Increasing tramadol utilisation under strict regulatory control of opioid prescribing - A cross-sectional study in Taiwan from 2002 through 2016

Opioid analgesics prescribing trends 2010-2019 in Slovenia: National database study

OBJECTIVE

Significant increases in global opioid use have been reported in recent decades. This study analyzed opioid utilization in outpatient care in Slovenia between 2010 and 2019.

METHODS

This retrospective cross-sectional study performed a nationwide database analysis of all outpatient opioid analgesic prescriptions based on Slovenian health insurance claims data. Prevalence was defined as the number of recipients prescribed at least one opioid per 1000 inhabitants. Opioid consumption was presented as the total number of dispensed prescriptions per 1000 inhabitants and dispensed defined daily doses (DDD) per 1000 inhabitants for each year analyzed.

RESULTS

The age-standardized prevalence of opioid recipients decreased by 21.5% during the study period. Total opioid consumption decreased both in the number of prescriptions (-9.2%) and DDD (-5.4%). Tramadol consumption decreased in terms of the number of prescriptions (-12.2%) and DDD (-2.7%), whereas prescriptions for strong opioids increased (10.2%) and DDDs decreased (-16.2%). The results suggest less intensive prescribing of strong opioids and more intensive prescribing for tramadol. The most frequently used strong opioids were fentanyl and oxycodone/naloxone.

CONCLUSIONS

The prevalence of opioid recipients and opioid consumption is decreasing in Slovenia. Further research is needed to understand whether this finding reflects safe use or underuse of these important analgesics.

Longitudinal Trajectory of Opioid Prescribing and its Associated Serious Adverse Events: A Population-Wide Cohort Study in Taiwan

Chronic opioid prescribing (COP) for noncancer pain is highly restricted in Taiwan, but tramadol is not listed in the regulation on chronic prescribing. This study investigated the trajectories of COP in noncancer pain when considering tramadol in Taiwan and identified the risk of serious adverse events. This population-wide longitudinal cohort study used the Taiwan National Health Insurance claims records from 2001 to 2016. Adults prescribed opioids (including tramadol) and without cancer were selected. Patients who received COP (opioid supply days for 28 days or continuous opioid supply for 14 days) in the first patient quarter were included, and serious adverse events were identified. Group-based trajectory models were applied to identify patients with a similar trajectory of quarterly COP. The Cox proportional hazard model was applied to assess the association between adverse events and patients' trajectories. Of the 2,360,358 noncancer opioid users, 476,934 (20.2%) received COP in the first quarter. Four groups of COP trajectory were identified, and 59,310 (12.8%) patients received COP quarterly over 2 years. Patients categorized into the trajectory of long-term COP had a significantly higher crude incidence rate of cardiovascular death, seizure, and hypoglycemia. Still, there is no newly developed opioid use disorder. There was a substantial underestimate in COP in Taiwan when tramadol was not considered. Notably, 10% of them could receive COP for over 2 years. The result raises concern about unmet pain management needs and the limited accessibility of alternative treatments for noncancer pain.

Trends in Opioid Utilisation in Hungary, 2006-2020: A Nationwide Retrospective Study with Multiple Metrics

BACKGROUND

Opioid use is well-documented in several countries: some countries struggle with overuse while others have almost no access to opioids. For Europe, limited data are available. This study analysed Hungarian opioid utilisation in ambulatory care between 2006 and 2020.

METHODS

We obtained national drug utilization data on reimbursed opioid analgesics (ATC code: N02A) from a national health insurance database for a 15-year period. We investigated utilisation trends, using three volume-based metrics (defined daily dose per 1000 inhabitants per day (DID), oral morphine equivalent per 1000 inhabitants per day, packages dispensed per 1000 inhabitants per year). We stratified data based on administration routes, analgesic potency and reimbursement categories.

