Explanation of why it would be better to present just one level of the Prenatal Care indicator

[RoderickJones]

I am not in favor of mapping/visualizing all 4 levels of the prenatal care indicator, even though the portal table that’s being used in the Atlas does contain 4 levels. In general, the indicator is defined as the percent of mothers who received prenatal care in the first trimester of pregnancy (or the inverse, i.e., those who did not get care in the first trimester). Let me provide some explanation for the opinion I’m expressing.

In every dataset we work with, there are missing values. Everytime I do an analysis I need to assess the extent to which those missing values could lead to misinterpretation of the results. In many instances, the missing values are distributed at random (or close to it) and the conclusions we come to in looking at the results are not substantially affected by the missing values.

Take a moment to look at this table of missing values on birth certificates in Chicago over the course of the 2000s:Table 80 on page 106 of 107 in this pdf – http://www.cityofchicago.org/city/en/depts/cdph/provdrs/pol_plan_report/news/2012/dec/cdph_releases_comprehensivereportonbirthsinchicago.html See how prenatal care has a relatively high proportion of missing values, with variation over time. In addition there happens to be variation associated with community area of residence as well.

When this problem presents itself, my approach varies with the audience. In the Births report, we simply conducted the analyses on the complete data (excluding the missings, rather than imputing values for them).

For purposes of Open Data, I chose to make all 4 categories available, and in that way, provide transparency within the dataset itself about the extent of the missing values for this indicator (i.e., the Not Given category). Even though I made this available, I don’t think this category is useful to users of the Atlas.

What I believe would be most meaningful (although still imperfect) is to take the approach of the Births report – to define the indicator as a percent with numerator=# getting prenatal care in the 1st trimester; denominator=sum of all categories except Not Given (i.e., 1st trimester+2nd trimester+3rd trimester).

Obviously this requires additional math on our Open Data table, so I can understand if this is beyond your scope. But I wanted to convey the perspective that reporting all 4 levels of the prenatal care indicator probably would strike most public health oriented people as odd.

[danxoneil]

Eric:

Thanks for the explanation. This works for me-- we will make the change.

Derek:

Do you forsee any implementation issues?

[derekeder]

@RoderickJones thanks for that explanation. Definitely makes sense to remove the extra charts.

We could do the math on our end, though I wonder if it would be useful to others if you added an additional 'percent 1st trimester prenatal care' column to the CDPH dataset since, as you describe, its the most meaningful.

[danxoneil]

@RoderickJones, can you comment on this? Would love to close the issue?

[RoderickJones]

My comment is, the most important change has been made - the site now displays 1st trimester rather than all of the categories. In terms of us doing additional math on the portal table, at this point I don't think we will end up doing that. Ultimately, the best option might be to make it possible for user to know the source of the tabular data (i.e., the portal), where they would find all the categories if they wanted, as well as the dataset description. Issue can be closed, if it hinged on us doing additional math on the portal table.

[derekeder]

This has been addressed. Closing.