Here is the design of a clinical trial:

Official Title: A Comparative Effectiveness Randomised Placebo Controlled Pilot Trial of the Management of Acute Lumbar Radicular Pain: Evaluate Route Versus Pharmacology of Intervention, and Feasibility in Public Hospital and Community Practice Settings.

Included conditions:
- Acute Sciatica

Study Armgroups:
- {'label': 'Arm 1', 'type': 'EXPERIMENTAL', 'description': 'Betamethasone OR Dexamethasone Injectable CT - fluoroscopic guided transforaminal lumbar epidural steroid', 'interventionNames': ['Drug: Betamethasone OR Dexamethasone Injectable', 'Other: Sham Injection and/or oral placebo']}
- {'label': 'Arm 2', 'type': 'EXPERIMENTAL', 'description': 'Normal Saline Flush, 0.9% Injectable Solution CT - fluoroscopic guided transforaminal lumbar epidural normal saline', 'interventionNames': ['Drug: Normal Saline Flush, 0.9% Injectable Solution', 'Other: Sham Injection and/or oral placebo']}
- {'label': 'Arm 3', 'type': 'EXPERIMENTAL', 'description': 'Dexamethasone Oral Tablet:\n\nOral dexamethasone 15 day tapered dosing is as follows: (i) days 1-5, 4 mg morning and evening, (ii) days 6-10, 2 mg morning and evening, and (iii) days 11-15, 1mg morning and evening.', 'interventionNames': ['Drug: Dexamethasone Oral Tablet', 'Other: Sham Injection and/or oral placebo']}
- {'label': 'Arm 4', 'type': 'OTHER', 'description': 'Sham Injection and/or oral placebo: CT/fluoroscopic guided (parameters set to zero) transforaminal lumbar sham (needle placement down to muscle and no injection of any fluid) AND placebo oral tablets taper.', 'interventionNames': ['Other: Sham Injection and/or oral placebo']}

Interventions:
- {'type': 'DRUG', 'name': 'Betamethasone OR Dexamethasone Injectable', 'description': 'Procedural agents. The steroid and local anaesthetic preparation will be standardized to replicate current radiology interventional practices that use either particulate or non-particulate steroids. Betamethasone Sodium Phosphate/Acetate 5.7 mg/ml Injectable is a particulate corticosteroid and is used with the local anaesthetic bupivacaine 0.5% (1ml). Dexamethasone 4mg (1ml) is a non-particulate corticosteroid and is used with the local anaesthetic lignocaine 1% (1ml).', 'armGroupLabels': ['Arm 1'], 'otherNames': ['celestone chondrase 5.7 mg/ml injectable suspension']}
- {'type': 'DRUG', 'name': 'Normal Saline Flush, 0.9% Injectable Solution', 'description': 'Procedural agents. The local anaesthetic preparation used with the Normal Saline Flush, 0.9% Injectable Solution, will be standardized to replicate current radiology interventional practices: either local anaesthetic bupivacaine 0.5% (1ml) or local anaesthetic lignocaine 1% (1ml).', 'armGroupLabels': ['Arm 2'], 'otherNames': ['There is no other name.']}
- {'type': 'DRUG', 'name': 'Dexamethasone Oral Tablet', 'description': 'Dexamethasone Oral Tablet: 15 day taper dosing is: days 1-5 8mg (4mg bd) , days 6-10 4 mg (2mg bd), and days 11-15 2 mg (1mg bd). The dexamethasone is over-encapsulated in a gelatine capsule that is identical to the placebo capsule in appearance.', 'armGroupLabels': ['Arm 3'], 'otherNames': ['Dexmethsone']}
- {'type': 'OTHER', 'name': 'Sham Injection and/or oral placebo', 'description': 'The sham Injection procedure is needle placement down to muscle at the designated spinal level and no injection of any fluid. The oral placebo is a gelatine capsule packed with filler.', 'armGroupLabels': ['Arm 1', 'Arm 2', 'Arm 3', 'Arm 4'], 'otherNames': ['There is no other name']}

Primary Outcomes:
- {'measure': 'Oswestry Disability Index (ODI) version 2.0', 'description': 'ODI is a functional status measure specifically developed for disorders of the spine', 'timeFrame': '3 weeks'}

Please estimate the sample size based on the assumption: 
The statistical test used is the independent two-sample t-test with a two-tailed alpha of 0.05. The pilot study has 85% power, while the full-scale study aims for 90% power. A 20% dropout rate is considered for the full-scale study.
Sample size
        Most trials of subacute and chronic sciatica of a selective CT fluoroscopy TESI have a sample size of 30 participants per arm. The primary outcome in this pilot/feasibility study is the ODI at 3 weeks comparing epidural steroid and sham injection (arm 1Â vsÂ arm 4). With 15 participants per arm, there is 85% power to detect a difference of 17 ODI points between these two arms, given a SD of change of ODI of 15.1 points.31 Statistical test on which calculation is based is the independent two-sample t-test with a two-tailed alpha of 0.05 (Stata V.14). This is a total of 60 participants in this pilot/feasibility study. This is sufficient to evaluate feasibility of the study design, study conduct and determine sample size for a full-scale multicentre study. However, this ODI difference is a large unrealistic effect. The minimum clinically important difference in ODI scores in one study was 7.0 points,47 and an international consensus group found empirical evidence of 4 to 15 ODI points48 and recommended a cut-off value of 10 ODI points. In a full-scale study recruiting participants with acute sciatica of less than 4 weeksâ duration, an ODI difference of at least 10 ODI points is very reasonable. A sample size of 49 participants per arm wouldÂ provide 90% power to detect a minimum clinically important difference of 10 ODI points assuming a SD of 15.1 with a two-tailed alpha of 0.05 (Stata V.14). Allowing for 20% dropout (which at 3 weeks is unlikely but at 48 weeks is more likely), 236 participants wouldÂ be recruited, 59 to each arm. Although there are six possible comparisons in a four-arm trial, controlling for typeÂ 1 error rate is not needed when several different experimental arms are compared with the control.49 50 Therefore, no multiplicity adjustment is needed for (1) comparison Iâarm 1 versusÂ arm 4 (epidural steroid is superior to control), (2) comparison IIâarm 2 versusÂ arm 4 (epidural saline is superior to control) and (3) comparison IIIâarm 3 versusÂ arm 4 (oral steroid is superior to control). However, in order to proceed to comparison IV, arm 1 versusÂ arm 3 (epidural steroid is superior to oral steroids), we must first demonstrate that comparisons I and III were statistically significant, and there must be a typeÂ 1 error consideration.51 Furthermore, if the hypothesis is that oral steroid is non-inferior to epidural steroids, then the ignorable difference must also be prespecified. The pilot/feasibility study will provide data that will be helpful in determining these sample size calculations. The feasibility study will be informative regarding the estimated mean difference in this population, its SD and pattern of missing data at each of the study visits.