CASE-CONTROL STUDY
TOBACCO OVERVIEW OF RISK

This website has been established for the purposes of providing public access to the paper resulting from a European case control study for lung cancer and smoking, called the “Case-Control Study – Tobacco Overview of Risk (C-TOR)”. C-TOR was designed as a multi-centre, epidemiological study with its focus on determining if there is a significant difference in the risk of developing lung cancer associated with smoking cigarettes with different tar levels.

The reasons for creating this website are the following:

• A commitment was made to those involved (e.g., independent ethics committees and investigators) in the study that the findings would be published.
• There have been four unsuccessful attempts to have the findings published in traditional journals.
• There are no other significant studies which address the potential impact of the tar content in ultra-low tar cigarettes.
• The experts engaged in the analysis and drafting of the paper believe that findings and, where appropriate, the data from this large and important study should be made available.

The website provides a route for researchers in the field to gain access to the data set and the Statistical Analysis Plan (SAP) on which the paper was based. This data set has been anonymised in order to protect the personal data of those that took part in the study.

The website contains the following elements:

• The paper: An Epidemiologic Study of the Impact of Cigarette Tar Yield on the Risk of Lung Cancer
• A copy of the original 2005 protocol on which basis the study was initiated
• An explanatory page summarising the key elements of the study background
• A study data request application form
• A description of the Life Event History Calendar (LEHC) CAPI technique and its use in this project
• A restricted section containing the study data and the final Statistical Analysis Plan

The study was financially sponsored by Philip Morris International (PMI). The company’s role was limited to financial support only. Neither PMI nor any of its affiliates or associate companies had any involvement in the data collection or its analyses. A condition of the contract related to the study was that PMI would not receive any advance information concerning the results and would only receive a copy of the final paper when it was submitted to a journal for publication.