Epi in the News

Good afternoon Sujit,
I´ll try to answer the question:
1. What kind of analysis was used to get these findings? What is the epidemiologic measure corresponding to "seven times more" and "three times higher"?
From what I have read:
- Observational cross sectional cohort study:
He analyses both the exposure and outcome and it seems like he is comparing the prevalence in that groupd to another (the expectec number)
He only analyses those who worked in the factory, and it is not clear to me if his reference was the population prevalence of cancer among people in the same town, or the state prevalence.
So, if this was the study design:
I think he used the prevalence ratio
7 times higher and 3 times higher, means that the probability of cancer in the asbesto factory workers was 7 times higher. It is the same as saying, the prevalence ratio was 7-fold higher in the exposed group.
Thank you!

Good day, Sujit

Is this a retrospective cohort study with the incidence rate ratio as the measure of association?

Best
Amy

Hi Sujit,

My answers to the above questions are:

1. This is a retrospective cohort study. The incidence rates of different cancers among workers who had worked in the insulation factory (cohort group) have been compared with the general population rates (comparison group).

2. Cox regression analysis was used to get these findings after adjusting for confounding factors.

3. The epidemiologic measures used is hazard ratio (which can be interpreted as the incidence rate ratio).

Thank you!
Madhutandra

Hi all - The word 'expected' is what makes me think the analysis used standardization. That is, with a historic cohort of workers, compared against a reference population. And the measure will be an SMR.

Just my guess. -s