 # Beta coefficient calculation

I’m curious about how beta coefficient is calculated.

1. Below is the beta calculator spreadsheet from an old training material for Bangkok(2015). The first screenshot shows how relative risk is calculated while the second one shows how beta is calculated.

These two formula suggest that relative risk=1+(excess risk/100) and that Beta=In(relative risk/ exposure change),correct?

This is where I got confused. Column E,K and L are values of relative risk( RR). However, the user manual(2015) states that beta is converted from odd ratio. Are we making some assumptions about these two terms while using benMAP?

1. I looked at the updated self-paced training materials and it looks like beta values in those seven cities are given to us now. Are they applicable to the whole region or just the given city?

Hi Tammy,

1. That spreadsheet was designed to calculate a beta coefficient from either a relative risk or a percentage risk. You’re correct that the beta is generally calculated as a natural log of the relative risk (or an odds ratio) divided by the unit change in exposure.
2. Which 7 cities are you referring to? Can you tell me which of the self-paced training guides you’re referring to?

Thanks,
Neal_

Hi Neal,

1.Thank you so much for clearing up the confusion! I appreciate it.

1. I was referring to the newly added self paced training materials shown below.
I apologize for not being accurate. Some of the regional exercises are designed for a whole country while others are for a major city. I was wondering if the functions and parameters given in the exercises are applicable to the whole region.

Thanks!

Regards,

Tammy

Hi Tammy,

I now understand your question. We selected cities that are meant to be representative of the broader region. In certain cases the parameters (e.g. the concentration-response relationships) might be applicable to the broader country or continent. In other instances, the input data will not (e.g. population data).

If you have a particular analysis in mind, post it to the user forum, and perhaps the user community can suggest appropriate input data to use.

Best wishes,
Neal Fann

Thanks! I appreciate it.