Table 1 Model input parameters

Individual characteristics

Age (years)

Individual-level data

Mean = 18.90

U@Uni RCT

SD = 2.49

Gender

Individual-level data

42% Male

58% Female

Fruit and vegetables (portions per day)

Individual-level data

Mean = 6.52

SD = 4.94

Alcohol (units per week)

Individual-level data

Mean = 11.51

SD = 18.62

Physical activity (minutes per week)

Individual-level data

Mean = 163.35

SD = 121.74

Smoking status

Individual-level data

12% Smoker

88% Non-smoker

Costs

U@Uni cost (full development)

Lognormal

Mean ln(cost) = 12.2763

Costing analysis

SD ln(cost) = 0.0513

U@Uni cost (roll-out)

Lognormal

Mean ln(cost) = 10.3349

Costing analysis

SD ln(cost) = 0.0663

Intervention effect regression coefficients

β₀ Fruit and vegetables: constant

Multivariate normal (see section C of Additional file 1 for covariance matrix)

Mean = 3.0095

U@Uni RCT

β₁ Fruit and vegetables: baseline behaviour coefficient

Mean = 0.2482

β₂ Fruit and vegetables: age coefficient

Mean = 0.0586

β₃ Fruit and vegetables: gender coefficient (1 = male; 0 = female)

Mean = -0.0252

β₄ Fruit and vegetables: intervention coefficient (i.e. mean effect of U@Uni on portions of fruit and vegetables per day compared to control)

Mean = -0.1116

ϵ Fruit and vegetables: residual

Normal

Mean = -3.18 × 10^-09

U@Uni RCT

SD = 4.8973

β₀ Alcohol: constant

Multivariate normal (see section C of Additional file 1 for covariance matrix)

Mean = 18.9219

U@Uni RCT

β₁ Alcohol: baseline behaviour coefficient

Mean = 0.4834

β₂ Alcohol: age coefficient

Mean = -0.5772

β₃ Alcohol: gender coefficient (1 = male; 0 = female)

Mean = -0.4252

β₄ Alcohol: intervention coefficient (i.e. mean effect of U@Uni on units of alcohol per week compared to control)

Mean = -0.4275

ϵ Alcohol: residual

Normal

Mean = 1.85 × 10^-08

U@Uni RCT

SD = 19.9055

β₀ Physical activity: constant

Multivariate normal (see section C of Additional file 1 for covariance matrix)

Mean = 161.3326

U@Uni RCT

β₁Physical activity: baseline behaviour coefficient

Mean = 0.2339

β₂ Physical activity: age coefficient

Mean = -2.7763

β₃ Physical activity: gender coefficient (1 = male; 0 = female)

Mean = -2.0189

β₄ Physical activity: intervention coefficient (i.e. mean effect of U@Uni on minutes of physical activity per week compared to control)

Mean = 4.0141

ϵ Physical activity: individual residual

Normal

Mean = -1.38 × 10^-07

U@Uni RCT

SD = 106.0016

Probability smokers quit smoking (U@Uni)

Beta

α = 27

U@Uni RCT

β = 33

Probability non-smokers start smoking (U@Uni)

Beta

α = 14

U@Uni RCT

β = 466

Probability smokers quit smoking (do nothing)

Beta

α = 19

U@Uni RCT

β = 45

Probability non-smokers start smoking (do nothing)

Beta

α = 27

U@Uni RCT

β = 462

Lag effects (years until full effect of behaviour change on mortality risk)

Fruit and vegetables lag

Lognormal

Mean = 2.7438

Expert elicitation

SD = 0.1247

Alcohol lag

Gamma

α = 1.3541

Expert elicitation

β = 0.6537

Physical activity lag

Normal

Mean = 5.5000

Expert elicitation

SD = 1.4642

Smoking lag

Normal

Mean = 5.5000

Expert elicitation

SD = 1.1110

Distribution of individual-level duration of U@Uni behavioural effect (years)**

Mean duration

Beta

α = 1.8179

Expert elicitation

β = 0.1304

Scale = 4.5000

Standard deviation of duration

Beta

α = 2.9109

Expert elicitation

β = 0.2691

Scale = 3.3800

Hazard ratios for effect of health behaviours on mortality risk

Fruit and vegetable consumption

Lognormal

Mean = 0.0953

Kvaavik et al. (2010) [11]

SD = 0.0673

Alcohol consumption

Lognormal

Mean = 0.1655

Kvaavik et al. (2010) [11]

SD = 0.0840

Physical activity

Lognormal

Mean = 0.3577

Kvaavik et al. (2010) [11]

SD = 0.0641

Smoking status

Lognormal

Mean = 0.3577

Kvaavik et al. (2010) [11]

SD = 0.0873

Utility ordinary least squares regression model coefficients

β₀ Constant

Multivariate normal (see section F of Additional file 1 for covariance matrix)

Mean = 0.9490

Analysis of Health Survey for England 2008 [1]

β₁ Age coefficient

Mean = -0.0038

β₂ Gender (1 = male; 0 = female) coefficient

Mean = 0.0142

β₃ Fruit and vegetables (portions per day) coefficient

Mean = 0.0207

β₄ Alcohol (units per week) coefficient

Mean = 0.0016

β₅ Smoke (smoker = 1; non-smoker = 2) coefficient

Mean = -0.0541

β₆ Physical activity (minutes per week) coefficient

Mean = 0.0002

β₇ Age²

Mean = -4.31 × 10^-06

β₈ Fruit and vegetables²

Mean = -0.0033

β₉ Fruit and vegetables³

Mean = 0.0001

β₁₀ Alcohol²

Mean = -2.77 × 10^-05

β₁₁ Alcohol³

Mean = 6.45 × 10^-08

β₁₂ Physical activity²

Mean = -2.59 × 10^-07

β₁₃ Physical activity³

Mean = 4.88 × 10^-11

β₁₄ Age*Fruit and vegetables β₀ interaction

Mean = 4.94 × 10^-05

β₁₅ Age*Alcohol interaction

Mean = 1.61 × 10^-05

β₁₆ Age*Physical activity

Mean = 2.47 × 10^-06