Table 1: Characteristics of the patient and the population samples.

Population samplePatient sample 𝑃 -value1

Age, mean (sd)47.4 (14.1)46.8 (14.3)47.1 (14.2)52.4 (14.7)56.0 (10.8)55.5 (11.5)<0.0001

QEESI (median) 𝑃 -value2

 Chemical Int.<0.0001
 Other Int.<0.0001
 Life Impact0.<0.0001
 Masking Index4.<0.0001

SCL-92 (median)


SCL-92 (mean)


Occupational social class ( 𝑛 (%)) 𝑃 -value3

I + II:224 (17.2)17 (9.0)
III + IV:426 (32.6)35 (18.5)
V + VI + VII:566 (43.4)124 (65.6)
Missing:89 (6.8)13 (6.9)

Occupational social class: I + II: professionals and executives and medium-level white-collar employees; III + IV: low-level white-collar employees and skilled workers; V + VI + VII: unskilled and semiskilled workers, individuals receiving pension or disability benefits, and students.
1Independent samples   𝑡 -test for equality of means (total) between population and patient samples.
2Mann-Whitney test (total) comparing population and patient samples.
3Chi-squared test comparing population and patient samples.