Table 1 Key inputs in the model

 Prevalence of CHI^b

0.003%

Estimated scope of the national CHI service (NHS England CHI Service Standard Contract, 2013) [4]

 Number of newly diagnosed patients with CHI per year^a,b

95

Expert opinion (GOSH, 2015; NORCHI, 2016) [19, 30]

 Maximum age of patients that have received a near-total pancreatectomy^b

54

Harold N. Lovvorn III, 1999 [23]

 Daily cost of inpatient care at local hospital (excess)^a

£486.62

NHS Reference Costs (2015–16) [20]

 Daily cost of inpatient care at specialist centre (excess)^a

£486.62

NHS Reference Costs (2015–16) [20]

 Daily cost of neonatal care (excess)^a

£274.11

NHS Reference Costs (2015–16) [20]

 Cost of inpatient care, per non-elective long stay at local hospital^a

£2186.61

NHS Reference Costs (2015–16) [20]

 Annual cost of paediatric outpatient diabetes care^b

£2925.00

NHS National Tariff (2014–15) [31]

 Total annual cost of IDDM for patients managed by multiple daily insulin injections (including severe and non-severe events)^b

£2183.00

Evans, 2015 (2013)* [32]

 Cost of insertion of central venous catheter (Hickman line)^a

£5925.98

NHS Reference Costs (2015–16) [20]

 Proportion of CHI patients responsive to first line therapy at local hospital^a,b

75%

Expert opinion (NORCHI, 2016) [13]

 Proportion of IDDM patients managed by multiple daily injections^b

90%

Expert opinion (GOSH and NORCHI, 2016) [13, 19]

 Incidence of IDDM at 11 years post near-total pancreatectomy^b

96%

Arya, 2014 [15]

 Proportion of CHI patients with diffuse disease responsive to octreotide^b

30%

Expert opinion (NORCHI, 2016) [13]

 Number of days until discharge from hospital following successful first-line therapy^a,b

14

Expert opinion (GOSH and NORCHI, 2016) [13, 19]

 Number of days to assess response to medical treatment in neonatal care^a

10

Expert opinion (GOSH, 2016) [19]

 Number of days from octreotide non-response until surgery^a

21

Expert opinion (NORCHI), 2016 [30]