RESULTS

Total opioid utilisation increased during the study period according to all three metrics (74% in DID) and reached 5.31 DID by 2020. Upward trends were driven by an increase both in weak and strong opioid use (79% vs. 53%). The most commonly used opioids were fentanyl (in the strong category; 0.76 DID in 2020) and tramadol (in the weak category; 2.62 DID in 2020). Overall, tramadol was also the most commonly used opioid throughout the study period. Oral administration of opioid medications was dominant. Based on reimbursement categories, musculoskeletal pain was becoming a more frequent indication for opioid use (1552% increase in DID), while opioid use for cancer pain declined significantly during the study period (-33% in DID).

CONCLUSIONS

Our low utilisation numbers might indicate underuse of opioid analgesia, especially for cancer pain.

A machine learning algorithm for predicting prolonged postoperative opioid prescription after lumbar disc herniation surgery. An external validation study using 1,316 patients from a Taiwanese cohort

BACKGROUND CONTEXT

Preoperative prediction of prolonged postoperative opioid prescription helps identify patients for increased surveillance after surgery. The SORG machine learning model has been developed and successfully tested using 5,413 patients from the United States (US) to predict the risk of prolonged opioid prescription after surgery for lumbar disc herniation. However, external validation is an often-overlooked element in the process of incorporating prediction models in current clinical practice. This cannot be stressed enough in prediction models where medicolegal and cultural differences may play a major role.

PURPOSE

The authors aimed to investigate the generalizability of the US citizens prediction model SORG to a Taiwanese patient cohort.

STUDY DESIGN

Retrospective study at a large academic medical center in Taiwan.

PATIENT SAMPLE

Of 1,316 patients who were 20 years or older undergoing initial operative management for lumbar disc herniation between 2010 and 2018.

OUTCOME MEASURES

The primary outcome of interest was prolonged opioid prescription defined as continuing opioid prescription to at least 90 to 180 days after the first surgery for lumbar disc herniation at our institution.

METHODS

Baseline characteristics were compared between the external validation cohort and the original developmental cohorts. Discrimination (area under the receiver operating characteristic curve and the area under the precision-recall curve), calibration, overall performance (Brier score), and decision curve analysis were used to assess the performance of the SORG ML algorithm in the validation cohort. This study had no funding source or conflict of interests.

RESULTS

Overall, 1,316 patients were identified with sustained postoperative opioid prescription in 41 (3.1%) patients. The validation cohort differed from the development cohort on several variables including 93% of Taiwanese patients receiving NSAIDS preoperatively compared with 22% of US citizens patients, while 30% of Taiwanese patients received opioids versus 25% in the US. Despite these differences, the SORG prediction model retained good discrimination (area under the receiver operating characteristic curve of 0.76 and the area under the precision-recall curve of 0.33) and good overall performance (Brier score of 0.028 compared with null model Brier score of 0.030) while somewhat overestimating the chance of prolonged opioid use (calibration slope of 1.07 and calibration intercept of -0.87). Decision-curve analysis showed the SORG model was suitable for clinical use.

CONCLUSIONS

Despite differences at baseline and a very strict opioid policy, the SORG algorithm for prolonged opioid use after surgery for lumbar disc herniation has good discriminative abilities and good overall performance in a Han Chinese patient group in Taiwan. This freely available digital application can be used to identify high-risk patients and tailor prevention policies for these patients that may mitigate the long-term adverse consequence of opioid dependence: https://sorg-apps.shinyapps.io/lumbardiscopioid/.

Association between tramadol use and seizures: A nationwide case-case-time-control study

PURPOSE

Tramadol may lower the seizure threshold; however, there is no conclusive evidence to confirm this. This study aimed to determine whether the use of tramadol is associated with the occurrence of seizures.

METHODS

We conducted a case-case-time-control (CCTC) study by identifying patients who had received tramadol and seizure diagnosis in a nationwide healthcare database in South Korea between 2003 and 2015. Each case was matched for age and sex to one future case to adjust for time trends in exposure without selection bias from the use of an external control group. The use of tramadol was assessed during a risk period of 1-30 days, and two reference periods, 61-90 days and 91-120 days, preceding the first diagnosis of seizures. We calculated the adjusted odds ratio (aOR) by dividing the OR in cases (case-crossover) by the OR in future cases (control-crossover). We performed a dose-response analysis using the average daily dose.

