Koji Otani, Shin-Ichi Kikuchi, Shoji Yabuki, Akira Onda, Takuya Nikaido, Kazuyuki Watanabe, Shin-Ichi Konno Department of Orthopaedic Surgery, Fukushima Medical University School of Medicine, Fukushima, Japan Purpose: Lumbar spinal stenosis (LSS) is a common condition in the aging population. However, limited information exists on discrepancies between LSS symptoms and imaging findings and/or prognostic factors of LSS, as well as the relationship between changes in LSS symptoms and quality of life (QoL) during the natural course of LSS. The purpose of the current study was to clarify any changes in clinically diagnosed LSS at a one-year follow-up, and identify its prognostic factors, using a community-dwelling cohort.Participants and methods: In this study, the presence of LSS, its associated comorbidities, and the status of QoL pertaining to general health and low-back pain were assessed in 1,080 community-dwelling volunteers. The same assessment was carried out a year after the initial survey. Clinically diagnosis as LSS (LSS-positive) was determined by a validated diagnostic support tool in the form of a self-administered, self-reported history questionnaire. QoL was assessed using the 36-Item Short Form Health Survey and the Roland–Morris Disability Questionnaire.Results: Among subjects who were LSS-positive in the initial assessment, 54% were clinically diagnosed as negative for LSS (LSS-negative) after the one-year period, whereas 10% of those who were initially diagnosed as LSS-negative changed to LSS-positive during the same period. With the improvement or deterioration of LSS-positive/negative status, low-back pain-related QoL and some components of the 36-Item Short Form Health Survey similarly improved or deteriorated. Decisive prognostic factors of LSS-positive status were not determined at the one-year follow-up.Conclusion: Approximately half of the subjects who had initially been diagnosed as LSS-positive converted to LSS-negative after one year. Prognostic factors of LSS-positive diagnosis after one-year follow-up were not detected. Keywords: epidemiology, natural history, quality of life, prognostic factors, comorbidities