Anti-Nuclear Antibody (ANA) and Anti-Double Stranded DNA (Anti-ds DNA) Tests by Family Physicians

Choosing Wisely Canada Recommendation

• Don’t order ANA as a screening test in patients without specific signs or symptoms of systemic lupus erythematosus (SLE) or another connective tissue disease.

Practice Points

1. The number of ANA tests ordered in NL relative to the incidence of connective tissue disease is very high (> 12,000 tests/year). 57% of tests were ordered by Family Physicians (FPs).
2. ANA is not indicated unless a connective tissue disease is a significant possibility. The majority of tests in NL were ordered in low risk groups: males and females > 60 years of age.
3. ANA > 1:80 is required to consider the presence of SLE. False positive results are quite common and as such, it is recommended that ANA testing be undertaken in people in whom a connective tissue disease is a strong possibility.
4. ANA is not indicated as a screening test to evaluate fatigue, back pain, and other musculoskeletal pain in the absence of other clinical manifestations to suggest connective tissue disease, nor is it indicated to confirm a diagnosis of rheumatoid arthritis or osteoarthritis.
5. ANA testing need only be ordered once.
6. ANA costs $24 per test.

The Problem

The number of ANA and anti-ds DNA tests ordered relative to the incidence of connective tissue diseases is very high.

From 1 Apr 2016 – 31 Mar 2018 (2 years) there were 24,428 ANA and 7,909 anti-ds DNA tests performed in NL. The rates of testing are 23,448 ANA tests annually/million population and 7,461 anti-ds DNA/million.

Our Data

• From 1 Apr 2016 – 31 Mar 2018, there were a total of 24,428 ANA tests performed in NL.
• 57% were ordered by FPs.

• 7% were repeat tests.

• 33% of ANA tests were in male patients and 32% in people >60 years.
• 53% of tests were in low risk groups: males and people >60 years.
• 48% of anti-ds DNA were in low risk groups.

• 48% of tests ordered by FPs were in groups at low risk for SLE connective tissue disease.

• From 1 Apr 2016 – 31 Mar 2018, 50 FPs ordered ≥50 ANA tests.

What You Can Do

• Only test patients with signs or symptoms of SLE or other connective tissue diseases (CTD).
• CTD patients typically present with at least one of the following clinical findings unexplained by other causes:
  • arthritis
  • pleurisy or pericarditis
  • photosensitive rash
  • laboratory evidence of renal disorder
  • hemolytic anemia, immune thrombocytopenia or neutropenia
  • skin changes of scleroderma, dermatomyositis or vasculitis
  • clinical and laboratory evidence of myositis
  • Raynaud’s phenomenon
  • neurologic signs
• Check out Choosing Wisely Canada’s Rheumatology Recommendations
• Other References: British Columbia Guidelines