RESULTS

We identified 2,523 incident cases with matched future cases (mean age, 45.4 years; 50% men). The aOR for seizure with tramadol use was 0.94 (95% confidence interval [CI], 0.98-1.43) in the CCTC analysis, with a case-crossover OR of 1.19 (0.98-1.43) and control-crossover OR of 1.27 (1.03-1.56). The dose-response analysis showed a similar trend in the main analysis: a low-dose aOR of 0.80 (0.50-1.28) and a high-dose aOR of 0.92 (0.41-2.11).

CONCLUSION

We could not identify a significant association between transient use of tramadol and incidence of seizures in clinical practice.

Metformin Reduces the Risk of Diverticula of Intestine in Taiwanese Patients with Type 2 Diabetes Mellitus

Aim: To investigate the risk of diverticula of intestine associated with metformin use. Methods: This retrospective cohort study used the Taiwan's National Health Insurance database to enroll 307,548 ever users and 18,839 never users of metformin. The patients were followed up starting on January 1, 2006 and ending on a date up to December 31, 2011. To address confounding by indication, hazard ratios were derived from Cox regression based on the inverse probability of treatment weighting using propensity score. Results: During follow-up, newly diagnosed cases of diverticula were identified in 1,828 ever users (incidence rate: 125.59 per 100,000 person-years) and 223 never users (incidence rate: 268.17 per 100,000 person-years). Ever users had an approximately 54% lower risk, as shown by the overall hazard ratio of 0.464 (95% confidence interval 0.404-0.534). While patients categorized in each tertile of cumulative duration of metformin therapy were compared to never users, a dose-response pattern was observed with hazard ratios of 0.847 (0.730-0.983), 0.455 (0.391-0.531) and 0.216 (0.183-0.255) for the first (<27.37 months), second (27.37-59.70 months) and third (>59.70 months) tertiles, respectively. The findings were similar when the diagnosis of diverticula was restricted to the small intestine or to the colon. Subgroup analyses suggested that the lower risk of diverticula of intestine associated with metformin use was significant in all age groups of <50, 50-64 and ≥65 years, but the magnitude of risk reduction attenuated with increasing age. Conclusion: Metformin treatment is associated with a significantly reduced risk of diverticula of intestine.

Use of Tramadol or Other Analgesics in Patients Treated in the Emergency Department as a Risk Factor for Opioid Use

The objective of this cohort study was to determine the association between the use of tramadol in emergency departments and the later consumption of opioids at the outpatient level in a group of patients from Colombia. Based on a medication dispensation database, patients over 18 years of age treated in different clinics in Colombia who for the first time received tramadol, dipyrone, or a nonsteroidal anti-inflammatory drug (NSAID) in the emergency room between January and December 2018 were identified. Three mutually exclusive cohorts were created, and each patient was followed up for 12 months after the administration of the analgesic to identify new formulations of any opioid. A Cox proportional-hazards regression model was constructed to identify variables associated with receiving a new opioid. A total of 12,783 patients were identified: 6020 treated with dipyrone, 5309 treated with NSAIDs, and 1454 treated with tramadol. The mean age was 47.1 ± 20.4 years, and 61.6% were women. A total of 17.3% (n = 2207) of all patients received an opioid during follow-up. Those treated with tramadol received a new opioid with a higher frequency (n = 346, 23.8%) than the other cohorts (14.7% NSAIDs and 17.9% dipyrone, both p < 0.001). In the tramadol group, using more than 10 mg of morphine equivalents was associated with a greater use of new opioids (HR:1.47, 95%CI:1.12-1.93). Patients treated with tramadol in emergency departments have a higher risk of opioid use at the one-year follow-up than those treated with NSAIDs or dipyrone.