scholarly journals Measurement Disparities in Frailty Among Kidney Transplant Patients: Impact of Differential Item Functioning

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 447-447
Author(s):  
Nadia Chu ◽  
Alden Gross ◽  
Xiaomeng Chen ◽  
Qian-Li Xue ◽  
Karen Bandeen-Roche ◽  
...  
Keyword(s):  
Weight Loss ◽  
Differential Item Functioning ◽  
Kidney Transplant ◽  
Frailty Phenotype ◽  
Multiple Indicators ◽  
Transplant Patients ◽  
Black Candidates ◽  
Item Functioning ◽  
The Impact ◽  
Low Activity

Abstract Frailty is commonly measured for clinical risk stratification during transplant evaluation and is more prevalent among older, non-White kidney transplant (KT) patients. However, group differences may be partially attributable to misclassification resulting from measurement bias (differential item functioning/DIF). We examined the extent that DIF affects estimates of age, sex, and race differences in frailty (physical frailty phenotype/PFP) prevalence among 4,300 candidates and 1,396 recipients. We used Multiple Indicators Multiple Causes with dichotomous indicators to assess uniform DIF in PFP criteria attributable to age (≥65vs.18-64 years), sex, and race (Black vs.White). Among candidates (mean age=55 years), 41% were female, 46% were Black, and 19% were frail. After controlling for mean frailty level, females were more likely to endorse exhaustion (OR=1.20,p=0.003), but less likely to endorse low activity (OR=0.83,p=0.01). Younger candidates were more likely to endorse weight loss (OR=1.30,p=0.005), exhaustion (OR=1.60,p<0.001), and low activity (OR=1.80,p<0.001). Black candidates were more likely to endorse exhaustion (OR=1.25,p<0.001), but less likely to endorse weakness (OR=0.79,p<0.001). Among recipients (mean age=54 years), 40% were female, 39% were Black, and 15% were frail. Younger recipients were more likely to endorse weight loss (OR=1.55,p=0.005) and low activity (OR=1.61,p=0.02); however, no DIF was detected by sex or race. Results highlight the impact of DIF for specific PFP measures by age, sex, and race among candidates, but only by age for recipients. Further research is needed to ascertain whether candidate- and/or recipient-specific thresholds to correct for DIF could improve risk prediction and equitable access to KT for older, female, and Black candidates.

scholarly journals Clinical Relevance of Corticosteroid Withdrawal on Graft Histological Lesions in Low-Immunological-Risk Kidney Transplant Patients

2021 ◽  
Vol 10 (9) ◽  
pp. 2005
Author(s):  
Domingo Hernández ◽  
Juana Alonso-Titos ◽  
Teresa Vázquez ◽  
Myriam León ◽  
Abelardo Caballero ◽  
...  
Keyword(s):  
Kidney Transplant ◽  
Rejection Rate ◽  
Open Label ◽  
Post Transplantation ◽  
Protocol Biopsy ◽  
Corticosteroid Withdrawal ◽  
Transplant Patients ◽  
Prospective Phase ◽  
Kidney Transplant Patients ◽  
The Impact

The impact of corticosteroid withdrawal on medium-term graft histological changes in kidney transplant (KT) recipients under standard immunosuppression is uncertain. As part of an open-label, multicenter, prospective, phase IV, 24-month clinical trial (ClinicalTrials.gov, NCT02284464) in low-immunological-risk KT recipients, 105 patients were randomized, after a protocol-biopsy at 3 months, to corticosteroid continuation (CSC, n = 52) or corticosteroid withdrawal (CSW, n = 53). Both groups received tacrolimus and MMF and had another protocol-biopsy at 24 months. The acute rejection rate, including subclinical inflammation (SCI), was comparable between groups (21.2 vs. 24.5%). No patients developed dnDSA. Inflammatory and chronicity scores increased from 3 to 24 months in patients with, at baseline, no inflammation (NI) or SCI, regardless of treatment. CSW patients with SCI at 3 months had a significantly increased chronicity score at 24 months. HbA1c levels were lower in CSW patients (6.4 ± 1.2 vs. 5.7 ± 0.6%; p = 0.013) at 24 months, as was systolic blood pressure (134.2 ± 14.9 vs. 125.7 ± 15.3 mmHg; p = 0.016). Allograft function was comparable between groups and no patients died or lost their graft. An increase in chronicity scores at 2-years post-transplantation was observed in low-immunological-risk KT recipients with initial NI or SCI, but CSW may accelerate chronicity changes, especially in patients with early SCI. This strategy did, however, improve the cardiovascular profiles of patients.

scholarly journals Effect of Remdesivir on COVID-19 PCR Positivity and Cycle Threshold in Kidney Transplant Recipients

2021 ◽  
Vol 2 (3) ◽  
pp. 291-293
Author(s):  
Ryan J. Winstead ◽  
Johanna Christensen ◽  
Sara Sterling ◽  
Megan Morales ◽  
Dhiren Kumar ◽  
...  
Keyword(s):  
Kidney Transplant ◽  
Transplant Recipients ◽  
Kidney Transplant Recipients ◽  
Cycle Threshold ◽  
Transplant Patients ◽  
Kidney Transplant Patients ◽  
Polymerase Chain ◽  
New Diagnosis ◽  
The Impact ◽  
Median Change

