Applied Mixed Models in Medicine

Brown, Helen; Prescott, R. J.

doi:10.1002/9781118778210

Cited by 290 publications

(327 citation statements)

References 0 publications

Supporting

Mentioning

319

Contrasting

Unclassified

Order By: Relevance

“…Multivariate analysis of the main predictors of complications was performed by using logistic regression model [26,27]. Because the unit of observation (patient) was different from the unit of analysis (center), a within-center correlation of outcomes was taken into account by means of a random-effect analysis with grouping by center [28]. Centers were also separated according to the hospital academic status (academic vs. non-academic center).…”

Section: Resultsmentioning

confidence: 99%

Adverse events of computed tomography colonography: An Italian National Survey

Iafrate¹,

Iussich²,

Correale³

et al. 2013

Digestive and Liver Disease

View full text Add to dashboard Cite

a b s t r a c tAim: To retrospectively study the frequency and magnitude of complications associated with computed tomography (CT) colonography in clinical practice. Methods: A questionnaire on complications of CT colonography was sent to Italian public radiology departments identified as practicing CT colonography with a reasonable level of training. The frequency of complications and possible risk factors were retrospectively determined. Responses were collated and row frequencies determined. A multivariate analysis of the factors causing adverse events was also performed. Results: 40,121 examinations were performed in13 centers during the study period. No deaths were reported. Bowel perforations occurred in 0.02% (7 exams). All perforations were asymptomatic and occurred in patients undergoing manual insufflation. Five perforations (71%) occurred in procedures performed following a recent colonoscopy. There was no significant difference between perforations associated with rectal balloon (0.017%) and those that were not (0.02%). Complications related to vasovagal reaction (either with or without spasmolytic) occurred in 0.16% (63 exams). All vasovagal reactions resolved in less than 3 h, without any sequelae. Conclusions: Perforation rate at CT colonography in Italy is comparable with elsewhere in the world, occurring regardless of the experience of radiology centers. Although the risk is very small, it may not be negligible when compared with the risk of diagnostic colonoscopy.

show abstract

Section: Resultsmentioning

confidence: 99%

Adverse events of computed tomography colonography: An Italian National Survey

Iafrate¹,

Iussich²,

Correale³

et al. 2013

Digestive and Liver Disease

View full text Add to dashboard Cite

show abstract

“…DNAm measures can be conceptualized as repeat measures within an individual. For this reason, we used a 2-level multilevel model, 46 to examine associations of individual-level SES with multiple measures of DNAm within each gene. This approach allowed us to account for correlations between DNAm levels within an individual by including a random intercept for each person.…”

Section: Resultsmentioning

confidence: 99%

Life course socioeconomic status and DNA methylation in genes related to stress reactivity and inflammation: The multi-ethnic study of atherosclerosis

et al. 2015

View full text Add to dashboard Cite

y Co-first authors. Keywords: DNA methylation, gene expression, inflammation, socioeconomic status, stress reactivityEpigenetic changes, such as DNA methylation, have been hypothesized to provide a link between the social environment and disease development. The purpose of this study was to examine associations between life course measures of socioeconomic status (SES) and DNA methylation (DNAm) in 18 genes related to stress reactivity and inflammation using a multi-level modeling approach that treats DNAm measurements as repeat measures within an individual. DNAm and gene expression were assessed in purified monocytes for a random subsample of 1,264 nonHispanic white, African-American, and Hispanic participants aged 55-94 from the Multi-Ethnic Study of Atherosclerosis (MESA). After correction for multiple testing, we found that low childhood SES was associated with DNAm in 3 stressrelated genes (AVP, FKBP5, OXTR) and 2 inflammation-related genes (CCL1, CD1D), low adult SES was associated with DNAm in one stress-related gene (AVP) and 5 inflammation-related genes (CD1D, F8, KLRG1, NLRP12, TLR3), and social mobility was associated with DNAm in 3 stress-related genes (AVP, FKBP5, OXTR) and 7 inflammation-related genes (CCL1, CD1D, F8, KLRG1, NLRP12, PYDC1, TLR3). In general, low SES was associated with increased DNAm. Expression data was available for 7 genes that showed a significant relationship between SES and DNAm. In 5 of these 7 genes (CD1D, F8, FKBP5, KLRG1, NLRP12), DNAm was associated with gene expression for at least one transcript, providing evidence of the potential functional consequences of alterations in DNAm related to SES. The results of this study reflect the biological complexity of epigenetic data and underscore the need for multi-disciplinary approaches to study how DNAm may contribute to the social patterning of disease.

