Posts Tagged ‘statistics’

Texas Pregnancy Mortality Rates Double Due to Bad UI Design

Saturday, April 14th, 2018

Here’s a cautionary tale.

Two years ago, you may have heard that Texas’ maternal mortality rate had just doubled. No one was quite sure why—some blamed a recent shuttering of family-planning services, others a lack of concern for women’s health generally—but it seemed most were confident Texas was a cautionary tale. The U.S. maternal mortality rate overall had been rising for years, even as nearly every other developed country saw declines. Surely, the new numbers out of Texas portended what could happen across the country if we didn’t change soon.

It turns out that the numbers in Texas were wrong. The extent to which they were incorrect was just published in Obstetrics & Gynecology, as investigated by several researchers who went back and double-checked the cause-of-death for 147 total deaths in Texas in 2012.

Though we only now realize how flawed the data were, this isn’t entirely a recent revelation. Experts suspected that something was wrong with the data, they just weren’t sure what. The authors of that original study noted that “in the absence of war, natural disaster, or severe economic upheaval, the doubling of a mortality rate within a 2-year period in a state with almost 400,000 annual births seems unlikely.” Their suspicions turned out to be right. Instead of roughly 36 deaths per 100,000 births, the mortality rate was more like 14.6 deaths per 100,000 births.

Texas is, in fact, a cautionary tale, just not in the way we all thought. It’s been collecting data poorly for years now, and they’re not alone—maternal mortality rates could be wrong all over the U.S. Ever since some states introduced a checkbox to their death certificates asking about pregnancy back in 2003, the stats on maternal mortality have been skewed. A 2017 study concluded that this addition “appears to be the main driver of the increases in [maternal mortality rates] during the last decade.” States with and without the checkbox differ so much in reported data that we haven’t published an official national maternal mortality rate since 2007. The data just haven’t been good enough.

But they have to be better. Maternal mortality rates are still high nationally by many estimates, and understanding the extent of the problem is crucial if America is going to save mothers’ lives.

When researchers found that twofold increase in maternal mortality in Texas two years ago, they suspected it was so extreme as to be an error. Texas was one of the states that implemented a new checkbox on death certificates that asked about the pregnancy status of the deceased, and as mentioned before it was already known that states with that checkbox tend to report higher maternal death rates. This is in part because asking about whether the deceased was pregnant increases the rate at which it’s reported—when you start looking for pregnancy-related deaths, you’ll tend to find more. But it’s also because people make mistakes.

The recent paper notes that it may be a simple design problem that’s contributed significantly to the apparent rise in maternal mortality: “Texas’ current electronic death registration system displays pregnancy status options as a dropdown list. The “pregnant at the time of death” option is directly below the “not pregnant within the past year” option; this could have led to erroneous selection and could explain why pregnancy at the time of death was reported for nearly 76% of the 74 obstetric-coded deaths with no evidence of pregnancy on review.”

The authors also note that the number of death certificates being submitted electronically in Texas jumped from 63 to 91 percent from 2010 to 2012. Having a bunch of new users entering information into death certificate software may have exacerbated the misreporting.

They suggest two main solutions: better training for workers who report death information, and instead of a drop-down menu, try buttons. Separate buttons for “pregnant” and “not pregnant” force the user to move the mouse to totally different areas to make a selection, rather than clicking in a small drop-down menu where it’s easy to make a mistake and not realize it before moving on to the next question.

Texas may have had a double-whammy situation, but the problems they ran into are true of all checkbox states.

Those states that chose to implement a pregnancy checkbox on their death certificates have seen a 149.8 percent in maternal mortality (as of 2012 data). But a study from last year estimated that a whopping 90.3 percent of that change was likely due to the checkbox issues alone.

“Because pregnancy-related deaths are so uncommon, the frequency of the box being checked in error can significantly impact the maternal mortality rate reported,” Elliott Main, medical director of the California Maternal Quality Care Collaborative, told the Washington Post.

If we assumed that the non-checkbox-adopting states showed the true rate, the study authors reasoned, the true rate would be 14.4 percent.

