Table 1.
Characteristics of Cases in the Los Angeles County HIV Transmission Network Diagnosed in High, Medium, and Low Growth Clusters Using Multivariable Ordinal Logistic Regressiona
| Attributes | Total n (%)2 | Low Cluster Growth n (%)b | Medium Cluster Growth n (%) b | High Cluster Growth n (%) b | AORc | 95% CI |
|---|---|---|---|---|---|---|
| Total population | 5226 (100) | 2621 (100) | 1301 (100) | 1304 (100) | – | – |
| Birth sex | ||||||
| Male | 4749 (91) | 2317 (88) | 1203 (92) | 1229 (94) | 1.30 | 1.02–1.67 |
| Female | 477 (9) | 304 (12) | 98 (8) | 75 (6) | Ref. | – |
| Age at diagnosis | ||||||
| 13–19 | 177 (3) | 59 (2) | 58 (4) | 60 (5) | 1.25 | .94–1.66 |
| 20–29 | 1813 (35) | 730 (28) | 482 (37) | 501 (46) | Ref. | – |
| 30–39 | 1493 (29) | 772 (29) | 370 (28) | 351 (27) | 0.65 | .57–.74 |
| 40–49 | 1100 (21) | 645 (25) | 266 (21) | 189 (15) | 0.52 | .45–.61 |
| 50–59 | 521 (10) | 329 (13) | 102 (8) | 88 (7) | 0.49 | .40–.60 |
| 60+ | 122 (2) | 86 (3) | 21 (2) | 15 (1) | 0.35 | .24–.53 |
| Race/ethnicity | ||||||
| White | 1124(21) | 557 (21) | 288 (22) | 279 (21) | Ref. | – |
| Black/African American | 1040 (20) | 574 (22) | 237 (18) | 229 (18) | 0.79 | .67–.95 |
| Hispanic/Latino | 2655 (51) | 1264 (48) | 695 (53) | 696 (53) | 1.07 | .92–1.23 |
| Asian/Pacific Islander | 240 (5) | 134 (5) | 46 (4) | 60 (5) | 0.80 | .61–1.06 |
| Otherd | 167 (3) | 92 (4) | 35 (3) | 40 (3) | 0.75 | .55–1.04 |
| Poverty level at ZIP code of diagnosise | ||||||
| 25th percentile | 487 (9) | 249 (10) | 115 (9) | 123 (9) | Ref. | – |
| 50th percentile | 989 (19) | 474 (18) | 246 (19) | 269 (21) | 1.00 | .81–1.24 |
| 75th percentile | 1332 (26) | 711 (27) | 316 (24) | 305 (23) | 0.83 | .68–1.02 |
| >75th percentile | 2418 (46) | 1187 (45) | 624 (48) | 607 (47) | 0.97 | .80–1.18 |
| CD4+ count at diagnosis | ||||||
| ≥500 cells/mm3 | 1561 (30) | 681 (26) | 438 (34) | 442 (34) | 1.88 | 1.62–2.18 |
| 200–499 cells/mm3 | 2247 (43) | 1030 (39) | 587 (45) | 630 (48) | 1.80 | 1.57–2.06 |
| <200 cells/mm3 | 1412 (27) | 908 (35) | 274 (21) | 230 (18) | Ref. | – |
| Missing | 6 (<1) | 2 (<1) | 2 (<1) | 2 (<1) | 2.36 | .55–10.07 |
| Transmission risk | ||||||
| MSM | 3729 (71) | 1741 (66) | 979 (75) | 1009 (77) | Ref. | – |
| PWIDf | 224 (4) | 113 (4) | 59 (5) | 52 (4) | 0.96 | .74–1.25 |
| Heterosexual sexual contact | 155 (3) | 95 (4) | 34 (3) | 26 (2) | 0.86 | .59–1.28 |
| Unidentified | 1118 (22) | 672 (26) | 229 (17) | 217 (17) | 0.77 | .66–.89 |
Abbreviations: AOR, adjusted odds ratio; CI, confidence interval; HIV, human immunodeficiency virus; MSM, men who have sex with men; PWID, people who inject drugs.
aLikelihood ratio test of proportional odds assumption was performed to assess whether the associated log odds is equal to that comparing high and medium growth clusters to low growth clusters (P = .187).
bColumn percentages.
cAdjusted odds ratio comparing cases in high growth clusters at diagnosis compared with cases in low and medium growth clusters at diagnosis.
dIncludes American Indian/Alaskan Native, multiracial, or unknown race/ethnicity.
eFraction of population in ZIP code of diagnosis living below 100% of the federal poverty level.
fPWID includes MSM who reported injection drug use.