show abstract

“…A mixed model addresses the dependence of observations in a repeated measurement design by modeling the within-person and between-person variances simultaneously. 20,21 It allows for an analysis of repeated measures with unbalanced times of measurement. 22 We analyzed the correlations of 1,5-AG and FA with other glycemic parameters calculated from CGMS data for the two visits using a mixed model with AR(1) covariance between the two visits.…”

Section: Resultsmentioning

confidence: 99%

“…22 We analyzed the correlations of 1,5-AG and FA with other glycemic parameters calculated from CGMS data for the two visits using a mixed model with AR(1) covariance between the two visits. [20][21][22][23] Statistical significance was established as P < 0.05.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of Glycemic Variability in Well-Controlled Type 2 Diabetes Mellitus

Chon

Lee²,

Fraterrigo³

et al. 2013

Diabetes Technology & Therapeutics

View full text Add to dashboard Cite

Aims: It is necessary to evaluate glucose variability and postprandial hyperglycemia in patients with well-controlled type 2 diabetes mellitus because of the limitations associated with hemoglobin A1c (HbA1c) measurements. We evaluated parameters reflecting postprandial hyperglycemia and glycemic variability in patients with optimal HbA1c. Patients and Methods: Thirty-nine patients with HbA1c levels below 7% were recruited to the study. A continuous glucose monitoring system (CGMS) was applied for two 72-h periods. 1,5-Anhydroglucitol (1,5-AG) and fructosamine (FA) were measured as parameters for postprandial hyperglycemia and glucose variability. Using CGMS data, the following postprandial hyperglycemia parameters were calculated: mean postprandial maximum glucose (MPMG) and area under the curve for glucose above 180 mg/dL (AUC-180). To measure glycemic variability, we calculated mean amplitude of glucose excursion (MAGE) using a classical (MAGE c ) and new method (MAGE group of sign [MAGE gos ]). Results: The baseline HbA1c level was 6.3 -0.3%. The mean MPMG was 10.34 -1.84 mmol/L, and the mean AUC-180 was 0.17 -0.23 mmol/L/day. The mean MAGE gos was 3.27 -1.29 mmol/L, and MAGE c was 4.30 -1.43 mmol/L, indicating glycemic variability in our patients. The mean levels of 1,5-AG and FA were 16.7 -7.4 lg/mL and 273.0 -22.5 lmol/L, respectively. In a correlation analysis, FA was significantly correlated with MPMG, AUC-180, MAGE gos , and MAGE c . In contrast, 1,5-AG was only correlated with AUC-180. Conclusions: This study demonstrated postprandial hyperglycemia and glycemic variability in subjects with well-controlled diabetes. FA may reflect postprandial hyperglycemia and glycemic variability, but 1,5-AG may be of limited value for assessing glucose variability in patients with well-controlled type 2 diabetes mellitus.

show abstract

Applied Mixed Models in Medicine

Cited by 290 publications

References 0 publications

Adverse events of computed tomography colonography: An Italian National Survey

Adverse events of computed tomography colonography: An Italian National Survey

Life course socioeconomic status and DNA methylation in genes related to stress reactivity and inflammation: The multi-ethnic study of atherosclerosis

Evaluation of Glycemic Variability in Well-Controlled Type 2 Diabetes Mellitus

Contact Info

Product

Resources

About