Risk Factors for Chronic Opioid Use Following Hip and Knee Arthroplasty: Evidence from New Zealand Population Data

Does the type of lower extremity fracture affect long-term opioid usage? A meta-analysis

INTRODUCTION

 Patients recovering from musculoskeletal trauma have a heightened risk of opioid dependence and misuse, as these medications are typically required for pain management. The purpose of this meta-analysis was to examine the association between fracture type and chronic opioid use following fracture fixation in patients who sustain lower extremity trauma.

MATERIALS AND METHODS

A meta-analysis was performed using PubMed and Web of Science to identify articles reporting chronic opioid use in patients recovering from surgery for lower extremity fractures. 732 articles were identified using keyword and MeSH search functions, and 9 met selection criteria. Studies were included in the final analysis if they reported the number of patients who remained on opioids 6 months after surgery for a specific lower extremity fracture (chronic usage). Logistic regressions and descriptive analyses were performed to determine the rate of chronic opioid use within each fracture type and if age, year, country of origin of study, or pre-admission opioid use influenced chronic opioid use following surgery.

RESULTS

Bicondylar and unicondylar tibial-plateau fractures had the largest percentage of patients that become chronic opioid users (29.7-35.2%), followed by hip (27.8%), ankle (19.7%), femoral-shaft (18.5%), pilon (17.2%), tibial-shaft (13.8%), and simple ankle fractures (2.8-4.7%).Most opioid-naive samples had significantly lower rates of chronic opioid use after surgery (2-9%, 95% CI) when compared to samples that allowed pre-admission opioid use (13-50%, 95% CI). There were no significant associations between post-operative chronic opioid use and age, year, or country of origin of study.

CONCLUSIONS

 Patients with lower extremity fractures have substantial risk of becoming chronic opioid users. Even the lowest rates of chronic opioid use identified in this meta-analysis are higher than those in the general population. It is important that orthopedic surgeons tailor pain-management protocols to decrease opioid usage after lower extremity trauma.

Functional somatic syndromes are associated with inferior outcomes and increased complications after hip and knee arthroplasty: a systematic review

BACKGROUND

Functional somatic syndromes (FSSs), defined as chronic physical symptoms with no identifiable organic cause, may impact results after hip and knee arthroplasty. The purpose of this study was to perform a systematic review assessing the relationship between FSSs and clinical outcomes after primary total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA).

METHODS

The PubMed and Web of Science databases were queried from January 1955 through December 2021 for studies investigating the impact of at least one FSS (fibromyalgia, irritable bowel syndrome (IBS), chronic headaches, and chronic low back pain) on outcomes after primary THA/TKA/UKA. Outcomes of interest included patient-reported outcome measures (PROMs), postoperative opioid use, complications, revisions, and costs of care.

RESULTS

There were twenty-eight studies, including 768,909 patients, of which 378,384 had an FSS. Five studies reported preoperative PROMs prior to THA/TKA, all of which showed worse PROMs among patients with at least 1 FSS diagnosis. Thirteen studies reported postoperative PROMs after THA/TKA, all of which demonstrated worse PROMs among patients with at least 1 FSS diagnosis. Patients with FSS diagnoses were more likely to continue using opioids at 3, 6, and 12 months following TKA, THA, and UKA. Medical and surgical complications, as well as revision rates, were higher among patients with FSSs.

CONCLUSION

Patients with FSSs have inferior PROMs and are at increased risk for prolonged postoperative opioid use, medical and surgical complications, and revision after hip and knee arthroplasty. Improved understanding of the factors influencing the success of hip and knee arthroplasty is critical. Future studies should address the biopsychosocial determinants of health that can impact outcomes after total joint arthroplasty.

The long-term impacts of opioid use before and after joint arthroplasty: matched cohort analysis of New Zealand linked register data

BACKGROUND

Opioids are commonly used both before and after total joint arthroplasty (TJA).

OBJECTIVE

The objective of this study was to estimate the long-term effects of pre- and perioperative opioid use in patients undergoing TJA.

METHODS

We used linked population datasets to identify all (n =18,666) patients who had a publicly funded TJA in New Zealand between 2011 and 2013. We used propensity score matching to match individuals who used opioids either before surgery, during hospital stay, or immediately post-discharge with individuals who did not based on a comprehensive set of covariates. Regression analysis was used to estimate the effect of opioid use on health and socio-economic outcomes over 5 years.

