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Sybil Farmer

Shrewsbury College

ORCID: 0000-0002-7977-2163

Publishes on Cerebral Palsy and Movement Disorders, Botulinum Toxin and Related Neurological Disorders, Stroke Rehabilitation and Recovery. 37 papers and 1.7k citations.

37Publications
1.7kTotal Citations

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Interventions for improving upper limb function after stroke
Alex Pollock, Sybil Farmer, Marian Brady et al.|Cochrane Database of Systematic Reviews|2014
Cited by 848Open Access

BACKGROUND: Improving upper limb function is a core element of stroke rehabilitation needed to maximise patient outcomes and reduce disability. Evidence about effects of individual treatment techniques and modalities is synthesised within many reviews. For selection of effective rehabilitation treatment, the relative effectiveness of interventions must be known. However, a comprehensive overview of systematic reviews in this area is currently lacking. OBJECTIVES: To carry out a Cochrane overview by synthesising systematic reviews of interventions provided to improve upper limb function after stroke. SEARCH METHODS: We comprehensively searched the Cochrane Database of Systematic Reviews; the Database of Reviews of Effects; and PROSPERO (an international prospective register of systematic reviews) (June 2013). We also contacted review authors in an effort to identify further relevant reviews. SELECTION CRITERIA: We included Cochrane and non-Cochrane reviews of randomised controlled trials (RCTs) of patients with stroke comparing upper limb interventions with no treatment, usual care or alternative treatments. Our primary outcome of interest was upper limb function; secondary outcomes included motor impairment and performance of activities of daily living. When we identified overlapping reviews, we systematically identified the most up-to-date and comprehensive review and excluded reviews that overlapped with this. DATA COLLECTION AND ANALYSIS: Two overview authors independently applied the selection criteria, excluding reviews that were superseded by more up-to-date reviews including the same (or similar) studies. Two overview authors independently assessed the methodological quality of reviews (using a modified version of the AMSTAR tool) and extracted data. Quality of evidence within each comparison in each review was determined using objective criteria (based on numbers of participants, risk of bias, heterogeneity and review quality) to apply GRADE (Grades of Recommendation, Assessment, Development and Evaluation) levels of evidence. We resolved disagreements through discussion. We systematically tabulated the effects of interventions and used quality of evidence to determine implications for clinical practice and to make recommendations for future research. MAIN RESULTS: Our searches identified 1840 records, from which we included 40 completed reviews (19 Cochrane; 21 non-Cochrane), covering 18 individual interventions and dose and setting of interventions. The 40 reviews contain 503 studies (18,078 participants). We extracted pooled data from 31 reviews related to 127 comparisons. We judged the quality of evidence to be high for 1/127 comparisons (transcranial direct current stimulation (tDCS) demonstrating no benefit for outcomes of activities of daily living (ADLs)); moderate for 49/127 comparisons (covering seven individual interventions) and low or very low for 77/127 comparisons.Moderate-quality evidence showed a beneficial effect of constraint-induced movement therapy (CIMT), mental practice, mirror therapy, interventions for sensory impairment, virtual reality and a relatively high dose of repetitive task practice, suggesting that these may be effective interventions; moderate-quality evidence also indicated that unilateral arm training may be more effective than bilateral arm training. Information was insufficient to reveal the relative effectiveness of different interventions.Moderate-quality evidence from subgroup analyses comparing greater and lesser doses of mental practice, repetitive task training and virtual reality demonstrates a beneficial effect for the group given the greater dose, although not for the group given the smaller dose; however tests for subgroup differences do not suggest a statistically significant difference between these groups. Future research related to dose is essential.Specific recommendations for future research are derived from current evidence. These recommendations include but are not limited to adequately powered, high-quality RCTs to confirm the benefit of CIMT, mental practice, mirror therapy, virtual reality and a relatively high dose of repetitive task practice; high-quality RCTs to explore the effects of repetitive transcranial magnetic stimulation (rTMS), tDCS, hands-on therapy, music therapy, pharmacological interventions and interventions for sensory impairment; and up-to-date reviews related to biofeedback, Bobath therapy, electrical stimulation, reach-to-grasp exercise, repetitive task training, strength training and stretching and positioning. AUTHORS' CONCLUSIONS: Large numbers of overlapping reviews related to interventions to improve upper limb function following stroke have been identified, and this overview serves to signpost clinicians and policy makers toward relevant systematic reviews to support clinical decisions, providing one accessible, comprehensive document, which should support clinicians and policy makers in clinical decision making for stroke rehabilitation.Currently, no high-quality evidence can be found for any interventions that are currently used as part of routine practice, and evidence is insufficient to enable comparison of the relative effectiveness of interventions. Effective collaboration is urgently needed to support large, robust RCTs of interventions currently used routinely within clinical practice. Evidence related to dose of interventions is particularly needed, as this information has widespread clinical and research implications.

