance forms—the greatest evidence of benefit was found for tango-based and PD-specific dance forms. GRADE High.
A benefit of music therapy on quality of life was supported by six out of eight (75%) studies, including five RCTs. GRADE High.
A benefit of singing on quality of life was supported by six out of eight (75%) studies, including one parallel-group RCT,27 and one cross-over RCT28 which found a significant effect on some but not all quality-of-life measures. GRADE Moderate.
A benefit of theatre on quality of life was shown by two out of three (67%) studies, including one RCT. GRADE Moderate.
A benefit of singing on speech was shown by 17 out of 20 (85%) studies, including multiple RCTs. GRADE Moderate.
A benefit of dance on motor function was shown by 50 out of 54 (93%) studies, including multiple RCTs, nine of which supported tango-based dance. GRADE High.
A benefit of music therapy on motor function was shown by five out of seven (71%) studies, including three RCTs. GRADE High.
A benefit of singing on motor function was shown by three out of four (75%) studies, including a cross-over RCT. GRADE Low.
A benefit of dance on cognitive status was shown by 15 out of 20 (75%) studies, including multiple RCTs across different dance forms. GRADE Moderate.
Overall, across outcomes, where dance was considered, the evidence was greatest for tango-based and PD-specific dance forms. There was either no or limited evidence for the following: dance, music therapy, singing and theatre for functional communication; dance, music therapy and theatre for speech; theatre for motor function; music therapy, singing and theatre for cognitive status. GRADE calculations are shown in online supplemental file 16. The risk of bias profile as well as the potential impact of risk of bias on the outcomes of the narrative synthesis are shown in online supplemental file 17.
An assessment of the extent to which key uncertainties identified by Barnish and Barran5 have been resolved is presented in box 3. This shows that none the five key uncertainties have been fully resolved. Three uncertainties have been partially addressed. These are a lack of control arms, a lack of research into functional communication and a lack of standardisation of outcome measures. However, it should be noted that despite increased research on this outcome, there remains no evidence for the benefit of performing arts on functional communication. It is unclear whether underrepresentation of men has been addressed—while the percentage of men in included studies in this review (55%) was higher than in the Barnish and Barran5 review (53%), it is unclear whether this difference is meaningful. One uncertainty—a lack of studies comparing different performing arts modalities (eg, music and dance)—has not been addressed.
Assessment of progress since February 2020 in resolving key uncertainties
Key uncertainty 1: ‘no studies comparing different artistic modalities (eg, dance vs singing)’. Review authors’ assessment: Not addressed. There remain no studies comparing any two dance interventions: singing interventions and music therapy interventions. This is a significant limitation in assessing which performing arts modality may be most promising on PD and whether any specific demographic or clinical characteristics may influence this.
Key uncertainty 2: ‘lack of a control arm in 16 (42%) dance studies and 10 (83%) singing studies’. Review authors’ assessment: Partially addressed. Of the newly available studies over the period 2020–2025, 42% of dance studies lack a control (no change), but this is only 38% for singing studies (major improvement). More than half of the newly available studies across modalities have a control arm.
Key uncertainty 3: ‘a relative lack of evidence on functional communication (only two studies, both on singing)’. Review authors’ assessment: Partially addressed. One new dance study and three new singing studies were available for functional communication. However, there remains no substantive evidence supporting the benefit of performing arts on this outcome.
Key uncertainty 4: ‘underrepresentation of men in studies compared with the population with PD’. Review authors’ assessment: Unclear. The mean percentage of men in the included studies (database inception to February 2025) was 55%. This is higher than in the 2020 review (53%), although it is unclear if this difference is meaningful. Furthermore, both values appear to underestimate the proportion of men in the population with PD. According to a review by Cerri et al,36 PD is twice as common in men than women, while women tend to have more rapidly progressing disease.
Key uncertainty 5: ‘lack of standardisation of outcome measures’. Review authors’ assessment: Partially addressed. Progress was noted on using key measures more frequently for assessed concepts, facilitating more meta-analysis sets. However, some inconsistency remains in the measures used.
Meta-analysis
We searched for MCIDs for the meta-analysed outcomes in a population with PD and found the following:
Unified Parkinson's Disease Rating Scale (UPDRS-III)—MCID for improvement 3.25 units29 or 4.83 units.30 Both studies were conducted in a European setting and posited plausible MCIDs. We preferred the 3.25 units value from Horvath et al29 because it was a more controlled study environment where all participants had been diagnosed according to the UK Brain Bank Criteria,31 compared with the more pragmatic and ‘naturalistic’ setting of Sánchez-Ferro et al.30
Parkinson's Disease Questionnaire (PDQ-39)—MCID for improvement −4.72 units.32
Timed Up and Go (TUG)—No PD-specific MCID was identified for TUG, although an MCID of 3.4 seconds33 was available in a degenerative disc disease population, which we considered to be likely relatively generalisable.