RESULTS

Opioid use in the 3 months prior to surgery was associated with significant increases in healthcare utilization and costs (number of hospitalizations 6%, days spent in hospital 14.4%, opioid scripts dispensed 181%, and total healthcare costs 11%). Also increased were the rate of receiving social benefits (2 percentage points) and the rates of opioid overdose (0.5 percentage points) and mortality (3 percentage points). Opioid use during hospital stay or post-discharge was associated with increased long-term opioid use, but there was little evidence of other adverse effects.

CONCLUSIONS

Opioid use before TJA is associated with significant negative health and economic consequences and should be limited. This has implications for opioid prescribing in primary care. There is little evidence that peri- or post-operative opioid use is associated with significant long-term detriments.

Sex and age differences in the use of analgesic drugs before and after primary total hip arthroplasty in 105,520 Danish patients

BACKGROUND

We examined analgesic drug use before and after total hip arthroplasty (THA) by sex and age, and impact of comorbidity in that context.

METHODS

Using Danish nationwide medical registries, we included 105,520 THA patients (1996-2018). We calculated prevalence of overall analgesic drug use and use of NSAIDs and opioids separately in four quarters before (-Q4 to -Q1) and after THA (Q1 to Q4). -Q4 and Q4 was compared using prevalence rate ratios (PRR) with 95% confidence interval (CI).

RESULTS

Among women, analgesic drug use was 46% in -Q4, 65% in Q1, but decreased to 31% in Q4 (PRR: 0.68 (CI: 0.67-0.69)). Among men, these numbers were 39% in -Q4, 62% in Q1, and 23% in Q4 (PRR: 0.61 (CI: 0.60-0.63)). Analgesic drug use was higher among older patients in all quarters except Q1. Analgesic drug use decreased from 40% in -Q4 to 25% in Q4 (PRR: 0.62 (CI: 0.59-0.64)) in patients <55 years, and from 44% to 30% in patients >85 years, (PRR: 0.67 (CI: 0.63-0.71)). Women used more NSAIDs and opioids than men. Older patients used more opioids compared to younger, while variation in NSAID use by age was small. Decrease in analgesic drug use from -Q4 to Q4 was least pronounced in patients with comorbidity history.

CONCLUSIONS

Women and older patients have higher prevalence of analgesic drug use before and after THA, and a smallest reduction in analgesic drug use from before to after THA. Comorbidity history modified these associations.

Preoperative Versus Perioperative Risk Factors for Delayed Pain and Opioid Cessation After Total Joint Arthroplasty: A Prospective Cohort Study

INTRODUCTION

The evolution of pre- versus postoperative risk factors remains unknown in the development of persistent postoperative pain and opioid use. We identified preoperative versus comprehensive perioperative models of delayed pain and opioid cessation after total joint arthroplasty including time-varying postoperative changes in emotional distress. We hypothesized that time-varying longitudinal measures of postoperative psychological distress, as well as pre- and postoperative use of opioids would be the most significant risk factors for both outcomes.

METHODS

A prospective cohort of 188 patients undergoing total hip or knee arthroplasty at Stanford Hospital completed baseline pain, opioid use, and emotional distress assessments. After surgery, a modified Brief Pain Inventory was assessed daily for 3 months, weekly thereafter up to 6 months, and monthly thereafter up to 1 year. Emotional distress and pain catastrophizing were assessed weekly to 6 months, then monthly thereafter. Stepwise multivariate time-varying Cox regression modeled preoperative variables alone, followed by all perioperative variables (before and after surgery) with time to postoperative opioid and pain cessation.

RESULTS

The median time to opioid and pain cessation was 54 and 152 days, respectively. Preoperative total daily oral morphine equivalent use (hazard ratio-HR 0.97; 95% confidence interval-CI 0.96-0.98) was significantly associated with delayed postoperative opioid cessation in the perioperative model. In contrast, time-varying postoperative factors: elevated PROMIS (Patient-Reported Outcomes Measurement Information System) depression scores (HR 0.92; 95% CI 0.87-0.98), and higher Pain Catastrophizing Scale scores (HR 0.85; 95% CI 0.75-0.97) were independently associated with delayed postoperative pain resolution in the perioperative model.

