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The Spine Blog

Friday, July 6, 2018

Risk factors and reasons for readmission following spine surgery

Hospital readmission is a costly problem that CMS is trying to address through financial penalties for institutions with high readmission rates, so hospital leaders are highly motivated to reduce these rates. Readmission following spine surgery is not uncommon, and high quality data are needed to determine risk factors and reasons for readmission that can be targeted for improvement. Most prior studies on this topic have used large administrative databases to address the question, and these frequently lack sufficient accuracy and granularity to allow for the identification of specific actionable improvement targets. In order to address these shortcomings in the literature, Dr. Hills and colleagues from Vanderbilt University Medical Center analyzed 6 years of their spine surgery registry to identify risk factors and reasons for readmissions within 90 days of discharge following elective spine surgery for degenerative conditions. They included over 2,700 spine surgery patients with at least 3 months of follow-up and identified readmissions at their institution and outside institutions through a patient self-reported survey. The overall readmission rate was 5.6%, with about half of readmissions for surgery-related complications, 40% for medical reasons, and 10% for pain control. Timing of readmission varied depending on the cause, with a mean of 12 days for CSF leak, 23 days for surgical site infection, 6 days for non-infectious wound complication, 38 days for surgical failure (i.e. hardware failure, inadequate decompression, etc.), 12 days for medical readmission, and 6 days for pain control. Of the surgery-related readmissions, surgical site infection was the most common cause (30%), with the remainder split about equally between CSF leak, non-infectious wound complication, and surgical failure. Multivariate analysis demonstrated that a history of MI, history of osteoporosis, higher pre-operative leg or arm pain scores, longer operative duration, and lumbar surgery (as opposed to cervical surgery) were all independent risk factors for readmission.

This paper is a nice addition to the literature as it uses a single-institution registry that allowed for chart review at a much more detailed level than is possible from an administrative database study. The authors were able to understand the specific reasons for readmission, which is not possible with billing codes. The overall findings were not surprising, namely that patients with a higher comorbidity burden undergoing big operations were at higher risk for readmission. The authors suggested that medical and pain readmissions are the easiest to address and suggested that PCP visits shortly after discharge and nursing phone calls to address pain management might decrease readmissions for these problems. Psychosocial challenges are also an important driver of readmission that the authors did not address in this paper. These problems can limit some patients' ability to cope with recovery after surgery and function independently. Mental illness, substance abuse, lack of social support, and poverty can all contribute to readmission for "medical" or "pain" reasons, and these are difficult to measure in a study or address peri-operatively. This type of paper can help us identify patients pre-operatively that we know are at high risk for post-operative problems, whether they be medical, pain-related, or psychosocial. Once identified, we can direct resources to support these patients to help reduce their risk of readmission. In general, the cost of these targeted resources, whether an additional PCP visit, nurse phone calls, pain clinic consultation, or social work assistance, is typically far less than the cost of a readmission.

Please read Dr. Hills's article on this topic in the July 15 issue. Does this change how you think about reducing readmissions following elective spine surgery? Let us know by leaving a comment on The Spine Blog.

Adam Pearson, MD, MS

Associate Web Editor

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