RESULTS
A total of 229 children aged ≥6 years were included for folate and vitamin B12 measurements (Table Participant characteristics at enrolment in the ODYSSEY trialAbbreviations: ABC, abacavir; ATV, atazanavir; Baylor, Baylor College of Medicine Children's Foundation; BMI, body mass index; DRV, darunavir; DTG, dolutegravir; EFV, efavirenz; FTC, emtricitabine; IQR, interquartile range; JCRC, Joint Clinical Research Centre; LPV/r, lopinavir/ritonavir; MUJHU, Makerere University‐Johns Hopkins University (MU‐JHU) Research Collaboration; NRTIs, nucleotide reverse transcriptase inhibitors; SOC, standard‐of‐care; TDF, tenofovir disoproxil fumarate; ZDV, zidovudine; 3TC, lamivudine.Excludes two children enrolled in ODYSSEY ≥6 years who had no MCV data.Of the 229 children included, 225 (98%) had an available plasma folate result at enrolment. By week 4, 226 (99%) children were still in follow‐up, of whom 218 (96%) had an available plasma folate result; three met the definition for treatment change prior to week 4 (1 DTG, 2 SOC). Two hundred and fifteen (94%) children had samples collected for prospective evaluation of folate and vitamin B12 at median 144 weeks (IQR 132, 167) post randomization, and of these, 214 children had available results for RBC folate, vitamin B12 and plasma folate (“week ≥96 measurement”). Of these 214 children, 9 (7 DTG, 2 SOC) met the definition of a treatment change prior to their ≥96 week sample being taken.Overall, 679 children aged ≥6 years were enrolled in the ODYSSEY trial and had available MCV data (at enrolment, and at least one measure subsequently); characteristics were generally similar to those enrolled in the sub‐study in the three Ugandan sites, although more children in the Ugandan sites were on second‐line ART.