CONCLUSIONS

These findings highlight preoperative opioid use as a key determinant of delayed postoperative opioid cessation, while postoperative elevations in depressive symptoms and pain catastrophizing are associated with persistent pain after total joint arthroplasty providing the rationale for continued risk stratification before and after surgery to identify patients at highest risk for these distinct outcomes. Interventions targeting these perioperative risk factors may prevent prolonged postoperative pain and opioid use.

Post-total joint arthroplasty opioid prescribing practices vary widely and are not associated with opioid refill: an observational cohort study

INTRODUCTION

Optimized health system approaches to improving guideline-congruent care require evaluation of multilevel factors associated with prescribing practices and outcomes after total knee and hip arthroplasty.

MATERIALS AND METHODS

Electronic health data from patients who underwent a total knee or hip arthroplasty between January 2016-January 2020 in the Military Health System Data were retrospectively analyzed. A generalized linear mixed-effects model (GLMM) examined the relationship between fixed covariates, random effects, and the primary outcome (30-day opioid prescription refill).

RESULTS

In the sample (N = 9151, 65% knee, 35% hip), the median discharge morphine equivalent dose was 660 mg [450, 892] and varied across hospitals and several factors (e.g., joint, race and ethnicity, mental and chronic pain conditions, etc.). Probability of an opioid refill was higher in patients who underwent total knee arthroplasty, were white, had a chronic pain or mental health condition, had a lower age, and received a presurgical opioid prescription (all p < 0.01). Sex assigned in the medical record, hospital duration, discharge non-opioid prescription receipt, discharge morphine equivalent dose, and receipt of an opioid-only discharge prescription were not significantly associated with opioid refill.

CONCLUSION

In the present study, several patient-, care-, and hospital-level factors were associated with an increased probability of an opioid prescription refill within 30 days after arthroplasty. Future work is needed to identify optimal approaches to reduce unwarranted and inequitable healthcare variation within a patient-centered framework.

A Safe Number of Perioperative Opioids to Reduce the Risk of New Persistent Usage Among Opioid-Naïve Patients Following Total Joint Arthroplasty

BACKGROUND

Higher initial opioid dosing increases the risk of prolonged opioid use following total joint arthroplasty (TJA), and the safe amounts to prescribe are unknown. We examined the relationship between perioperative opioid exposure and new persistent usage among opioid-naïve patients after total knee and hip arthroplasty.

METHODS

In this retrospective cohort study, 22,310 opioid-naïve patients undergoing primary TJA between 2018 and 2019 were identified within a commercial claims database. Perioperative opioid exposure was defined as total dose of opioid prescription in morphine milligram equivalents (MME) between 1 month prior to and 2 weeks after TJA. New persistent usage was defined as at least one opioid prescription between 90 and 180 days postoperatively. Multivariate regression analyses were performed to examine the relationship between the perioperative dosage group and the development of new persistent usage.

RESULTS

For the total patient cohort, 8.1% developed new persistent usage. Compared to patients who received <300 MME, patients who received 600-900 MME perioperatively had a 77% increased risk of developing new persistent usage (odds ratio 1.77, 95% CI, 1.44-2.17), and patients who received ≥1,200 MME perioperatively had a 285% increased risk (odds ratio 3.85, 95% CI, 3.13-4.74).

CONCLUSION

We found a dose-dependent association between perioperative MME and the risk of developing new persistent usage among opioid-naïve patients following TJA. We recommend prescribing <600 MME (equivalent to 80 pills of 5 mg oxycodone) during the perioperative period to reduce the risk of new persistent usage.

LEVEL OF EVIDENCE

Level III.

Preoperative Patient-Reported Data Indicate the Risk of Prolonged Opioid Use After Hand and Upper Extremity Surgeries

PURPOSE

Opioids play an important role in pain management after surgery but also increase the risk of prolonged opioid use in patients. The identification of patients who are more likely to use opioids after intended short-term treatment is critical for employing alternative management approaches or targeted interventions for the prevention of opioid-related problems. We used patient-reported data (PRD) and electronic health record information to identify factors predictive of prolonged opioid use after surgery.

