Insomnia was not well defined in CPSII. There was only a weak correlation of reported insomnia with short sleep and little interaction. Reported insomnia was associated with no excess mortality hazard whatsoever, once sleeping pill use and other comorbidities were controlled. The absence of significant insomnia hazard noted in CPSI and CPSII has likewise been observed in smaller epidemiologic studies that controlled for comorbidities.9,10,19,23,34- 38 There is evidence that sleep complaints of various forms (not necessarily insomnia) predict coronary heart disease, but the odds ratios may be reduced with control for medications.39 Moreover, some studies indicate that primary insomnia causes no substantial impairment of function.1,11 For example, patients with insomnia may have no demonstrable loss of daytime alertness.1,40 Less than 25% of patients referred for insomnia have primary insomnia as a first diagnosis.41 Although there may be risks in depression, anxiety, heart disease, cancer, lack of exercise, sleep apnea, and other conditions in which insomnia is often present, patients with insomnia without underlying comorbidities can be reassured that there appears to be no survival risk, as long as the patients refrain from long-term use of sleeping pills. In one study, awakening during the night predicted decreased mortality,8 similar to the hazard ratios less than 1.0 shown in Table 1. However, we are not persuaded that insomnia is beneficial, because we found no dose-response relationship of insomnia frequency to decreasing hazard ratio, and a protective effect of insomnia was not suggested by the simplified models before 32-covariate adjustment. By comparison, mortality increased progressively in both men and women from 7 to 10 hours of sleep and with increasing sleeping pill use, and these associations were even stronger before adjustment for 32 covariates.