Table 6.

Parameter distributions used in the probabilistic sensitivity analysis (PSA)

Parameter		Distribution
Probability of quitting at 6 months in the control group	0.049(SE: 0.4)	Beta	α = 1.28, Β = 26.75
RR of quitting at 6 month with T2S	2.20 (95 % CI 1.8–2.68)	Lognormal	Ln (SD) = −1.49, Ln (mean) = 0.98
Relapse rate after 1 year	0.30 (SE: 0.13)	Beta	α = 3.43, Β = 8
Health state values	Smoker 0.76 (SD: 0.12) Former smoker 0.78 (SD: 0.12) Stroke 0.58 (SD: 0.12) CHD 0.48 (SD: 0.12) Lung cancer: 0.80 (SD: 0.12) MI: 0.80 (SD: 0.12) COPD: 0.73 (SD: 0.12)	Beta	Smoker α = 153.27, Β = 48.40 Former smoker α = 82.88, Β = 23.38 Stroke α = 156.41, Β = 113.26 Lung cancer α = 141.42, Β = 35.36 MI α = 141.42, Β = 35.36 COPD α = 159.14, Β = 58.86 CHD α = 7.84, Β = 8.49
Baseline quit rate	0.01 (SE: 0.004)	Beta	α = 6.18, Β = 611.57
Unit cost of text-based intervention	£17.80 (SE: 25.49)	Gamma	α = 0.49, Β = 36.50
Unit cost of smoking-related disease	Lung cancer: £5,921 Stroke: £2,218 CHD: £1,144 MI: £2,341 COPD: £997	Gamma	Lung cancer α = 8.82, Β = 623.52 Stroke α = 1.24, Β = 166.19 CHD α = 0.33, Β = 3.226 MI α = 1.38, Β = 3.704 COPD α = 0.25, Β = 3.704