METHODS

We used our institutional registry containing data on all patients who underwent elective upper extremity surgeries. We evaluated factors associated with prolonged opioid use in the cohort from the year 2018 to 2019. We then validated our results using the 2020 cohort. The predictive variables included preoperative PRD and electronic health record data. Opioid use was determined based on patient reports and/or filled opioid prescriptions 3 months after surgery. We conducted bivariate regression, followed by multivariable regression analyses, and model validation using area under the receiver operating curve.

RESULTS

We included 2,114 patients. In our final model on the 2018-2019 electronic health records and PRD data (n = 1,589), including numerous patient-reported outcome questionnaire scores, patients who were underweight and had undergone trauma-related surgery had higher odds of being on opioids at 3 months. Additionally, each 5-unit decrease in the preoperative Patient-Reported Outcomes Measurement Information System Global Physical Health score was associated with a 30% increased odds of being on opioids at 3 months. The area under the receiver operating curve of our model was 70.4%. On validation using data from the 2020 cohort, the area under the receiver operating curve was 60.3%. The Hosmer-Lemeshow test indicated a good fit.

CONCLUSIONS

We found that preoperative questionnaire scores were associated with prolonged postoperative opioid use, independent of other variables. Furthermore, PRD may provide unique patient-level insights, alongside other factors, to improve our understanding of postsurgical pain management.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Opioid use and patient outcomes in an Australian hip and knee arthroplasty cohort

Background

To determine the prevalence of opioid use in Australian hip (THA) or knee (TKA) cohort, and its association with outcomes.

Methods

About 837 primary THA or TKA subjects prospectively completed Oxford Scores, and Knee or Hip Osteoarthritis Outcomes Score(KOOS/HOOS) and opioid use in the previous week before arthroplasty. Subjects repeated the baseline survey at 6 months, with additional questions regarding satisfaction.

Results

Opioid use was reported by 19% preoperatively and 7% at 6 months. Opioid use was 46% at 6 weeks and 10% at 6 months after TKR, and 16% at 6 weeks and 4% at 6 months after THR. Preoperative opioid use was associated with back pain(OR 2.2, P = 0.006), anxiety or depression(OR 1.8, P = 0.001) and Oxford knee scores <30(OR 5.6, P = 0.021) in TKA subjects, and females in THA subjects(OR 1.7, P = 0.04). There was no difference between preoperative opioid users and non‐users for satisfaction, or KOOS or HOOS scores at 6 months. 77% of patients taking opioids before surgery had ceased by 6 months, and 3% of preoperative non users reported opioid use at 6 months. Opioid use at 6 months was associated with preoperative use (OR 6.6–14.7, P < 0.001), and lower 6 month oxford scores (OR 4.4–83.6, P < 0.01).

Conclusion

One in five used opioids before arthroplasty. Pre‐operative opioid use was the strongest risk factor for opioid use at 6 months, increasing odds 7–15 times. Prolonged opioid use was rarely observed in the opioid naïve (<5% TKA and 1% THA). Preoperative opioid use was not associated with inferior outcomes or satisfaction.

Machine learning algorithms predict extended postoperative opioid use in primary total knee arthroplasty

PURPOSE

Adequate postoperative pain control following total knee arthroplasty (TKA) is required to achieve optimal patient recovery. However, the postoperative recovery may lead to an unnaturally extended opioid use, which has been associated with adverse outcomes. This study hypothesizes that machine learning models can accurately predict extended opioid use following primary TKA.

METHODS

A total of 8873 consecutive patients that underwent primary TKA were evaluated, including 643 patients (7.2%) with extended postoperative opioid use (> 90 days). Electronic patient records were manually reviewed to identify patient demographics and surgical variables associated with prolonged postoperative opioid use. Five machine learning algorithms were developed, encompassing the breadth of state-of-the-art machine learning algorithms available in the literature, to predict extended opioid use following primary TKA, and these models were assessed by discrimination, calibration, and decision curve analysis.

RESULTS

The strongest predictors for prolonged opioid prescription following primary TKA were preoperative opioid duration (100% importance; p < 0.01), drug abuse (54% importance; p < 0.01), and depression (47% importance; p < 0.01). The five machine learning models all achieved excellent performance across discrimination (AUC > 0.83), calibration, and decision curve analysis. Higher net benefits for all machine learning models were demonstrated, when compared to the default strategies of changing management for all patients or no patients.

