Statistical and conceptual issues in defining post-operative cognitive dysfunction

A Pilot Study Evaluating Presurgery Neuroanatomical Biomarkers for Postoperative Cognitive Decline After Total Knee Arthroplasty in Older Adults

“…Abnormal cognitive decline was a z-score ≤−1.96. Using this method, we then examined tests for false positives, which is a consideration for POCD test sensitivity (49). Chi-square analyses assessed differences in POCD frequency.…”

“…We further examined our hypotheses regarding POCD types with tests known for their sensitivity in examining memory and executive function. Examining cognitive change over time with a non-surgery control group allowed us to examine for potential false positives with specific cognitive measures (49). This approach was very useful given our small sample size, which prohibited a more powerful confirmatory factor analysis.…”

Review of Transcranial Doppler Ultrasound to Detect Microemboli during Orthopedic Surgery

“…23,24 One study calculated the incidence of cognitive change by using the 20% rule (a decrease in cognitive score of 20% in 20% of the tests) 25 and showed that the number of emboli was not different in patients with and without cognitive change. 8 Three studies used group analyses to calculate the mean change in cognitive scores and showed that there was no difference in cognitive change between patients with and without detectable HITS.…”

The prediction of Change: Normative neuropsychological trajectories

“…Meaningful change is typically determined when an observed difference score exceeds a specified confidence interval set around the mean of the expected change score. These procedures are increasingly being used in outcomes research such as epilepsy surgery Hermann et al, 1996Hermann et al, , 1999Martin et al, 2002;Sawrie et al, 1996;Seidenberg et al, 1998), cardiac procedures (Andrew, Baker, Bennetts, Kneebone, & Knight, 2001;Bruggemans, van de Vijver, & Huysmans, 1999;Collie, Darby, Falleti, Silbert, & Maruff, 2002;Kneebone, Andrew, Baker, & Knight, 1998;Lehrner et al, 2005; M. S. Lewis, Maruff, Silbert, Evered, & Scott, 2006), traumatic brain injury (Dikman et al, 1999;Ferland, Ramsay, Engeland, & O'Hara, 1998;McCrea et al, 2005;Temkin, Heaton, Grant, & Dikmen, 1999), post-operative cognitive dysfunction (Farag, Chelune, Schubert, & Mascha, 2006;M. Lewis, Maruff, & Silbert, 2004;Maze & Todd, 2007;Murkin, 2001), and aging Ivnik et al, 1999;Knight, McMahon, Skeaff, & Green, 2007;Raymond, Hinton-Bayre, Radel, Ray, & Marsh, 2006;Sawrie, Marson, Boothe, & Harrell, 1999;Tombaugh, 2005).…”