{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,10,30]],"date-time":"2026-10-30T19:38:49Z","timestamp":1793389129085,"version":"4.5.0"},"posted":{"date-parts":[[2025,2,25]]},"group-title":"Dermatology","reference-count":26,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2025,2,25]],"date-time":"2025-02-25T00:00:00Z","timestamp":1740441600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2025,2,25]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Some pulse oximeters perform worse in people with darker skin, and this may be due to inadequate diversity of skin pigment in device development study cohorts. Guidance is needed to accurately and equitably characterize skin pigment to ensure diversity in research cohorts. We tested multiple methods for characterizing skin pigment to assess comparability and impact on cohort diversity.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Objectives<\/jats:title>\n                  <jats:list list-type=\"bullet\">\n                    <jats:list-item>\n                      <jats:p>Assess reliability and comparability of common skin pigment measurement methods<\/jats:p>\n                    <\/jats:list-item>\n                    <jats:list-item>\n                      <jats:p>Compare findings from different anatomical sites<\/jats:p>\n                    <\/jats:list-item>\n                    <jats:list-item>\n                      <jats:p>Demonstrate that pigment cannot be assumed from US National Institutes for Health (NIH) race categories<\/jats:p>\n                    <\/jats:list-item>\n                  <\/jats:list>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>We used three subjective methods (perceived Fitzpatrick pFP, Monk Skin Tone MST and Von Luschan VL) and two objective methods (Konica Minolta CM-700d spectrophotometer and Delfin Skin Color Catch DSCC colorimeter) for individual typology angle (ITA), across multiple measurement sites in adults. We calculated \u0394E to estimate operator perceptibility thresholds for subjective methods and to determine reproducibility for objective methods. We used each method to categorize participants as \u2018light, medium, or dark\u2019 and compared the impact of method selection on cohort diversity.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>We studied 789 participants, with 33,856 assessments. The MST had the widest luminosity range, and VL had the least discernible adjacent categories. With \u2018dark\u2019 defined as ITA &lt;-30\u00b0, 14% of participants were categorized \u2018dark\u2019 as compared to 26% by pFP or 16% by MST. Approximately half of the \u2018dark\u2019 cohort had an ITA &lt;-50\u00b0. With an ITA threshold &lt;-50\u00b0, only 7% of the cohort was categorized as \u2018dark.\u2019 When \u2018Black or African American\u2019 self-identification was used to define \u2018dark\u2019, 23% of the cohort was categorized as such. Each self-assigned NIH race category included a wide range of ITA and subjective scale categories. Both ITA and L* from the KM-700d and DSCC demonstrated strong correlation (\u2374 &gt; 0.7).<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusion<\/jats:title>\n                  <jats:p>Common methods for skin pigment characterization, especially the use of race or subjective scales, have significant limitations. When applied to the same cohort, different methods yield significantly different results, and some may overestimate diversity. Previously published ITA thresholds for defining \u2018dark\u2019 skin are too light and lead to underrepresentation of people with darker skin.<\/jats:p>\n                <\/jats:sec>","DOI":"10.1101\/2025.02.21.25322707","type":"posted-content","created":{"date-parts":[[2025,2,25]],"date-time":"2025-02-25T16:05:31Z","timestamp":1740499531000},"source":"Crossref","is-referenced-by-count":8,"title":["Comparison of methods for characterizing skin pigment diversity in research cohorts"],"prefix":"10.64898","author":[{"given":"Michael S.","family":"Lipnick","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Danni","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tyler","family":"Law","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"suffix":"Jr.","given":"Kelvin","family":"Moore","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jenna C.","family":"Lester","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ellis P.","family":"Monk","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carolyn M.","family":"Hendrickson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Chou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Hughes","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ella","family":"Behnke","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seif","family":"Elmankabadi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lily","family":"Ortiz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fekir","family":"Negussie","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gregory","family":"Leeb","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Odinakachukwu","family":"Ehie","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isabella","family":"Auchus","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elizabeth N.","family":"Igaga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ronald","family":"Bisegerwa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Olubunmi","family":"Okunlola","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philip","family":"Bickler","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John","family":"Feiner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leonid","family":"Shmuylovich","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2025022707400599000_2025.02.21.25322707v1.1","doi-asserted-by":"publisher","DOI":"10.4187\/respcare.09795"},{"key":"2025022707400599000_2025.02.21.25322707v1.2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMc2029240"},{"key":"2025022707400599000_2025.02.21.25322707v1.3","first-page":"e2330856","article-title":"Clinical Outcomes Associated With Overestimation of Oxygen Saturation by Pulse Oximetry in Patients Hospitalized With COVID-19. 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