Comparing Regression Adjustment, Matching, and Inverse Probability Weights in Small Sub-Populations in the HIV SUCCESS Consortium: A Real-World Data Example
Objectives To understand the trade-offs between different statistical modeling approaches, using real world data with small sub-populations, with rare exposures and increasingly rare outcomes. In particular, to compare adjusted regression, inverse probability weighting, and matching. Methods Data for these analyses came from the RADAR (N=1,134) and combined CNICS/JHHCC (N=14,434) cohorts. We estimated prevalence ratios (PRs) for self-reported use of specific substances comparing subpopulations (SP), SP-1 vs SP-3 and SP-2 vs SP-3, where SP-1 was the largest proportion (92% in RADAR, 81% in CNICS/JHHCC), SP2 was moderate proportion (18% in CNICS/JHHCC) and SP-3 was the smallest proportion (8% in RADAR, 1% in CNICS/JHHCC) of the population. We calculated PRs using 1) unadjusted relative risk regression (RR); and adjusted estimates controlling for age, race/ethnicity, study site, and year of interview using: 2) standard adjustment in RR; 3) stabilized inverse probability of treatment weighting (IPTW); and 4) matching with up to 3 matches from SP-1 or SP-2 per SP-3 participant. Results For most substances, all methods yielded consistent estimates. There were large weights in some of the IPTW analyses and in three cases these resulted in substantially divergent estimates. For the comparison between SP-1 and SP-3, the estimate for smoking was 1.3-fold greater in the matched analysis (PR=1.33, 95% CI: 1.02-1.75) than in IPTW (PR=1.03, 95% CI: 0.78-1.37 ATE and PR=1.05, 95% CI: 0.88-1.26 ATT). Even more extreme divergence in estimates was observed for differences between SP-2 and SP-3 with respect to methamphetamine/amphetamine, (IPTW-ATE: PR=1.51, 95% CI: 0.79-2.89; IPTW-ATT: PR=2.36, 95% CI: 1.36-4.12); vs Matching: PR=2.71, 95%CI: 1.47-4.99) and cocaine (IPTW-ATE: PR=1.15, 95% CI: 0.55-2.38; IPTW-ATT: PR=1.81, 95% CI: 1.03-3.18); vs Matching: PR=1.38, 95%CI: 0.76-2.53). Conclusion The combination of a rare exposure and a rare outcome can produce challenges for commonly used confounding adjustment strategies, and it is often best to compare different modeling approaches to gain greater insight.
Impact of SGLT2 Inhibitors on Kidney Function Among People With HIV: A US Prospective Multisite Study
Background: Sodium–glucose cotransporter 2 inhibitors (SGLT2i) are nephroprotective but are associated with early eGFR decline, also termed “eGFR dip.” Despite elevated risk of kidney disease, this phenomenon is understudied among people with HIV (PWH). Methods: In a 1:1 propensity score–matched cohort study using data from 9 Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) sites, we compared new SGLT2i users with new users of other antihyperglycemic classes. We estimated adjusted hazard ratios (aHRs) for time to ≥10% and ≥30% eGFR decline using multivariable Cox proportional hazards models and analyzed eGFR change using multivariable linear mixed models. In addition, longer-term eGFR trends over 24 months were visualized using locally weighted scatterplot smoothing (LOWESS) curves. Results: Among 1554 eligible PWH, we obtained 295 matched pairs. Over 6 months, eGFR decline incidence of ≥10% and ≥30% was higher among users of SGLT2i versus other antihyperglycemic classes (58.2% vs. 37.4%; aHR: 1.79; 95% CI: 1.40%–2.28%; and 17.3% vs. 9.8%; aHR: 1.69; 95% CI: 1.05–2.73; respectively). The adjusted mean eGFR change at 6 months was −2.62 mL/min/1.73 m 2 for SGLT2i versus 0.05 mL/min/1.73 m 2 for other classes. Long-term eGFR trends revealed an expected initial decline after SGLT2i initiation, followed by stabilization and a slower subsequent decline compared with other classes. Conclusions: Acute eGFR dips were more common among PWH initiating SGLT2i relative to other antihyperglycemic classes, although overall declines were small, transient, and consistent with the general population. Further research is needed to explore the long-term effects of SGLT2i in PWH.
Age modifies the association between sex and the plasma inflammatory proteome in treated HIV
BACKGROUND Among antiretroviral therapy–suppressed (ART-suppressed) people with HIV (PWH), women have higher levels of some inflammatory markers than men, but the effect of sex on the inflammatory proteome, and whether age modifies these differences, remain unclear. METHODS Plasma inflammatory protein levels were assessed in ART-suppressed PWH from the Center for AIDS Research Network of Integrated Clinical Systems. The relationship between sex and plasma proteins — including 22 interferon-α response pathway proteins — was assessed, adjusting for confounders and assessing interactions by age. RESULTS Of 922 participants, 162 (18%) were female. The median age was 47, above which the majority of women had undetectable plasma anti-Müllerian hormone levels, a biomarker of ovarian reserve. Age modified the influence of sex on the inflammatory proteome. Older age (>47) was associated with greater increases among women than men in 194 proteins. Interferon-α response proteins were higher in men in those ≤ 47 but higher in women in those > 47 (interaction P < 0.001). Among the 131 proteins associated with mortality risk ( q < 0.05), only 5 differed by sex among those ≤ 47, while 79 differed by sex in those > 47, with nearly all being higher in women. Women had decreased mortality than men ≤ 47 ( P < 0.001) but had similar mortality > 47 ( P = 0.84). CONCLUSION The menopausal transition appears to increase systemic type I interferon responses and inflammation in women with HIV, which may contribute to a loss of female advantage in mortality. FUNDING NIH National Heart, Lung, and Blood Institute; National Institute of Neurological Disorders and Stroke; National Institute of Allergy and Infectious Diseases.
