Table 3.

Interobserver Reproducibility of Quantitative Autofluorescence in Patients With Recessive Stargardt Disease 1 Specified per Study Site

	All sites	Site #1	Site #2	Site #3	Site #4	Site #5	Site #6
	Intraclass correlation, ICC estimate (95% CI)
Interobserver Reproducibility	0.95 (0.93–0.97)	0.99 (0.98–0.99)	0.98 (0.90–0.99)	0.91 (0.84–0.95)	0.87 (0.64–0.94)	n.a.†	0.95 (0.90–0.98)
Screening values only	0.96 (0.94–0.97)	0.98 (0.96–0.99)	0.98 (0.91–0.99)	0.90 (0.78–0.95)	0.79 (0.43–0.92)	n.a.†	0.90 (0.73–0.97)
Baseline values only	0.95 (0.91–0.97)	1.00 (0.99–1.00)	0.98 (0.86–0.99)	0.95 (0.88–0.98)	0.93 (0.60–0.98)	0.46 (−0.15–0.88)	1.00 (0.99–1.00)
	One sample t-test of difference, mean difference in qAF units ±SD (P value)
Interobserver reproducibility	16.30 ± 45.09 (P < 0.001)*	4.22 ± 26.71 (P = 0.128)	21.86 ± 26.64 (P < 0.001)*	9.44 ± 68.81 (P = 0.357)	21.03 ± 32.28 (P < 0.001)*	n.a.†	9.16 ± 34.60 (P = 0.144)
Screening values only	14.59 ± 47.77 (P < 0.001)*	7.23 ± 33.74 (P = 0.129)	23.13 ± 30.22 (P < 0.001)*	8.74 ± 84.72 (P = 0.589)	22.64 ± 40.98 (P = 0.023)*	n.a.†	13.64 ± 48.54 (P = 0.279)
Baseline values only	18.29 ± 41.85 (P < 0.001)*	0.51 ± 13.27 (P = 0.804)	20.24 ± 21.55 (P < 0.001)*	10.53 ± 33.68 (P = 0.202)	19.42 ± 21.30 (P = 0.001)*	162.56 ± 67.53 (P = 0.001)*	4.69 ± 8.68 (P = 0.047)*
	Coefficient of repeatability, CR ±%
Interobserver Reproducibility	±20.2	±20.8	±10.8	±25.4	±18.4	n.a.†	±15.0
Screening values only	±23.8	±26.9	±11.8	±31.3	±24.4	n.a.†	±22.5
Baseline values only	±18.2	±6.4	±9.0	±18.8	±10.6	±24.3	±3.1

Interobserver reproducibility: site value was subtracted from reading center value.

CI, confidence interval; CR, coefficient of repeatability; ICC, intraclass correlation; SD, standard deviation;

^†Not applicable due to protocol change for this site.

^* P < 0.05.