Information regarding Coronavirus disease 2019 in the transplant population is lacking. Recently it has been suggested that cycle threshold values obtained on polymerase chain reaction tests may serve as a marker of disease severity with lower values (i.e., higher viral load) being associated with higher mortality. This study was done to assess the impact of remdesivir use on the time to a negative COVID-19 PCR as well as the degree of change between two Ct’s based on treatment. A total of 30 kidney transplant patients with a new diagnosis of COVID-19 were assessed. Serial PCR results were followed from the time of diagnosis then every 2–4 weeks until negative. In patients who received remdesivir immediately after COVID-19 confirmation compared to no remdesivir, time to negative PCR was not statistically different with a median duration of 57 days in both groups (p = 0.369). The change in the Ct between the first and the second PCR test was also not statistically different between groups with a median change of 18.4 cycles in the remdesivir group and 15.7 cycles without remdesivir (p = 0.516). The results of this small single-center analysis suggest that remdesivir may not be beneficial in shortening time to a negative COVID-19 PCR.

scholarly journals Differential item functioning of the Boston Naming Test in cognitively normal African American and Caucasian older adults

2009 ◽  
Vol 15 (5) ◽  
pp. 758-768 ◽  
Author(s):  
OTTO PEDRAZA ◽  
NEILL R. GRAFF-RADFORD ◽  
GLENN E. SMITH ◽  
ROBERT J. IVNIK ◽  
FLOYD B. WILLIS ◽  
...  
Keyword(s):  
African American ◽  
Item Response Theory ◽  
Differential Item Functioning ◽  
Item Response ◽  
Group Performance ◽  
Response Theory ◽  
Boston Naming Test ◽  
Item Functioning ◽  
The Impact ◽  
Naming Test

AbstractScores on the Boston Naming Test (BNT) are frequently lower for African American when compared with Caucasian adults. Although demographically based norms can mitigate the impact of this discrepancy on the likelihood of erroneous diagnostic impressions, a growing consensus suggests that group norms do not sufficiently address or advance our understanding of the underlying psychometric and sociocultural factors that lead to between-group score discrepancies. Using item response theory and methods to detect differential item functioning (DIF), the current investigation moves beyond comparisons of the summed total score to examine whether the conditional probability of responding correctly to individual BNT items differs between African American and Caucasian adults. Participants included 670 adults age 52 and older who took part in Mayo’s Older Americans and Older African Americans Normative Studies. Under a two-parameter logistic item response theory framework and after correction for the false discovery rate, 12 items where shown to demonstrate DIF. Of these 12 items, 6 (“dominoes,” “escalator,” “muzzle,” “latch,” “tripod,” and “palette”) were also identified in additional analyses using hierarchical logistic regression models and represent the strongest evidence for race/ethnicity-based DIF. These findings afford a finer characterization of the psychometric properties of the BNT and expand our understanding of between-group performance. (JINS, 2009, 15, 758–768.)

RETROSPECTIVE STUDY ON THE IMPACT OF HEPATITIS C VIRUS INFECTION ON KIDNEY TRANSPLANT PATIENTS OVER 20 YEARS

1998 ◽  
Vol 66 (4) ◽  
pp. 471-476 ◽  
Author(s):  
Touru Hanafusa ◽  
Yasuji Ichikawa ◽  
Hidefumi Kishikawa ◽  
Masahiro Kyo ◽  
Takanobu Fukunishi ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Retrospective Study ◽  
Hepatitis C ◽  
Virus Infection ◽  
Kidney Transplant ◽  
Hepatitis C Virus Infection ◽  
Transplant Patients ◽  
Kidney Transplant Patients ◽  
The Impact

scholarly journals Effect of CYP3A4*22, POR*28, and PPARA rs4253728 on Sirolimus In Vitro Metabolism and Trough Concentrations in Kidney Transplant Recipients

2013 ◽  
Vol 59 (12) ◽  
pp. 1761-1769 ◽  
Author(s):  
Jean-Baptiste Woillard ◽  
Nassim Kamar ◽  
Sandra Coste ◽  
Lionel Rostaing ◽  
Pierre Marquet ◽  
...  
Keyword(s):  
Adverse Events ◽  
Kidney Transplant ◽  
Calcineurin Inhibitor ◽  
Transplant Recipients ◽  
Kidney Transplant Recipients ◽  
Transplant Patients ◽  
Kidney Transplant Patients ◽  
Trough Concentrations ◽  
The Impact

