Dataset Information

Estimating the accuracy of anal cytology in the presence of an imperfect reference standard.

ABSTRACT:

Background

The study aim is to estimate sensitivity and specificity of anal cytology for histologic HSIL in analyses adjusted for the imperfect biopsy reference standard.

Methods and principal findings

Retrospective cohort study of an anal dysplasia screening program for HIV infected adults. We estimated the prevalence of histologic HSIL by concurrent cytology category and the associated cytology ROC area. Cytology operating characteristics for HSIL were estimated and adjusted for the imperfect reference standard by 3 methodologies. The study cohort included 261 patients with 3 available measures: (1) referral cytology; (2) HRA cytology; and (3) HRA directed biopsy. The prevalence of biopsy HSIL varied according to the concurrent HRA cytology result: 64.5% for HSIL or ASC-H, 12.6% for LSIL, 10.9% for ASCUS, and 6.3% for no abnormality. The cytology ROC area was 0.78. The observed prevalence of HSIL was 37% (referral cytology), 24% (HRA cytology), and 24% (HRA biopsy). Unadjusted estimates of sensitivity and specificity of cytology were 0.66 and 0.90, respectively. Adjusted estimates varied from 0.47-0.89 (sensitivity) and 0.89-1.0 (specificity).

Conclusions

Analysis of a single dataset yields widely different estimates of anal cytology operating characteristics that depend on difficult to verify assumptions regarding the accuracy of the imperfect reference standard.

SUBMITTER: Mathews WC

PROVIDER: S-EPMC2924391 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Estimating the accuracy of anal cytology in the presence of an imperfect reference standard.

Mathews William C WC Cachay Edward R ER Caperna Joseph J Sitapati Amy A Cosman Bard B Abramson Ian I

PloS one 20100819 8

<h4>Background</h4>The study aim is to estimate sensitivity and specificity of anal cytology for histologic HSIL in analyses adjusted for the imperfect biopsy reference standard.<h4>Methods and principal findings</h4>Retrospective cohort study of an anal dysplasia screening program for HIV infected adults. We estimated the prevalence of histologic HSIL by concurrent cytology category and the associated cytology ROC area. Cytology operating characteristics for HSIL were estimated and adjusted for ...[more]

PMID: 20808869

Similar Datasets

Project description:Background and objectivesFormal evaluation of kidney function before and after hematopoietic cell transplant is important to determine conditioning regimens, type of transplant, and medication dosing. Serum creatinine and estimating equations may not accurately assess kidney function.Design, study, participants, & measurementsExisting estimating equations for GFR were compared with an iohexol measure of GFR in a prospective cohort study of 50 patients undergoing hematopoietic cell transplant and subsequent care at the Fred Hutchinson Cancer Research Institute from 2009 to 2013. Patients underwent iohexol GFR, serum creatinine, and cystatin C determination at baseline and day 100 posthematopoietic cell transplant. Iohexol GFR measurements were compared with the CKD Epidemiology Collaboration, Inker CKD Epidemiology Collaboration cystatin C with and without serum creatinine, Modification of Diet in Renal Disease, and Cockcroft-Gault estimating equations using Bland-Altman analysis and McNemar's test. The iohexol measurements were also compared with blood samples collected simultaneously on filter paper.ResultsMean differences between iohexol GFR and eGFR on the basis of Bland-Altman analyses ranged from -20.6 to +15.4 ml/min per 1.73 m(2) at baseline and -12.7 to +12.9 ml/min per 1.73 m(2) at day 100. The CKD Epidemiology Collaboration and Modification of Diet in Renal Disease estimating equations classified 64% of patients with a GFR<90 at baseline compared with 38% by iohexol GFR (P=0.003 and P<0.01, respectively). No statistically significant differences were seen at day 100. The filter paper GFR had a mean difference of 0 at baseline and 5.9 at day 100. Additionally, 21%-37% and 57%-89% of eGFRs were within 10% and 30%, respectively, of the iohexol GFR at baseline, and 16%-34% and 72%-84% were within 10% and 30%, respectively, of the iohexol GFR at day 100; 98% of the filter paper estimates at baseline were within 30%, and 46% were within 10% of iohexol GFR.ConclusionsThe estimating equations are neither accurate nor precise in the hematopoietic cell transplant population, and clinical decision may require measurement of GFR.

Dataset Information

Estimating the accuracy of anal cytology in the presence of an imperfect reference standard.

Background

Methods and principal findings

Conclusions

Publications

Estimating the accuracy of anal cytology in the presence of an imperfect reference standard.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets