Table 1.

The proportion of referrals defined as false positive from all sources. Numbers are lower for the subset with both gender and practice type as it was not possible to ascertain both metrics from all referrals.

Source of referral	False positive
General Medical Practitioner (n = 131)	4 (3%)
Optometrist (n = 366)	105 (29%)
Pre-registration optometrist (n = 26)	11 (42%)
Diabetic retinopathy screening service (n = 9)	0
Female optometrists (n = 122)	47 (39%)
Females in multiple practice (n = 82)	36 (44%)
Females in independent practice (n = 40)	11 (28%)
Male optometrists (n = 159)	36 (23%)
Males in multiple practice (n = 68)	21 (31%)
Males in independent practice (n = 91)	15 (16%)
Multiple optical practice (n = 206)	74 (36%)
Independent optical practice (n = 169)	38 (22%)