Quality Assurance

Data Analysis Plan

As an important element of quality assurance it was decided to "freeze" the raw cohort data and to publish the analytical strategy before merging the exposure and outcome data and starting with the risk analysis. Publication of the data analysis plan before starting the analysis was endorsed by the Scientific Advisory Board and by the IARC Ethics Committee.

Raw cohort data
The study data files need to be preserved unaltered after the collection phase is completed and before the analysis phase starts. In order to prove the integrity of the data files, the files were aggregated in a single compressed file in .rar format and protected with a password. After that, the following SHA256 hash of the file was calculated:
Algorithm : SHA256
Hash : 2D55CF6BE6C383671AD6733EE04DB4F2FE446A40B2410884C3837B6B2377EAFA

The SHA256 hash is a one-way function that produces a fixed size text for any size of source data. It is not an encryption therefore the hash cannot be decrypted back to the original data. Consequently, it is safe to make the hash public.

If the <filename.rar> file containing the study data files remains unmodified, any future SHA256 hash calculation of the file should result in the same hash value.

The cohort data (demographic data of workers, vital status, follow-up, cause of death (if applicable)) and the exposure to dust data were preserved on 25.10.2019 producing the Hash shown above.

Data Analysis Plan
The Data Analysis Plan was made public on 11.12.2019, using the study′s website.

Download Data Analysis Plan.