Parameter | Value GA 23–27 weeks (95% CI; distribution) | Value GA 28–32 weeks (95% CI; distribution) | Source |

Effect of AM-PICC on the probability of LOI | |||

Relative risk of AM-PICC vs S-PICC | 1.06 (0.70 to 1.60; lognormal) | PREVAIL trial (subgroup of infants born ≤32 weeks GA). | |

Effect of LOI on NDI and death | |||

Relative risk of the effect of LOI on death at 6 months | 1 (fixed) | Assumed that LOI has no effect on death at 6 months in the base case. | |

OR for the effect of LOI on NDI at 2 years of age | 1.51 (1.33 to 1.70; lognormal) | Meta-analysis of Stoll et al2 and Schlapbach et al.24 | |

OR for the effect of LOI on death at 2 years of age | 2.74 (1.43 to 5.24; lognormal) | Meta-analysis of Schlapbach et al24 and Bassler et al.25 | |

Probabilities using S-PICC | |||

Probability of LOI | 0.14 (0.09 to 0.20; beta) | 0.04 (0.02 to 0.08; beta) | PREVAIL trial (subgroup of infants born ≤32 weeks GA). |

Probability of death between PICC insertion and 6 months | 0.20 (0.16 to 0.23; beta) | 0.03 (0.03 to 0.04; beta) | Santhakumaran et al.13 |

Probability of death between 6 months and 2 years | 0.02 (0.01 to 0.03; beta) | 0.01 (0.00 to 0.02; beta) | Mangham et al.12 Estimates refer to a population of infants with different LOI status and applied to the non-infected infants (see online supplementary material 1). |

Probability of developing NDI | 0.45 (0.42 to 0.49; dirichlet) | 0.26 (0.25 to 0.28; dirichlet) | Mangham et al.12 Estimates refer to a population of infants with different LOI status and applied to the non-infected infants. |

Distribution by NDI levels, given that NDI occurred | |||

Mild NDI | 0.54 (0.51 to 0.58; dirichlet) | 0.73 (0.70 to 0.76; dirichlet) | Mangham et al12 assumed to be similar for both sepsis and non-sepsis groups. Severe NDI calculated as the complement. |

Moderate NDI | 0.29 (0.28 to 0.30; dirichlet) | 0.16 (0.15 to 0.17; dirichlet) | |

Health-related quality of life (to calculate QALYs) | |||

No NDI | 0.96 (0.94 to 0.97; beta) | Petrou et al29 | |

Mild NDI decrement | 0.18 (0.14 to 0.31; gamma) | Petrou et al29 | |

Moderate NDI decrement | 0.30 (0.24 to 0.46; gamma) | Petrou et al29 | |

Severe NDI decrement | 0.56 (0.44 to 0.77; gamma) | Petrou et al29 | |

Costs | |||

Difference in cost between PICCs (AM-PICC vs S-PICC) | £53.70 | Personal communication from the manufacturer | |

Healthcare costs between PICC insertion and 6 months | £105 873.47 (101 444.99 to 110 495.27; gamma) | £62 255.37 (54 711.87 to 70 838.93; gamma) | PREVAIL trial and linked datasets (NNRD, PICANet, HES). |

Healthcare costs between 6 months and 2 years | £5989.17 (5989.14 to 5994.98) | £3026.17 (3026.43 to 3028.73) | NHS Reference Cost 15/1627 derived from HES inpatient, A&E and outpatient data. |

Annual costs between age 2 and 10 years | |||

No NDI | £388 (£285 to £509; gamma) | Petrou et al28 ; inflated to 2016 | |

Mild NDI | £753 (£584 to £946; gamma) | Petrou et al28; inflated to 2016 | |

Moderate NDI | £814 (£560 to £1063; gamma) | Petrou et al28; inflated to 2016 | |

Severe NDI | £1487 (£1096 to £1943; gamma) | Petrou et al28; inflated to 2016 | |

Annual costs after age 11 years | |||

No NDI | £686 (£440 to £993; gamma) | Petrou et al29: inflated to 2016 | |

Mild NDI | £987 (£782 to £1222; gamma) | Petrou et al29 ; inflated to 2016 | |

Moderate NDI | £1252 (£933 to 1624; gamma) | Petrou et al29 ; inflated to 2016 | |

Severe NDI | £1976 (£1411 to £2648; gamma) | Petrou et al29 ; inflated to 2016 |

GA, gestational age; HES, Hospital Episode Statistics; LOI, late-onset infection; NDI, neurodevelopmental impairment; NHS, National Health Service; NNRD, National Neonatal Research Database; PICANet, Paediatric Intensive Care Network; PICC, peripherally inserted central catheter; QALY, quality-adjusted life year.