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Dive into the research topics where Michael J. Silverberg is active.

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Featured researches published by Michael J. Silverberg.


The New England Journal of Medicine | 2009

Effect of Early versus Deferred Antiretroviral Therapy for HIV on Survival

Mari M. Kitahata; Stephen J. Gange; Alison G. Abraham; Barry Merriman; Michael S. Saag; Amy C. Justice; Robert S. Hogg; Steven G. Deeks; Joseph J. Eron; John T. Brooks; Sean B. Rourke; M. John Gill; Ronald J. Bosch; Jeffrey N. Martin; Marina B. Klein; Lisa P. Jacobson; Benigno Rodriguez; Timothy R. Sterling; Gregory D. Kirk; Sonia Napravnik; Anita Rachlis; Liviana Calzavara; Michael A. Horberg; Michael J. Silverberg; Kelly A. Gebo; James J. Goedert; Constance A. Benson; Ann C. Collier; Stephen E. Van Rompaey; Heidi M. Crane

BACKGROUND The optimal time for the initiation of antiretroviral therapy for asymptomatic patients with human immunodeficiency virus (HIV) infection is uncertain. METHODS We conducted two parallel analyses involving a total of 17,517 asymptomatic patients with HIV infection in the United States and Canada who received medical care during the period from 1996 through 2005. None of the patients had undergone previous antiretroviral therapy. In each group, we stratified the patients according to the CD4+ count (351 to 500 cells per cubic millimeter or >500 cells per cubic millimeter) at the initiation of antiretroviral therapy. In each group, we compared the relative risk of death for patients who initiated therapy when the CD4+ count was above each of the two thresholds of interest (early-therapy group) with that of patients who deferred therapy until the CD4+ count fell below these thresholds (deferred-therapy group). RESULTS In the first analysis, which involved 8362 patients, 2084 (25%) initiated therapy at a CD4+ count of 351 to 500 cells per cubic millimeter, and 6278 (75%) deferred therapy. After adjustment for calendar year, cohort of patients, and demographic and clinical characteristics, among patients in the deferred-therapy group there was an increase in the risk of death of 69%, as compared with that in the early-therapy group (relative risk in the deferred-therapy group, 1.69; 95% confidence interval [CI], 1.26 to 2.26; P<0.001). In the second analysis involving 9155 patients, 2220 (24%) initiated therapy at a CD4+ count of more than 500 cells per cubic millimeter and 6935 (76%) deferred therapy. Among patients in the deferred-therapy group, there was an increase in the risk of death of 94% (relative risk, 1.94; 95% CI, 1.37 to 2.79; P<0.001). CONCLUSIONS The early initiation of antiretroviral therapy before the CD4+ count fell below two prespecified thresholds significantly improved survival, as compared with deferred therapy.


Annals of Internal Medicine | 2010

Opioid Prescriptions for Chronic Pain and Overdose: A Cohort Study

Kate M. Dunn; Kathleen Saunders; Carolyn M. Rutter; Caleb J. Banta-Green; Joseph O. Merrill; Mark D. Sullivan; Constance Weisner; Michael J. Silverberg; Cynthia I. Campbell; Bruce M. Psaty; Michael Von Korff

