The researchers classified shift workers as people working in an industry with at least 40% shift workers (the exposed group).
This led the IARC to classify shift work in category two on the list of causes of cancer, that is, as a 'probable causative link'.
In 2007 IARC classified shift work, in particular night work, as being group 2A for breast cancer (Straif et al, 2007).
In 2007, IARC classified shift work, especially night work, as a group 2A probable human carcinogen, causing female breast cancer (Straif et al, 2007).
The research on the shift work/cancer relationship is not conclusive, but it was enough for the International Agency for Research on Cancer IARCC) to classify shift work as a probable human carcinogen in 2007.
We classified shift work schedules according to the original study methodological descriptions as evening, night, rotating, mixed, and irregular or unspecified (see extra table A for individual study level definitions).
The International Agency for Research on Cancer has classified shift work involving disruption of circadian rhythm as a probable carcinogen (1) on the basis of sufficient experimental evidence in animals and limited evidence in humans, primarily for risk of breast cancer.
If the mean F0 of the 10 trials immediately preceding the Mismatch stage fell within the baseline 95% CI, the participant was classified as 'no shift'; if the F0 was outside the 95% CI, the participant was classified as 'up' if it was higher and 'down' if it was lower.
Moreover, what are counted as standard cases may vary with the purposes operative in attempting to classify, and may shift as new cases come to be counted as of a specific type.[13] It's important here to separate two questions.
