Table 1

Base-case model parameters

Tranexamic acid risk ratio treatment effect
 Head injury0.78Log normal (μ=−0.248, σ=0.1)CRASH-3 trial8
 Non-head injury1N/ACRASH-3 trial8
28 risk of death
 Head injury death (UK)0.061Beta (α=42, β=643)CRASH-3 trial8
 Head injury death (Pakistan)0.079Beta (α=165, β=1919)CRASH-3 trial8
 Non-head injury death (UK)0.018Beta (α=12, β=673)CRASH-3 trial8
 Non-head injury death (Pakistan)0.005Beta (α=11, β=2073)CRASH-3 trial8
Long-term standardised mortality ratios
 First year, postinjury4.00Normal (95% CI 3.27 to 4.90)McMillan12
 Beyond first year, postinjury2.26Normal (95% CI 1.84 to 2.77)McMillan12
 Good recovery0.894Beta (α=50, β=5.9)Ward Fuller15
 Moderate disability0.675Beta (α=30.5, β=14.7)Ward Fuller15
 Severe disability0.382Beta (α=10.9, β=17.7)Ward Fuller15
 Vegetative state−0.178Beta (α=16.1, β=−106.3)Ward Fuller15
 Average utility (weighted average of above disabilities)*0.75By component (based on above distributions for disabilities)ˆCalculated
Costs (UK)
 Tranexamic acid (full dose)£6.00N/ABNF18
 Sodium chloride£3.25N/ABNF18
 Needle and syringe£0.05N/ANICE20
 Hospital cost£4741Gamma (k=31.4, θ=0.43)†NHS Reference costs23/CRASH-3 trial8
 Monitoring costs (first year post, injury)£11 662By component (see online supplementary materials)Beecham et al 25 /
Lecky et al 26
 Monitoring costs (after first year, postinjury)£2505By component (see online supplementary materials)Lecky et al 26/expert opinion
Costs (Pakistan)
 Tranexamic acid (full dose)US$1.92N/ADrug information system19
 Sodium chlorideUS$0.46N/ADrug information system19
 Needle and syringeUS$0.20N/ADziekan et al 21
 Hospital costUS$92Gamma (k=21.8, θ=0.34)†WHO CHOICE24/CRASH-3 trial8
 Monitoring costsUS$0N/AExpert opinion
  • *Deterministic and probabilistic average utility values are estimated from a weighted average of CRASH-3 patients with good recovery (3094), moderate disability (1288), severe disability (677) and vegetative state (124).

  • †Gamma distribution for hospital length of stay (UK: 13.7 days, Pakistan: 7.4 days).

  • BNF, British National Formulary; N/A, not available; NHS, National Health Service; NICE, National Institute for Health and Care Excellence.