E terms to the model as covariates. To assess the association of baseline serum albumin concentration and change in CD4+ T- cell count between consecutive visits over time, we included the interactions between serum albumin concentration and time since ART initiation and its splines. The robust score test was used to determine whether the categorical serum albumin concentration groups differed in CD4+ T-cell count trajectory. Confounders included in proportional hazard and GEE models were selected on the basis of our risk factor analysis and a review of the literature and consisted of sex and baseline age, BMI, WHO HIV disease stage (except for incidence of WHO stage IV disease or death), CD4+ T-cell count, hemoglobin concentration, and ALT concentration. Baseline CD4+ T cell count was not adjusted for in CD4+ T-cell analyses because this would have yielded biased estimates. Effect modification by all covariates listed above, randomized multivitamin regimen, and ART regimen were considered for all analyses. To assess whether effect modification was significant, we used the likelihood ratio test, for proportional hazard models, and the robust score test, for GEE analyses. Missing data for covariates were retained in the analysis, using the missing indicator method for variables [30]. All P values were 2 sided, and a P value of .05 was considered statistically significant. Statistical analyses were performed using SAS v 9.2 (SAS Institute, Cary, NC, USA).JID 2013:207 (1 May)Sudfeld et alTable 1. Baseline Characteristics of 2145 Study Participants at Antiretroviral Therapy (ART) Initiation, by Serum Albumin Concentration, and Univariate and Multivariate Risk Factor Analyses for HypoalbuminemiaNo. ( ) of Subjects, by Serum Albumin Concentration Characteristic Sex Female (ref) Male Age, y 30 (ref) 300 400 50 BMI 16.0 16.08.5 18.55 25.0 WHO HIV disease stage I/II III IV CD4+ T-cell count, cells/L 50 5000 10000 200 Hemoglobin level, g/dL 8.5 8.51 11 ALT level, IU/L 40 40 ART regimenb d4T, 3TC, NVP d4T, 3TC, EFV AZT, 3TC, NVP AZT, 3TC, EFV 198 (16.Veratridine 3) 581 (47.8) 326 (26.8) 111 (9.1) 28 (2.3) 179 (14.9) 741 (61.5) 257 (21.3) 360 (26.3) 654 (47.8) 67 (7.0) 227 (19.2) 215 (18.1) 507 (42.8) 236 (19.9) 120 (10.5) 484 (42.2) 543 (47.3) 1102 (90.6) 114 (9.4) 695 (57.7) 96 (7.9) 113 (9.3) 312 (25.7) 122 (13.1) 466 (50.2) 248 (26.7) 93 (10.0) 105 (11.4) 250 (27.0) 484 (52.4) 85 (9.2) 120 (14.0) 573 (67.0) 162 (18.9) 208 (23.5) 198 (22.4) 286 (32.3) 193 (21.8) 308 (34.3) 416 (46.3) 175 (19.5) 800 (86.FMK-MEA 1) 129 (13.PMID:23415682 9) 575 (61.8) 107 (11.5) 60 (6.5) 187 (20.1) 1.0 1.17 (1.00.36) 1.13 (.96.34) 1.20 (.97.47) 2.00 (1.79.23) 1.47 (1.33.64) 1.0 .79 (.38.64) 1.0 1.87 (1.58.21) 2.51 (2.10.01) 1.05 (.91.22) 1.07 (.92.23) .80 (.7092) 1.0 2.95 (2.56.40) 1.90 (1.64.20) 1.0 1.0 1.27 (1.11.45) … … … … .001 .001a .117a .001a .001a .229a 1.0 1.13 (.98.30) 1.17 (1.00.36) 1.23 (1.02.49) 1.56 (1.38.77) 1.30 (1.17.44) 1.0 .78 (.6494) 1.0 1.51 (1.28.77) 1.72 (1.44.06) .96 (.84.11) .99 (.87.14) .91 (.80.04) 1.0 2.47 (2.13.88) 1.77 (1.53.06) 1.0 1.0 1.20 (1.06.36) … … … … .003 .001a .762a .001a .001a .033a 831 (68.3) 385 (31.7) 653 (70.3) 276 (29.7) 1.0 .95 (.85.06) .336 1.0 1.03 (1.28.77) .491 35 g/L (n = 1216) 35 g/L (n = 929)Univariate Analysis RR (95 CI) PMultivariate Analysis RR (95 CI) PHypoalbuminemia was defined as a serum albumin concentration of 35 g/L. Abbreviations: ALT, alanine transaminase; BMI, body mass index (calculated as the weight in kilograms.