An algorithm was developed to assign GRADE levels of evidence to comparisons within systematic reviews
Alex Pollock, Sybil Farmer, Marian Brady et al.|Journal of Clinical Epidemiology|2015
Cited by 187Open Access

OBJECTIVES: One recommended use of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach is supporting quality assessment of evidence of comparisons included within a Cochrane overview of reviews. Within our overview, reviewers found that current GRADE guidance was insufficient to make reliable and consistent judgments. To support our ratings, we developed an algorithm to grade quality of evidence using concrete rules. METHODS: Using a pragmatic, exploratory approach, we explored the challenges of applying GRADE levels of evidence and developed an algorithm to applying GRADE levels of evidence in a consistent and transparent approach. Our methods involved application of algorithms and formulas to samples of reviews, expert panel discussion, and iterative refinement and revision. RESULTS: The developed algorithm incorporated four key criteria: number of participants, risk of bias of trials, heterogeneity, and methodological quality of the review. A formula for applying GRADE level of evidence from the number of downgrades assigned by the algorithm was agreed. CONCLUSION: Our algorithm which assigns GRADE levels of evidence using a set of concrete rules was successfully applied within our Cochrane overview. We propose that this methodological approach has implications for assessment of quality of evidence within future evidence syntheses.

A systematic review of randomised controlled trials assessing effectiveness of prosthetic and orthotic interventions
Aoife Healy, Sybil Farmer, Anand Pandyan et al.|PLoS ONE|2018
Cited by 116Open Access

BACKGROUND: Assistive products are items which allow older people and people with disabilities to be able to live a healthy, productive and dignified life. It has been estimated that approximately 1.5% of the world's population need a prosthesis or orthosis. OBJECTIVE: The objective of this study was to systematically identify and review the evidence from randomized controlled trials assessing effectiveness and cost-effectiveness of prosthetic and orthotic interventions. METHODS: Literature searches, completed in September 2015, were carried out in fourteen databases between years 1995 and 2015. The search results were independently screened by two reviewers. For the purpose of this manuscript, only randomized controlled trials which examined interventions using orthotic or prosthetic devices were selected for data extraction and synthesis. RESULTS: A total of 342 randomised controlled trials were identified (319 English language and 23 non-English language). Only 4 of these randomised controlled trials examined prosthetic interventions and the rest examined orthotic interventions. These orthotic interventions were categorised based on the medical conditions/injuries of the participants. From these studies, this review focused on the medical condition/injuries with the highest number of randomised controlled trials (osteoarthritis, fracture, stroke, carpal tunnel syndrome, plantar fasciitis, anterior cruciate ligament, diabetic foot, rheumatoid and juvenile idiopathic arthritis, ankle sprain, cerebral palsy, lateral epicondylitis and low back pain). The included articles were assessed for risk of bias using the Cochrane Risk of Bias tool. Details of the clinical population examined, the type of orthotic/prosthetic intervention, the comparator/s and the outcome measures were extracted. Effect sizes and odds ratios were calculated for all outcome measures, where possible. CONCLUSIONS: At present, for prosthetic and orthotic interventions, the scientific literature does not provide sufficient high quality research to allow strong conclusions on their effectiveness and cost-effectiveness.

Selective dorsal rhizotomy for children with cerebral palsy: the Oswestry experience
Gaynor Cole, Sybil Farmer, Andrew Roberts et al.|Archives of Disease in Childhood|2007
Cited by 61Open Access

BACKGROUND: Although three randomised control trials have shown that selective dorsal rhizotomy (SDR) reduces spasticity in children with cerebral palsy, a meta-analysis of the results demonstrated that the procedure conferred only small functional benefit on the patient. AIM: To determine whether applying strict criteria for patient selection as practised in Oswestry leads to improved outcomes, using gait analysis as an outcome measure. METHODS: Ambulant children with cerebral palsy were selected for SDR using very strict clinical criteria. Instrumented gait analysis was used as the main outcome measure. RESULTS: Of 53 children referred for the procedure, only 19 (35%) fulfilled our strict criteria for selection. These children underwent surgery and when pre- and post-SDR data were compared, they showed improvement in cosmesis of gait, clinical examination and temporal, kinetic and kinematic parameters of gait. After SDR the children walked, on average, 0.15 m/s faster, with a step length improvement of 0.11 m. Changes were seen at hip, knee and ankle, with those at the knee being most marked. A 0.3 grade improvement in knee extensor power on clinical examination led to a 13 degrees improvement in stance phase knee extension. Knees also became less stiff, with an 82 degrees /s improvement in the rate of flexion into swing phase. A functional tool (the GMFCS) applied retrospectively also confirmed post-operative improvement, with 15 of the 19 children improving by at least one level. CONCLUSION: Application of strict selection criteria when considering children for SDR leads to encouraging results as demonstrated by gait analysis and other measures.