Year: 2018
Type: article
Study design: Clinical Trial
Abstract: Objectives: Investigations involving the influence of patient expectations on clinical outcomes are gaining popularity in the literature.Our purpose was to determine if 1) expectations about an intervention change after the intervention has been applied and 2) those changes in expectation are related to pain-related outcomes.Methods: Ninety healthy volunteers were randomized to thoracic spinal manipulation (SMT), cranio-cervical flexion exercise (CCF), or no intervention (control) and then provided with a picture of the intervention.Pain sensitivity was assessed using thermal quantitative sensory testing using standardized methods for assessing patients with pain-related conditions.Participants then rated their expectation of pain-relief before the intervention (pre-intervention expectation).Immediately after the intervention, participants again rated their expectation for pain relief (post-intervention expectation) and pain sensitivity was assessed again.Proportions of participants expecting less, same or more pain were compared among intervention groups and pre-and post-intervention.The influence of expectations was examined by building separate regression models.Results: Before the intervention was performed a greater than expected proportion of participants in the control group expected more pain after the intervention than in both the SMT and CF groups.These proportion of participants changed AFTER the intervention.More participants in the control group expected the same pain after lying quietly, than expected more or less pain.In both intervention groups the number expecting 'more pain' decreased and the number expecting the 'same pain' increased.There was no influence of expectation on the results for temporal summation.However, for single suprathreshold responses, there were main effects for pre-intervention expectation (people expecting more pain reported more pain before and after intervention) and interactions for post-intervention expectations and time; that is, people expecting less pain had less pain during post-intervention testing.Discussion: These results suggest several things relevant to clinical practice.First, expectations changed within one treatment session even without the usual clinical contextual cues thought to be necessary for this to occur.Next, pre-interventions appear to be related to overall pain reporting and may represent a very general influence on outcomes.Post-intervention expectations were more significant predictors of the pain reported by participants during the post-test suggesting temporal salience and intrinsic judgment about the impact of the intervention.
Institution: University of Florida
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W2899558977