BACKGROUND Long-term opioid therapy for chronic noncancer pain is becoming increasingly common in community practice. Concomitant with this change in practice, rates of fatal opioid overdose have increased. The extent to which overdose risks are elevated among patients receiving medically prescribed long-term opioid therapy is unknown. OBJECTIVE To estimate rates of opioid overdose and their association with an average prescribed daily opioid dose among patients receiving medically prescribed, long-term opioid therapy. DESIGN Cox proportional hazards models were used to estimate overdose risk as a function of average daily opioid dose (morphine equivalents) received at the time of overdose. SETTING HMO. PATIENTS 9940 persons who received 3 or more opioid prescriptions within 90 days for chronic noncancer pain between 1997 and 2005. MEASUREMENTS Average daily opioid dose over the previous 90 days from automated pharmacy data. Primary outcomes--nonfatal and fatal overdoses--were identified through diagnostic codes from inpatient and outpatient care and death certificates and were confirmed by medical record review. RESULTS 51 opioid-related overdoses were identified, including 6 deaths. Compared with patients receiving 1 to 20 mg/d of opioids (0.2% annual overdose rate), patients receiving 50 to 99 mg/d had a 3.7-fold increase in overdose risk (95% CI, 1.5 to 9.5) and a 0.7% annual overdose rate. Patients receiving 100 mg/d or more had an 8.9-fold increase in overdose risk (CI, 4.0 to 19.7) and a 1.8% annual overdose rate. LIMITATIONS Increased overdose risk among patients receiving higher dose regimens may be due to confounding by patient differences and by use of opioids in ways not intended by prescribing physicians. The small number of overdoses in the study cohort is also a limitation. CONCLUSION Patients receiving higher doses of prescribed opioids are at increased risk for overdose, which underscores the need for close supervision of these patients. PRIMARY FUNDING SOURCE National Institute of Drug Abuse.


Clinical Infectious Diseases | 2012

Risk of Anal Cancer in HIV-Infected and HIV-Uninfected Individuals in North America

Michael J. Silverberg; Bryan Lau; Amy C. Justice; Eric A. Engels; M. John Gill; James J. Goedert; Gregory D. Kirk; Gypsyamber D’Souza; Ronald J. Bosch; John T. Brooks; Sonia Napravnik; Nancy A. Hessol; Lisa P. Jacobson; Mari M. Kitahata; Marina B. Klein; Richard D. Moore; Benigno Rodriguez; Sean B. Rourke; Michael S. Saag; Timothy R. Sterling; Kelly A. Gebo; Natasha Press; Jeffrey N. Martin; Robert Dubrow

BACKGROUND Anal cancer is one of the most common cancers affecting individuals infected with human immunodeficiency virus (HIV), although few have evaluated rates separately for men who have sex with men (MSM), other men, and women. There are also conflicting data regarding calendar trends. METHODS In a study involving 13 cohorts from North America with follow-up between 1996 and 2007, we compared anal cancer incidence rates among 34 189 HIV-infected (55% MSM, 19% other men, 26% women) and 114 260 HIV-uninfected individuals (90% men). RESULTS Among men, the unadjusted anal cancer incidence rates per 100 000 person-years were 131 for HIV-infected MSM, 46 for other HIV-infected men, and 2 for HIV-uninfected men, corresponding to demographically adjusted rate ratios (RRs) of 80.3 (95% confidence interval [CI], 42.7-151.1) for HIV-infected MSM and 26.7 (95% CI, 11.5-61.7) for other HIV-infected men compared with HIV-uninfected men. HIV-infected women had an anal cancer rate of 30/100 000 person-years, and no cases were observed for HIV-uninfected women. In a multivariable Poisson regression model, among HIV-infected individuals, the risk was higher for MSM compared with other men (RR, 3.3; 95% CI, 1.8-6.0), but no difference was observed comparing women with other men (RR, 1.0; 95% CI, 0.5-2.2). In comparison with the period 2000-2003, HIV-infected individuals had an adjusted RR of 0.5 (95% CI, .3-.9) in 1996-1999 and 0.9 (95% CI, .6-1.2) in 2004-2007. CONCLUSIONS Anal cancer rates were substantially higher for HIV-infected MSM, other men, and women compared with HIV-uninfected individuals, suggesting a need for universal prevention efforts. Rates increased after the early antiretroviral therapy era and then plateaued.


Pharmacoepidemiology and Drug Safety | 2009

Trends in long-term opioid therapy for chronic non-cancer pain

Denise M. Boudreau; Michael Von Korff; Carolyn M. Rutter; Kathleen Saunders; G. Thomas Ray; Mark D. Sullivan; Cynthia I. Campbell; Joseph O. Merrill; Michael J. Silverberg; Caleb J. Banta-Green; Constance Weisner

To report trends and characteristics of long‐term opioid use for non‐cancer pain.


