Study Design: A prospective study in a hospital. Purpose: To investigate whether each disability based on the three sub-categories of the Roland-Morris disability questionnaire (RDQ) during hospitalization is associated with itself at 1 year postoperatively in patients with degenerative lumbar spinal stenosis (LSS). Overview of Literature: Although the total score of the RDQ represents whole pain-related disabilities or health-related quality of life, it is a shortcoming that multi-dimensional changes in disabilities are difficult to understand when only using the RDQ. Methods: Fifty-seven patients with LSS (men, 28; women, 29; 63.0 +/- 12.1 years) were included. Disabilities, pain intensity and depressive feelings were assessed at preoperation, discharge and 1 year postoperatively. Results: The range of "mental and physical activities (MPA)," "functional movements on/around a bed (FM)" and " walking function (WF)" scores were 0 to 13 (median, 8), 0 to 6 (median, 6) and 0 to 4 (median, 3) at preoperation; 0 to 12 (median, 0), 0 to 6 (median, 0), and 0 to 4 (median, 0) at discharge; and 0 to 8 (median, 0), 0 to 5 (median, 0), and 0 to 4 (median, 0) at 1 year postoperatively, respectively. The following significant multiple regression equations were obtained: MPA at 1 year postoperatively=0.56 (MPA at discharge)- 0.10 (depression at discharge)+0.90 (adjusted r(2)=0.41), FM at 1 year postoperatively=0.35 (MPA at discharge)-0.06 (depression at discharge)+0.40 (adjusted r(2)=0.45) and WF at 1 year postoperatively=0.59 (WF at discharge)-0.08 (depression at discharge)+0.63 (adjusted r(2)=0.29). Conclusions: In our LSS population, each disability based on MPA and WF at discharge is associated with itself in the future. Therefore, disabilities excluding functional movements are longitudinally independent.
