Quality Appraisal of Diagnostic Accuracy Studies in Fine-Needle Aspiration Cytology: A Survey of Risk of Bias and Comparability

Accuracy, Sensitivity and Specificity of Fine Needle Aspiration Biopsy for Salivary Gland Tumors: A Retrospective Study from 2006 to 2011

Objective:

This article concerns evaluation of the sensitivity, specificity and accuracy of FNAB for pre-surgical diagnosis of benign and malignant lesions of major and minor salivary glands of patients treated in the Department of Head and Neck Surgery of Erasto Gartner Hospital.

Methods:

This retrospective study analyzed medical records from January 2006 to December 2011 from patients with salivary gland lesions who underwent preoperative FNAB and, after surgical excision of the lesion, histopathological examination.

Results:

The study had a cohort of 130 cases, but 34 cases (26.2%) were considered unsatisfactory regarding cytology analyses. Based on the data, sensitivity was 66.7% (6/9), specificity was 81.6% (71/87), accuracy was 80.2% (77/96), the positive predictive value was 66,7% (6/9) and the negative predictive value was 81.6% (71/87).

Conclusion:

Despite the high rate of inadequate samples obtained in the FNAB in this study the technique offers high specificity, accuracy and acceptable sensitivity.

Endoscopic ultrasound-guided fine needle aspiration is highly accurate for the diagnosis of perirectal recurrence of colorectal cancer

BACKGROUND

Endoscopic ultrasound-guided fine needle aspiration is highly accurate for the diagnosis of malignancies surrounding the gastrointestinal tract. There is a lack of information on the usefulness of this technique in the diagnosis of colorectal cancer recurrence.

OBJECTIVE

The purpose of this work was to investigate the performance characteristics of endoscopic ultrasound-guided fine needle aspiration for the cytologic diagnosis of perirectal recurrence of colorectal cancer.

DESIGN

This was a retrospective study on the clinical and radiologic suspicion of perirectal recurrence of colorectal cancer.

SETTINGS

The study was conducted at 4 tertiary hospitals.

PATIENTS

Consecutive patients with suspicion of perirectal recurrence of colorectal cancer undergoing endoscopic ultrasound-guided fine needle aspiration between 2000 and 2013 were included in this study.

INTERVENTIONS

The study intervention was endoscopic ultrasound-guided fine needle aspiration.

MAIN OUTCOME MEASURES

Endoscopic ultrasound-guided fine needle aspiration performance characteristics and outcome (malignant or benign) were analyzed. The gold standard was cytologic results if malignancy or follow-up if benignity.

RESULTS

A total of 58 patients were included (32 men; mean age, 64.2 ± 10.0 years [range, 44-88 years]). The location of the initial neoplasm was the rectum for 42 patients and the colon for 16 patients. Endoscopic ultrasound findings included a mass in the anastomosis (n = 8), perirectal fat (n = 23), lymph nodes (n = 20), or asymmetric thickness of the rectal wall (n = 6). Cytology showed malignancy in 38 patients (67%), benign features in 17 (30%), and was not evaluable in 2. Mean follow-up to confirm a benign outcome was 51.3 ± 30.3 months (range, 5.2-180.0 months). Final outcome was recurrence in 40 patients (69%) and benignity in 18 patients (31%). Performance characteristics of endoscopic ultrasound-guided fine needle aspiration were sensitivity (97%), specificity (100%), positive predictive value (100%), negative predictive value (94%), and accuracy (98%). In the intention to diagnose analysis, the corresponding values were 95%, 100%, 100%, 90%, and 96%.

LIMITATIONS

This was a retrospective series with a limited number of patients.

CONCLUSIONS

Endoscopic ultrasound-guided fine needle aspiration is a highly accurate tool for the cytologic diagnosis of perirectal recurrence in patients with previous colorectal cancer.

Diagnostic accuracy of fine needle aspiration cytology in providing a diagnosis of cervical lymphadenopathy among HIV-infected patients

BACKGROUND

Opportunistic infections and malignancies cause lymphadenopathy in HIV-infected patients. The use and accuracy of fine needle aspiration cytology in diagnosing of cervical lymphadenopathy among HIV-infected patients is not well studied in Uganda.

OBJECTIVE

The aim of this study was to determine the diagnostic accuracy of fine needle aspiration cytology in providing a diagnosis of cervical lymphadenopathy among HIV-infected patients in Uganda.

