Susan E Buskin

University of Washington Seattle, Seattle, Washington, United States

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Publications (51)159.44 Total impact

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    ABSTRACT: Background: US guidelines now recommend that all HIV-infected persons receive antiretroviral therapy). HIV prevention is increasingly focused on ensuring that infected persons are diagnosed soon after HIV acquisition and quickly link to care and initiate antiretroviral therapy. We examined trends in time from HIV diagnosis to viral load suppression in King County, WA, to gauge improvement in our HIV care continuum over time. Methods: We used HIV surveillance data and Cox proportional hazards to evaluate how the time from diagnosis to viral suppression changed among persons newly diagnosed as having HIV in King County, WA, between 2007 and 2013. Results: A total of 1490 (84%) of 1766 newly diagnosed persons achieved viral suppression in a median time of 213 days (95% confidence interval, 203-229). Thirty-six percent of all persons diagnosed in 2007 and 77% in 2013 were virally suppressed within 12 months of HIV diagnosis (P < 0.0001). Differences in time to suppression by calendar year persisted when stratifying by CD4 count at diagnosis. Race was not significantly associated with time to viral suppression. Conclusions: Time from HIV diagnosis to viral suppression dramatically declined between 2007 and 2013, and more than three quarters of recently HIV-diagnosed individuals in King County, WA, now achieve viral suppression within a year of diagnosis. This improvement was evident among all persons newly diagnosed as having HIV, regardless of race/ethnicity or CD4 count at time of diagnosis.
    Full-text · Article · Dec 2015 · Sexually transmitted diseases
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    ABSTRACT: Objective: HIV preexposure prophylaxis (PrEP) is efficacious, but uptake has been slow. In Washington State, most insurance plans, including Medicaid, pay for PrEP, and the state, support a PrEP drug assistance program. We assessed trends in PrEP awareness and use among MSM in Washington. Design and setting: Serial cross-sectional survey conducted annually at the Seattle Pride Parade between 2009 and 2015. Methods: In a convenience sample of MSM who reside in Washington State and deny ever testing HIV positive (n = 2168), we evaluated the association between calendar year and self-report of PrEP uptake and awareness using descriptive statistics and multivariable relative risk and logistic regression. Regression models included HIV risk and demographic covariates. Results: In 2015, 23% [95% confidence interval (CI): 16, 31%] of high-risk MSM reported 'currently' taking PrEP. The percentage of high-risk MSM who reported 'ever' taking PrEP increased from 5% in 2012 to 31% in 2015. PrEP use among low-risk MSM was low and stable, between 1 and 3% in 2012-2015. In multivariable analyses, PrEP use was associated with latter calendar years (2015 vs. 2012: adjusted relative risk = 2.29, 95% CI: 1.16, 4.52) and elevated HIV risk (adjusted relative risk = 2.92, 95% CI: 2.00, 4.25). The percentage of high and low-risk MSM, who had heard of PrEP, increased from 13 to 86% and 29 to 58%, respectively, between 2009 and 2015. Conclusion: PrEP awareness is high and the use has rapidly increased over the last year among MSM in Seattle, Washington, USA. These findings demonstrate that high levels of PrEP use can be achieved among MSM at high-risk for HIV infection.
    No preview · Article · Nov 2015 · AIDS (London, England)
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    ABSTRACT: We develop a new approach for estimating the undiagnosed fraction of HIV cases, the first step in the HIV Care Cascade. The goal is to address a critical blindspot in HIV prevention and treatment planning, with an approach that simplifies data requirements and can be implemented with open-source software. The primary data required is HIV testing history information on newly diagnosed cases. Two methods are presented and compared. The first is a general methodology based on simplified back-calculation that can be used to assess changes in the undiagnosed fraction over time. The second makes an assumption of constant incidence, allowing the estimate to be expressed as a simple closed formula calculation. We demonstrate the methods with an application to HIV diagnoses among men who have sex with men (MSM) from Seattle/King County. The estimates suggest that 6% of HIV-infected MSM in King County are undiagnosed, about one-third of the comparable national estimate. A sensitivity analysis on the key distributional assumption gives an upper bound of 11%. The undiagnosed fraction varies by race/ethnicity, with estimates of 4.9% among white, 8.6% of African American, and 9.3% of Hispanic HIV-infected MSM being undiagnosed.
    Full-text · Article · Aug 2015 · PLoS ONE

