Patients were recruited consecutively from an ongoing
epidemiological examination (that did not focus on CAP or
clinical interventions) using an initial rough screening for
pain symptoms. Then, 144 families were contacted for a
detailed screening and informed of the possibility of training.
Only 36 families consented to participate. The attrition
rate in our study is high—but not exceptionally high when
compared to other clinical studies. Karlson and Rapoff [19]
reported a 37% (range 0–75%) average rate of enrollment
refusal. We can only speculate on the reasons for nonparticipation,
e.g., that the level of suffering was not great
enough. However, data are lacking to support this
interpretation.