METHODS

We consecutively recruited adult HIV-infected patients with cervical lymphadenopathy admitted to Mulago Hospital medical wards. Clinical examination, fine needle aspiration and lymph node biopsy were performed. We estimated the sensitivity, specificity; negative and positive predictive values using histology as the gold standard.

RESULTS

We enrolled 108 patients with a mean age of 33 years (range, 18-60), 59% were men and mean CD4 was 83(range, 22-375) cells/mm(3). The major causes of cervical lymphadenopathy were: tuberculosis (69.4%), Kaposi's sarcoma-KS (10.2%) and reactive adenitis (7.4%). Overall fine needle aspiration cytology accurately predicted the histological findings in 65 out of 73 cases (89%) and missed 7 cases (9.5%). With a sensitivity of 93.1%, specificity of 100%, positive predictive value of 100% and negative predictive value of 78.7% for tuberculosis and 80%; 98.4%;88.9% and 98.9% for KS respectively. No fine needle aspiration complications were noted.

CONCLUSIONS

Fine needle aspiration cytology is safe and accurate in the diagnosis of tuberculosis and KS cervical lymphadenopathy among HIV-positive patients.

Verification and classification bias interactions in diagnostic test accuracy studies for fine-needle aspiration biopsy

BACKGROUND

Reliable estimates of accuracy are important for any diagnostic test. Diagnostic accuracy studies are subject to unique sources of bias. Verification bias and classification bias are 2 sources of bias that commonly occur in diagnostic accuracy studies. Statistical methods are available to estimate the impact of these sources of bias when they occur alone. The impact of interactions when these types of bias occur together has not been investigated.

METHODS

We developed mathematical relationships to show the combined effect of verification bias and classification bias. A wide range of case scenarios were generated to assess the impact of bias components and interactions on total bias.

RESULTS

Interactions between verification bias and classification bias caused overestimation of sensitivity and underestimation of specificity. Interactions had more effect on sensitivity than specificity. Sensitivity was overestimated by at least 7% in approximately 6% of the tested scenarios. Specificity was underestimated by at least 7% in less than 0.1% of the scenarios.

CONCLUSIONS

Interactions between verification bias and classification bias create distortions in accuracy estimates that are greater than would be predicted from each source of bias acting independently.

Verification bias in diagnostic accuracy studies for fine- and core needle biopsy of salivary gland lesions in otolaryngology journals: a systematic review and analysis

BACKGROUND

Diagnostic test accuracy (DTA) studies for needle biopsy are frequently published in otolaryngology journals, but this body of literature has not been assessed for verification bias.

METHODS

We conducted a systematic review of DTA studies on needle biopsy of salivary gland lesions appearing in otolaryngology journals. Studies were assessed by 2 reviewers for verification bias.

RESULTS

We identified 95 DTA studies for needle biopsy of salivary gland lesions. Eighty-one studies (84%) had verification bias. Five of the biased studies provided sufficient data to estimate the extent of bias. Verification bias was associated with an overestimate of sensitivity and an underestimate of specificity. Studies on core needle biopsy (CNB) had a lower rate of verification bias than fine-needle aspiration (FNA) studies.

CONCLUSION

Verification bias is common in DTA studies of needle biopsy for salivary gland lesions published in ear, nose, and throat (ENT) journals. Such studies overestimated sensitivity and underestimated specificity.

Ultrasound-guided core needle biopsy of salivary gland lesions: a systematic review and meta-analysis

OBJECTIVES/HYPOTHESIS

To obtain summary estimates of the sensitivity and specificity of core needle biopsy for assessment of salivary gland lesions and to investigate sources of variation in accuracy between study locations.

STUDY DESIGN

Data sources were PubMed, Embase, CAB Abstracts, CINAHL, BIOSIS, LILACS, PakMediNet, Trip Database, and the National Guideline Clearinghouse. Scopus was used to perform forward (citation) and backward (reference) searches of all potentially relevant studies.

METHODS

Screening, data extraction, and quality assessment were independently performed by two different assessors. Meta-analysis was performed using bivariate mixed-effects binary regression as implemented in Stata 12. Quality assessment was performed using the QUADAS-2.

RESULTS

The summary estimates of sensitivity and specificity of core needle biopsy for diagnosis of malignancy were 96% (95% confidence interval [CI] = 87-99) and 100% (95% CI = 84-100), respectively. There was no significant heterogeneity in accuracy between studies. The quality of included studies was high, with low risk of verification bias. The risk of hematoma was 1.6% per procedure.

CONCLUSIONS

Core needle biopsy has high sensitivity and specificity, and has low risk of complications. There is no significant variation in accuracy between study locations.