Purpose

Use of electronic health records (EHRs) in health research may lead to the false assumption of complete event ascertainment. We estimated "observation windows" (OWs), defined as periods within which the assumption of complete ascertainment of events is more likely to hold, as a quality control approach to reducing the likelihood of this false assumption. We demonstrated the impact of OWs on estimating the rates of type II diabetes mellitus (diabetes) from HIV clinical cohorts.

Methods

Data contributed by 16 HIV clinical cohorts to the NA-ACCORD were used to identify and evaluate OWs for an operationalized definition of diabetes occurrence as a case study. Procedures included (1) gathering cohort-level data; (2) visualizing and summarizing gaps in observations; (3) systematically establishing start and stop dates during which the assumption of complete ascertainment of diabetes events was reasonable; and (4) visualizing the diabetes OWs relative to the cohort open and close dates to identify immortal person-time. We estimated diabetes occurrence event rates and 95% confidence intervals in the most recent decade that data were available (January 1, 2007, to December 31, 2016).

Results

The number of diabetes events decreased by 17% with the use of the diabetes OWs; immortal person-time was removed decreasing total person-years by 23%. Consequently, the diabetes rate increased from 1.23 (95% confidence interval [1.20, 1.25]) per 100 person-years to 1.32 [1.29, 1.35] per 100 person-years with the use of diabetes OWs.

Conclusions

As the use of EHR-curated data for event-driven health research continues to expand, OWs have utility as a quality control approach to complete event ascertainment, helping to improve accuracy of estimates by removing immortal person-time when ascertainment is incomplete.

From 2005 to 2018, among 32013 adults with human immunodeficiency virus entering care, median time to antiretroviral therapy (ART) prescription declined from 69 to 6 days, CD4 count at entry into care increased from 300 to 362 cells/μL, and CD4 count at ART prescription increased from 160 to 364 cells/μL.

Background

The updated Veterans Aging Cohort Study (VACS) Index 2.0 combines general and human immunodeficiency virus (HIV)-specific biomarkers to generate a continuous score that accurately discriminates risk of mortality in diverse cohorts of persons with HIV (PWH), but a score alone is difficult to interpret. Using data from the North American AIDS Cohort Collaboration (NA-ACCORD), we translate VACS Index 2.0 scores into validated probability estimates of mortality.

Methods

Because complete mortality ascertainment is essential for accurate calibration, we restricted analyses to cohorts with mortality from the National Death Index or equivalent sources. VACS Index 2.0 components were ascertained from October 1999 to April 2018. Mortality was observed up to March 2019. Calibration curves compared predicted (estimated by fitting a gamma model to the score) to observed mortality overall and within subgroups: cohort (VACS/NA-ACCORD subset), sex, age <50 or ≥50 years, race/ethnicity, HIV-1 RNA ≤500 or >500 copies/mL, CD4 count <350 or ≥350 cells/µL, and years 1999-2009 or 2010-2018. Because mortality rates have decreased over time, the final model was limited to 2010-2018.

Results

Among 37230 PWH in VACS and 8061 PWH in the NA-ACCORD subset, median age was 53 and 44 years; 3% and 19% were women; and 48% and 39% were black. Discrimination in NA-ACCORD (C-statistic = 0.842 [95% confidence interval {CI}, .830-.854]) was better than in VACS (C-statistic = 0.813 [95% CI, .809-.817]). Predicted and observed mortality largely overlapped in VACS and the NA-ACCORD subset, overall and within subgroups.

Conclusions

Based on this validation, VACS Index 2.0 can reliably estimate probability of all-cause mortality, at various follow-up times, among PWH in North America.

Background

 The role of active hepatitis C virus (HCV) replication in chronic kidney disease (CKD) risk has not been clarified.

Methods

 We compared CKD incidence in a large cohort of HIV-infected subjects who were HCV seronegative, HCV viremic (detectable HCV RNA), or HCV aviremic (HCV seropositive, undetectable HCV RNA). Stages 3 and 5 CKD were defined according to standard criteria. Progressive CKD was defined as a sustained 25% glomerular filtration rate (GFR) decrease from baseline to a GFR < 60 mL/min/1.73 m2. We used Cox models to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

 A total of 52 602 HCV seronegative, 9508 HCV viremic, and 913 HCV aviremic subjects were included. Compared with HCV seronegative subjects, HCV viremic subjects were at increased risk for stage 3 CKD (adjusted HR 1.36 [95% CI, 1.26, 1.46]), stage 5 CKD (1.95 [1.64, 2.31]), and progressive CKD (1.31 [1.19, 1.44]), while HCV aviremic subjects were also at increased risk for stage 3 CKD (1.19 [0.98, 1.45]), stage 5 CKD (1.69 [1.07, 2.65]), and progressive CKD (1.31 [1.02, 1.68]).

