Skip to main content

Do wearable healthcare devices work?

A report came out from Stanford School of Medicine about a study of Apple Watch's health monitoring features. Some headline writers are proclaiming that "finally, there is proof that these watches benefit our health!" For example, Apple Watch Stanford Study Shows How It Can Save Lives (link). When you read the official story, you will learn the following facts about the study: The research is funded by Apple It was a purely observational study in which they follow (400,000) people who wear Apple Watches Participants must own both an Apple Watch and an iPhone to be eligible (plus meeting other criteria) There was no "control" group - they did not follow anyone who did not use Apple Watch or use any other health monitoring wearables Every participant is self-selected The device issued warnings to only 0.5 percent of the participants (~ 2,160) Those who received a warning were directed to a video consultation; and the doctor decided whether or not to send the participant an ECG patch, which is used to establish the "ground truth". Only about 30 percent were sent patches, and of those, 70 percent (450) returned the patches for analysis. Only those who had ECG data were analyzed. One third of these were shown to have experienced "atrial fibrillation" (irregular heartbeat). This means that two-thirds got false alarms. But if we include the 70% who were not sent patches after the video consultation as false alarms as well, then out of every 100 warnings, only 7 were validated. There is no discussion of false negatives: did any of the 99.5 percent who did not receive warnings experienced irregular heartbeats? We do know that if there were significant false negatives, then more warnings would have to be sent, which pushes up false alarms. Despite the headlines, any lives saved were extrapolated. There are some major methodological limitations about this study. Firstly, the study design prevents drawing conclusions of the type "People wearing Apple Watches .... compared to those who did not wear Apple Watches." It does not include anyone not wearing Apple Watches. Secondly, it's difficult to interpret the accuracy metrics. Is 20 percent false alarms a good or bad number? Is 0.5 percent receiving warnings a reasonable proportion given the demographic and health characteristics of the study population? Hopefully, this study is just the beginning, and more rigorous studies are being planned.  

from Big Data, Plainly Spoken (aka Numbers Rule Your World) https://ift.tt/2OeCfTC
via IFTTT
Labels:

Comments

Post a Comment

Popular posts from this blog

Controlling legend appearance in ggplot2 with override.aes

[This article was first published on Very statisticious on Very statisticious , and kindly contributed to R-bloggers ]. (You can report issue about the content on this page here ) Want to share your content on R-bloggers? click here if you have a blog, or here if you don't. In ggplot2 , aesthetics and their scale_*() functions change both the plot appearance and the plot legend appearance simultaneously. The override.aes argument in guide_legend() allows the user to change only the legend appearance without affecting the rest of the plot. This is useful for making the legend more readable or for creating certain types of combined legends. In this post I’ll first introduce override.aes with a basic example and then go through three additional plotting scenarios to how other instances where override.aes comes in handy. Table of Contents R packages Introducing override.aes Adding a guides() layer Using the guide argument in scale_*() Changing multiple aesthetic par...
Post a Comment
Read more

Using RStudio and LaTeX

(This article was first published on r – Experimental Behaviour , and kindly contributed to R-bloggers) This post will explain how to integrate RStudio and LaTeX, especially the inclusion of well-formatted tables and nice-looking graphs and figures produced in RStudio and imported to LaTeX. To follow along you will need RStudio, MS Excel and LaTeX. Using tikzdevice to insert R Graphs into LaTeX I am a very visual thinker. If I want to understand a concept I usually and subconsciously try to visualise it. Therefore, more my PhD I tried to transport a lot of empirical insights by means of  visualization . These range from histograms, or violin plots to show distributions, over bargraphs including error bars to compare means, to interaction- or conditional effects of regression models. For quite a while it was very tedious to include such graphs in LaTeX documents. I tried several ways, like saving them as pdf and then including them in LaTeX as pdf, or any other file ...
Post a Comment
Read more