  • No preview · Article · Jul 2015 · Journal of the International AIDS Society

  • No preview · Article · Jul 2015 · Journal of the International AIDS Society
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    ABSTRACT: Background : The U.S. HIV staging system is being revised to more comprehensively track early and acute HIV infection (AHI). We evaluated our ability to identify known cases of AHI using King County (KC) HIV surveillance data. Methodology : AHI cases were men who have sex with men (MSM) with negative antibody and positive pooled nucleic acid amplification (NAAT) tests identified through KC testing sites. We used KC surveillance data to calculate inter-test intervals (ITI, time from last negative to first positive test) and the serologic algorithm for recent HIV seroconversion (STARHS). For surveillance data, AHI was defined as an ITI of ≤ 30 days and early infection as an ITI ≤ 180 days or STARHS recent result. Dates of last negative HIV tests were obtained from lab reports in the HIV surveillance system or data collected for HIV Incidence Surveillance. Results : Between 2005 and 2011, 47 MSM with AHI were identified by pooled NAAT. Of the 47 cases, 36% had ITI < 1 day, 60% had an ITI < 30 days, and 70% (95% CI=55-82%) had an ITI ≤ 6 months and would have been identified as early HIV infection. Of the 47, 38% had STARHS testing and 94% were STARHS recent. Conclusion : MSM with known AHI were not identified by proposed definitions of AHI and early infection. These known AHI cases were frequently missed by HIV surveillance because concurrent negative antibody tests were not reported. Successful implementation of the revisions to the HIV staging system will require more comprehensive reporting.
    Preview · Article · Sep 2014 · The Open AIDS Journal
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    ABSTRACT: Objectives: To assess the HIV care continuum among HIV-infected persons residing in Seattle and King County, WA, at the end of 2011 and compare estimates of viral suppression derived from different population-based data sources. Methods: We derived estimates for the HIV care continuum using a combination of HIV case and laboratory surveillance data supplemented with individual investigation of cases that seemed to be unlinked to or not retained in HIV care, a jurisdiction-wide population-based retrospective chart review, and local data from the CDC's Medical Monitoring Project and National HIV Behavioral Surveillance. Results: Adjusting for in- and out-migration of persons diagnosed with HIV, laboratory surveillance data supplemented with individual case investigation suggest that 67% of persons diagnosed with HIV and 57% of all HIV-infected persons living in King County at the end of 2011 were virally suppressed (plasma HIV RNA <200 copies/mL). The viral suppression estimates we derived from a population-based chart review and adjusted local Medical Monitoring Project data were similar to the surveillance-derived estimate and identical to each other (59% viral suppression among all HIV-infected persons). Conclusions: The level of viral suppression in King County is more than twice the national estimate and exceeds estimates of control for other major chronic diseases in the United States. Our findings suggest that national care continuum estimates may be substantially too pessimistic and highlight the need to improve HIV surveillance data.
    No preview · Article · Aug 2014 · JAIDS Journal of Acquired Immune Deficiency Syndromes
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    ABSTRACT: U.S. guidelines recommend genotyping for persons newly diagnosed with HIV infection to identify transmitted drug resistance mutations associated with decreased susceptibility to NRTIs, NNRTIs, and PIs. To date, testing for integrase strand transfer inhibitor (INSTI) mutations has not been routinely recommended. We aimed to evaluate the prevalence of transmitted INSTI mutations among persons with primary HIV-1 infection in Seattle, WA. Persons with primary HIV-1 infection have enrolled in an observational cohort at the University of Washington Primary Infection Clinic since 1992. We performed a retrospective analysis of plasma specimens collected prospectively from the 82 antiretroviral-naive subjects who were enrolled from 2007-13, after FDA-approval of the first INSTI. Resistance testing was performed by consensus sequencing. Specimens for analysis had been obtained a median of 24 (IQR 18-41, range 8-108) days after the estimated date of HIV-1 infection. All subjects were infected with HIV-1 subtype B except for one subject infected with subtype C. Consensus sequencing identified no subjects with major INSTI mutations (T66I, E92Q, G140S, Y143C/H/R, S147G, Q148H/K/R, N155H). Using exact binomial confidence intervals, the upper bound of the 95% CI was 4.4%. Although our sample size was small, this study does not support the need at this time to evaluate integrase mutations as part of routine consensus sequencing among persons newly diagnosed with HIV-1 infection. However, it is likely that the prevalence of transmitted INSTI mutations may increase with the recent commercial introduction of additional INSTIs and presumably greater INSTI use among persons living with HIV-1.