Conclusions

 Compared with HIV-infected subjects who were HCV seronegative, both HCV viremic and HCV aviremic individuals were at increased risk for moderate and advanced CKD.

Background

Human immunodeficiency virus (HIV)-infected patients coinfected with hepatitis B (HBV) and C (HCV) viruses are at increased risk of end-stage liver disease (ESLD). Whether modern antiretroviral therapy has reduced ESLD risk is unknown.

Methods

Twelve clinical cohorts in the United States and Canada participating in the North American AIDS Cohort Collaboration on Research and Design validated ESLD events from 1996 to 2010. ESLD incidence rates and rate ratios according to hepatitis status adjusted for age, sex, race, cohort, time-updated CD4 cell count and HIV RNA were estimated in calendar periods corresponding to major changes in antiretroviral therapy: early (1996-2000), middle (2001-2005), and modern (2006-2010) eras.

Results

Among 34 119 HIV-infected adults followed for 129 818 person-years, 380 incident ESLD outcomes occurred. ESLD incidence (per 1000 person-years) was highest in triply infected (11.57) followed by HBV- (8.72) and HCV- (6.10) coinfected vs 1.27 in HIV-monoinfected patients. Adjusted incidence rate ratios (95% confidence intervals) comparing the modern to the early antiretroviral era were 0.95 (.61-1.47) for HCV, 0.95 (.40-2.26) for HBV, and 1.52 (.46-5.02) for triply infected patients. Use of antiretrovirals dually activity against HBV increased over time. However, in the modern era, 35% of HBV-coinfected patients were not receiving tenofovir. There was little use of HCV therapy.

Conclusions

Despite increasing use of antiretrovirals, no clear reduction in ESLD risk was observed over 15 years. Treatment with direct-acting antivirals for HCV and wider use of tenofovir-based regimens for HBV should be prioritized for coinfected patients.

Background

People living with human immunodeficiency virus (HIV; PLWH) have a markedly elevated anal cancer risk, largely due to loss of immunoregulatory control of oncogenic human papillomavirus infection. To better understand anal cancer development and prevention, we determined whether recent, past, cumulative, or nadir/peak CD4+ T-cell count (CD4) and/or HIV-1 RNA level (HIV RNA) best predict anal cancer risk.

Methods

We studied 102 777 PLWH during 1996-2014 from 21 cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. Using demographics-adjusted, cohort-stratified Cox models, we assessed associations between anal cancer risk and various time-updated CD4 and HIV RNA measures, including cumulative and nadir/peak measures during prespecified moving time windows. We compared models using the Akaike information criterion.

Results

Cumulative and nadir/peak CD4 or HIV RNA measures from approximately 8.5 to 4.5 years in the past were generally better predictors for anal cancer risk than their corresponding more recent measures. However, the best model included CD4 nadir (ie, the lowest CD4) from approximately 8.5 years to 6 months in the past (hazard ratio [HR] for <50 vs ≥500 cells/µL, 13.4; 95% confidence interval [CI], 3.5-51.0) and proportion of time CD4 <200 cells/µL from approximately 8.5 to 4.5 years in the past (a cumulative measure; HR for 100% vs 0%, 3.1; 95% CI, 1.5-6.6).

Conclusions

Our results are consistent with anal cancer promotion by severe, prolonged HIV-induced immunosuppression. Nadir and cumulative CD4 may represent useful markers for identifying PLWH at higher anal cancer risk.

Background

The United States National HIV/AIDS Strategy established goals to reduce disparities in retention in human immunodeficiency virus (HIV) care, antiretroviral therapy (ART) use, and viral suppression. The impact of sex, age, and sexual HIV acquisition risk (ie, heterosexual vs same-sex contact) on the magnitude of HIV-related racial/ethnic disparities is not well understood.

Methods

We estimated age-stratified racial/ethnic differences in the 5-year restricted mean percentage of person-time spent in care, on ART, and virally suppressed among 19 521 women (21.4%), men who have sex with men (MSM; 59.0%), and men who have sex with women (MSW; 19.6%) entering HIV care in the North American AIDS Cohort Collaboration on Research and Design between 2004 and 2014.

Results

Among women aged 18-29 years, whites spent 12.0% (95% confidence interval [CI], 1.1%-20.2%), 9.2% (95% CI, .4%-20.4%), and 13.5% (95% CI, 2.7%-22.5%) less person-time in care, on ART, and virally suppressed, respectively, than Hispanics. Black MSM aged ≥50 years spent 6.3% (95% CI, 1.3%-11.7%), 11.0% (95% CI, 4.6%-18.1%), and 9.7% (95% CI, 3.6%-16.8%) less person-time in these stages, respectively, than white MSM ≥50 years of age. Among MSM aged 40-49 years, blacks spent 9.8% (95% CI, 2.4%-16.5%) and 11.9% (95% CI, 3.8%-19.3%) less person-time on ART and virally suppressed, respectively, than whites.

