Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Accumulation of major depressive episodes over time in a prospective study indicates that retrospectively assessed lifetime prevalence estimates are too low | BMC Psychiatry BioMed Central Research article Open Access Accumulation of major depressive episodes over time in a prospective study indicates that retrospectively assessed lifetime prevalence estimates are too low Scott B Patten Address Department of Community Health Sciences University of Calgary Calgary Canada Email Scott B Patten - patten@ Published 8 May 2009 Received 7 October 2008 BMC Psychiatry 2009 9 19 doi 1471-244X-9-19 Accepted 8 May 2009 This article is available from http 1471-244X 9 19 2009 Patten licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Most epidemiologic studies concerned with Major Depressive Disorder have employed cross-sectional study designs. Assessment of lifetime prevalence in such studies depends on recall of past depressive episodes. Such studies may underestimate lifetime prevalence because of incomplete recall of past episodes recall bias . An opportunity to evaluate this issue arises with a prospective Canadian study called the National Population Health Survey NPHS . Methods The NPHS is a longitudinal study that has followed a community sample representative of household residents since 1994. Follow-up interviews have been completed every two years and have incorporated the Composite International Diagnostic Interview short form for major depression. Data are currently available for seven such interview cycles spanning the time frame 1994 to 2006. In this study cumulative prevalence was calculated by determining the proportion of respondents who had one or more major depressive episodes during this follow-up interval. Results The annual prevalence of MDD ranged between 4 and 5 of the population during each assessment consistent
