Four-hourly temperature charts relating to 63 febrile neutropenic epis
odes in 32 patients were assessed for a circadian distribution to the
onset of fever (>37.5-degrees-C) using the Edward's test. A highly sig
nificant distribution was found with the maximum incidence of febrile
events between the hours of 5 p.m. and midnight (acrophase 9.30 p.m.).
Patients were 5.53 times more likely to develop fever at 9.30 p.m. th
at 9.30 a.m.