Here is the design of a clinical trial:

Official Title: Randomized, Double-Blinded, Oseltamivir-and-Placebo-Controlled Clinical Study About Lingdancao Granules in the Treatment of Seasonal Influenza

Included conditions:
- Influenza

Study Armgroups:
- {'label': 'Drugs for experimental group', 'type': 'EXPERIMENTAL', 'description': 'Lingdancao granules, 4 packs per time (3g/pack), three times per day; analogous oseltamivir phosphate capsule, 1 capsule per time, twice per day.Drugs must be used on the day of fever and last for five days continuously.', 'interventionNames': ['Drug: Lingdancao granules', 'Drug: analogous oseltamivir phosphate capsule']}
- {'label': 'Drugs for positive control group', 'type': 'ACTIVE_COMPARATOR', 'description': 'Oseltamivir phosphate capsule (tamiflu), 1 capsule per time (75mg), twice per day; analogous Lingdancao granules, 4 packs per time, three times per day.Drugs must be used on the day of fever and last for five days continuously.', 'interventionNames': ['Drug: Oseltamivir phosphate capsule', 'Drug: analogous Lingdancao granules']}
- {'label': 'Drugs for placebo control group', 'type': 'PLACEBO_COMPARATOR', 'description': 'Analogous Lingdancao granules, 4 packs per time, three times per day, analogous oseltamivir phosphate capsule, 1 capsule per time, twice per day.Drugs must be used on the day of fever and last for five days continuously.', 'interventionNames': ['Drug: analogous oseltamivir phosphate capsule', 'Drug: analogous Lingdancao granules']}

Interventions:
- {'type': 'DRUG', 'name': 'Lingdancao granules', 'description': '4 packs per time (3g/pack), three times per day', 'armGroupLabels': ['Drugs for experimental group'], 'otherNames': ['Lingdancao granules,z53021634']}
- {'type': 'DRUG', 'name': 'analogous oseltamivir phosphate capsule', 'description': '1 capsule per time, twice per day', 'armGroupLabels': ['Drugs for experimental group', 'Drugs for placebo control group'], 'otherNames': ['analogous oseltamivir phosphate capsule,0221503013']}
- {'type': 'DRUG', 'name': 'Oseltamivir phosphate capsule', 'description': '1 capsule per time (75mg), twice per day', 'armGroupLabels': ['Drugs for positive control group'], 'otherNames': ['tamiflu,0221503013']}
- {'type': 'DRUG', 'name': 'analogous Lingdancao granules', 'description': '4 packs per time, three times per day', 'armGroupLabels': ['Drugs for placebo control group', 'Drugs for positive control group'], 'otherNames': ['analogous Lingdancao granules,z53021634']}

Primary Outcomes:
- {'measure': 'The time needed for alleviation of all influenza symptoms', 'description': 'fever,nasal obstruction, running nose, sore throat, cough, myalgia, fatigue, headache, aversion to cold and sweating', 'timeFrame': 'Up to 30 days'}

Please estimate the sample size based on the assumption: 
Significance level (alpha) is 0.05, power is 0.80, and an expansion rate of 20% to account for dropouts.
Sample size calculation
        Eligible subjects, aged 14â65 years will be accepted. Recommendations from WHO for influenza-like illnesses (ILIs) were used as the basis for influenza surveillance. If a patient presents with an acute cough and fever, clinicians must be highly vigilant to test for infections caused by the influenza virus. In general, the rate of ILI cases that lead to a clinical diagnosis of influenza infection is approximately 18%â80%, which is higher than other clinical diagnoses, for example, acute infections of the upper respiratory tract.27 33 We selected adult patients with ILI for inclusion into the study.
        Furthermore, this trial is a confirmatory study on the treatment of influenza by CLD granules. The patients will be randomly assigned in three groups: positive group, test group and placebo group. In this trial, the number of sample cases was estimated based on the test hypothesis that the test group was superior to the placebo group and the test group was not inferior to the positive control group.
        The main index of treatment effectiveness is the period of time until subsidence of symptoms (hours). It has been reported that the average period of time for remission of these symptoms in the placebo group was about 5 days (120âhours).32 This trial requires that the average time for symptomatic remission of the test group should be at least 12âhours shorter than the placebo group, it means the permissible error (Î´) of the superiority trial is 12âhours. In order to be considered clinically significant, the mean time for symptomatic remission in the positive group must <12âhours compared with the placebo group, which means Î´ of the superiority trial is within 12âhours (table 6).
        
          Table 6
          
            The average time for symptom relief
          
          
            
              
                Group
                Average time for symptom relief (hours)
                SD
              
            
            
              
                Positive
                96
                50
              
              
                Test
                108
                50
              
              
                Placebo
                120
                50
              
            
          
        
        Based on the above data, the SAS Software was used to estimate the sample size required for âone-way analysis of varianceâ. The calculation result is designed for three parallel groups (table 7).
        
          Table 7
          
            The calculation of sample size
          
          
            
              
                Power
                Alpha
                Cases/group
                Expand 20%
                Total cases
              
            
            
              
                0.80
                0.05
                85
                106
                318
              
            
          
        
        For achieving adequate participant enrolment, patients are recruited for clinical trials mainly through local advertising. And each participant will receive financial compensation after they finish the entire treatment. For patients who drop out, payments will be prorated for the length of time they stayed in the study, but payment will not be made until the study would have been completed.