Proportion of eligible patients randomised, reasons for refusals

Demographic and clinical characteristics of screened and enrolled patients

Randomisation success

Whether interventions as stipulated in the protocol are adhered to

Whether blinding had been successfully implemented

Whether assessments are made with satisfactory follow-up rates

Inter-rater and intra-rater reliability of primary outcomes

Safety aspects

Feasibility of recruitment (sites and patients)

Patient eligibility—previous observational studies had predicted that 50% of patients would be eligible

Feasibility of the protocol, in particular the effectiveness of delivery of the cooling protocol

Evidence that adequate statistical power for the trial will be achieved based on a number of parameters, including: baseline HIV prevalence; HIV incidence

Evidence that adequate statistical power will be achieved based on various parameters, including: initial and repeated HIV testing uptake; antiretroviral therapy uptake; proportion of participants who know their HIV status and who disclose their HIV status; migration between and out of clusters

Evidence that adequate statistical power for the trial will be achieved based on a number of parameters, including extent of sexual partnerships with people outside trial setting

60% of patients referred for bariatric surgery to be eligible for the trial (if necessary, revising the eligibility criteria)

Initially, 30% and then 50% of patients consent to randomisation

<5% failure to receive allocated intervention

<15% lost to follow-up

Recruitment of ≥36 families who would be eligible for the main study

90% of patients randomised to Mandolean therapy would be successfully eating off the device at least five times a week

≥80% would attend the 3-month nurse appointment for both study groups

≥60% of those using Mandolean therapy would demonstrate a decrease in speed of meal consumption (longer meals) since baseline within 3 months of starting therapy

Recruitment of ≥30 patients in 6 months

Consent rate of ≥40%

≤20% failure to receive the alternative intervention

<50% of patients in injection group proceed to surgery

Recruitment of ≥68 participants in 95 days

Service provider (a national charity) should recruit, train and retain enough volunteers to deliver the telephone befriending service

Collect valid primary outcome data for 56 (80%) of those recruited at the 6 month follow-up

60 participants recruited

≥70% of those randomised to Booster interventions receive interventions per protocol

≥75% of those recruited to provide 3 months follow-up measures, including primary outcome measure

33 patients (10% of total target recruitment randomised in 6 months)

82 patients (25% of total sample size) recruited in 15 months

Patient willingness to be randomised

Surgeon willingness to randomise

Whether requiring surgical competence in both procedures limits recruitment

20 eligible patients screened per month

30% of eligible patients recruited initially, increasing to 50% within 6 months at each centre