AIDS | 2008

Cd4+ count and risk of non-aids diseases following initial treatment for Hiv infection

Jason V. Baker; Grace Peng; Joshua Rapkin; Donald I. Abrams; Michael J. Silverberg; Rodger D. MacArthur; Winston Cavert; W. Keith Henry; James D. Neaton

Background:Reductions in AIDS-related morbidity and mortality following the advent of combination antiretroviral therapy have coincided with relative increases in chronic non-AIDS end-organ diseases among HIV+ patients. Objective:To examine the association of latest CD4+ counts with risk of non-AIDS diseases in a cohort of 1397 patients who initiate antiretroviral therapy. Methods:CD4+ counts and HIV RNA levels along with fatal, and non-fatal, AIDS and non-AIDS diseases (liver, cardiovascular, renal, and cancer) were assessed over a median follow-up of 5 years. Cox proportional regression models were used to study risk associations. Results:A total of 227 patients experienced an AIDS event and 80 patients developed a non-AIDS disease event. Both AIDS and non-AIDS diseases rates (events/100 person-years), respectively, declined with higher latest CD4+ counts: 13.8 and 2.1 with latest CD4+ counts less than 200 cells/μl; 2.0 and 1.7 for counts of 200–350 cells/μl; and 0.7 and 0.7 for counts greater than 350 cells/μl. After adjusting for baseline covariates and the latest HIV RNA level, risk of AIDS and non-AIDS diseases were lowered by 44% (95% confidence interval for hazard ratio 0.50–0.62, P < 0.01) and 14% (95% confidence interval for hazard ratio 0.77–0.96, P = 0.01), respectively, for each 100 cell/μl higher latest CD4+ count. Conclusion:Higher CD4+ counts on antiretroviral therapy are associated with lower rates of non-AIDS diseases and AIDS. These findings expand our understanding of the implications of HIV-related immunodeficiency and motivate randomized studies to evaluate the effects of antiretroviral therapy on a broad set of clinical outcomes at CD4+ counts greater than 350 cells/μl.


The Clinical Journal of Pain | 2008

De Facto Long-term Opioid Therapy for Noncancer Pain

Michael Von Korff; Kathleen Saunders; Gary Thomas Ray; Denise M. Boudreau; Cynthia I. Campbell; Joseph O. Merrill; Mark D. Sullivan; Carolyn M. Rutter; Michael J. Silverberg; Caleb J. Banta-Green; Constance Weisner

ObjectivesThis paper describes characteristics of opioid use episodes for noncancer pain and defines thresholds for de facto long-term opioid therapy. MethodsCONSORT (CONsortium to Study Opioid Risks and Trends) includes adult members of 2 health plans serving over 1% of the US population. Opioid use episodes beginning in the years 1997 to 2005 were classified as acute, episodic, long-term/lower dose, or long-term/higher dose. ResultsOn the basis of evaluation of the likelihood of opioid use continuing, long-term opioid therapy was defined by episodes lasting longer than 90 days with 10+ opioid prescriptions or 120+ days supply of opioids dispensed. Long-term/higher dose episodes (<1.5% of all opioid use episodes) were characterized by daily or near daily use, a mean duration of about 1000 days, and an average daily dose of about 55 mg. They accounted for more than half the total morphine equivalents dispensed from the years 1997 to 2006. Short-acting, non-Schedule II opioids (eg, hydrocodone with acetaminophen) were, by far, the most commonly prescribed medications for acute, episodic, and long-term episodes. Long-acting (sustained-release) opioids were the predominately prescribed medication in a minority of long-term episodes (6% to 12%). DiscussionLong-term opioid therapy was characterized by the diversity in medications prescribed, dosage levels, and frequency of use. The proposed threshold for long-term opioid therapy provides a checkpoint for physicians to review whether an explicit decision to sustain opioid therapy has been reached, and to ensure that a documented treatment plan and provisions for monitoring medication use and patient outcomes are in place.


