Skip to main content

Table 1 Key model input parameters

From: Lifetime cost-effectiveness and equity impacts of the Healthy Primary School of the Future initiative

Input parameters Mean value 95% CI Distribution (se) Data source and assumptions e
Population estimates Number of boys and girls aged 4 until 12 years of age    CBS Statline.
Intervention effect estimate     Bartelink et al. (2019)
Relative effect after 2 years of intervention in children aged 4–12 years BMI z-score    Assumption: full effect maintenance over lifetime a
HPSF: −0.083 [−0.15;-0.02] Gamma (0.08)
PAS: −0.066 [−0,13;-0.00] Gamma (0.09)  
BMI (standard deviation 2.55 kg/m2)    
HPSF: −0.21 [− 0.38;-0.05] Gamma (0.08)
PAS: −0.17 [−0.33;-0.00] Gamma (0.09)
SES-specific 2-year relative effects BMI z-score    Bartelink et al. (2019). Converted to BMI effects with standard deviation of 2.55 (based on the study sample at baseline).
HPSF vs control   
low SES: −0.103 [−0.22;-0.02] Gamma (0.16)
middle SES: −0.049 [−0.16;-0.06] Gamma (0.14)
high SES: −0.063 [−0.18;-0.05] Gamma(0.15)
PAS vs control   
low SES: −0.067 [− 0.18;-0.05] Gamma (0.15)
middle SES: −0.056 [−0.18;-0.06] Gamma (0.16)
high SES: −0.051 [−0.16;-0.06] Gamma (0.14)
Effect maintenance scenarios     Oosterhoff et al. (2020)
1.Constant- and decreasing effects after primary school
Maintenance factor uncontrolled environment
HPSF: 0.22 [0.04;0.39] Lognormal (0.09)  
PAS: 0.22 [0.06;0.37] Lognormal (0.08)  
2. Increasing- and decreasing effects after primary school
Relative BMI effect with household multiplier
    
HPSF: −0.30 [−0.42;-0.18] Gamma(0.06)
PAS: −0.19 [−0.27;-0.12] Gamma (0.04)
3. Increasing effects
Maintenance factor household maintainer
    
HPSF: 1.67 [1.48;1.85] Lognormal (0.09)
PAS: 1.10 [1.01;1.19] Lognormal (0.05)
Intervention cost estimate     Oosterhoff et al. (2019)
Net intervention costs, societal perspectiveb HPSF: €153 per year (€0.96 per day) (2016)   Fixed  
PAS: €346 per year (€2.16 per day) (2016)   Fixed  
Net intervention costs, healthcare perspective b HPSF: €715 per year (€4.47 per day) (2016)   Fixed  
Childhood and adolescence     
Weight status     
Cut-off values of overweight and obesity (kg/m2)    Fixed Cole et al. (2000)
BMI distribution Dutch children Age and sex-specific values for skewness and variation    Schönbeck et al. (2011)
Health-related quality of life     
Utility weights Normal weight: 0.85 [0.84;0.87] Beta (0.01) Brown et al. (2018)
  Overweight: 0.83 [0.81;0.85] Beta (0.01)  
  Obesity: 0.82 [0.79;0.84] Beta (0.01)  
Health resource use     
Average number of GP visits / year 59.6% children visiting GP * 6.7 visits / year   Fixed Statline (n.d.)
Average number of specialist visits / year 27.0% children visiting GP * 9.7 visits / year   Fixed Statline (n.d.)
Ratio of HC costs for overweight vs. normal weight 1   Fixed Gortmaker et al. [based on Table A.3.2]
Ratio of HC costs for obesity vs. normal weight 1.22 [1.21;1.22] Lognormal (0.00)  
Cost price per GP visit b €34   Fixed Zorginstituut Nederland (2015)
Cost price per specialist visit b €94   Fixed Zorginstituut Nederland (2015)
School absenteeism     
Median number of school absenteeism days / year c 5.0   Gamma (3.26) Additional analysis based on data collection as described by Willeboordse et al. (2016)
Ratio of absenteeism for overweight vs. normal weight 1.27 [1.03;1.56] Lognormal (0.14) An et al. (2017)
Ratio of absenteeism for obesity vs. normal weight 1.54 [1.33;1.78] Lognormal (0.11)  
Cost price per school absenteeism day b €27   Fixed Drost et al. (2014)
Adulthood     
Weight status a Normal weight, overweight, obesity   Log-odds Fifth Dutch Growth Study. Schönbeck et al. (2009)
Chronic diseases d Obesity related diseases: acute myocardial infarction, coronary heart disease, stroke, renal, colorectal, breast, prostate, and endometrium cancer, diabetes mellitus, hip, knee arthritis, and low back pain.
Indirect-related diseases: Chronic obstructive pulmonary disease, lung, stomach, esophagus, larynx, bladder, pancreas, and oral cavity cancer
  Prevalence: log-oddsIncidence: lognormal RIVM Chronic Disease Model.
Hoogenveen et al. (2010), van Baal et al. (2006)
Adulthood     
Health-related quality of life     
Utility weights (for chronic disease)    Fixed Dutch Burden of Disease Study. Melse et al. (2000)
Health resource use & unit costs     
Disease healthcare costs    Fixed Dutch Cost of Illness Study. Slobbe et al. (2006)
Productivity costs     
Sick leave days Overweight women: 3.64   Fixed Lehnert et al. (2014)
Overweight men: 0  
Obese women: 5.19  
Obese men: 3.48  
Net labour participation 72.2%   Fixed CBS Statline (2017)
Working hours per week 31.4 (6.28 per day / 5 days a week)   Fixed CBS Statline (2017)
Productivity costs / hour b €36   Fixed Zorginstituut Nederland (2015)
  1. Notes: BMI z-score Body mass index standardized score, CI Confidence interval, GP General practitioner, HC Healthcare, HPSF The Healthy Primary School of the Future, HRQOL Health-related quality of life, PAS The Physical Activity School, QALY Quality-adjusted life year
  2. a In the adulthood model, the uncertainty of the intervention effect was incorporated by including the overweight and obesity prevalence rates at young adulthood as probabilistic parameters. This uncertainty parameter reflected the boundaries of the 95% confidence interval of the intervention effect on BMI. The overweight and obesity prevalence rates at 20 years of age were included as multivariate normal distributions with a perfect correlation
  3. b Updated to 2018 prices
  4. c The analysis was based on crossectional data (baseline year). Regression analysis with a Poisson distribution was used to reflect the count data. The effect of weight status (normal weight [reference level], overweight and obesity) on school absenteeism days was analysed. Analysis were additionally adjusted for sex, grade, school type, socioeconomic status and ethnicity
  5. d We used coupled sets of random draws for the prevalence, incidence and mortality for the chronic diseases in the probabilistic sensitivity analysis
  6. e References can be found in Additional File 3