Zugui Zhang, PhD

Director of Biostatistics

Publications

Evaluation of a Systems-Based Tobacco Cessation Program Using Bedside Volunteers
Evaluation of a Systems-Based Tobacco Cessation Program Using Bedside Volunteers
Taylor D, Medaglio D, Jurkovitz C, Patterson F, Zhang Z, Gbadebo A, Bradley E, Wessells R, Goldenberg E

Nicotine Tob. Res. 2018 Nov;

PMID: 30462274

Abstract

Introduction: Hospitalization and post-discharge provides an opportune time for tobacco cessation. This study tested the feasibility, uptake, and cessation outcomes of a hospital-based tobacco cessation program, delivered by volunteers to the bedside with post-discharge referral to Quitline services. Patient characteristics associated with Quitline uptake and cessation were assessed.
Methods: Between February and November 2016, trained hospital volunteers approached inpatient tobacco users on six pilot units. Volunteers shared a cessation brochure and used the ASK-ADVISE-CONNECT model to connect ready-to-quit patients to the Delaware Quitline via fax-referral. Volunteers administered a follow-up survey to all admitted tobacco users via telephone or email at 3-months post-discharge.
Results: Of the 743 admitted tobacco users, 531 (72%) were visited by a volunteer, and 97% (531/547) of those approached, accepted the visit. Over one third (201/531; 38%) were ready-to-quit and fax-referred to the Quitline, and 36% of those referred accepted Quitline services. At 3-months post discharge, 37% (135/368) reported not using tobacco in the last 30 days; intent-to-treat cessation rate was 18% (135/743). In a multivariable regression model of Quitline fax-referral completion, receiving NRT during hospitalization was the strongest predictor (OR: 1.97; 95% CI: 1.34-2.90). In a model of 3-month cessation, receiving Quitline services (OR: 3.21, 95%CI: 1.35-7.68) and having coronary artery disease (OR: 2.28; 95% CI: 1.11-4.68) were associated with tobacco cessation, but a volunteer visit was not.
Conclusions: An "opt-out" tobacco cessation service using trained volunteers is feasible for connecting patients to Quitline services.
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Impact of tart cherry juice on systolic blood pressure and low-density lipoprotein cholesterol in older adults: a randomized controlled trial
Impact of tart cherry juice on systolic blood pressure and low-density lipoprotein cholesterol in older adults: a randomized controlled trial
Chai SC, Davis K, Wright RS, Kuczmarski MF, Zhang Z

Food Funct 2018 Jun;9(6):3185-3194

PMID: 29862410

Abstract

Hypertension and dyslipidemia are major risk factors for cardiovascular disease (CVD). Common treatments for high blood pressure (BP) and dyslipidemia include medications, but there is question as to whether natural sources may be adequate to reduce CVD risk factors. We examined the effects of tart cherry juice on lipid profiles, BP, glucose, insulin, and homeostatic model assessment-insulin resistance (HOMA-IR) in older adults. In this randomized-controlled clinical trial, 17 men and 20 women between the ages of 65-80 years were randomly assigned to consume 480 ml of tart cherry juice or control drink daily for 12 weeks. Control beverages were matched for energy and sugar content. Outcome variables were assessed at baseline and after 12 weeks of tart cherry juice or control drink. Systolic BP and low-density lipoprotein cholesterol (LDL) exhibited treatment × time interaction effects. At the end of the study, participants in the tart cherry group had lower levels of LDL cholesterol (difference of -20.6 with P = 0.001) and total cholesterol (difference of -19.11 with P = 0.01), and higher levels of glucose (difference of 7.94 with P = 0.001), triglycerides (difference of 6.66 with P = 0.01) and BMI (difference of 1.06 with P = 0.02) than in the control group. Neither tart cherry juice nor control significantly altered body weight, high-density lipoprotein cholesterol, diastolic BP, insulin and HOMA-IR. Our findings show that tart cherry juice can lower the levels of systolic BP and LDL cholesterol. However, larger and longer follow-up studies are needed to further assess cardio-protective effects of tart cherry juice.
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Cost-effectiveness of Daratumumab-based Triplet Therapies in Patients With Relapsed or Refractory Multiple Myeloma
Cost-effectiveness of Daratumumab-based Triplet Therapies in Patients With Relapsed or Refractory Multiple Myeloma
Zhang TT, Wang S, Wan N, Zhang L, Zhang Z, Jiang J