AIDS | 2009

HIV INFECTION AND THE RISK OF CANCERS WITH AND WITHOUT A KNOWN INFECTIOUS CAUSE

Michael J. Silverberg; Chun Chao; Wendy A. Leyden; Lanfang Xu; Beth Tang; Michael A. Horberg; Daniel Klein; Charles P. Quesenberry; William Towner; Donald I. Abrams

Objective:To evaluate the risk of cancers with and without a known infectious cause in HIV-infected persons. Design:Retrospective cohort study. Methods:Adult HIV-infected and matched HIV-uninfected members of Kaiser Permanente followed between 1996 and 2007 for incident AIDS-defining cancers (ADCs), infection-related non-AIDS-defining cancers (NADCs; anal squamous cell, vagina/vulva, Hodgkins lymphoma, penis, liver, human papillomavirus-related oral cavity/pharynx, stomach) and infection-unrelated NADC (all other NADCs). Results:We identified 20 277 HIV-infected and 202 313 HIV-uninfected persons. HIV-infected persons experienced 552 ADC, 221 infection-related NADC, and 388 infection-unrelated NADC. HIV-uninfected persons experienced 179 ADC, 284 infection-related NADC, and 3418 infection-unrelated NADC. The rate ratio comparing HIV-infected and HIV-uninfected persons for ADC was 37.7 [95% confidence interval (CI): 31.7–44.8], with decreases in the rate ratio over time (P < 0.001). The rate ratio for infection-related NADC was 9.2 (95% CI: 7.7–11.1), also with decreases in the rate ratio over time (P < 0.001). These results were largely influenced by anal squamous cell cancer and Hodgkins lymphoma. The rate ratio for infection-unrelated NADC was 1.3 (95% CI: 1.2–1.4), with no change in the rate ratio over time (P = 0.44). Among infection-unrelated NADCs, other anal, skin, other head and neck, and lung cancer rates were higher and prostate cancer rates lower in HIV-infected persons. Among all infection-unrelated NADCs, the rate ratio decreased over time only for lung cancer (P = 0.007). Conclusion:In comparison with those without HIV infection, HIV-infected persons are at particular risk for cancers with a known infectious cause, although the higher risk has decreased in the antiretroviral therapy era. Cancers without a known infectious cause are modestly increased in HIV-infected persons compared with HIV-uninfected persons.


Clinical Infectious Diseases | 2010

Late Presentation for Human Immunodeficiency Virus Care in the United States and Canada

Keri N. Althoff; Stephen J. Gange; Marina B. Klein; John T. Brooks; Robert S. Hogg; Ronald J. Bosch; Michael A. Horberg; Michael S. Saag; Mari M. Kitahata; Amy C. Justice; Kelly A. Gebo; Joseph J. Eron; Sean B. Rourke; M. John Gill; Benigno Rodriguez; Timothy R. Sterling; Liviana Calzavara; Steven G. Deeks; Jeffrey N. Martin; Anita Rachlis; Sonia Napravnik; Lisa P. Jacobson; Gregory D. Kirk; Ann C. Collier; Constance A. Benson; Michael J. Silverberg; Margot B. Kushel; James J. Goedert; Rosemary G. McKaig; Stephen E. Van Rompaey