CONCLUSION

The study findings show excellent model performance for the prediction of extended postoperative opioid use following primary total knee arthroplasty, highlighting the potential of these models to assist in preoperatively identifying at risk patients, and allowing the implementation of individualized peri-operative counselling and pain management strategies to mitigate complications associated with prolonged opioid use.

LEVEL OF EVIDENCE

IV.

Preoperative Opioids and the Dose-Dependent Effect on Outcomes After Total Hip Arthroplasty

BACKGROUND

The purpose of this study is to identify the preoperative daily opioid dose associated with increased complications after primary total hip arthroplasty (THA).

METHODS

Primary THA patients in the Humana claims database (2007-2020) with an opioid prescription within 3 months prior to surgery were identified. Patients were stratified based on daily opioid dose: Tier 1, <5 milligram morphine equivalents (MME); Tier 2, 5-10 MME; Tier 3, 11-25 MME; Tier 4, 26-50 MME; Tier 5, >50 MME. Each tier was matched 1:1 to opioid-naïve patients. Emergency department (ED) visits, readmissions, and postoperative complications were compared.

RESULTS

In total, 67,719 patients using preoperative opioids were identified and matched. 17.0% of patients using preoperative opioids visited the ED within 90 days, compared to 13.3% of opioid-naïve patients (P < .001). About 9.5% of patients using preoperative opioids were readmitted within 90 days, compared to 7.4% of opioid-naïve patients (P < .001). When stratified by tier, opioid users in all tiers had higher risk of ED visits and readmission. Rates of superficial infection, periprosthetic joint infection, and dislocation were increased in patients taking preoperative opioids in Tiers 2 through 5. Patients in Tiers 3 through 5 had an increased risk of revision surgery.

CONCLUSION

Preoperative opioid use is associated with a dose-dependent increase in complications after THA. Just one 5 mg hydrocodone tablet daily leads to a significant increase in ED visits and readmission, while higher doses are associated with dislocation, superficial infection, periprosthetic joint infection, and revision surgery. Continued education regarding the harmful effects of opioids prescribed for the nonoperative treatment of osteoarthritis is still needed.

LEVEL OF EVIDENCE

Level III.

Tramadol prescribed at discharge is associated with lower odds of chronic opioid use after elective total joint arthroplasty

INTRODUCTION

We aimed to study the association between tramadol prescribed at discharge (after elective total hip and knee arthroplasty (THA/TKA) surgery) and chronic opioid use postoperatively.

METHODS

This retrospective cohort study queried the Truven MarketScan database and identified patients who underwent an elective THA/TKA surgery between 2016 and 2018 and were prescribed opioids at discharge (n=81 049). Multivariable analysis was conducted to study the association between tramadol prescription at discharge and chronic opioid use, with additional analysis adjusting for the amount of opioids prescribed in oral morphine equivalents. Chronic opioid use was defined as filling ≥10 opioid prescriptions or prescriptions for ≥120 pills within the period from 90 days to 1 year after surgery.

RESULTS

Overall, tramadol was prescribed at discharge in 11.0% of all THA/TKA cases. Of those, 26.9% and 73.1% received tramadol only or tramadol with another opioid, respectively. Chronic opioid use was observed in 5.4% of cases. After adjustment for relevant covariates, prescription of tramadol combined with another opioid at discharge was associated with lower odds of chronic opioid use comparing to prescription of other opioids (OR 0.69 CI 0.61 to 0.78).

DISCUSSION

Among patients undergoing elective THA/TKA surgery and discharged with a prescription of opioids, we found that prescription of tramadol combined with another opioid was associated with lower odds of chronic opioid use. This finding must be considered in the context of the tramadol's pharmacology, as well-described genetic differences in metabolism that can make it ineffective in many patients, while for patients with ultrarapid metabolism can cause drug-drug interactions and adverse events, including feelings of high and seizures.

Does In-Hospital Opioid Use Affect Opioid Consumption After Total Joint Arthroplasty?

BACKGROUND

Preoperative opioid use strongly correlates with greater postoperative opioid use and complications following total joint arthroplasty (TJA). However, there is a lack of information regarding the effect of opioid consumption during the hospital stay and within the operating room on postoperative opioid use.