    No preview · Article · May 2014 · Antiviral therapy
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    ABSTRACT: Background: HIV laboratory surveillance data (reported CD4 count and viral load results) are often used to identify persons living with HIV/AIDS (PLWHA) who are out of HIV care, but many health departments lack resources to investigate all cases missing recent data. A risk scoring tool could identify cases most likely to benefit from HIV care re-linkage efforts. Methodology: We derived and internally validated a risk scoring tool using data from public health investigations of HIV cases in King County, WA that had no lab results reported to our health department for ≥12 months prior to 4/30/2012. We separately derived and validated risk scores for 1) out-migration or death (“Gone”) and 2) currently residing in area and contactable (“In Area, Contactable”). The investigation protocol included queries to a governmenta records database, medical records searches, calls to HIV medical and social service providers, and calls and letters to PLWHA. We randomly divided the dataset in half, and used one dataset for risk score development and the other for validation. Results: Among 5,708 diagnosed PLWHA in King County, 1128 (20%) had no lab reported for ≥12 months prior to 4/30/2012. Of these, 413 (37%) were determined through case investigation to have out-migrated or died, 219 (19%) were in the area and successfully contacted, 168 (15%) were in the area but were not contacted because new lab results were reported before contact was attempted, and 328 (29%) were not conclusively determined to be out of area and were not contactable. The final model for each risk score included 3 variables: years since last laboratory report (<5, 5-9, >9), county of residence at the time of HIV diagnosis (King or not), and years of age at the time of ascertainment of gap in laboratory results (≤40, 41-65, >65). The “Gone” score had modest discriminatory accuracy [area under the receiver-operator characteristic (ROC) curve = 0.65] as did the In Area, Contactable” score (AUC=0.72). Internal validation demonstrated similar predictive ability of both risk scores in the validation group. Conclusions: We found that a combination of 3 variables available in standard HIV surveillance predicted the likelihood that a PLWHA was residing locally and contactable. Although the accuracy of this score requires external validation, choosing not to investigate cases with “In Area, Contactable” scores of <3 would allow health departments to avoid approximately one-third of all investigations while missing only 5% of contactable persons.
    No preview · Conference Paper · Mar 2014
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    ABSTRACT: Prevention and clinical efforts are increasingly focused on improving the HIV care cascade, the sequential steps from diagnosis to engagement in care and viral suppression. Monitoring of this cascade is largely dependent on HIV laboratory surveillance data. However, little is known about the completeness of these data or the true care status of individuals for whom no data are reported. We investigated people presumed to be living with HIV/AIDS in King County, WA, who had no laboratory results reported to HIV surveillance for at least 1 year between 2006 and 2010. We determined whether each person had relocated, died, or remained in the county. Of 7379 HIV-infected people presumed living in King County, 2545 (35%) had 1 or more 12-month gap in laboratory reporting. Among these individuals, 47% had relocated, 7% died, and 38% remained in King County; we were unable to determine the status of 8%. Of individuals remaining in the area, 91% had evidence of returning to or being in HIV care. Case investigations reduced the proportion of individuals thought to be out of care in 2011 from 27% to 16%. Investigations of individuals without laboratory results reported to HIV surveillance identified large numbers of people who are no longer living in the area. Our findings suggest that current estimates of the HIV care cascade may be too pessimistic and that individual case investigations are required to accurately define the size and composition of the population of people living with HIV in local areas.
    No preview · Article · Jan 2014 · Sexually transmitted diseases
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    ABSTRACT: Antiretroviral therapy (ART) is the cornerstone of HIV clinical care and is increasingly recognized as a key component of HIV prevention. However, the benefits of ART can be realized only if HIV-infected persons maintain high levels of adherence. We present interview data (collected from June 2007 through September 2008) from a national HIV surveillance system in the United States-the Medical Monitoring Project (MMP)-to describe persons taking ART. We used multivariate logistic regression to assess behavioral, sociodemographic, and medication regimen factors associated with three measures that capture different dimensions of nonadherence to ART: dose, schedule, and instruction. The use of ART among HIV-infected adults in care was high (85%), but adherence to ART was suboptimal and varied across the three measures of nonadherence. Of MMP participants currently taking ART, the following reported nonadherence during the past 48 hours: 13% to dose, 27% to schedule, and 30% to instruction. The determinants of the three measures also varied, although younger age and binge drinking were associated with all aspects of nonadherence. Our results support the measurement of multiple dimensions of medication-taking behavior in order to avoid overestimating adherence to ART.