Clin Ther 2018 Jul;40(7):1122-1139

PMID: 30006069

Abstract

PURPOSE: The prominent efficacy of the addition of daratumumab to lenalidomide and dexamethasone (DRd) or the addition to bortezomib and dexamethasone (DVd) was proven previously for patients with relapsed or refractory multiple myeloma (RRMM). However, the cost-effectiveness of adding daratumumab to traditional doublet regimens versus doublet regimens alone (DRd vs Rd; DVd vs Vd) was unknown.
METHODS: We developed a semi-Markov model by using a US payer perspective and 10-year time horizon to estimate the cost and quality-adjusted life years (QALYs) for treatments. Clinical data were obtained from the POLLUX (Phase 3 Study Comparing DRd Versus Rd in Subjects with Relapsed or Refractory Multiple Myeloma [RRMM]) and CASTOR (Phase 3 Study Comparing DVd Versus Vd in Subjects with RRMM) trials. Deterministic and probabilistic sensitivity analyses were conducted to evaluate model uncertainty.
FINDINGS: The incremental cost-effectiveness ratio (ICER) for DVd compared with Vd was $284,180 per QALY; the ICER for DRd compared with Rd was $1,369,062 per QALY. Only when the price of daratumumab was reduced to 37% (US $702/vial) of the current price could the addition of daratumumab to Vd be cost-effective under the US willingness-to-pay (WTP) of $50,000/QALY. However, under no discount level of the daratumumab price is the addition of daratumumab to Rd acceptable. When the WTP increased to $300,000/QALY, the addition of DVd had a 56.7% probability of being cost-effective compared with the Vd regimen.
IMPLICATIONS: Due to the high price of daratumumab, neither the addition of daratumumab to Rd nor Vd proved to be cost-effective under US WTP. However, if the daratumumab price fell to a certain discount level, the DVd regimen might be cost-effective.
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Observation Status, Poverty, and High Financial Liability Among Medicare Beneficiaries
Observation Status, Poverty, and High Financial Liability Among Medicare Beneficiaries
Goldstein JN, Zhang Z, Schwartz JS, Hicks LS

Am. J. Med. 2018 Jan;131(1):101.e9-101.e15

PMID: 28774801

Abstract

BACKGROUND: Medicare beneficiaries hospitalized under observation status are subject to cost-sharing with no spending limit under Medicare Part B. Because low-income status is associated with increased hospital use, there is concern that such beneficiaries may be at increased risk for high use and out-of-pocket costs related to observation care. Our objective was to determine whether low-income Medicare beneficiaries are at risk for high use and high financial liability for observation care compared with higher-income beneficiaries.
METHODS: We performed a retrospective, observational analysis of Medicare Part B claims and US Census Bureau data from 2013. Medicare beneficiaries with Part A and B coverage for the full calendar year, with 1 or more observation stay(s), were included in the study. Beneficiaries were divided into quartiles representing poverty level. The associations between poverty quartile and high use of observation care and between poverty quartile and high financial liability for observation care were evaluated.
RESULTS: After multivariate adjustment, the risk of high use was higher for beneficiaries in the poor (Quartile 3) and poorest (Quartile 4) quartiles compared with those in the wealthiest quartile (Quartile 1) (adjusted odds ratio [AOR], 1.21; 95% confidence interval [CI], 1.13-1.31; AOR, 1.24; 95% CI, 1.16-1.33). The risk of high financial liability was higher in every poverty quartile compared with the wealthiest and peaked in Quartile 3, which represented the poor but not the poorest beneficiaries (AOR, 1.17; 95% CI, 1.10-1.24).
CONCLUSIONS: Poverty predicts high use of observation care. The poor or near poor may be at highest risk for high liability.
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Cost-effectiveness of revascularization strategies: the ASCERT study
Cost-effectiveness of revascularization strategies: the ASCERT study
Zhang Z, Kolm P, Grau-Sepulveda MV, Ponirakis A, O'Brien SM, Klein LW, Shaw RE, McKay C, Shahian DM, Grover FL, Mayer JE, Garratt KN, Hlatky M, Edwards FH, Weintraub WS