The meta-analysis results for each analysis set are as follows:
Analysis set 1, Brazilian/Samba dance versus usual care on UPDRS-III, MD −10.24, 95% CI −17.06 to −3.41, p=0.003 in favour of dance, I2=74%, clinically significant, GRADE Very low.
Analysis set 2, Brazilian/Samba dance versus usual care on PDQ-39, MD −16.37, 95% CI −28.76 to −3.97, p=0.010 in favour of dance, I2=0%, clinically significant, GRADE Moderate.
Analysis set 3, PD-specific dance versus exercise on TUG, MD 0.67, 95% CI −0.36 to 1.70, p=0.20, I2=0%, not clinically significant (NCS), GRADE Moderate.
Analysis set 4, PD-specific dance versus usual care on TUG, MD −2.11, 95% CI −6.33 to 2.12, p=0.33, I2=64%, NCS, GRADE Very low.
Analysis set 5, PD-specific dance versus usual care on PDQ-39, MD −7.81, 95% CI −11.87 to −3.75, p=0.0002 in favour of dance, I2=3%, clinically significant, GRADE Very low.
Analysis set 6, tango-based dance versus exercise on UPDRS-III, MD=−0.13, 95% CI −5.41 to 5.14, p=0.96, I2=57%, NCS, GRADE Low.
Analysis set 7, tango-based dance versus usual care on UPDRS-III, MD −9.89, 95% CI −16.65 to −3.13. p=0.004 in favour of dance, I2=97%, clinically significant, GRADE Low.
Analysis set 8, tango-based dance versus exercise on TUG, MD −1.99, 95% CI −2.34 to −1.65, p<0.00001 in favour of dance, I2=0%, NCS, GRADE Moderate.
Analysis set 9, theatre versus physiotherapy on UPDRS-III, MD 1.01, 95% CI −4.33 to 6.34, p=0.71, I2=0%, NCS, GRADE Low.
Results for subgroup and sensitivity analyses as well as GRADE26 calculations are shown in online supplemental file 16.
Discussion
Summary
This paper presents an updated systematic review of evidence on the benefit of dance, music therapy, singing and theatre on five standard outcomes. This offers 5 years of additional evidence compared with the Barnish and Barran5 review, which addressed the same research question. Furthermore, as a secondary focus, we assessed how the field has evolved since February 2020. The narrative synthesis supported a benefit for nine combinations of performing arts modalities and outcomes, covering four performing arts modalities: dance, music therapy, singing and theatre. Within dance, the greatest support was for tango-based and PD-specific dance forms. Furthermore, we demonstrated that while the evidence base has gained 38 studies since Barnish and Barran,5 strengthening the evidence for many combinations of performing arts modalities and outcomes, key uncertainties identified by Barnish and Barran5 have only been partially addressed. Issues remain with a lack of studies comparing different performing arts modalities, lack of control arms in a significant minority of studies, a lack of focus on functional communication, underrepresentation of men compared with the population with PD and inconsistency in outcome measures used. The meta-analysis, while limited by differences in comparators and outcomes that limit the number of studies that can be pooled, showed statistically significant benefits of Brazilian/Samba dance versus usual care on PDQ-39 (quality of life), tango-based dance versus exercise on TUG (motor function), PD-specific dance versus usual care on PDQ-39, Brazilian/Samba dance versus usual care on UPDRS-III (motor function) and tango-based dance versus usual care on UPDRS-III, the latter three also being clinically significant. Certainty assessed by GRADE was stronger when assessed across all studies in the narrative synthesis than when assessed on the meta-analysis sets. This is likely because relatively few studies could be pooled in the meta-analyses due to differences in comparators and outcome measures.
Interpretation of findings
Our work updates the findings of Barnish and Barran5 by 5 years using a comparable design. Unlike most other recent reviews,9–13 15–17 we provide a broad comparative perspective across performing arts modalities. The new evidence gathered since February 20205 is generally consistent with the earlier evidence, but the addition of 38 new studies in the narrative synthesis strengthens the evidence base and permits the development of nine combinations of performing arts modalities and outcomes supported by the narrative synthesis. Consistent with Barnish and Barran,5 evidence for dance is greatest for tango-based and PD-specific dance forms. As in box 3, progress has been made on some key uncertainties identified by Barnish and Barran,5 but they remain unresolved. Greater standardisation of intervention-comparator-outcome combinations has facilitated the development of additional meta-analysis sets. However, as in Barnish and Barran5 review, the meta-analysis remains limited as only a small proportion of studies from the systematic review can be pooled. Therefore, the narrative synthesis and meta-analysis have to be seen as complementary to each other. The meta-analysis offers the benefit of demonstrating clinical significance for the benefits of PD-specific dance versus usual care on quality of life, Brazilian/Samba dance versus usual care on motor function and tango-based dance versus usual care on motor function.
