Table 1 Prevalence rates of uncorrected refractive error (n = 629).

	No	Number with uncorrected refractive error	Uncorrected refractive error, percentage (95% CI)	Crude odds ratio (95% CI)	p Value (χ2 test)
Total	629	140	22.3 (19.0 to 25.6)
Sex
Male	294	61	20.7 (16.1 to 25.3)	1 (referent)
Female	335	79	23.6 (19.1 to 28.1)	1.18 (0.81 to 1.72)	0.442
Race
Chinese	425	91	21.4 (17.5 to 25.3)	1 (referent)
Malay	125	28	22.4 (15.1 to 29.7)	1.06 (0.66 to 1.71)
Indian and others	79	21	21.0 (13.5 to 30.3)	1.33 (0.77 to 2.30)	0.597
Age (years)
12	578	126	21.8 (18.4 to 25.2)	1 (referent)	0.100
13	27	4	14.8 (1.4 to 28.2)	0.62 (0.21 to 1.84)	(trend)
>13	24	10	41.7 (22.0 to 61.4)	2.56 (1.11 to 5.91)
Educational stream
Express	336	66	19.6 (15.4 to 23.8)	1 (referent)	0.014
Normal academic	161	33	20.5 (14.3 to 26.7)	1.05 (0.66 to 1.68)	(trend)
Normal technical	132	41	31.1 (23.2 to 39.0)	1.84 (1.17 to 2.91)
Number of parents with refractive error
0	236	54	22.9 (17.5 to 28.2)	1 (referent)	0.904
1	211	43	20.4 (14.9 to 25.8)	0.86 (0.55 to 1.36)	(trend)
2	182	43	23.6 (17.4 to 29.8)	1.04 (0.66 to 1.65)
Existing eye condition(s)
Emmetropia only	137	10	7.3 (6.56 to 8.04)	1 (referent)	<0.001
Myopia only	304	80	26.3 (21.4 to 31.3)	4.54 (2.27 to 9.07)
Hyperopia only	27	3	11.1 (2.35 to 29.2)	1.59 (0.41 to 6.20)
Astigmatism only	20	4	20.0 (5.73 to 43.7)	3.18 (0.89 to 11.3)
Two or more of the above	141	43	30.5 (22.9 to 38.1)	5.57 (2.67 to 11.6)
Use of visual aid—spectacles or contact lenses
Habitually worn	365	95	26.0 (21.5 to 30.5)	1 (referent)	0.009
Habitually not worn	264	45	17.0 (12.5 to 21.5)	0.58 (0.39 to 0.87)
Consult optician
Ever	411	110	26.8 (22.5 to 31.0)	1 (referent)	<0.001
Never	218	30	13.8 (9.19 to 18.3)	0.44 (0.28 to 0.68)