J. Am. Coll. Cardiol. 2015 Jan;65(1):1-11

PMID: 25572503

Abstract

BACKGROUND: ASCERT (American College of Cardiology Foundation and the Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategies) was a large observational study designed to compare the long-term effectiveness of coronary artery bypass graft (CABG) and percutaneous coronary intervention (PCI) to treat coronary artery disease (CAD) over 4 to 5 years.
OBJECTIVES: This study examined the cost-effectiveness of CABG versus PCI for stable ischemic heart disease.
METHODS: The Society of Thoracic Surgeons and American College of Cardiology Foundation databases were linked to the Centers for Medicare and Medicaid Services claims data. Costs for the index and observation period (2004 to 2008) hospitalizations were assessed by diagnosis-related group Medicare reimbursement rates; costs beyond the observation period were estimated from average Medicare participant per capita expenditure. Effectiveness was measured via mortality and life-expectancy data. Cost and effectiveness comparisons were adjusted using propensity score matching with the incremental cost-effectiveness ratio expressed as cost per quality-adjusted life-year gained.
RESULTS: CABG patients (n = 86,244) and PCI patients (n = 103,549) were at least 65 years old with 2- or 3-vessel coronary artery disease. Adjusted costs were higher for CABG for the index hospitalization, study period, and lifetime by $10,670, $8,145, and $11,575, respectively. Patients undergoing CABG gained an adjusted average of 0.2525 and 0.3801 life-years relative to PCI over the observation period and lifetime, respectively. The life-time incremental cost-effectiveness ratio of CABG compared to PCI was $30,454/QALY gained.
CONCLUSIONS: Over a period of 4 years or longer, patients undergoing CABG had better outcomes but at higher costs than those undergoing PCI.
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Risk factors for cardiovascular events and bleeding complications following non-cardiac surgery or procedure in patients with drug eluting stent placement
Risk factors for cardiovascular events and bleeding complications following non-cardiac surgery or procedure in patients with drug eluting stent placement
Tiwari D, Jurkovitz CT, Zhang Z, Bowen J, Kolm P, Wygant G, Weintraub WS

Heart Asia 2014;6(1):69-75

PMID: 27326174

Abstract

OBJECTIVES: Previous studies suggest an increased incidence of cardiovascular (CV) events after P2Y12 receptor blocker cessation. The aim of this study was to examine the effect of P2Y12 receptor blocker cessation and other risk factors on the risk of CV events and bleeding events after non-cardiac surgery/procedure in patients with drug-eluting stents (DES).
DESIGN: Retrospective cohort study.
SETTING: Single large healthcare system in the northeast of the USA.
PATIENTS: All adult patients who had a coronary drug eluting stent (DES) placed between 2002 and 2007 in our institution.
INTERVENTIONS: No randomised intervention. The principal exposure was cessation of P2Y12 receptor blocker.
METHODS: This was a retrospective study of all adult patients who had a coronary DES placed between 2002 and 2007 in our institution. We considered all non-cardiac procedures up to 1 year after DES placement. Generalised estimating equations were used to identify the independent risk factors. Multiple imputations were used to replace missing values.
MAIN OUTCOME MEASURES: The outcomes were CV events including death from any cause and bleeding, occurring within 30 days after the procedure.
RESULTS: From 2002 to 2007, 6397 patients had DES, 873 (13.6%) had at least one non-cardiac procedure. A total of 3.6% (33/927) of the admissions were complicated by at least one cardiovascular event and 6.9% (55/795) were complicated by bleeding. Urgent procedure (versus elective) was the only independent risk factor for CV events (OR=4.82, 95% CI 1.95 to 11.89). Older age, diabetes, urgent procedures, orthopaedic and vascular surgery compared to unclassified surgery were independent risk factors for bleeding.
CONCLUSIONS: Non-cardiac procedures are common within 1 year after DES placement. Urgent nature of procedure is a risk factor for CV events and bleeding complications. Older age, diabetes, type of surgery, are risk factors associated only with bleeding events.
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