Some broader contextual factors need to be considered. Some of the studies identified published since the Barnish and Barran5 review were conducted during or towards the end of the COVID-19 period. People with PD may be considered a vulnerable group, leading to challenges in carrying out group activities during this period and potential selection biases and group dynamic differences. Different art forms may be complementary rather than be seen in opposition to each other. For example, dance interventions typically involve some form of musical accompaniment, while singing activities may involve some degree of movement. Art forms may relate to the symptoms of PD, for example, arts activities that foster a positive group identity8 34 may help address social isolation in PD,35 while arts interventions may in particular target speech, cognitive and motor function.
Strengths and limitations
The use of a comparable design to Barnish and Barran5 review, the use of a standardised outcome set, the inclusion of a meta-analysis and a thorough search strategy are key strengths of our work. The use of standardised data extraction forms minimises inconsistency in the information collected between studies; the use of standardised risk of bias tools maintains a standardised objective approach to assessing study quality and the use of two independent reviewers minimises any effect of the preferences of individual reviewers when selecting studies for inclusion.
There are, however, limitations in the review process. Only one suitably experienced researcher was available to design and run searches. It was not possible to convene a PPI panel with an appropriate membership that could provide insight into the dilemma about male recruitment in performing arts studies. PROSPERO registration was not possible because data collection had already started, as a result of using the data extraction forms from Barnish and Barran5 for studies identified in their review. Non-English-language articles could not be included, as they were not included in the review5 we are updating and its search strategy was not designed to identify non-English-language articles, which are also harder to retrieve as full texts through academic libraries. Limitations of the evidence base included differences in comparators and outcome measures; clinical, methodological and statistical heterogeneity; studies without a control arm; and male underrepresentation (discussed in online supplemental file 17) compared with the population with PD. Furthermore, pooling randomised and nonrandomised studies in the meta-analysis is a limitation resulting from the lack of RCTs with the same comparators and outcomes and means that pooled analyses may not fully benefit from the protective effect of randomisation against bias.
Implications for research and practice
Future research should focus on addressing methodological limitations identified through the risk of bias assessment as well as key remaining uncertainties as shown in box 3. Studies should look at comparing the effectiveness of different performing arts modalities (eg, singing vs dance) and look at combinations of performing arts modalities and outcomes which have to date not been assessed (eg, the benefit of dance for speech). Greater standardisation of control arms and outcome measures and reporting of change scores with a measure of variance will make meta-analyses more robust and may enable a network meta-analysis to be used. RCTs and high-quality comparative real-world evidence studies should be prioritised. Future studies should include a greater focus on functional communication—this should not be limited to singing studies, as it is possible for example that expressive dance forms may offer a communicative benefit. Studies should attempt to recruit a sample that is more reflective of the population with PD in terms of gender—or if this is not possible, alternatively to offer analyses stratified by or adjusted for gender. Furthermore, studies should consider clinical significance as well as statistical significance to ensure relevance to decision-making and to facilitate confirmation of whether the observed benefits in the narrative synthesis for a range of combinations between performing arts modalities and outcome domains are clinically significant. The evidence is not sufficiently mature and robust to make specific recommendations for clinical practice; however, there is preliminary evidence to support the benefit of performing arts, especially dance, and healthcare providers may wish to incorporate the arts into their service provision.
Conclusion
We present a 5-year update of the first systematic review to assess the benefit of dance, music therapy, singing and theatre on five key outcomes in PD—quality of life, functional communication, speech, motor function and cognitive status. Evidence from the narrative synthesis shows that the new evidence since the Barnish and Barran5 review has generally strengthened the case for the benefit of performing arts in PD and allowed the development of nine supported combinations of performing arts modalities and outcome domains. However, methodological limitations remain, and key uncertainties are only partially resolved. While limited by differences in outcome measures and comparators between studies, meta-analysis identified five combinations of performing arts modality, comparator and outcome measures that showed a statistically significant benefit for the performing arts. This included clinically significant benefits for PD-specific dance versus usual care on quality of life, tango-based dance versus usual care on motor function and Brazilian/Samba dance versus usual care on motor function.
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information. All data relevant to the study are included in the article or uploaded as online supplemental material. The presented work is a systematic review. All relevant information is provided in the manuscript and appendices. This includes the data extraction form completed with the data from all included studies and analytical code for the meta-analyses.
Ethics statements
Patient consent for publication
Ethics approval
Not applicable.
References
Footnotes
Contributors The work was managed and directed by MSB, who had the initial idea for the work. All authors contributed to the acquisition, reviewing and interpretation of data. MSB wrote the first draft of the manuscript, and BH and SER revised the manuscript for important intellectual content. All authors reviewed the final submission version of the manuscript and approved the submission. All authors take appropriate responsibility for the work they undertook. Overall responsibility for the work rests with MSB, who is the guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests MSB and RVN-H are experienced recreational musicians and have been involved in promoting the arts to the public. MSB declares having received expenses but not payment for arts promotion activities (this is not within the past 5 years). SER declares no conflicts of interest.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.