A multivariate zero-inflated binomial model for the analysis of correlated proportional data.

In this paper, a new multivariate zero-inflated binomial (MZIB) distribution is proposed to analyse the correlated proportional data with excessive zeros. The distributional properties of purposed model are studied. The Fisher scoring algorithm and EM algorithm are given for the computation of estimates of parameters in the proposed MZIB model with/without covariates. The score tests and the likelihood ratio tests are derived for assessing both the zero-inflation and the equality of multiple binomial probabilities in correlated proportional data. A limited simulation study is performed to evaluate the performance of derived EM algorithms for the estimation of parameters in the model with/without covariates and to compare the nominal levels and powers of both score tests and likelihood ratio tests. The whitefly data is used to illustrate the proposed methodologies.

Efficacy and safety of polymer-free stent versus polymer-permanent drug-eluting stent in patients with acute coronary syndrome: a meta-analysis of randomized control trials.

BACKGROUND: The efficacy and safety of polymer-free stent (PFS) versus permanent polymer drug-eluting stent (PPDES) in patients undergoing percutaneous coronary intervention (PCI) remain controversial. Our meta-analysis was undertaken to evaluate and compare the efficacy and safety of PFS with those of PPDES in patients undergoing PCI. METHODS: We searched PubMed, Cochrane Library, EMBASE, and Clinical Trials.gov databases for randomized controlled trials (RCTs). The primary endpoints were incidence of stent thrombosis (ST) and target-lesion revascularization (TLR). The secondary endpoints included the incidence of major adverse cardiovascular events (MACE), myocardial infarction (MI), cardiac death (CD), late lumen loss (LLL), and diameter stenosis (DS). Subgroup analyses were also conducted based on the follow-up time. RESULTS: Eleven RCTs met the including criteria, and 8616 patients were included in the study. No significant differences were observed between PFS and PPDES treatments in the incidence of ST (RR 0.90; 95% CI: 0.62-1.31; P = 0.58; I 2  = 0), TLR (RR 0.87; 95% CI: 0.76-1.00; P = 0.05; I 2  = 37%), CD (RR 0.89; 95% CI: 0.72-1.10; P = 0.28; I 2  = 0), MI (RR 0.87; 95% CI: 0.71-1.05; P = 0.15; I 2  = 0), LLL (SMD 0.01; 95% CI: -0.29-0.30; P = 0.96; I2 = 90%), and DS (SMD -0.01; 95% CI: - 0.25 to 0.23; P = 0.93; I2 = 83%). Meanwhile, the patients with PFS had a lower incidence of MACE (RR 0.87; 95% CI: 0.78-0.97; P = 0.01; I 2  = 0) than those with PPDES. CONCLUSION: In the overall analysis, patients with PFS presented a lower risk of MACE versus PPDES, but no significant difference were obtained in the risk of ST, TLR, MI, CD, DDD and DS. In the Short term follow up, patients with PSF presented a lower risk of TLR compared with PPDES.

[Association between metabolic syndrome and chronic kidney disease].

OBJECTIVE: To explore the associations between the metabolic syndrome (MS) and chronic kidney disease (CKD) in patients admitted to our department. METHODS: A total of 525 consecutive patients were included in this cross-sectional study. Body height, weight, waist circumference, biochemical and serum lipid profile were measured. An oral glucose tolerance test (OGTT) was performed in patients without diabetes. CKD was defined by creatinine-based estimates of glomerular filtration rate (eGFR). The MS was defined according to IDF (International Diabetes Federation) definition. RESULTS: (1) Serum creatinine (Cr) was significantly increased and the mean level of eGFR was significantly reduced in patients with MS compared to those without MS [Cr (93.81 +/- 31.06) micromol/L vs. (108.65 +/- 36.05) micromol/L, P < 0.001; eGFR (61.14 +/- 17.40) ml.min(-1).1.73 m(-2) vs. (73.64 +/- 17.03) ml.min(-1).1.73 m(-2), P < 0.001]. (2) eGFR decreased in proportion to increasing number of the MS components and was the lowest when patients had 5 components of the MS (P < 0.001). (3) Compared to patients without MS, the multivariate-adjusted (adjustment for age, sex, chronic heart failure and the use of ACEI or ARB medication) odds ration (95% CI) of CKD was 4.34 (95% CI: 2.77 - 6.81) in patients with MS. Compared to patients without any components or only with one component, the multivariate-adjusted odds ratios (95% CI) of CKD were 3.12 (1.41 - 6.89), 8.21 (3.78 - 17.82) and 14.72 (6.14 - 35.30) for those with 3, 4 and 5 components, respectively. In the multivariate models, elevated blood pressure, hyperglycemia, abdominal obesity and elevated triglycerides were significantly associated with an increased odds ratio (95% CI) of CKD, 1.75 (1.04 - 2.92), 1.98 (1.26 - 3.11), 2.42 (1.41 - 4.16) and 2.65 (1.68 - 4.19), respectively. CONCLUSION: There are positive associations between MS, its components and CKD. The risk of CKD increased in proportion to increased number of MS components. Elevated blood pressure, hyperglycemia, abdominal obesity and hypertriglyceridemia also increase the risk of CKD.