Table 1

Input parameters to simulation model in baseline scenario

ParameterResourcesValue in baseline scenarioDistribution typeData sources
Referral rate100 patients/monthPoissonExpert opinion
Group induction (one group session per week)Nurse
Physician Surgeon
Up to 20 patients/weekExisting data
Following group induction
 Patient assessment93%BernoulliExisting
 Do not continue7%BernoulliData
Patient assessment (once a week)NurseUp to 20 patients/week
Following patient assessment
 Lifestyle clinic5%BernoulliExisting
 Pharmacotherapy clinic16%BernoulliData
 Eligibility for surgery clinic79%Bernoulli
Lifestyle clinic (two group sessions per week)DieticianUp to 8 patients/weekExisting data
 Six separate appointments/patient
 Time period between appointments20 working days (1 month)TriangularExpert opinion
Pharmacotherapy clinic (once a week)PhysicianUp to 14 patients/ weekExisting data
Following PharmacotherapyExpert
 Receive drugs (drug A)84% success rateBernoulliopinion
 Receive drug B (if drug A fails)80% success rateBernoulli
 Time period for second appointment90 days (3 months)Triangular
 Time period for third appointment120 days (6 months)Triangular
 If drugs A and B fail,Expert
 Referral to surgery15%BernoulliOpinion
 Referral to lifestyle clinic10%Bernoulli
Eligibility clinic (outpatients)Physician PsychiatristUp to 10 patients/weekExisting data
Following Eligibility clinicExisting
 Decision clinic (surgery)60%Data
 Psychiatric review30%
 DNA surgery10%
Decision (for surgery) clinicSurgeon Dietician8 patients/weekExisting data
Preassessment clinic (2 weeks before the scheduled operation)Anaesthetist Nurse8 patients/weekExisting data
Operations (three types of surgical procedures)Surgeon
3 half day theatre lists/weekExisting data
 Gastric band (1 h procedure)19%Bernoulli
 Sleeve gastrectomy (1.5 h)22%Bernoulli
 Gastric bypass (2 h)59%Bernoulli
Postoperative length of stay followingBedsDepending on type of surgeryExpert opinion
 Gastric band1 day
 Sleeve gastrectomy2 days
 Gastric bypass2 days