Lesson: Bad UI design kills! Or at least fools you into thinking someone’s been killed…

(Hat tip: Instapundit.)

Firearm Releated Homicides Have Declined for Five Straight Years

Saturday, December 15th, 2012

So sayeth the FBI.

  • 2007: 10,129 Firearm Homicides
  • 2008: 9,528 Firearm Homicides
  • 2009: 9,199 Firearm Homicides
  • 2010: 8,874 Firearm Homicides
  • 2011: 8,583 Firearm Homicides
  • They may have declined for longer than that, but the table only goes back to 2007, and the 2012 data period obviously hasn’t ended yet.

    Between concealed carry laws and DC. vs. Heller, more law-abiding citizens are carrying guns than ever before, but gun violence isn’t up, it’s down.

    I guess John Lott was right.

    How the Washington Post Lies About Guns And Crime Through Omission

    Monday, October 25th, 2010

    Like many liberal publications, the Washington Post has a long history of promoting gun control. Today they published a lengthy, reasonably well researched article by David S. Fallis asserting that Realco, a gun shop in Forestville, Maryland, sold more “crime guns” (i.e., guns used in crimes) than any other dealer.

    The relevant paragraphs:

    86 guns sold by Realco [have] been linked to homicide cases during the past 18 years, far outstripping the total from any other store in the region, a Washington Post investigation has found. Over that period, police have recovered more than 2,500 guns sold by the shop, including over 300 used in non-fatal shootings, assaults and robberies.

    In Maryland, Realco towers over the other 350 handgun dealers in the state as a source of guns confiscated in the District and Prince George’s County, the most violent jurisdictions in the area. Nearly one out of three guns The Post traced to Maryland dealers came from Realco. The rest were spread among other shops across the state.

    Let us for the moment take these figures at face value. However, to my mind the biggest and most obvious problem with the story wasn’t what was in it, but what was missing, the elephant in the room Mr. Fellis failed to mention even once: race.

    Not once do the words “African American” appear in the article, nor does the word “black” appear in reference to race.

    But it is well know to anyone with even passing familiarity with Washington, D.C. that the whites in the District live overwhelmingly in the northwest “white pipeline” that runs from roughly Capitol Hill all the way up through Georgetown to the Virginia border, while blacks predominate in the rest of the city, but especially in the southeast.

    Take a look at this map depicting the ethnic demography of the Washington, DC area created by Eric Fischer:

    In Fisher’s map, white people are red dots, black people are blue, Hispanics are orange, and Asians are green.

    Now take a look at Realco’s location in comparison to Washington DC:

    Realco is not only the closest gun shop to D.C., it is smack dab in the middle of the most overwhelmingly black neighborhood in the greater D.C. area. Also, if I’m reading this map correctly, no less than three Metro bus lines (J11, J12, and J13) run right past the store at 6108 Marlboro Pike.

    The reason this matters is that blacks in the United States commit a disproportionate share of violent crimes compared to the total population. Look at Table 43 of the FBI’s U.S. crime statistics for 2009. 49.3% of those arrested for murder and nonnegligent manslaughter were black, despite blacks making up only 12.4% of the U.S. population. (The reasons black crime rates are so high is are a source of endless debate (see nature vs. nurture, just for starters) and beyond the scope of this essay.)

    So all other things being equal, Realco being the source of so many guns eventually used in crime makes sense, since it is the nearest gun store to the district, as well as the gun store situated most closely to a demographic group that suffers from demonstrably higher levels of violent crime than other demographic groups. Thus Occam’s Razor suggests that we look no further than the obvious for the real facts surrounding Realco.

    It’s a pity David S. Fallis didn’t feel the need to share this most basic demographic context for crime with his readers.

    I have to go off and walk my dog, but I’ll probably post another piece on this subject tomorrow to touch on some angles I don’t have time to address just right now.

    (And if anyone has a better source for comprehensive crime statistics broken down by race specifically for D.C. and Prince George’s County, I’d love to take a look at them.)

    Edited to add: Here’s my followup to this piece.

    And here’s Dwight’s analysis.