Purpose of study: The purpose of this study was to evaluate the quality of life in spinal surgery patients from a public health perspective, in particular, to determine the level of disability preoperatively and the amount of change postoperatively. Spinal surgery outcomes were compared with various groups of chronic diseases (ie, tracer groups), including congestive heart failure, myocardial infarction, hypertension and diabetes type 2.Methods used: A prospective analysis of 212 patients underwent spinal reconstructive surgery between June 1994 and December 1999. The Short Form (SF)-36 instrument was used to obtain baseline, 1-year and 2-year postoperative data. The Physical Component Summary (PCS) scores of the SF-36 was used to compare change from baseline, first- and second-year follow-up between spine surgery patients and patients of tracer groups. The criterion of individual change (5.43 T score points or more) for the Physical Component Summary Scale is based on two standard errors of measurement and used extensively with the tracer groups in the research literature. Chi-squared tests were used to test significance of change because of the convenient analysis by categories: improved, same or worse.of findings: The mean T scores and the percentage abnormal for baseline on the PCS showed the spinal surgery patients were significantly more disabled. The percentage of subjects abnormal at baseline is as follows: hypertension, 14.9; myocardial infarction, 17.1; diabetes type 2, 17.5; congestive heart failure, 36.8, and spine surgery patients doubled their baseline PCS score, with 73.6. Outcomes show the tracer groups had undergone little change as opposed to the spinal surgery patients, who showed an overall 60% improvement (only 12.5% worsened) by the end of the second year. In comparison, patients in the myocardial infarction group showed only a 20.6% improvement (20.6% worsened) at the end of the second years. Lastly, the differences, at first- and second-year follow-up, between spinal surgery and each of the tracer groups is statistically significant (p=.001).Relationship between findings and existing knowledge: In general, most of the literature uses group means to analyze individual change. However, these methods provide only statistical significance, and the clinician seeks clinical significance. For example, the question asked in this study was, What were the outcomes (ie, improved, same or worsened) of the patients who underwent surgical intervention of the spine? Furthermore, the use of group means is an irrelevant form of analysis, because it contradicts the fundamental definition of ecological fallacy, which states that one cannot infer from group means individual outcomes. Therefore, the relationship between these findings and the existing body of knowledge is groundbreaking with use of clinical criteria as a standard to evaluate clinical significance in spinal surgery patients.Overall significance of findings: As a result of using clinical criteria in studying individual change, investigators have shown spinal surgery patients have substantial preoperative disability and better outcomes in comparison to chronic disease patients. Moreover, the use of clinical criteria enable investigators to define abnormalities in quality of life, and comparable data for the criteria on tracer groups are available in the research literature.Disclosures: No disclosures.Conflict of interest: No conflicts.