BACKGROUND Recent studies have identified new candidate polymorphisms in the genes related to CYP3A activity or calcineurin inhibitor dose requirements in kidney transplant recipients. These genes and polymorphisms are CYP3A4 (cytochrome P450, family 3, subfamily A, polypeptide 4) (rs35599367-C>T; *22); POR [P450 (cytochrome) oxidoreductase] (rs1057868-C>T; *28); and PPARA (peroxisome proliferator-activated receptor alpha) (rs4253728-G>A). We investigated the impact of these polymorphisms on sirolimus (SRL) in vitro hepatic metabolism, SRL trough concentrations (C0), and SRL adverse events in kidney transplant recipients. METHODS The clinical study included 113 stable kidney transplant patients switched from a calcineurin inhibitor to SRL (SRL C0 measured at 1, 3, and 6 months thereafter). We investigated SRL metabolism in vitro using human liver microsomes derived from individual donors (n = 31). Microsomes and patients were genotyped by use of Taqman® allelic discrimination assays. The effects of polymorphisms and covariates were studied using multilinear regression imbedded in linear mixed-effect models or logistic regressions. RESULTS In vitro, the CYP3A4*22 allele resulted in approximately 20% lower metabolic rates of SRL (P = 0.0411). No significant association was found between CYP3A4, CYP3A5, or PPARA genotypes and SRL dose, C0, or C0/dose in kidney transplant patients. POR*28 was associated with a minor but significant decrease in SRL log-transformed C0 [CT/TT vs CC, β = −0.15 (0.05); P = 0.0197] but this did not have any impact on the dose administered, which limited the relevance of the finding. After adjustment for nongenetic covariates and correction for false discovery finding, none of the single-nucleotide polymorphisms tested showed significant association with SRL adverse events. CONCLUSIONS These recently described polymorphisms do not seem to substantially influence the pharmacokinetics of SRL or the occurrence of SRL adverse events in kidney transplant recipients.

Geriatric Anxiety Scale: item response theory analysis, differential item functioning, and creation of a ten-item short form (GAS-10)

2014 ◽  
Vol 27 (7) ◽  
pp. 1099-1111 ◽  
Author(s):  
Anne E. Mueller ◽  
Daniel L. Segal ◽  
Brandon Gavett ◽  
Meghan A. Marty ◽  
Brian Yochim ◽  
...  
Keyword(s):  
Older Adults ◽  
Item Response Theory ◽  
Psychometric Properties ◽  
Differential Item Functioning ◽  
Item Response ◽  
Short Form ◽  
Anxiety Scale ◽  
Response Theory ◽  
Item Functioning ◽  
The Impact

ABSTRACTBackground:The Geriatric Anxiety Scale (GAS; Segal et al. (Segal, D. L., June, A., Payne, M., Coolidge, F. L. and Yochim, B. (2010). Journal of Anxiety Disorders, 24, 709–714. doi:10.1016/j.janxdis.2010.05.002) is a self-report measure of anxiety that was designed to address unique issues associated with anxiety assessment in older adults. This study is the first to use item response theory (IRT) to examine the psychometric properties of a measure of anxiety in older adults.Method:A large sample of older adults (n = 581; mean age = 72.32 years, SD = 7.64 years, range = 60 to 96 years; 64% women; 88% European American) completed the GAS. IRT properties were examined. The presence of differential item functioning (DIF) or measurement bias by age and sex was assessed, and a ten-item short form of the GAS (called the GAS-10) was created.Results:All GAS items had discrimination parameters of 1.07 or greater. Items from the somatic subscale tended to have lower discrimination parameters than items on the cognitive or affective subscales. Two items were flagged for DIF, but the impact of the DIF was negligible. Women scored significantly higher than men on the GAS and its subscales. Participants in the young-old group (60 to 79 years old) scored significantly higher on the cognitive subscale than participants in the old-old group (80 years old and older).Conclusions:Results from the IRT analyses indicated that the GAS and GAS-10 have strong psychometric properties among older adults. We conclude by discussing implications and future research directions.

scholarly journals A Simulation Study to Assess the Effect of the Number of Response Categories on the Power of Ordinal Logistic Regression for Differential Item Functioning Analysis in Rating Scales

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Elahe Allahyari ◽  
Peyman Jafari ◽  
Zahra Bagheri
Keyword(s):  
Logistic Regression ◽  
Sample Size ◽  
Differential Item Functioning ◽  
Rating Scales ◽  
Error Rates ◽  
Ordinal Logistic Regression ◽  
Type I ◽  
Item Functioning ◽  
Quality Of Life Scale ◽  
The Impact

Objective.The present study uses simulated data to find what the optimal number of response categories is to achieve adequate power in ordinal logistic regression (OLR) model for differential item functioning (DIF) analysis in psychometric research.Methods.A hypothetical ten-item quality of life scale with three, four, and five response categories was simulated. The power and type I error rates of OLR model for detecting uniform DIF were investigated under different combinations of ability distribution (θ), sample size, sample size ratio, and the magnitude of uniform DIF across reference and focal groups.Results.Whenθwas distributed identically in the reference and focal groups, increasing the number of response categories from 3 to 5 resulted in an increase of approximately 8% in power of OLR model for detecting uniform DIF. The power of OLR was less than 0.36 when ability distribution in the reference and focal groups was highly skewed to the left and right, respectively.Conclusions.The clearest conclusion from this research is that the minimum number of response categories for DIF analysis using OLR is five. However, the impact of the number of response categories in detecting DIF was lower than might be expected.

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