Table 2.

Correlation between calendar year and ocular parameters.

Variable	Linear regression		Adjusted for age and sex
	β	p-value	β	p-value
Model 1: examination results
Tear break-up time (s)	− 0.228	< 0.001*	− 0.233	< 0.001*
Schirmer test (mm)	0.030	0.632	0.105	0.110
Tear strip meniscometry (mm)	− 0.117	0.257	− 0.105	0.304
Corneal staining score	0.069	0.008*	0.066	0.011*
Model 2: symptoms
Dryness	0.020	0.435	0.027	0.290
Irritation	0.022	0.384	0.018	0.489
Pain	0.056	0.030*	0.067	0.010*
Fatigue	− 0.024	0.357	− 0.019	0.452
Blurring	0.132	< 0.001*	0.120	< 0.001*
Photophobia	0.053	0.042*	0.056	0.031*

Calendar years 2015, 2016, and 2017 = 0, 2018 and 2019 = 1.