The double Maddox rod test is often used to measure cyclodeviations and to monitor change over time. The purpose of this study was to estimate test-retest reliability and the amount of cyclodeviation that would be considered real change using 95% limits of agreement. We retrospectively studied 86 clinically stable patients with double Maddox rod measurements 5-175 days apart (median, 69 days). The range of cyclodeviation at the first measurement was 6° incyclodeviation to 15° excyclodeviation. We calculated the half width of the 95% limits of agreement to be 4.7°, which means that a change of ≥5° in cyclodeviation would be considered a real change. The threshold of 5° should be used when assessing change between two measurements made with double Maddox rods.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health