We collected and analyzed data from 780 family physicians,
representing a response rate of 16%. Low response rates increase
the risk of non-response bias. The potential for such a bias
was first assessed by comparing the 156 “late” respondents (i.e.,
those responding after having received the reminder) with the
624 “early” respondents. Our findings (not shown here) indicate
no statistically significant differences between these two sets of
respondents. Next, we compared the demographic characteristics
of our sample with those of the target population, i.e., QFGP members.