Sleep quality subtypes in midlife women.
Eighty-two midlife women (40-59 years) were classified as poor or good sleepers according to either self-reported sleep quality or a sleep efficiency index (SEI) criterion, for comparison of wakefulness, fragmentation and other somnographic sleep variables; as well as psychological (SCL-90) and somatic symptom distress. When classified solely by self-report, the good and poor sleeper groups did not differ on any somnographic variables but self-declared poor sleepers had higher psychological distress scores than good sleepers (p less than or equal to 0.01). When classified solely by the SEI criterion, the good and poor sleepers did not differ on psychological distress but, as expected, differed on various somnographic wakefulness as well as rapid eye movement and stage 2 sleep variables. Further analysis of four subgroups derived by combining objective and subjective, good and poor sleep scores indicated that 15% of this sample (n = 12) perceived but had no objective evidence of poor sleep, and this group scored highest in psychological distress. Only seven women perceived poor sleep in concert with demonstrating low SEI. They scored highest in menopausal symptoms but not in general psychological distress.