Table 2

Characteristics of responders and non-responders (n = 1249).

RespondersaNon-respondersP-value
Frequency (%)627 (50.2%)622 (49.8%)NSb
Age, years
 Mean (SD)46.6 (27.4)36.0 (26.6)<0.001c
 Median (IQR)49 (23 to 70)32 (11 to 54)
Sex, female %60.159.2NSb
Townsend 2001, median (IQR)−0.08 (−1.47 to 1.70)0.70 (−1.17 to 1.96)0.01d

  • ↵a Including 57 individuals returning blank questionnaires.

  • ↵b χ2 test.

  • ↵c t-test.

  • ↵d Mann Whitney U test. SD = standard deviation. IQR = interquartile range. NS = not significant.