Why Pokemon Go probably won't save us from obesity

When Pokemon Go came out last year, many people lauded the possibility of the augmented reality game to increase physical activity and health. I even wrote a semi-serious piece advocating that the government subsidise the game. However, the bubble has burst, and the game is pretty much dead now (at least, compared to where it began).

Aside from the overall decline in player numbers though, it seems that any benefits in terms of increased physical activity have been grossly overestimated. In its annual Christmas issue, the British Medical Journal had an (open access) article by Katherine Howe (Harvard) and others, on the effect of Pokemon Go on physical activity. The authors conducted a survey of 1182 iPhone 6 users in the U.S., and used screen captures of the number of steps the Pokemon Go players and non-players took. They compared players (before and after starting to play Pokemon Go) with non-players (before and after the median start date for the players), in a difference-in-difference analysis. Here's what they found:

Playing Pokémon GO was common across various subgroups of the population... players, however, tended to be younger, have a lower education and household income, and be obese, and were more likely to be single and less likely to be black compared with non-players... In the four weeks before installation of Pokémon GO, participants who played the game took on average 4256 (SD 2697) steps daily. The corresponding number for non-players in the four weeks preceding 8 July (median date of Pokémon GO installation among the players) was 4126 (SD 2930). After installation of the game, the daily steps among players increased sharply before gradually returning to the pre-installation levels, whereas the number of daily steps for non-players remained at similar levels throughout the study period...  The difference in difference analysis confirmed the pattern: Pokémon GO was associated with an increase in daily steps of 955 (95% confidence interval 697 to 1213) during the first week, the effect was gradually attenuated over the subsequent weeks, and by week 6 it was not significant...

In other words, Pokemon Go had a very small effect on physical activity - the authors note that an extra 1000 steps is about 11 minutes of walking, which is much less than any guidelines recommend. And that effect had more than halved within four weeks, and was essentially gone within six weeks. Hardly cause to hail the game as a solution to obesity. Back to the treadmill, I guess.

[HT: Stats Chat, back in December]

Read more:

• Why government should subsidise people to play Pokemon Go
• Pokemon Go - Why it might be best not to catch them all
• Pokemon Go - How much are you willing to pay to catch them all?