The Journal of Bone and Joint Surgery published a study examining the variation in data collection methods and how they impact study results for lumbar spinal fusion procedures.
The researchers examined a retrospective cohort study of patients undergoing lumbar spinal fusion procedures from 2009 to 2011 logged in either the Nationwide Inpatient Sample or the National Surgical Quality Improvement Program. They directly compared the demographic characteristics, comorbidities and inpatient adverse events between the two databases.
There were 144,098 patients included from the Nationwide Inpatient Sample and 8,434 patients from the National Surgical Quality Improvement Program with only small variation in demographic differences. Here are five things to know from the study:
1. There was a huge difference between the databases in the rates specific comorbidities were documented. Non-morbid obesity was documented at a 9.33 percent rate in the National Inpatient Sample and 36.93 percent in the National Surgical Quality Improvement Program.
2. The peripheral vascular disease was documented at a 2.35 percent rate in the Nationwide Inpatient Sample and 0.6 percent among the National Surgical Quality Improvement Program.
3. The specific inpatient adverse event rates were also significantly different between the two databases. For example, sepsis was documented at rates of 0.38 percent in the Nationwide Inpatient Sample and 0.81 percent in the National Surgical Quality Improvement Program.
4. The National Inpatient Sample documented acute kidney injury at a 1.79 percent rate while the National Surgical Quality Improvement Program reported acute kidney injury at a 0.21 percent rate.
5. The study authors concluded that as orthopedic surgery studies become more prevalent, authors and reviewers as well as researchers should view these studies with caution. "This study shows that two commonly used databases can identify demographically similar patients undergoing a common orthopaedic procedure; however, the databases documented markedly different rates of comorbidities and inpatient adverse events. The differences are likely the result of the very different mechanisms through which the databases collect their comorbidity and adverse data."