A method for determination of hematocrit using the mobile app “HaemoCalc”: Validity, reliability, and effect of user expertise

Abstract We evaluated validity, reliability, and effect of user expertise of “HaemoCalc”, a mobile phone application for hematocrit (Hct) measurement from fingerpick blood samples, compared to a traditional Hawksley microhaematocrit reader (MHR). Experiment 1 examined the effect pitch angle during i...

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Main Authors: Lawrence D. Hayes, Nilihan E. M. Sanal‐Hayes, Maryam Ellam, Marie Mclaughlin, Michelle G. Swainson, Nicholas F. Sculthorpe
Format: Article
Language:English
Published: Wiley 2025-04-01
Series:Physiological Reports
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Online Access:https://doi.org/10.14814/phy2.70314
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author Lawrence D. Hayes
Nilihan E. M. Sanal‐Hayes
Maryam Ellam
Marie Mclaughlin
Michelle G. Swainson
Nicholas F. Sculthorpe
author_facet Lawrence D. Hayes
Nilihan E. M. Sanal‐Hayes
Maryam Ellam
Marie Mclaughlin
Michelle G. Swainson
Nicholas F. Sculthorpe
author_sort Lawrence D. Hayes
collection DOAJ
description Abstract We evaluated validity, reliability, and effect of user expertise of “HaemoCalc”, a mobile phone application for hematocrit (Hct) measurement from fingerpick blood samples, compared to a traditional Hawksley microhaematocrit reader (MHR). Experiment 1 examined the effect pitch angle during image capture exerted on the validity of Hct values. Twenty participants' samples were analyzed at 0°, 10°, and 20° directly over the sample, and 33° with a 10 cm setback. Analysis of variance (ANOVA) revealed a significant effect of angle on Hct values (p < 0.01). Measurements at 33° pitch differed from other angles and the MHR (p < 0.001, d = 2.31–3.06). Bland–Altman analysis showed good agreement at 0°, 10°, and 20° (mean differences: −0.4% to 1.0%) but poor agreement at 33° (mean difference: −4.4%, LOA: −0.7% to 8.4%). Experiment 2 assessed inter‐ and intra‐rater reliability of expert and novice users (n = 12). Participants performed three trials each. HaemoCalc and MHR showed excellent reliability (ICC = 0.95–1.00). No differences were observed between experts and novices (p = 1.000, d = 0.01–0.39). HaemoCalc is a valid and reliable tool for Hct measurement at small pitch angles and in expert and novice users. The HaemoCalc app offers scalability, repeatability, health and safety benefits, and potential applications in medical education and remote learning.
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spelling doaj-art-15f3e44bdad64b50822f7d358e7ea7642025-08-20T02:20:25ZengWileyPhysiological Reports2051-817X2025-04-01138n/an/a10.14814/phy2.70314A method for determination of hematocrit using the mobile app “HaemoCalc”: Validity, reliability, and effect of user expertiseLawrence D. Hayes0Nilihan E. M. Sanal‐Hayes1Maryam Ellam2Marie Mclaughlin3Michelle G. Swainson4Nicholas F. Sculthorpe5Lancaster Medical School Lancaster University Lancaster UKSchool of Health and Society University of Salford Salford UKLancaster Medical School Lancaster University Lancaster UKPhysical Activity for Health Research Centre, Institute for Sport, P.E. and Health Sciences University of Edinburgh, Moray House School of Education and Sport Edinburgh UKLancaster Medical School Lancaster University Lancaster UKSport and Physical Activity Research Institute, School of Health and Life Sciences University of the West of Scotland Glasgow UKAbstract We evaluated validity, reliability, and effect of user expertise of “HaemoCalc”, a mobile phone application for hematocrit (Hct) measurement from fingerpick blood samples, compared to a traditional Hawksley microhaematocrit reader (MHR). Experiment 1 examined the effect pitch angle during image capture exerted on the validity of Hct values. Twenty participants' samples were analyzed at 0°, 10°, and 20° directly over the sample, and 33° with a 10 cm setback. Analysis of variance (ANOVA) revealed a significant effect of angle on Hct values (p < 0.01). Measurements at 33° pitch differed from other angles and the MHR (p < 0.001, d = 2.31–3.06). Bland–Altman analysis showed good agreement at 0°, 10°, and 20° (mean differences: −0.4% to 1.0%) but poor agreement at 33° (mean difference: −4.4%, LOA: −0.7% to 8.4%). Experiment 2 assessed inter‐ and intra‐rater reliability of expert and novice users (n = 12). Participants performed three trials each. HaemoCalc and MHR showed excellent reliability (ICC = 0.95–1.00). No differences were observed between experts and novices (p = 1.000, d = 0.01–0.39). HaemoCalc is a valid and reliable tool for Hct measurement at small pitch angles and in expert and novice users. The HaemoCalc app offers scalability, repeatability, health and safety benefits, and potential applications in medical education and remote learning.https://doi.org/10.14814/phy2.70314hematocritlimits of detectionmedical educationmobile appred blood cellssoftware validation
spellingShingle Lawrence D. Hayes
Nilihan E. M. Sanal‐Hayes
Maryam Ellam
Marie Mclaughlin
Michelle G. Swainson
Nicholas F. Sculthorpe
A method for determination of hematocrit using the mobile app “HaemoCalc”: Validity, reliability, and effect of user expertise
Physiological Reports
hematocrit
limits of detection
medical education
mobile app
red blood cells
software validation
title A method for determination of hematocrit using the mobile app “HaemoCalc”: Validity, reliability, and effect of user expertise
title_full A method for determination of hematocrit using the mobile app “HaemoCalc”: Validity, reliability, and effect of user expertise
title_fullStr A method for determination of hematocrit using the mobile app “HaemoCalc”: Validity, reliability, and effect of user expertise
title_full_unstemmed A method for determination of hematocrit using the mobile app “HaemoCalc”: Validity, reliability, and effect of user expertise
title_short A method for determination of hematocrit using the mobile app “HaemoCalc”: Validity, reliability, and effect of user expertise
title_sort method for determination of hematocrit using the mobile app haemocalc validity reliability and effect of user expertise
topic hematocrit
limits of detection
medical education
mobile app
red blood cells
software validation
url https://doi.org/10.14814/phy2.70314
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