Q&A column

In summary, the goal of amendments is to correct inaccuracies in patient reports. The CAP does not provide numeric benchmarks for amendments.

1. College of American Pathologists. ANP.12185 Amended reports. In: Anatomic pathology checklist. Sept. 22, 2021.
2. Zarbo RJ, Meier FA, Raab SS. Error detection in anatomic pathology. Arch Pathol Lab Med. 2005;129(10):1237–1245.
3. Nakhleh RE, Nosé V, Colasacco C, et al. Interpretive diagnostic error reduction in surgical pathology and cytology: guideline from the College of American Pathologists Pathology and Laboratory Quality Center and the Association of Directors of Anatomic and Surgical Pathology. Arch Pathol Lab Med. 2016;140(1):29–40.
4. Meier FA, Zarbo RJ, Varney RC, et al. Amended reports: development and validation of a taxonomy of defects. Am J Clin Pathol. 2008;130(2):238–246.
5. Parkash V, Domfeh A, Cohen P, et al. Are amended surgical pathology reports getting to the correct responsible care provider? Am J Clin Pathol. 2014;142(1):58–63.
6. Staats PN, Parkash V, Otis CN, Sharma P, Ioffe O, Bracamonte ER. The current state of communication of urgent and significant, unexpected diagnoses in anatomic pathology. Arch Pathol Lab Med. 2020;144(9):1067–1074.
7. Wilkerson ML, Henricks WH, Castellani WJ, Whitsitt MS, Sinard JH. Management of laboratory data and information exchange in the electronic health record. Arch Pathol Lab Med. 2015;139(3):319–327.
8. Committee on Diagnostic Error in Health Care; Board on Health Care Services; Institute of Medicine; National Academies of Sciences, Engineering, and Medicine. Balogh EP, Miller BT, Ball JR, eds. Improving Diagnosis in Health Care. National Academies Press; 2015.

Vinita Parkash, MBBS, MPH
Associate Professor of Pathology
Yale School of Medicine
New Haven, Conn.
Member, CAP Surgical Pathology Committee

Nadine S. Aguilera, MD
Professor of Pathology
University of Virginia School of Medicine
Charlottesville, Va.
Member, CAP Surgical Pathology Committee

Mojgan Hosseini, MD
Associate Professor of Pathology
University of California, San Diego
La Jolla, Calif.
Member, CAP Surgical Pathology Committee

Aaron Auerbach, MD
Senior Pathologist, Hematopathology
Joint Pathology Center
Silver Spring, Md.
Chair, CAP Surgical Pathology Committee

(The views expressed by Dr. Auerbach are his and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. government.)

Q. What is the best practice for performing a urine specific gravity test? Which method is preferred—a refractometer or an automated dipstick? Should we correct for elevated glucose and protein or report high specific gravity? Should we correct for x-ray dyes or add a comment and list possible interfering substances?

A.A refractometer is the preferred method for measuring urine specific gravity.

CLIA regulations specify that it is the laboratory director’s responsibility to ensure test methods can provide the quality of results required for patient care. Consequently, the medical practice committees or laboratory directors at some institutions have determined that the performance characteristics of automated and visual dipsticks do not meet patient care requirements. Our institution uses refractometry to perform all urine specific gravity measurements.

There is no need to correct for glucose, protein, or contrast dyes since they contribute to urine specific gravity and the assessment of hydration status. Glucose, protein, and contrast dyes are not interfering substances.

Abbey BM, Heelan KA, Brown GA, Bartee RT. Validity of HydraTrend reagent strips for the assessment of hydration status. J Strength Cond Res. 2014;28(9):2634–2639.

Adams JD, Capitan-Jiménez C, Burchfield JM, Jansen LT, Kavouras SA. Smartphone-based analysis of urine reagent strips is inaccurate for assessing underhydration. Telemed J E Health. 2020;26(5):683–686.

Adams JD, Capitan-Jiménez C, Huggins RA, Casa DJ, Mauromoustakos A, Kavouras SA. Urine reagent strips are inaccurate for assessing hypohydration: a brief report. Clin J Sport Med. 2019;29(6):506–508.

Algiraigri AH, Truong TH, Lyon ME. Chemotherapy readiness in pediatric oncology: assessing an automated method to measure urine specific gravity. Hematol Oncol Stem Cell Ther. 2021;14(2):110–113.

Brandon CA. Urine specific gravity measurement: reagent strip versus refractometer. Clin Lab Sci. 1994;7(5):308–310.

Costa CE, Bettendorff C, Bupo S, Ayuso S, Vallejo G. Comparative measurement of urine specific gravity: reagent strips, refractometry and hydrometry. Article in Spanish. Arch Argent Pediatr. 2010;108(3):234–238.

de Buys Roessingh AS, Drukker A, Guignard JP. Dipstick measurements of urine specific gravity are unreliable. Arch Dis Child. 2001;85(2):155–157.

Rowat A, Smith L, Graham C, Lyle D, Horsburgh D, Dennis M. A pilot study to assess if urine specific gravity and urine colour charts are useful indicators of dehydration in acute stroke patients. J Adv Nurs. 2011;67(9):1976–1983.

Standard: Laboratory director responsibilities. 42 CFR §493.1445(e)(3i). https://bit.ly/493-1445-e3i

Tim Skelton, MD, PhD
Medical Director, Core Laboratory and Laboratory Informatics
Lahey Hospital and Medical Center
Burlington, Mass.
Member, CAP Hematology/Clinical Microscopy Committee