Table 1. Baseline characteristics of HIV-infected North Carolina Medicaid patients initiating abacavir or tenofovir as a part of a new combination antiretroviral therapy (cART) regimen before and after inverse probability weighting.
| New cART Recipients | IP Weighteda | |||
|---|---|---|---|---|
| abacavir (n=611) No. (%) |
tenofovir (n=1,605) No. (%) |
abacavir (n=1582 ) No. (%) |
tenofovir (n=1557) No. (%) |
|
| Sex | ||||
| Female | 300 (49) | 758 (47) | 777 (49) | 744 (48) |
| Age (years) | ||||
| <40 | 247 (40) | 364 (60) | 684 (43) | 674 (43) |
| 40-50 | 373 (61) | 238 (39) | 630 (40) | 602 (39) |
| >50 | 485 (27) | 126 (21) | 269 (17) | 281 (18) |
| Race | ||||
| Black | 450 (74) | 1221 (75) | 1195 (76) | 1182 (76) |
| White | 113 (18) | 287 (18) | 296 (19) | 280 (18) |
| Asian | NAb | NAb | NAb | NAb |
| Native American/Pacific Islander | NAb | 24 (2) | 26 (2) | 22 (1) |
| Unknown | 41 (7) | 68 (4) | 63 (4) | 68 (4) |
| Comorbidity at baselinec | ||||
| Heart Failure | 32 (5) | 66 (5) | 64 (4) | 74 (5) |
| Peripheral Vascular Disease | NAb | 14 (1) | 12 (1) | NAb |
| Cerebrovascular Disease | 23 (4) | 45 (3) | 41 (3) | 45 (3) |
| Mild Liver Disease | 13 (2) | 65 (4) | 52 (3) | 52 (3) |
| Renal Disease | 29 (5) | 25 (2) | 25 (0.4) | 25(2) |
| Diabetes (uncomplicated) | 39 (6) | 96 (6) | 99 (6) | 94 (6) |
| Cancer | 24 (4) | 83 (5) | 80 (5) | 77 (5) |
| Chronic Pulmonary Disease | 44 (7) | 121 (8) | 115 (7) | 117 (8) |
| Prior Medications Used (180 days before entering study)d | ||||
| HMG-CoA Reductase Inhibitors | 53 (9) | 113 (7) | 116 (7) | 101 (6) |
| Calcium Channel Blockers | NAb | 31 (2) | 31 (2) | 31 (2) |
| Beta Blocking agents | 14 (2) | 55 (3) | 61 (4) | 43 (3) |
| Angiotensin Converting Enzyme Inhibitors (ACE-I) | 40 (7) | 97 (6) | 102 (6) | 85 (5) |
| No. Prior Medications Used (180 days before entering study) | ||||
| 0 | 96 (16) | 156 (10) | 161 (10) | 155 (10) |
| 1-15 | 412 (67) | 1,126 (70) | 1081 (68) | 1101 (71) |
| 15-20 | 49 (8) | 183 (11) | 191 (12) | 162 (10) |
| >20 | 54 (9) | 140 (9) | 150 (9) | 139 (9) |
| No. Hospitalizations (180 days before entering study) | ||||
| 0 | 377 (62) | 989 (62) | 963 (61) | 975 (63) |
| 0-2 | 121 (20) | 316 (20) | 302 (19) | 312 (20) |
| >2 | 113 (18) | 300 (19) | 317 (20) | 270 (17) |
| First Antiretroviral Regimene | ||||
| 2 NRTIs+boosted PI/ISTI | 165 (27) | 644 (40) | 684 (43) | 639 (41) |
| 2 NRTIs+NNRTI | 139 (23) | 805 (50) | 739 (47) | 762 (49) |
| 2 NRTIs+ unboosted PI | 111 (18) | 165 (27) | 132 (8) | 129 (8) |
| Triple NRTI | 196 (32) | 27 (2) | 27 (1.7) | 27 (2) |
| Year of Antiretroviral Initiation | ||||
| 2002 | 39 (6) | 31 (2) | 27 (1.7) | 31 (2) |
| 2003 | 100 (16) | 101 (6) | 99 (6) | 101 (6) |
| 2004 | 79 (13) | 146 (9) | 155 (10) | 146 (9) |
| 2005 | 150 (25) | 305 (19) | 329 (21) | 305 (20) |
| 2006 | 107 (18) | 346 (22) | 361 (23) | 342 (22) |
| 2007 | 37 (6) | 132 (8) | 137 (9) | 130 (8) |
| 2008 | 99 (16) | 2008 (34) | 474 (9) | 502 (32) |
Propensity score based on the following characteristics: age, race, sex, comorbidities, drug use in the 180 days prior to antiretroviral initiation, cardiovascular drug use in the 180 days prior to antiretroviral initiation, hospitalization in the 180 days prior to antiretroviral initiation, regimen type, year of initiation (6 indicator variables for year). The median propensity scores for the receipt of abacavir or tenofovir were 0.60 (IQR: 0.15, 0.82; Full Range: 0.02, 0.92) and 0.84 (IQR: 0.78, 0.88; Full Range: 0.15, 0.97) respectively. 49 patients who had characteristics that were always associated with abacavir (n=1) or tenofovir (n=48) initiation were excluded from weighted analysis. After trimming of non-overlap in the propensity score distributions, IP weights used to estimate the effect of initiation of cART regimens containing abacavir compared with tenofovir ranged from 0.02 to 12.0.
Numbers in cell < 11 (cannot be presented based on data use agreement with North Carolina Medicaid). Cells < 11 presented for pseudo-population as persons could be represented more than once.
Comorbidities include: Heart failure, peripheral vascular disease, cerebrovascular disease, mild liver disease, moderate/severe liver disease, renal disease, diabetes (uncomplicated), diabetes (complicated), cancer, metastatic carcinoma, connective tissue disease, chronic pulmonary disease, dementia. Comorbidities with > 11 subjects in at least one cell of the baseline population presented.
Angiotensin receptor blocking agent percentages not presented as there was at least one cell in the baseline population that had < 11 subjects.
NA indicates not available; NRTI, Nucleoside Reverse Transcriptase Inhibitor; NNRTI, Non-Nucleoside Reverse Transcriptase Inhibitor; PI, Protease Inhibitor. HMG-CoA, 3-hydroxy-3-methyl-glutaryl-CoA