Association between housing instability and frailty among people with HIV
Background: Housing instability and HIV are both associated with early onset of aging-related health conditions, including frailty. However, little is known about the relationship between housing and frailty among people with HIV. Methods: We analyzed data on adults in HIV care collected during routine clinical visits at 6 sites within the US Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) between 2019 and 2024. We measured frailty using a previously validated approach, defined as having at least three of four components (fatigue, weight loss, immobility, inactivity) vs. less than three components. Housing status was based on self-perceived living situation in the past month (“Stable,” “Unstable,” “Homeless,” or “Don’t know”). We estimated the association between most recent housing status and frailty with prevalence ratios from relative risk regression adjusted for sociobehavioral and clinical characteristics. Results: Among 6961 people with HIV (84% men, 16% women) with a median age of 52 years (IQR: 40–60), 11% ( n = 760) were frail and 9% ( n = 625) were unstably housed (5% unstable, 3% homeless, 1% do not know). Compared to individuals with stable housing, the prevalence of frailty more than doubled among those experiencing unstable housing [prevalence ratio = 2.41, 95% confidence interval (95% CI): 1.95–2.97] or homelessness (prevalence ratio = 2.05, 95% CI: 1.56–2.69). Stratified analyses indicated stronger associations among younger vs. older individuals and among those virally suppressed vs. unsuppressed. Conclusion: Housing instability and frailty were both prevalent and strongly associated among adults in HIV care, including within younger and virally suppressed subgroups. These findings highlight the importance of social determinants of health for clinical outcomes among all people with HIV.
Alcohol use disorder, but not current alcohol use is associated with falls among people with HIV in care
Background: Current understanding of associations between alcohol use and falls among people with HIV (PWH) is limited due to few and inconsistent studies. Given the prevalence of heavy episodic alcohol use reported among PWH, this remains an important question. Methods: Alcohol use was measured using the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) and self-reported alcohol use treatment and/or diagnosis of alcohol use disorder (collectively AUD) among PWH at eight CFAR Network of Integrated Clinical Systems (CNICS) sites from 2021 to 2024. Falls were self-reported using the components of the Falls Risk for Older People in the Community (FROP-Com) questionnaire. Cross-sectional associations between alcohol use and falls were examined using relative risk models adjusted for age, sex, race/ethnicity, and geographic location. Results: Among 5729 PWH, mean age was 55 years; 42% reported White and 41% reported Black/African American race/ethnicity; and 81% were male. Mean AUDIT-C score was 1.9 (range: 0–12); 27% reported heavy episodic drinking; 22% had AUD; and 22% reported falling in the past year. Reporting at least one fall in the past year was not associated with any measure of current alcohol use. AUD was associated with reporting at least one fall [prevalence ratio = 1.54; 95% confidence interval (CI) 1.39–1.70] and number of falls [one fall: prevalence ratio = 1.27 (95% CI: 1.08–1.50); at least two falls: prevalence ratio = 1.84 (95% CI: 1.58–2.15)]. Conclusion: Among PWH, 22% reported falling, which was associated with AUD, but not current alcohol use, suggesting that a mechanism other than acute intoxication could be responsible. Further longitudinal research is warranted to explore mechanisms for why AUD, but not current alcohol use, is associated with falls.
A randomized, double-blind, phase (Ph) III study of the irinotecan-based chemotherapy FOLFIRI plus ramucirumab (RAM) or placebo (PL) in patients (pts) with metastatic colorectal carcinoma (mCRC) progressive during or following first-line therapy with bevac
TPS3634 Background: Vascular endothelial growth factor (VEGF) and the VEGF receptor-2 (VEGFR-2) regulate angiogenesis and are overexpressed in CRC. RAM is a fully human IgG1 monoclonal antibody that inhibits binding of VEGF ligands to VEGFR-2 and inhibits VEGFR-2 activation and signaling. In a preclinical study, antiangiogenic and antitumor effects were observed when DC101, an antibody that targets murine VEGFR-2, was administered to mice bearing human colon cancer xenografts. Antitumor activity for RAM has been demonstrated in a Ph I study in pts with solid tumors over a wide range of RAM dose levels and in a Ph II study with RAM + mFOLFOX-6 as 1st-line therapy in pts with mCRC. Methods: This ongoing, randomized, double-blind, placebo-controlled Ph III study includes mCRC pts with measurable or nonmeasurable disease and ECOG performance status of 0-1 who have experienced disease progression during or within 6 months following 1st-line therapy with BEV, OXALI, and any FP. Randomization is stratified by geographic region, KRAS status, and time to progression after initiation of 1st-line therapy. Pts are randomized 1:1 to either RAM 8 mg/kg or PL every 14 days. Pts in both arms receive FOLFIRI (irinotecan: 180 mg/m2, folinic acid: 400 mg/m2, 5-fluorouracil: 400 mg/m2 bolus followed by 2400 mg/m2 continuous infusion over 46-48 hours). The primary endpoint is overall survival (OS). The sample-size estimate assumes 85% power to detect at least a 2.5-month median OS difference (HR = 0.8) between treatment arms with a 1-sided alpha of 0.025. Secondary endpoints include progression-free survival, tumor response, safety, pharmacokinetics, immunogenicity, and correlations between biomarkers and clinical outcome. CRC tissue and blood collection is mandatory for biomarker analyses. As of 05 January 2012, 238 of 1050 planned pts have been enrolled from 100 sites in North America, South America, Europe, Asia, and Australia.