Rheumatologists and the Requesting of Antinuclear Antibodies (ANA) Tests in Patients With Rheumatologic Complaints

Change from baseline (pre-intervention) ANA/new patient ratio (APR) at 12 months (post-intervention)

Number of ANA tests divided by the number of new patients

Time frame: Pre- and post-intervention (both 12 months)

Change from baseline (pre-intervention) % of positive ANA tests at 12 months (post-intervention)

Percentage of ANA tests reported as positive by the local laboratory. ANA tests reported as 'weakly positive' are regarded as negative.

Time frame: Pre- and post-intervention (both 12 months)

Change from baseline (pre-intervention) % of repeated ANA testing at 12 months (post-intervention)

Percentage of patients with ≥1 ANA test in 12 months (pre- or post-intervention period)

Time frame: Pre- and post-intervention (both 12 months)

Change from baseline (pre-intervention) % of ANA associated diagnoses at 12 months (post-intervention)

Percentage of patients, in which an ANA is done during the study period, with final diagnosis of SLE, SSc, PM/DM, MCTD or SS

Time frame: Pre- and post-intervention (both 12 months)

Change from baseline (pre-intervention) APR variation between rheumatologists at 12 months (post-intervention)

Standard deviation around the mean APR, calculated from the APRs of the individual rheumatologists

Time frame: Pre- and post-intervention (both 12 months)

Change from baseline (pre-intervention) reaching the of target APR at 12 months (post-intervention)

Difference (percentage) between the actual APR and the target-APR defined during the intervention

Time frame: Pre- and post-intervention (both 12 months)