Repeated ANA testing costly and has low utility, says Lancet study

Written By : Medha Baranwal |Medically Reviewed By : Dr. Kamal Kant Kohli Published On 2020-07-20T10:32:33+05:30 | Updated On 20 July 2020 10:32 AM IST

Australia: There is a little benefit in repeating antinuclear antibody (ANA) testing after it has yielded a negative result in the first place, suggests a recent study in The Lancet Rheumatology journal. According to the study, repeat ANA testing after a negative result has low utility and results in high cost.

ANA testing is used frequently as a diagnostic or screening test in patients having musculoskeletal or inflammatory symptoms. The value of repeat is unclear. Ai Li Yeo, Centre for Inflammatory Diseases, Monash University, Clayton, VIC, Australia, and colleagues sought to evaluate the frequency, utility, and cost of repeat ANA testing. They assessed the positive predictive value of a repeat ANA test for the diagnosis of rheumatological conditions associated with ANA.

The researchers analyzed data from a single multisite tertiary health network in Australia across a 7-year period in this retrospective cohort study. The results of ANA and other autoimmune test were obtained from the hospital pathology system with a positive ANA titre cutoff set at 1:160. Clinical information was obtained from clinical information systems on any patient who had a change in ANA result from negative to positive on repeat testing. The cost of repeated ANA testing was calculated using the Australian Government Medicare Benefits Schedule.

From March 19, 2011, to July 23, 2018, a total of 36 715 ANA tests were done in 28 840 patients at a total cost of US$675 029 (2018 equivalent).

Key findings of the study include:

14 058 (38·3%) of these ANA tests were positive.
7875 (21·4%) of the ordered tests were repeats in 4887 (16·9%) of the patients, among whom 2683 (54·9%) had initially negative tests, and 2204 (45·1%) had initially positive tests. 511 (19·0%) of the 2683 patients with initially negative tests had a positive result on at least one repeat test, with a median time to first positive result of 1·74 years (IQR 0·54–3·60).

A change from negative to positive ANA was associated with a new diagnosis in only five (1·1%) of the 451 patients with clinical information available and no previous diagnosis of an ANA-associated rheumatological condition, yielding a positive predictive value of 1·1%

"Repeat ANA testing after a negative result has low utility and results in high cost," wrote the authors.

The study, "Utility of repeated antinuclear antibody tests: a retrospective database study," is published in The Lancet Rheumatology.

DOI: https://doi.org/10.1016/S2665-9913(20)30084-9

Lancet RheumatologyANA testingantinuclear antibodies

Source : The Lancet Rheumatology

Medha Baranwal

MSc. Biotechnology

Medha Baranwal joined Medical Dialogues as an Editor in 2018 for Speciality Medical Dialogues. She covers several medical specialties including Cardiac Sciences, Dentistry, Diabetes and Endo, Diagnostics, ENT, Gastroenterology, Neurosciences, and Radiology. She has completed her Bachelors in Biomedical Sciences from DU and then pursued Masters in Biotechnology from Amity University. She has a working experience of 5 years in the field of medical research writing, scientific writing, content writing, and content management. She can be contacted at editorial@medicaldialogues.in. Contact no. 011-43720751

Dr. Kamal Kant Kohli

Dr Kamal Kant Kohli-MBBS, DTCD- a chest specialist with more than 30 years of practice and a flair for writing clinical articles, Dr Kamal Kant Kohli joined Medical Dialogues as a Chief Editor of Medical News. Besides writing articles, as an editor, he proofreads and verifies all the medical content published on Medical Dialogues including those coming from journals, studies,medical conferences,guidelines etc. Email: drkohli@medicaldialogues.in. Contact no. 011-43720751