Table 1.
Descriptive statistics for meteorological variables, and dry eye disease visits from July 1, 2014, to December 31, 2019, in Zhengzhou, China.
| Variables | Number of measurements | Min | P25 | P50 | P75 | Max | Mean | SD |
|---|---|---|---|---|---|---|---|---|
| Meteorological factors | ||||||||
| Mean temperature (°C) | 2010 | 0 | 8 | 17 | 25 | 34 | 16.44 | 9.38 |
| Air pressure (hPa) | 2010 | 128 | 1,008 | 1,017 | 1,025 | 1,011 | 1,045 | 42.07 |
| Relative humidity (%) | 2010 | 16 | 50 | 63 | 76 | 97 | 62.21 | 17.28 |
| Wind speed (m/s) | 2010 | 0 | 2 | 2 | 3 | 9 | 2.52 | 1.06 |
| No. of visits for DED | ||||||||
| Total | 5,204 | 0 | 1 | 2 | 4 | 25 | 3 | 3 |
| Gender | ||||||||
| Male | 1886 | 0 | 0 | 0 | 2 | 10 | 0.94 | 1.35 |
| Female | 3,318 | 0 | 0 | 1 | 1 | 15 | 1.65 | 1.99 |
| Age (years) | ||||||||
| 0–18 | 315 | 0 | 0 | 0 | 0 | 6 | 0.16 | 0.46 |
| 19–59 | 2,546 | 0 | 0 | 1 | 2 | 11 | 1.27 | 1.61 |
| 60- | 2,343 | 0 | 0 | 1 | 2 | 20 | 1.17 | 1.90 |
| Season | ||||||||
| Warm (April to September) | 2,741 | 0 | 1 | 2 | 4 | 17 | 2.72 | 2.76 |
| Cold (October to March) | 2,463 | 0 | 0 | 1 | 3 | 25 | 2.46 | 3.02 |
P25, P50, and P75 denote the 25th, 50th, and 75th percentiles.