Here is the design of a clinical trial:

Official Title: Diet or Additional Supplement to Increase Potassium Intake: An Adaptive Clinical Trial

Included conditions:
- Hypertension

Study Armgroups:
- {'label': 'Dietary Counselling', 'type': 'EXPERIMENTAL', 'description': 'All enrolled patients will undergo a 1:1 counselling with a registered dietitian (with possible inclusion of family members, as appropriate). The dietitian will undertake an assessment of the comorbidities (e.g. diabetes), dietary intake, dietary habits (e.g. eating out, food preparation, socio-cultural aspects) and provide an individually tailored strategy to increase potassium in the diet. Secondly, on a weekly basis, the dietitian will contact the patient by telephone, or electronically (as preferred by the patient) to reinforce the advice and provide support/advice as necessary.', 'interventionNames': ['Behavioral: Dietary Counselling']}
- {'label': 'Potassium Citrate Supplement', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients who are not able to successfully increase their potassium intake at 4 weeks with dietary counselling will receive potassium citrate supplements. They will receive oral potassium supplementation in the form of 50 to 100 mmol of potassium citrate (as 25 to 50 ml of the liquid solution).', 'interventionNames': ['Behavioral: Dietary Counselling', 'Drug: Potassium Citrate']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Dietary Counselling', 'description': 'Individually tailored strategy to increase potassium in the diet.', 'armGroupLabels': ['Dietary Counselling', 'Potassium Citrate Supplement']}
- {'type': 'DRUG', 'name': 'Potassium Citrate', 'description': 'Dosing of 50 to 100 mmol of potassium citrate per day (as 25 to 50 ml of the liquid solution).', 'armGroupLabels': ['Potassium Citrate Supplement'], 'otherNames': ['K-Citra']}

Primary Outcomes:
- {'measure': 'Successful increase in potassium intake', 'description': 'As estimated by 24 hour urine results at 4 weeks, achieving a urinary sodium \\> 90 mmol/day.', 'timeFrame': '4 weeks'}

Please estimate the sample size based on the assumption: 
Significance level: p < 0.05 for paired comparisons of continuous outcomes. Power: Not explicitly stated. Missing/dropout rate: Estimated at 20%. No interim analysis planned. Multiple imputation for missing data.
Sample size and analytical plan
        The study goal is to estimate the success rate of the dietary intervention, as well as the success rate of the two-stage approach. Dietary counselling alone will not exceed this degree of increase which was seen with supervised intake and meal provision, but there are no robust data to support an estimate of its effect. However, potassium supplementation at the dose proposed would very likely result in achieved potassium intake of >â90âmmol/day in all participants. A sample size of 100 participants will allow us to able to estimate both success rates to within a margin of error of at most 5%. At 4âweeks, there should be little loss to follow-up; however, we estimate this to be about 20% to be conservative. Thus, this trial will enrol 120 participants. Furthermore, there are no plans for additional analyses including subgroup. Multiple imputation will be done for any missing data.
        The primary outcome is a simple proportion of the participants who are able to achieve an increase in potassium intake. Secondary outcomes of the proportion of participants with persistent adequate potassium intake at 52âweeks, and safety outcomes, will also be reported as proportions. For the secondary outcomes of change in sodium, potassium, and blood pressure, the mean differences will be calculated and reported, and a paired t-test will be used to compare for statistical significance. There will be no interim analysis.
        The proportions will be summarized as absolute numbers and percentages. Continuous outcomes will be reported as mean (and 95% confidence intervals). A p value of <â0.05 will be used for the paired comparisons of the continuous outcomes (i.e. secondary outcomes of change in sodium, potassium and blood pressure).