Table 5.

Sensitivity and specificity for cut-off values evaluated for different specialist groups.

Specialist	Crowded acuity		Ratios
	Subnormal	Low vision	unC/C	TAC/unC	TAC/C
	<6/6 or 6/9a	6/18b	≥2	≥2	≥2
Youth health care physician
Sensitivity (95%-CI)	.76 (.61–.87)	.50 (.36–.64)	.40 (.27–.56)	.43 (.29–.59)	.74 (.57–.85)
Specificity (95%-CI)	.70 (.58–.80)	.97 (.89–.99)	.77 (.65–.86)	.95 (.86–.98)	.61 (.36–.64)
Ophthalmologist
Sensitivity (95%-CI)	.62 (.41–.79)	.29 (.14–.50)	.67 (.45–.83)	.27 (.13–.48)	.68 (.46–.85)
Specificity (95%-CI)	.54 (.43–.64)	.79 (.69–.87)	.79 (.69–.86)	.82 (.72–.89)	.53 (.42–.64)
Orthoptist special services
Sensitivity (95%-CI)	.62 (.41–.79)	.29 (.14–.50)	.67 (.45–.83)	.27 (.13–.48)	.68 (.46–.85)
Specificity (95%-CI)	.10 (.03–.29)	.29 (.14–.50)	.86 (.65–.95)	.33 (.15–.58)	.20 (.07–.45)

C, crowded acuity; unC, uncrowded acuity; TAC, grating acuity.

^aSubnormal vision is age dependent, 6/6 = 30 cycl/deg for children age 4y6m and older and 6/9 = 20 cycl/deg for younger children.

^b6/18 = 10 cycl/deg.