Effectiveness of Cryosurgery vs Curettage in the Treatment of Seborrheic Keratoses

studies. The European studies found a 1-year mortality varying between 19% and 41%. The younger age of patients with BP in our study (64.3 years) compared with the patient age in the European studies (74.0-82.6 years) might be responsible for this difference. The age distribution of the Chinese population differs from that of the European population in that Chinese persons 65 years or older represent only 6.83% of the total Chinese population, and those 80 years or older are only 0.88% of the total Chinese population. Our SMR results are in accord with those reported in previously published European studies (SMR ranged from 2.15 to 15.3). A US study did not find a difference in mortality for patients with BP. Only hospitalized patients were included in our study, and time to death after first BP hospitalization was evaluated rather than time to death from BP diagnosis, which may explain our relatively higher SMR. Several studies have suggested a relationship between BP and neurologic diseases. The presence of neurologic disease was related to elevated mortality in our study. Results from recent reports, in which neurological diseases also correlated with higher mortality, support our findings. The association of oral corticosteroid treatment alone with increased mortality may be because this treatment was used when patients with BP had poor general health.