    Full-text · Article · Sep 2012 · The Open AIDS Journal
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    ABSTRACT: Objectives The authors examined temporal trends and correlates of HIV testing frequency among men who have sex with men (MSM) in King County, Washington. Methods The authors evaluated data from MSM testing for HIV at the Public Health—Seattle & King County (PHSKC) STD Clinic and Gay City Health Project (GCHP) and testing history data from MSM in PHSKC HIV surveillance. The intertest interval (ITI) was defined as the number of days between the last negative HIV test and the current testing visit or first positive test. Correlates of the log10-transformed ITI were determined using generalised estimating equations linear regression. Results Between 2003 and 2010, the median ITI among MSM seeking HIV testing at the STD Clinic and GCHP were 215 (IQR: 124–409) and 257 (IQR: 148–503) days, respectively. In multivariate analyses, younger age, having only male partners and reporting ≥10 male sex partners in the last year were associated with shorter ITIs at both testing sites (p<0.05). Among GCHP attendees, having a regular healthcare provider, seeking a test as part of a regular schedule and inhaled nitrite use in the last year were also associated with shorter ITIs (p<0.001). Compared with MSM testing HIV negative, MSM newly diagnosed with HIV had longer ITIs at the STD Clinic (median of 278 vs 213 days, p=0.01) and GCHP (median 359 vs 255 days, p=0.02). Conclusions Although MSM in King County appear to be testing at frequent intervals, further efforts are needed to reduce the time that HIV-infected persons are unaware of their status.
    Full-text · Article · May 2012 · Sexually transmitted infections
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    ABSTRACT: Serologic studies indicate that herpes simplex virus (HSV)-1 and HSV-2 infections are highly prevalent among people infected with HIV. As an ulcerative genital disease, HSV may be important to HIV transmission and HIV-comorbidity. Routine clinical care of HSV in this population has not been described. Data were abstracted from medical records of HIV-infected individuals by the Adult/Adolescent Spectrum of HIV Disease Project. Clinician-documented HSV diagnosis and HSV treatment, defined as any prescription for acyclovir, valacyclovir, or famciclovir, were the outcomes of interest. We present descriptive statistics and trends in HSV diagnosis and treatment. Between 1989 and 2004, 61,299 people were followed in this study. HSV was diagnosed in 20% of the population, and 32% of the population received HSV antiviral prescriptions. Prescriptions for episodic treatment were given to 28% of patients, and 11% received prescriptions for suppressive therapy. The average annual rate of HSV diagnosis declined by 31% during the course of the study. Clinically recognized HSV infections were frequent despite declining rates of diagnosis. Providers should have a high index of suspicion for HSV and consider routine screening and suppressive therapy for patients at risk of clinical disease.
    No preview · Article · May 2012 · Sexually transmitted diseases
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    ABSTRACT: To compare population-based metrics for assessing progress toward the US National HIV/AIDS Strategy (NHAS) goals. Analysis of surveillance data from persons living with HIV/AIDS (PLWHA) in King County, Washington, USA, 2005-2009. We examined indicators of the timing of HIV diagnosis [intertest interval, CD4 cell count at diagnosis, and AIDS ≤ 1 year of diagnosis (late diagnosis)]; linkage to initial care (CD4 or viral load report ≤3 months after diagnosis) and sustained care (a laboratory report 3-9 months after linkage); engagement in continuous care in 2009 (at least two laboratory reports ≥3 months apart); and virologic suppression. Thirty-two percent of persons had late HIV diagnoses, 31% of whom reported testing HIV negative in the 2 years preceding their HIV diagnoses. Linkage to sustained care, but not linkage to initial care, was significantly associated with subsequent virologic suppression. Among 6070 PLWHA in King County, 65% of those with at least one viral load reported in 2009 and 53% of all PLWHA had virologic suppression. Although only 66% of all PLWHA were engaged in continuous care, 81% were defined as engaged using the denominator proposed in the NHAS (at least one laboratory result reported in 2009 excluding persons establishing care in the second half of the year). Proposed metrics for monitoring the HIV care continuum may not accurately measure late diagnoses or linkage to sustained care and are sensitive to assumptions about the size of the population of PLWHA. Monitoring progress toward achievement of NHAS goals will require improvements in HIV surveillance data and refinement of care metrics.
    Full-text · Article · Jan 2012 · AIDS (London, England)

