Here is the design of a clinical trial:

Official Title: The Effectiveness and Cost-effectiveness of Doin (Conduction Exercise) for Chronic Neck Pain: A Multi-center Randomized Controlled Trial

Included conditions:
- Chronic Neck Pain

Study Armgroups:
- {'label': 'Doin with Acupuncture', 'type': 'EXPERIMENTAL', 'description': 'An acupuncture physician will administer acupuncture at a total 6-12 acupoints in the upper and middle trapezius areas (mandatory points: both SI15, TE15, and LI16; and selective points: GB20, BL10, GV14, SI14, and Hyeopcheok (Huatuo Jiaji, EX B2) points at C3-5 levels). Cervical Doin (conduction exercise) will be performed with the needles in situ by increasing the cervical range of motion (rotation) with physician guidance and isometric resistance exercise as indicated.', 'interventionNames': ['Procedure: Doin with acupuncture', 'Device: Acupuncture']}
- {'label': 'Acupuncture', 'type': 'ACTIVE_COMPARATOR', 'description': 'An acupuncture physician will administer acupuncture at a total 6-12 acupoints in the upper and middle trapezius areas (mandatory points: both SI15, TE15, and LI16; and selective points: GB20, BL10, GV14, SI14, and Hyeopcheok (Huatuo Jiaji, EX B2) points at C3-5 levels).', 'interventionNames': ['Device: Acupuncture']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'Doin with acupuncture', 'description': 'Doin (conduction exercise) will be performed with the needles in situ by increasing the cervical range of motion (rotation) with physician guidance and isometric resistance exercise as indicated. Doin sessions will be conducted 2 times a week for 5 weeks (total 10 sessions).', 'armGroupLabels': ['Doin with Acupuncture'], 'otherNames': ['Doin Exercise with acupuncture', 'Do-in Exercise with acupuncture', 'Conduction Exercise with acupuncture']}
- {'type': 'DEVICE', 'name': 'Acupuncture', 'description': 'Acupuncture will be performed with manual stimulation (needle twirling) to evoke de-qi sensation. Acupuncture sessions will be conducted 2 times a week for 5 weeks (total 10 sessions).', 'armGroupLabels': ['Acupuncture', 'Doin with Acupuncture']}

Primary Outcomes:
- {'measure': 'Difference between visual analogue scale (VAS) of neck pain for the past 3 days at 5 weeks post-baseline and baseline', 'description': "VAS uses a 10cm line labeled at each end with scale anchors. In pain measurement using VAS, patients are asked to mark a point that represents their pain between the anchors of 'no pain' and 'worst pain possible' (labels may vary by study). Scores are recorded in millimeters with a total range of 0-100 millimeters.", 'timeFrame': 'Week 5 post-baseline (screening)'}

Please estimate the sample size based on the assumption: 
Level of significance, α=0.05; type II error (β) set to 0.2, with power set to 80%. The correlation coefficient (CC) between the baseline value and the mean difference value is approximately 0.24. Considering a 20% dropout rate.
Sample size estimation
        In order to estimate the number of eligible patients, we used the results of unpublished data from a pilot study with the following assumptions: level of significance, Î±=0.05; type II error (Î²) set to 0.2, with power set to 80%. According to unpublished data from a pilot study using VAS as the main evaluation tool for acupuncture with Doin therapy in neck pain patients, the effect size in comparison to that of controls was 0.55 based on 80% compliance (predicted rate of completingÂ >6 sessions during the 5-week treatment period); sample size was calculated using G*Power 3.1.7. The effect size resulting from a sample size of 106 participants (53 in each group) was calculated. In this study, analysis of covariance (ANCOVA), which adjusts the baseline pain scores, is the main analysis. Thus, in the preliminary study, the correlation coefficient (CC) between the baseline value and the mean difference value is approximately 0.24, and adjusting this with 1âCC2 and considering 20% dropout rate the appropriate sample size for this study will be 124.36