Investigate association between physical activity composition and a heath outcome directly (and obtain dose-response).
Categorise individuals by outcome and investigate how the categories differ in terms of the composition of physical activity.
This is our own tool developed in RStudio and made available through Shiny. It allows users to carry out standard linear regression analysis with compositional explanatory variables (and other standard covariates). The tool has been released recently, and is in an early stage of development, but feel free to give it a go, and let us know if you experience any problems.
We have a number of new features we would like to add to the tool time permitting (in particular producing ternary plots and modelling the results of isotemporal substitution on the overall population) in addition to improving the UI, but please let us know if you have any other suggestions.
The tool is freely available and we hope it is valuable to researchers in physical activity. Unfortunately we do not have the time and resources to provide full product support, or to carry out exhaustive product testing, and at this stage of development it is used on an "own-risk" basis. Nevertheless, we believe it will be a useful exploratory tool, and could provide an independent check on your own work.
MODEL SELECTION - STAGE ONE
MODEL SELECTION - STAGE TWO
Users will need to give consideration to the ethical issues associated with uploading their data before using these applications, and the appropriateness of additional anonymisation. We do not actively collect data uploaded onto the applications, however we are not able to give guarantees as to the duration that uploaded data will be held by our hosting service.
We're happy to provide users interested in using these tools with concerns about uploading their data with the means to run these tools on a private server. Please contact us if this would be of interest.
The applications are hosted on shinyapps.io. The information below is taken from their user guide.
"Each app is deployed into its own container, and the network access between containers is tightly controlled. All access to the apps is over SSL....
...The design of the system is for every account to have its own sub-directory structure, and to enforce the security at the file system and operating system levels. The storage for each container is not permanent, so if you need to store data, our strong recommendation is for you to push that data into your own data store. That could be a database such as Amazon’s RDS, or it could be on a file system accessible from within your application.
shinyapps.io is currently hosted on Amazon’s Web Services (AWS) infrastructure in the us-east-1 region. The infrastructure used is not the HIPAA-compliant stack, so if you need to be in a HIPAA-compliant environment, we recommend deploying and operating your own Shiny Server or Shiny Server Professional instance."