title: Expert Involvement Predicts mHealth App Downloads: Multivariate Regression Analysis of Urology Apps.
abstract: BACKGROUND
  Urological mobile medical (mHealth) apps are gaining popularity with both clinicians and patients. mHealth is a rapidly evolving and heterogeneous field, with some urology apps being downloaded over 10,000 times and others not at all. The factors that contribute to medical app downloads have yet to be identified, including the hypothetical influence of expert involvement in app development.
  
  
  OBJECTIVE
  The objective of our study was to identify predictors of the number of urology app downloads.
  
  
  METHODS
  We reviewed urology apps available in the Google Play Store and collected publicly available data. Multivariate ordinal logistic regression evaluated the effect of publicly available app variables on the number of apps being downloaded.
  
  
  RESULTS
  Of 129 urology apps eligible for study, only 2 (1.6%) had >10,000 downloads, with half having ≤100 downloads and 4 (3.1%) having none at all. Apps developed with expert urologist involvement (P=.003), optional in-app purchases (P=.01), higher user rating (P<.001), and more user reviews (P<.001) were more likely to be installed. App cost was inversely related to the number of downloads (P<.001). Only data from the Google Play Store and the developers' websites, but not other platforms, were publicly available for analysis, and the level and nature of expert involvement was not documented.
  
  
  CONCLUSIONS
  The explicit participation of urologists in app development is likely to enhance its chances to have a higher number of downloads. This finding should help in the design of better apps and further promote urologist involvement in mHealth. Official certification processes are required to ensure app quality and user safety.
authors.affiliation: Department of Urology, Erasmus University Medical Centre, Rotterdam, Netherlands. nuno@pereira-azevedo.com.
authors.forename: Nuno
authors.identifier: http://orcid.org/0000-0002-0442-6565
authors.initials: N
authors.lastname: Pereira-Azevedo
authors.forename: Luís
authors.identifier: http://orcid.org/0000-0003-3515-7772
authors.initials: L
authors.lastname: Osório
authors.forename: Vitor
authors.identifier: http://orcid.org/0000-0001-8105-0816
authors.initials: V
authors.lastname: Cavadas
authors.forename: Avelino
authors.identifier: http://orcid.org/0000-0002-4824-8123
authors.initials: A
authors.lastname: Fraga
authors.forename: Eduardo
authors.identifier: http://orcid.org/0000-0002-1478-629X
authors.initials: E
authors.lastname: Carrasquinho
authors.forename: Eduardo
authors.identifier: http://orcid.org/0000-0001-9859-9274
authors.initials: E
authors.lastname: Cardoso de Oliveira
authors.forename: Miguel
authors.identifier: http://orcid.org/0000-0002-6191-5912
authors.initials: M
authors.lastname: Castelo-Branco
authors.forename: Monique J
authors.identifier: http://orcid.org/0000-0001-6967-1708
authors.initials: MJ
authors.lastname: Roobol
keywords: eHealth; mHealth; mobile apps; new technologies; urology