Miquel Serra-Burriel, Matthew Keys, Maria Pellisé, Ariadna Sánchez, Francesc Balaguer, Antoni Castells, Center for Research in Health and Economics, UPF; Gastroenterology department, HCB

1. Miquel Serra-Burriel
Matthew Keys
Maria Pellisé
Ariadna Sánchez
Francesc Balaguer
Antoni Castells
On population-based organised
screening by FIT and colorectal
cancer mortality: a natural experiment
Center for Research in Health and Economics UPF
Gastroenterology department HCB
1

2. • Type of study: Natural experiment 1999-2016, ISRCTN11768442
• Objective: To evaluate the effects of population-based organized screening (PBOS)
adoption by FIT on CRC mortality of exposed before 2010 (n=11) vs non-exposed
(n=39) Spanish provinces
• Methods: difference-in-differences & generalized synthetic control
• Primary endpoint: Semiannual CRC-specific 1999 age-standardised mortality rates
(ASMR) (National Statistical Office of Spain) for the population aged 50-79
• Secondary endpoints: 50-69, all ages
• Subgroups analyses: by gender, region
• Placebo endpoints: 40-49 , >79, LC (Lung Cancer), IHD (Ischaemic Heart Disease),
STRK (Stroke), SC (Stomach Cancer), PC (Pancreatic Cancer), BC (Breast Cancer),
UTC (Urinary Tract Cancer), RF (Renal Failure), RI (Lower & Upper Respiratory
Infections), COPD (Chronic Obstructive Pulmonary Disease).
Study Design
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3. Setting
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Figure 1. Maps of Spain with spatial variation in semi-annual 50-79 CRC-
ASMR and implementation of PBOS
Abbreviations: CRC: colorectal cancer,
ASMR: age-standardised mortality rates.
Exposed: (N=11), n=3.824M
Non-exposed: (N=39), n=7.708M

4. Trends in outcomes
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Figure 2a. Evolution of 50 to 79 years-old semiannual ASMR, LOESS
smoothed average between exposed and non-exposed provinces

5. Trends in outcomes
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Figure 2b. Evolution of 50 to 79 years-old semiannual ASMR, LOESS
smoothed average between exposed and non-exposed provinces

6. Difference-in-differences
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Figure 3. Adjusted 50-79 ASMR differences-in-differences estimates,
lags and leads relative to implementation
PT holds

7. Generalised synthetic control
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Figure 4. Average effect of PBOS on 50-79 CRC-ASMR relative to
implementation with Generalised Synthetic Control

8. Placebo
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Figure 5a. Average treated trend with PBOS and estimated counterfactual
for semi-annual 50-79 ASMRs for 10 other major causes of death

9. Placebo
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Figure 5b. Average treated trend with PBOS and estimated counterfactual
for semi-annual 50-79 ASMRs for 10 other major causes of death

10. Placebo
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Figure 5c. Average treated trend with PBOS and estimated counterfactual
for semi-annual 50-79 ASMRs for 10 other major causes of death

11. 11
Figure S5.1.1. +79
CRC ASMR GSC
Figure S5.1.2. 40-49
CRC ASMR GSC
Placebo

12. Secondary endpoints
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Figure S4.1. Average effect of PBOS on 50-69 CRC-ASMR

13. Secondary endpoints
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Figure S3.0.1. Average effect of PBOS on 50-69 CRC-ASMR

14. Secondary endpoints
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Figure S4.2. Average effect of PBOS on all-ages CRC-ASMR

15. Secondary endpoints
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Figure S3.0.2. Average effect of PBOS on all-ages CRC-ASMR