Uber and Mothers Against Drunk Driving last week put out a report suggesting Uber helped reduced drunk-driving accidents. However, the claim gets a little wobbly when you take a closer look at the numbers, as ProPublica just did. Now MADD is backing away from the assertion, claiming the relationship is "purely correlational." Meanwhile, it turns out Uber started donating money to MADD last summer. Surely that is unrelated, right?

As ProPublica reported, Uber compared trend data related to drunk-driving crashes for drivers under age 30 in cities where Uber is available and in cities where Uber is not active. The numbers are trending down in both Uber and non-Uber markets. But they're down a little bit more in cities where Uber operates. Uber believes that this decline is because of Uber, but as ProPublica points out, there's no evidence for that.

Now MADD is backpedaling: "Nobody is saying that there is a causation relationship here, this is a correlation relationship. Purely correlational," Amy George, senior vice president of marketing and communications at MADD, tells ProPublica.

Funny, but last week in a press release MADD seemed to feel differently:

Released today, the study demonstrates that not only is Uber a convenient transportation option but that it can also be a powerful tool in the fight to reduce the number of drunk-driving crashes.

There's another twist, which is that Uber has been contributing financially to MADD. Last summer, Uber and MADD announced a partnership in which Uber would donate $1 to MADD for every ride taken and $10 for every new customer who used the service in a 24-hour period around the 4th of July, as long as customers used a promo code, UberMADD.

This past weekend Uber ran a similar promotion, donating a buck for every ride from 3 p.m. to midnight on Super Bowl Sunday when riders used the promo code ThinkandRide.

It is unclear how much money Uber has donated to MADD. I've reached out to MADD and to Uber and will update when I hear back.

UPDATE: Amy George of MADD says via email that MADD is not backing away from the report. "Absolutely not. To imply otherwise is incorrect. MADD strongly stands behind the report and that Uber is a powerful tool to reduce drunk driving. We have consistently said the data is correlative, and those correlations are valid at showing that Uber is having an impact."

[Photo: AP]