Brief Assessment of Patient Phenotype to Explain Variability in Postsurgical Pain and Opioid Consumption after Cesarean Delivery: Performance of a Novel Brief Questionnaire Compared to Long Questionnaires

Abstract

Background: Understanding factors that explain why some women experience greater postoperative pain and consume more opioids after cesarean delivery is crucial to building an evidence base for personalized prevention. Comprehensive psychosocial assessment with validated questionnaires in the preoperative period can be time-consuming. A three-item questionnaire has shown promise as a simpler tool to be integrated into clinical practice, but its brevity may limit the ability to explain heterogeneity in psychosocial pain modulators among individuals. This study compared the explanatory ability of three models: (1) the 3-item questionnaire, (2) a 58-item questionnaire (long) including validated questionnaires (e.g., Brief Pain Inventory, Patient Reported Outcome Measurement Information System [PROMIS]) plus the 3-item questionnaire, and (3) a novel 19-item questionnaire (brief) assessing several psychosocial factors plus the 3-item questionnaire. Additionally, this study explored the utility of adding a pragmatic quantitative sensory test to models.

Methods: In this prospective, observational study, 545 women undergoing cesarean delivery completed questionnaires presurgery. Pain during local anesthetic skin wheal before spinal placement served as a pragmatic quantitative sensory test. Postoperatively, pain and opioid consumption were assessed. Linear regression analysis assessed model fit and the association of model items with pain and opioid consumption during the 48 h after surgery.

Results: A modest amount of variability was explained by each of the three models for postoperative pain and opioid consumption. Both the brief and long questionnaire models performed better than the three-item questionnaire but were themselves statistically indistinguishable. Items that were independently associated with pain and opioid consumption included anticipated postsurgical pain medication requirement, surgical anxiety, poor sleep, pre-existing pain, and catastrophic thinking about pain. The quantitative sensory test was itself independently associated with pain across models but only modestly improved models for postoperative pain.

Conclusions: The brief questionnaire may be more clinically feasible than longer validated questionnaires, while still performing better and integrating a more comprehensive psychosocial assessment than the three-item questionnaire.

Figure 1.. Study flow chart.

Figure 2.. Daily pain and opioid consumption during the 48 hours after cesarean delivery.

Nurses assessed participants’ pain using a numeric rating scale 0–10 multiple times throughout the day. All opioid consumption was quantified as oral morphine milligram equivalents (MME). (A) Distribution of daily average pain scores, with each circle representing and individual patient’s average daily pain. (B) Distribution of daily total opioid consumption, with each circle representing an individual patient’s cumulative opioid consumption during that 24-hour period.

Figure 3.. Observed vs. estimated postoperative pain and opioid consumption.

The top row of graphs shows plots of estimated to actual values for pain under each of the models (3-item, Brief and Long). Each red circle represents one participant, with the x-position representing the estimated pain under the model and the y-position representing the actual observed pain value. Note that AUC pain scores were normalized for the 48 hours to render them in a 0–10 scale. The top row of graphs shows plots of estimated to actual values for cumulative opioid consumption under each of the models (3-item, Brief and Long), with each blue circle representing one participant, with the x-position representing the opioid consumption under the model and the y-position representing the actual observed opioid consumption.

Figure 4.. Comparison of items across Models.

Venn diagram illustrating items that were independently associated with postoperative pain (red ovals) and opioid consumption (blue ovals) across and within the 3-item, Brief and Long models.