Table 3.

Relationship between age categories and ptosis

Age category	Ptosis (3 months)		Total
	No (%)	Yes (%)
<60 years of age	30 (76.9)	9 (23.1)	39
60–69 years of age	32 (74.4)	11 (25.6)	43
70–79 years of age	50 (94.3)	3 (5.7)	53
>80 years of age	18 (81.8)	4 (18.2)	22
Total	130	27	157
Chi-square test1
	Value	df	Asymptotic significance(2-sided)
Pearson chi-square	8.038*	3	0.045
Likelihood ratio	9.170	3	0.027
Linear-by-linear association	2.798	1	0.094
N of valid cases	157
Symmetric measures2
	Value		P<0.05
Phi	0.226		0.045
Cramer’s V	0.226		0.045
N of valid cases	157

Notes:

^*1 cell (12.5%) have expected count <5. The minimum expected count is 3.78.

¹Chi-square test: statistical method assessing the relationship between observed and expected categorical values.

²Symmetric measures determine strength of relationship between the observed and expected categorical values.