BACKGROUND. Initiatives to improve early detection and access to human immunodeficiency virus (HIV) services have increased over time. We assessed the immune status of patients at initial presentation for HIV care from 1997 to 2007 in 13 US and Canadian clinical cohorts. METHODS. We analyzed data from 44,491 HIV-infected patients enrolled in the North American-AIDS Cohort Collaboration on Research and Design. We identified first presentation for HIV care as the time of first CD4(+) T lymphocyte (CD4) count and excluded patients who prior to this date had HIV RNA measurements, evidence of antiretroviral exposure, or a history of AIDS-defining illness. Trends in mean CD4 count (measured as cells/mm(3)) and 95% confidence intervals were determined using linear regression adjusted for age, sex, race/ethnicity, HIV transmission risk, and cohort. RESULTS. Median age at first presentation for HIV care increased over time (range, 40-43 years; P < .01), whereas the percentage of patients with injection drug use HIV transmission risk decreased (from 26% to 14%; P < .01) and heterosexual transmission risk increased (from 16% to 23%; P < .01). Median CD4 count at presentation increased from 256 cells/mm(3) (interquartile range, 96-455 cells/mm(3)) to 317 cells/mm(3) (interquartile range, 135-517 cells/mm(3)) from 1997 to 2007 (P < .01). The percentage of patients with a CD4 count > or = 350 cells/mm(3) at first presentation also increased from 1997 to 2007 (from 38% to 46%; P < .01). The estimated adjusted mean CD4 count increased at a rate of 6 cells/mm(3) per year (95% confidence interval, 5-7 cells/mm(3) per year). CONCLUSION. CD4 count at first presentation for HIV care has increased annually over the past 11 years but has remained <350 cells/mm(3), which suggests the urgent need for earlier HIV diagnosis and treatment.


General Hospital Psychiatry | 2009

Trends in long-term opioid therapy for noncancer pain among persons with a history of depression

Jennifer Brennan Braden; Mark D. Sullivan; G. Thomas Ray; Kathleen Saunders; Joseph O. Merrill; Michael J. Silverberg; Carolyn M. Rutter; Constance Weisner; Caleb J. Banta-Green; Cynthia I. Campbell; Michael Von Korff

OBJECTIVE We report trends in long-term opioid use among patients with a history of depression from two large health plans. METHODS Using claims data, age- and gender-adjusted rates for long-term (>90 days) opioid use episodes were calculated for 1997-2005, comparing those with and without a depression diagnosis in the prior 2 years. Opioid use characteristics were calculated for those with a long-term episode in 2005. RESULTS Incident and prevalent long-term opioid use rates were three times higher in those with a history of depression. Prevalent long-term use per 1000 in patients with a history of depression increased from 69.8 to 125.9 at Group Health and from 84.3 to 117.5 at Kaiser Permanente of Northern California between 1997 and 2005. Those with a history of depression were more likely to receive a higher average daily dose, greater days supply, and Schedule II opioids than nondepressed persons. CONCLUSION Persons with a history of depression are more likely to receive long-term opioid therapy for noncancer pain than those without a history of depression. Results suggest that long-term opioid therapy for noncancer pain is being prescribed to a different population in clinical practice than the clinical trial populations where opioid efficacy has been established.


American Journal of Public Health | 2010

Age and Gender Trends in Long-Term Opioid Analgesic Use for Noncancer Pain

Cynthia I. Campbell; Constance Weisner; Linda LeResche; G. Thomas Ray; Kathleen Saunders; Mark D. Sullivan; Caleb J. Banta-Green; Joseph O. Merrill; Michael J. Silverberg; Denise M. Boudreau; Derek D. Satre; Michael Von Korff

OBJECTIVES We describe age and gender trends in long-term use of prescribed opioids for chronic noncancer pain in 2 large health plans. METHODS Age- and gender-standardized incident (beginning in each year) and prevalent (ongoing) opioid use episodes were estimated with automated health care data from 1997 to 2005. Profiles of opioid use in 2005 by age and gender were also compared. RESULTS From 1997 to 2005, age-gender groups exhibited a total percentage increase ranging from 16% to 87% for incident long-term opioid use and from 61% to 135% for prevalent long-term opioid use. Women had higher opioid use than did men. Older women had the highest prevalence of long-term opioid use (8%-9% in 2005). Concurrent use of sedative-hypnotic drugs and opioids was common, particularly among women. CONCLUSIONS Risks and benefits of long-term opioid use are poorly understood, particularly among older adults. Increased surveillance of the safety of long-term opioid use is needed in community practice settings.

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Sonia Napravnik

University of North Carolina at Chapel Hill

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Kelly A. Gebo

Johns Hopkins University

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