  • No preview · Article · May 2011
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    ABSTRACT: To examine trends in and correlates of liver disease and viral hepatitis in an human immunodeficiency virus (HIV)-infected cohort. The multi-site adult/adolescent spectrum of HIV-related diseases (ASD) followed 29 490 HIV-infected individuals receiving medical care in 11 U.S. metropolitan areas for an average of 2.4 years, and a total of 69 487 person-years, between 1998 and 2004. ASD collected data on the presentation, treatment, and outcomes of HIV, including liver disease, hepatitis screening, and hepatitis diagnoses. Incident liver disease, chronic hepatitis B virus (HBV), and hepatitis C virus (HCV) were diagnosed in 0.9, 1.8, and 4.7 per 100 person-years. HBV and HCV screening increased from fewer than 20% to over 60% during this period of observation (P < 0.001). Deaths occurred in 57% of those diagnosed with liver disease relative to 15% overall (P < 0.001). Overall 10% of deaths occurred among individuals with a diagnosis of liver disease. Despite care guidelines promoting screening and vaccination for HBV and screening for HCV, screening and vaccination were not universally conducted or, if conducted, not documented. Due to high rates of incident liver disease, viral hepatitis screening, vaccination, and treatment among HIV-infected individuals should be a priority.
    Full-text · Article · Apr 2011 · World Journal of Gastroenterology
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    ABSTRACT: The purpose of this study was to determine if anonymous and confidential testers differ in recency of human immunodeficiency virus (HIV) infection at time of testing and prevalence of antiretroviral drug (ARV) resistance. We examined data from the Centers for Disease Control and Prevention-sponsored Antiretroviral Drug Resistance Testing project, which performed genotypic testing on leftover HIV diagnostic serum specimens of confidentially and anonymously tested ARV-naïve persons newly diagnosed with HIV in Colorado (n = 365 at 11 sites) and King County, Washington (n = 492 at 44 sites). The serologic testing algorithm for recent HIV seroconversion was used to classify people as likely to have been recently infected or not. Type of testing, anonymous or confidential, was not significantly associated with either timing of HIV testing by serologic testing algorithm for recent HIV seroconversion or resistance rates. Mutations conferring any level of ARV resistance were present in 17% of testers, and high-level resistance mutations were present in 10%. Anonymous testers were significantly more likely to have CD4+ counts >500 cells per mm(3) (45% vs. 28%; p = 0.018), indicative of an early infection. This study indicates that anonymous testers have demographic differences relative to confidential HIV testers but were not more likely to exhibit drug resistance. Findings related to when in the course of disease anonymous testers are tested are inconsistent, but anonymous testers had higher CD4 counts, which indicates early testing and is consistent with other studies.
    Full-text · Article · Mar 2011 · Microbial drug resistance (Larchmont, N.Y.)
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    ABSTRACT: Human immunodeficiency virus (HIV)-infected individuals are at increased risk for primary lung cancer (LC). We wished to compare the clinicopathologic features and treatment outcome of HIV-LC patients with HIV-indeterminate LC patients. We also sought to compare behavioral characteristics and immunologic features of HIV-LC patients with HIV-positive patients without LC. A database of 75 HIV-positive patients with primary LC in the HAART era was established from an international collaboration. These cases were drawn from the archives of contributing physicians who subspecialize in HIV malignancies. Patient characteristics were compared with registry data from the Surveillance Epidemiology and End Results program (SEER; n = 169,091 participants) and with HIV-positive individuals without LC from the Adult and Adolescent Spectrum of HIV-related Diseases project (ASD; n = 36,569 participants). The median age at HIV-related LC diagnosis was 50 years compared with 68 years for SEER participants (P < .001). HIV-LC patients, like their SEER counterparts, most frequently presented with stage IIIB/IV cancers (77% vs. 70%), usually with adenocarcinoma (46% vs. 47%) or squamous carcinoma (35% vs. 25%) histologies. HIV-LC patients and ASD participants had comparable median nadir CD4+ cell counts (138 cells/µL vs. 160 cells/µL). At LC diagnosis, their median CD4+ count was 340 cells/µL and 86% were receiving HAART. Sixty-three HIV-LC patients (84%) received cancer-specific treatments, but chemotherapy-associated toxicity was substantial. The median survival for both HIV-LC patients and SEER participants with stage IIIB/IV was 9 months. Most HIV-positive patients were receiving HAART and had substantial improvement in CD4+ cell count at time of LC diagnosis. They were able to receive LC treatments; their tumor types and overall survival were similar to SEER LC participants. However, HIV-LC patients were diagnosed with LC at a younger age than their HIV-indeterminate counterparts. Future research should explore how screening, diagnostic and treatment strategies directed toward the general population may apply to HIV-positive patients at risk for LC.
    No preview · Article · Nov 2010 · Clinical Lung Cancer
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    Preview · Article · Oct 2010 · Infectious Agents and Cancer
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    Full-text · Article · Oct 2010 · Infectious Agents and Cancer

Publication Stats

693 Citations
159.44 Total Impact Points

Institutions

  • 2005-2015
    • University of Washington Seattle
      • • Department of Epidemiology
      • • Department of Health Services
      Seattle, Washington, United States
  • 2007
    • King County
      Seattle, Washington, United States
  • 2004
    • Fred Hutchinson Cancer Research Center
      Seattle, Washington, United States