{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T05:20:58Z","timestamp":1787721658662,"version":"build-2784847793"},"reference-count":40,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T00:00:00Z","timestamp":1787702400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Sickle Cell Disease (SCD) causes acute and chronic complications. Hydroxyurea (HU) reduces vaso-occlusive crises (VOCs) and improves patients\u2019 outcomes. However, evidence on the real-world implementation and effectiveness of HU in resource-limited primary care settings, particularly those serving informal settlements, remains scarce. This study evaluates HU use and its effects in two Nairobi clinics serving informal settlements.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We retrospectively analyzed 2,206 clinical visits from 328 SCD (HbSS) patients (March 2019\u2013March 2021), comparing complication rates in HU users and non-users. Linear mixed and competing-risk Cox regression models assessed HU\u2019s effects on laboratory markers and clinical outcomes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>HU users had lower incidence rates of VOCs (19.6 vs. 24.7 per 10 person-years) and infections (11.3 vs. 12.4) than non-users. Adjusted analyses showed HU increased hemoglobin (+0.36\u202fg\/dL, 95% CI: 0.19 to 0.53) and MCV (+3.47\u202ffl, CI: 2.20 to 4.73). HU reduced the hazard of VOC (HR\u202f=\u202f0.82, 95% CI: 0.66 to 1.02) and infections (0.72, 0.55 to 0.95), but evidence for an effect on major complications was inconclusive due to substantial imprecision (1.39, 0.40 to 4.78). Lower HU doses (&amp;lt;20\u202fmg\/kg\/day) had similar hazard of VOCs as higher doses (20\u201325\u202fmg\/kg\/day), but reduced infection and major complication risks.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>HU reduces infections and VOCs, but does not relevantly impact major complications. Long-term studies are needed to evaluate its effectiveness in low-resource settings, where adherence is influenced by accessibility and socio-economic factors.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmed.2026.1889846","type":"journal-article","created":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T04:50:26Z","timestamp":1787719826000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Hydroxyurea treatment for sickle cell disease in Nairobi informal settlements: a retrospective cohort study"],"prefix":"10.3389","volume":"13","author":[{"given":"Maria Vittoria","family":"De Vita","sequence":"first","affiliation":[{"name":"Amici del Mondo World Friends \u2013 Ruaraka Uhai Neema Hospital","place":["Nairobi, Kenya"]},{"name":"Department for Oncology and Hematology, Charit\u00e9 \u2013 University Medical Center Berlin, Corporate Member of Freie Universit\u00e4t Berlin and Humboldt-Universit\u00e4t zu Berlin","place":["Berlin, Germany"]},{"name":"Children Sickle Cell Foundation","place":["Nairobi, Kenya"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matilu","family":"Mwau","sequence":"additional","affiliation":[{"name":"Kenya Medical Research Institute","place":["Nairobi, Kenya"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anastasia","family":"Omoding","sequence":"additional","affiliation":[{"name":"Children Sickle Cell Foundation","place":["Nairobi, Kenya"]},{"name":"Gertrude's Garden Children's Hospital, World-Class Paediatric","place":["Nairobi, Kenya"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Washington","family":"Njogu","sequence":"additional","affiliation":[{"name":"Amici del Mondo World Friends \u2013 Ruaraka Uhai Neema Hospital","place":["Nairobi, Kenya"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gianfranco","family":"Morino","sequence":"additional","affiliation":[{"name":"Amici del Mondo World Friends \u2013 Ruaraka Uhai Neema Hospital","place":["Nairobi, Kenya"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caleb Mike","family":"Mulongo","sequence":"additional","affiliation":[{"name":"Tunu Consulting Hub","place":["Nairobi, Kenya"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annette","family":"Aigner","sequence":"additional","affiliation":[{"name":"Center for Stroke Research Berlin, Charit\u00e9 \u2013 University Medical Center Berlin, Freie Universit\u00e4t Berlin and Humboldt-Universit\u00e4t zu Berlin","place":["Berlin, Germany"]},{"name":"Institute of Biometry and Clinical Epidemiology, Charit\u00e9 \u2013 University Medical Center Berlin","place":["Berlin, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lena","family":"Oevermann","sequence":"additional","affiliation":[{"name":"Department for Oncology and Hematology, Charit\u00e9 \u2013 University Medical Center Berlin, Corporate Member of Freie Universit\u00e4t Berlin and Humboldt-Universit\u00e4t zu Berlin","place":["Berlin, Germany"]},{"name":"German Center for Child and Adolescent Health (DZKJ), Partner Site Berlin","place":["Berlin, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,26]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"465","DOI":"10.1111\/j.1365-2141.2005.05411.x","article-title":"Predicting clinical severity in sickle cell anaemia","volume":"129","author":"Steinberg","year":"2005","journal-title":"Br J Haematol"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1016\/j.blre.2006.07.001","article-title":"Deconstructing sickle cell disease: reappraisal of the role of hemolysis in the development of clinical subphenotypes","volume":"21","author":"Kato","year":"2007","journal-title":"Blood 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