Background
SCS screening trial and purpose
Evidence for SCS screening trials as a predictor of long-term success
Hypothesis and aims
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compare the patient-related outcomes of an SCS screening trial strategy to a no-trial implantation-only strategy;
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determine the diagnostic performance (e.g. sensitivity and specificity) of an SCS screening trial;
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compare the cost-effectiveness of a screening trial strategy to a no-test implant-only strategy; and
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assess the expectations and experiences of patients for the use of an SCS screening trial.
Methods and design
Study design
Study population
Inclusion criteria
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Adults (≥ 18 years old) who are clinically considered to be candidates for SCS as per NICE TA159 [15].
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Pain of neuropathic nature of an intensity of at least 5 as assessed on a numerical rating scale (NRS).
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Patient has persistent pain for more than 6 months despite appropriate conventional medical and surgical management including transcutaneous electric nerve stimulation (TENS), acupuncture, oral analgesic agents, cognitive behavioural therapy as well as nerve blockade where appropriate.
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Satisfactory multidisciplinary assessment by a team with expertise in delivering SCS therapy.
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Patient capable of providing informed consent.
Exclusion criteria
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Patient refusal to participate in the study.
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Presence of an ongoing pain condition considered by the investigator to overshadow the neuropathic pain condition to be treated with SCS.
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Current or previous treatment with an implanted pain relief device.
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Current participation or planned participation in other studies that may confound the results of this study.
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Ongoing anticoagulation therapy, which cannot be safely discontinued.
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Poor cognitive ability or lack of capacity.
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Unable to undergo study assessments or complete questionnaires independently.
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Patient is pregnant or planning to become pregnant during the course of the study.
Recruitment of patients
Interventions
Screening trial and implantation strategy (usual care)
Implantation-only strategy
Outcome measures
Primary outcome
Secondary outcomes
Data collection and visits
Baseline visit
Implant visit
One-month telephone interview following permanent implant (optional)
Three-month and 6-month (end of study) visit following permanent implant
Data collection and follow-up for withdrawn subjects
Sample size determination
Margin of error | Sensitivitya (%) | Specificitya (%) |
---|---|---|
100% | 8.9 | 30.9 |
80% | 26.6 | 53.3 |
60% | 31.8 | 61.6 |
40% | 31.8 | 61.6 |
Randomisation
Statistical analysis
Diagnostic performance
Comparison of effectiveness
Economic evaluation
Qualitative analysis
Trial management and quality assurance
Trial Steering Committee
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major decisions such as a need to change the protocol for any reason;
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monitoring and supervising the progress of the trial;
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reviewing relevant information from other sources;
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reviewing data management and ethical arrangements; and
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informing and advising on all aspects of the trial.
Trial Management Group
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distribute the case report forms (CRFs) to participating centres;
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monitor the collection of data, process data, seek missing data and clarify ambiguous data;
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ensure the confidentiality and security of all trial forms and data;
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liaise with Exeter CTU regularly regarding data entry and randomisation;
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coordinate any interim and main analyses; and
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organise Steering Committee and Collaborator meetings.