Single item self-rated general health: SF-36 based observations from 16,910 spine surgery procedures

Purpose: In spine surgery single item patient-reported outcome assessment has been used for many years. Items 1 and 2 of SF-36 are used for assessment of general health. We used these items to explore single item, self-rated, general health assessment after spine surgery. Methods: Patients operated for lumbar disc herniation or lumbar spinal stenosis between 2007 and 2017, were recruited from the national Swedish spine register. A total of 16,910 procedures were eligible for analysis. The responsiveness of the SF-36 general health assessment items to surgical treatment was evaluated with the standardized response mean (SRM). Improvement in self-rated general health was used to dichotomize SF-36 profiles and EQ VAS distributions. Results: For disc herniation, 5852 (83%) patients reported improvement in general health 1 year after surgery. For spinal stenosis, the corresponding numbers were 6,482 (66%). The additional improvement after year 1 was small. The responsiveness of the SF-36 item 2 (the health transition item) to surgical treatment of disc herniation or spinal stenosis was substantial. There was a clear association between improvement in SF-36 item 2 and improvements in all domains of SF-36. Conclusions: Surgery for disc herniation or spinal stenosis improve patients’ perception of general health 1 year after surgery. The improvement in general health after year 1 is limited. The SF-36 item 2 is a responsive measure of self-rated general health that may be used for dichotomization of SF-36 and EQ VAS data when evaluating surgical outcome in spine surgery.