METHODS

We retrospectively reviewed 369 consecutive patients undergoing primary TJA at an academic center over a 9-month period. Ninety-day preoperative and postoperative opioid prescriptions were obtained from the state's drug monitoring database. In-hospital opioid consumption data was obtained from the preoperative unit, operating room, postanesthesia care unit (PACU), and hospital floor. Multivariate analysis was utilized to compare patients' total in-hospital opioid consumption with their preoperative and postoperative use, along with opioid use throughout the hospitalization.

RESULTS

Total in-hospital opioid consumption was independently associated with postoperative opioid use (r_s = 0.17, P = .0010). Opioids consumed on the hospital floor correlated with opioid use in the preoperative unit (r_s = 0.11, P = .0338) and PACU (r_s = 0.15, P = .0032). Increased preoperative opioid consumption was the greatest risk factor for excessive postoperative use (r_s = 0.44, P < .0001). A greater proportion of patients <65 years of age were high posthospital opioid consumers (P = .0146) and significantly more TKA patients were in the higher use groups (P = .0006).

CONCLUSION

In-hospital opioid use is independently associated with preoperative and postoperative consumption. Preoperative opioid use remains the greatest risk factor for increased opioid consumption after TJA. Multimodal approaches to decrease reliance on opioids for pain control during hospitalization may offer hope to further decrease postoperative usage.

LEVEL OF EVIDENCE

III.

Long-term opioid use in seniors following hip and knee arthroplasty in Ontario: a historical cohort study

PURPOSE

Canadian seniors who undergo hip and knee arthroplasty often experience significant postoperative pain, which could result in persistent opioid use. We aimed to document the impact of preoperative opioid use and other characteristics on postoperative opioid prescriptions in elderly patients following hip and knee replacement before widespread dissemination of opioid reduction strategies.

METHODS

We conducted a historical cohort study to evaluate postoperative opioid use in patients over 65 yr undergoing primary total hip and knee replacement over a ten-year period from 1 April 2006 to 31 March 2016, using linked de-identified Ontario administrative data. We determined the use of preoperative opioids and the duration of postoperative opioid prescriptions (short-term [1-90 days], prolonged [91-180 days], chronic [181-365 days], or undocumented).

RESULTS

The study included 49,638 hip and 85,558 knee replacement patients. Eighteen percent of hip and 21% of knee replacement patients received an opioid prescription within 90 days before surgery. Postoperatively, 51% of patients filled opioid prescriptions for 1-90 days, while 24% of hip and 29% of knee replacement patients filled prescriptions between 6 and 12 months, with no impact of preoperative opioid use. Residence in long-term care was a significant predictor of chronic opioid use (hip: odds ratio [OR], 2.64; 95% confidence interval [CI], 1.93 to 3.59; knee: OR, 2.46; 95% CI, 1.75 to 3.45); other risk factors included female sex and increased comorbidities.

CONCLUSION

Despite a main goal of joint arthroplasty being relief of pain, seniors commonly remained on postoperative opioids, even if not receiving opioids before surgery. Opioid reduction strategies need to be implemented at the surgical, primary physician, long-term care, and patient levels. These findings form a basis for future investigations following implementation of opioid reduction approaches.

Adverse drug reactions associated with the use of biological agents

Introduction

Biological drugs open new possibilities to treat diseases for which drug therapy is limited, but they may be associated with adverse drug reactions (ADRs).

Objective

To identify the ADRs associated with the use of biological drugs in Colombia.

Methods

This was a retrospective study of ADR reports from 2014 to 2019, contained in the database of Audifarma SA pharmacovigilance program. The ADRs, groups of associated drugs, and affected organs were classified.

Results

In total, 5,415 reports of ADRs associated with biological drugs were identified in 78 Colombian cities. A total of 76.1% of the cases corresponded to women. The majority were classified as type A (55.0%) and B (28.9%), and 16.7% were serious cases. The respiratory tract was the most affected organ system (16.8%), followed by the skin and appendages (15.6%). Antineoplastic and immunomodulatory drugs accounted for 70.6% of the reports, and the drugs related to the greatest number of ADRs were adalimumab (12.2%) and etanercept (11.6%).

Conclusions

The reporting of ADRs has increased in recent years and these reactions are mostly classified as tyoe A or B, categorized as serious in almost one-fifth of the reported cases and associated mainly with immunomodulators and antineoplastic agents. This type of study can support decision makers in ways that benefit patient safety and interaction with health systems.

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.