Table 1.

Comparison of Mailed Survey Responders and Nonresponders

VariableResponders (n = 180)Nonresponders (n = 146)P
Age40.4 ± 14.239.2 ± 12.5.442
Gender (female)71.0%59.5%.030
Some college education68.9%63.4%.289
Racial/ethnic minority16.0%35.6%<.001
Insomnia Severity Index14.4 ± 4.514.1 ± 4.6.493