Impact of a Transitional Pain Service on postoperative opioid trajectories: a retrospective cohort study.

INTRODUCTION: It has been well described that a small but significant proportion of patients continue to use opioids months after surgical discharge. We sought to evaluate postdischarge opioid use of patients who were seen by a Transitional Pain Service compared with controls. METHODS: We conducted a retrospective cohort study using administrative data of individuals who underwent surgery in Ontario, Canada from 2014 to 2018. Matched cohort pairs were created by matching Transitional Pain Service patients to patients of other academic hospitals in Ontario who were not enrolled in a Transitional Pain Service. Segmented regression was performed to assess changes in monthly mean daily opioid dosage. RESULTS: A total of 209 Transitional Pain Service patients were matched to 209 patients who underwent surgery at other academic centers. Over the 12 months after surgery, the mean daily dose decreased by an estimated 3.53 morphine milligram equivalents (95% CI 2.67 to 4.39, p<0.001) per month for the Transitional Pain Service group, compared with a decline of only 1.05 morphine milligram equivalents (95% CI 0.43 to 1.66, p<0.001) for the controls. The difference-in-difference change in opioid use for the Transitional Pain Service group versus the control group was -2.48 morphine milligram equivalents per month (95% CI -3.54 to -1.43, p=0.003). DISCUSSION: Patients enrolled in the Transitional Pain Service were able to achieve opioid dose reduction faster than in the control cohorts. The difficulty in finding an appropriate control group for this retrospective study highlights the need for future randomized controlled trials to determine efficacy.

Predictive Validity and Patterns of Change Over Time of the Sensitivity to Pain Traumatization Scale: A Trajectory Analysis of Patients Seen by the Transitional Pain Service Up to Two Years After Surgery.

Purpose: The Sensitivity to Pain Traumatization Scale (SPTS-12) was developed to assess the propensity to develop a traumatic stress response to pain. The SPTS-12 is a reliable and valid scale with a one-factor structure. The aim of the present study is to further examine the psychometric properties of the SPTS-12 by evaluating its criterion validity and how scores change over time in a sample of postsurgical patients at the Toronto General Hospital Transitional Pain Service. Participants and Methods: 361 adults (55% male; M age = 50.6 years, SD age = 14.3) completed questionnaires assessing symptoms of pain, anxiety, depression, and trauma at multiple visits to the Transitional Pain Service after surgery. Latent-class growth mixture modeling defined prototypical longitudinal patterns (latent trajectories) of SPTS-12 scores up to two years after surgery. One-way ANOVAs examined how trajectory classes differed over time on measures of daily opioid use (mg morphine equivalents (MME)), average pain intensity, pain interference, and depressive symptoms. Results: The final model consisted of five SPTS-12 trajectory groups; two characterized by a flat and unchanging pattern and three showing a small but statistically significant decrease over time. Analysis of pain-related outcomes predicted by SPTS-12 trajectories provided evidence of criterion validity of the SPTS-12. SPTS-12 trajectories did not significantly differ on daily MME at any time. Average pain, pain interference, and depression scores significantly differed across SPTS-12 trajectory groups at two or more postsurgical visits (all p < 0.05). Conclusion: The SPTS-12 shows fairly stable patterns and predicts important pain-related and psychosocial outcomes over time. Two SPTS-12 trajectories (#2 and #5) with high scores, comprising ~28% of the total sample, are associated with problematic outcomes on several pain and psychosocial measures. Targeting patients with high SPTS-12 scores for presurgical psychological treatment may prove beneficial in reducing the impact of CPSP.

Predictors of one year chronic post-surgical pain trajectories following thoracic surgery.

PURPOSE: Chronic post-surgical pain (CPSP) is a highly prevalent complication following thoracic surgery. This is a prospective cohort study that aims to describe the pain trajectories of patients undergoing thoracic surgery beginning preoperatively and up to 1 year after surgery METHODS: Two hundred and seventy nine patients undergoing elective thoracic surgery were enrolled. Participants filled out a preoperative questionnaire containing questions about their sociodemographic information, comorbidities as well as several psychological and pain-related statuses. They were then followed-up during their immediate postoperative period and at the three, six and 12 month time-points to track their postoperative pain, complications and pain-related outcomes. Growth mixture modeling was used to construct pain trajectories. RESULTS: The first trajectory is characterized by 185 patients (78.1%) with mild pain intensity across the 12 month period. The second is characterized by 32 patients (7.5%) with moderate pain intensity immediately after surgery which decreases markedly by 3 months and remains low at the 12 month follow-up. The final trajectory is characterized by 20 patients (8.4%) with moderate pain intensity immediately after surgery which persists at 12 months. Patients with moderate to severe postoperative pain intensity were much more likely to develop CPSP compared to patients with mild pain intensity. Initial pain intensity levels immediately following surgery as well as levels of pain catastrophizing at baseline were predicting pain trajectory membership. None of the surgical or anesthetic-related variables were significantly associated with pain trajectory membership. CONCLUSION: Patients who undergo thoracic surgery can have postoperative pain that follows one of the three different types of trajectories. Higher levels of immediate postoperative pain and preoperative pain catastrophizing were associated with moderately severe CPSP.