BACKGROUND: It is not completely clear whether there are differences in the evolution of the neuropsychological outcomes between the 2 intervention procedures (surgery and endovascular coiling) used in subarachnoid aneurysmatic hemorrhage. Some studies have investigated this topic but without completely controlling the effect of learning the tests.
OBJECTIVE: To analyze our data using 2 different statistical procedures that attempt to solve this problem.
METHODS: The sample consists of 70 patients who have suffered a subarachnoid hemorrhage: 40 treated by means of surgery and 30 by means of endovascular coiling. Two cognitive evaluations were performed at 4 and 12 months after the invention. Twenty-seven healthy subjects were also evaluated twice with a delay of 8 months. The data were analyzed using 2 different statistical procedures: one by Samra et al (2007) using z scores and the other by Crawford and Garthwaite (2007) using the regbuild.exe program.
RESULTS: The results indicate there are no important differences between the 2 treatment groups in the evolution of the cognitive alterations. Despite an improvement in cognitive scores on repeat testing at 12 months, neither of the 2 treatment groups showed the same level of test-retest learning as healthy control subjects.
CONCLUSION: The recovery of neuropsychological functions after a subarachnoid hemorrhage is similar with the 2 interventions. It is important to control the learning effect produced by the repeated administration of tests.