title: Reliability and validity of a smartphone pulse rate application for the assessment of resting and elevated pulse rate.
abstract: Purpose/hypothesis: This study was designed to investigate the test-retest reliability, concurrent validity, and the standard error of measurement (SEm) of a pulse rate assessment application (Azumio®'s Instant Heart Rate) on both Android® and iOS® (iphone operating system) smartphones as compared to a FT7 Polar® Heart Rate monitor. Number of subjects: 111.
  
  
  METHODS
  Resting (sitting) pulse rate was assessed twice and then the participants were asked to complete a 1-min standing step test and then immediately re-assessed. The smartphone assessors were blinded to their measurements.
  
  
  RESULTS
  Test-retest reliability (intraclass correlation coefficient [ICC 2,1] and 95% confidence interval) for the three tools at rest (time 1/time 2): iOS® (0.76 [0.67-0.83]); Polar® (0.84 [0.78-0.89]); and Android® (0.82 [0.75-0.88]). Concurrent validity at rest time 2 (ICC 2,1) with the Polar® device: IOS® (0.92 [0.88-0.94]) and Android® (0.95 [0.92-0.96]). Concurrent validity post-exercise (time 3) (ICC) with the Polar® device: iOS® (0.90 [0.86-0.93]) and Android® (0.94 [0.91-0.96]). The SEm values for the three devices at rest: iOS® (5.77 beats per minute [BPM]), Polar® (4.56 BPM) and Android® (4.96 BPM).
  
  
  CONCLUSIONS
  The Android®, iOS®, and Polar® devices showed acceptable test-retest reliability at rest and post-exercise. Both the smartphone platforms demonstrated concurrent validity with the Polar® at rest and post-exercise.
  
  
  CONCLUSIONS
  The Azumio® Instant Heart Rate application when used by either platform appears to be a reliable and valid tool to assess pulse rate in healthy individuals.
authors.affiliation: a School of Physical Therapy , Institute of Health Sciences - Houston Campus, Texas Woman's University , Houston , TX , USA.
authors.forename: Katy
authors.initials: K
authors.lastname: Mitchell
authors.affiliation: b Action Physical Therapy , Houston , TX , USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Graff
authors.affiliation: c Houston Methodist Orthopedics and Sports Medicine , Houston , TX , USA.
authors.forename: Corbin
authors.initials: C
authors.lastname: Hedt
authors.affiliation: d Green Oaks Physical Therapy Burleson , Burleson , TX , USA.
authors.forename: James
authors.initials: J
authors.lastname: Simmons
mesh_terms: D000328:Adult; D015444:Exercise; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications; D015588:Observer Variation; D017156:Photoplethysmography / Q000379:methods*; D011237:Predictive Value of Tests; D011674:Pulse; D015203:Reproducibility of Results; D012146:Rest; D000068997:Smartphone; D013997:Time Factors; D055815:Young Adult
keywords: Heart rate; measurement; smartphone