Conclusions

Racial/ethnic differences in HIV care persist in specific populations defined by sex, age, and sexual HIV acquisition risk. Clinical and public health interventions that jointly target these demographic factors are needed.

Background

Human immunodeficiency virus (HIV)-infected adults, particularly those of black race, are at high-risk for end-stage renal disease (ESRD), but contributing factors are evolving. We hypothesized that improvements in HIV treatment have led to declines in risk of ESRD, particularly among HIV-infected blacks.

Methods

Using data from the North American AIDS Cohort Collaboration for Research and Design from January 2000 to December 2009, we validated 286 incident ESRD cases using abstracted medical evidence of dialysis (lasting >6 months) or renal transplant. A total of 38 354 HIV-infected adults aged 18-80 years contributed 159 825 person-years (PYs). Age- and sex-standardized incidence ratios (SIRs) were estimated by race. Poisson regression was used to identify predictors of ESRD.

Results

HIV-infected ESRD cases were more likely to be of black race, have diabetes mellitus or hypertension, inject drugs, and/or have a prior AIDS-defining illness. The overall SIR was 3.2 (95% confidence interval [CI], 2.8-3.6) but was significantly higher among black patients (4.5 [95% CI, 3.9-5.2]). ESRD incidence declined from 532 to 303 per 100 000 PYs and 138 to 34 per 100 000 PYs over the time period for blacks and nonblacks, respectively, coincident with notable increases in both the prevalence of viral suppression and the prevalence of ESRD risk factors including diabetes mellitus, hypertension, and hepatitis C virus coinfection.

Conclusions

The risk of ESRD remains high among HIV-infected individuals in care but is declining with improvements in virologic suppression. HIV-infected black persons continue to comprise the majority of cases, as a result of higher viral loads, comorbidities, and genetic susceptibility.

Background

Persons with HIV (PWH) with persistently low CD4 counts despite efficacious antiretroviral therapy could have higher hospitalization risk.

Methods

In six US and Canadian clinical cohorts, PWH with virologic suppression for ≥1 year in 2005-2015 were followed until virologic failure, loss to follow-up, death, or study end. Stratified by early (Years 2-5) and long-term (Years 6-11) suppression and lowest pre-suppression CD4 count <200 and ≥200 cells/µL, Poisson regression models estimated hospitalization incidence rate ratios (aIRR) comparing patients by time-updated CD4 count category, adjusted for cohort, age, gender, calendar year, suppression duration, and lowest pre-suppression CD4 count.

Results

The 6997 included patients (19 980 person-years) were 81% cisgender men and 40% White. Among patients with lowest pre-suppression CD4 <200 cells/μL (44%), patients with current CD4 200-350 versus >500 cells/μL had an aIRR of 1.44 during early suppression (95% CI 1.01-2.06), and 1.67 (1.03-2.72) during long-term suppression. Among patients with lowest pre-suppression CD4 ≥200 (56%), patients with current CD4 351-500 versus >500 cells/μL had an aIRR of 1.22 (0.93-1.60) during early suppression and 2.09 (1.18-3.70) during long-term suppression.

Conclusions

Virologically suppressed patients with lower CD4 counts experienced higher hospitalization rates, and could potentially benefit from targeted clinical management strategies.

Background

Since the mid-1990s, effective antiretroviral therapy (ART) regimens have improved in potency, tolerability, ease of use, and class diversity. We sought to examine trends in treatment initiation and resulting human immunodeficiency virus (HIV) virologic suppression in North America between 2001 and 2009, and demographic and geographic disparities in these outcomes.

Methods

We analyzed data on HIV-infected individuals newly clinically eligible for ART (ie, first reported CD4+ count<350 cells/µL or AIDS-defining illness, based on treatment guidelines during the study period) from 17 North American AIDS Cohort Collaboration on Research and Design cohorts. Outcomes included timely ART initiation (within 6 months of eligibility) and virologic suppression (≤500 copies/mL, within 1 year). We examined time trends and considered differences by geographic location, age, sex, transmission risk, race/ethnicity, CD4+ count, and viral load, and documented psychosocial barriers to ART initiation, including non-injection drug abuse, alcohol abuse, and mental illness.

Results

Among 10,692 HIV-infected individuals, the cumulative incidence of 6-month ART initiation increased from 51% in 2001 to 72% in 2009 (Ptrend<.001). The cumulative incidence of 1-year virologic suppression increased from 55% to 81%, and among ART initiators, from 84% to 93% (both Ptrend<.001). A greater number of psychosocial barriers were associated with decreased ART initiation, but not virologic suppression once ART was initiated. We found significant heterogeneity by state or province of residence (P<.001).

Conclusions

In the last decade, timely ART initiation and virologic suppression have greatly improved in North America concurrent with the development of better-tolerated and more potent regimens, but significant barriers to treatment uptake remain, both at the individual level and systemwide.