Trends in major opioid analgesic consumption in Taiwan, 2002-2014

Assessing the impact of public funding in alleviating participant reduction and improving the retention rate in methadone maintenance treatment clinics in Taiwan: an interrupted time series analysis

BACKGROUND

Given the steady decline in patient numbers at methadone maintenance treatment (MMT) clinics in Taiwan since 2013, the government initiated Patients' Medical Expenditure Supplements (PMES) in January 2019 and the MMT Clinics Accessibility Maintenance Program (MCAM) in September 2019. This study aims to evaluate the impact of the PMES and MCAM on the enrollment and retention of patients attending MMT clinics and whether there are differential impacts on MMT clinics with different capacities.

METHODS

The monthly average number of daily participants and 3-month retention rate from 2013 to 2019 were extracted from MMT databases and subjected to single interrupted time series analysis. Pre-PMES (from February 2013 to December 2018) was contrasted with post-PMES, either from January 2019 to December 2019 for clinics funded solely by the PMES or from January 2019 to August 2019 for clinics with additional MCAM. Pre-MCAM (from January 2019 to August 2019) was contrasted with post-MCAM (from September 2019 to December 2019). Based on the monthly average number of daily patients in 2018, each MMT clinic was categorized as tiny (1-50), small (51-100), medium (101-150), or large (151-700) for subsequent stratification analysis.

RESULTS

In terms of participant numbers after the PMES intervention, a level elevation and slope increase were detected in the clinics at every scale except medium in MMT clinics funded solely by PMES. In MMT clinics with subsequent MCAM, a level elevation was only detected in small-scale clinics, and a slope increase in the participant numbers was detected in tiny- and small-scale clinics. The slope decrease was also detected in medium-scale clinics. In terms of the 3-month retention rate, a post-PMES level elevation was detected at almost every scale of the clinics, and a slope decrease was detected in the overall and tiny-scale clinics for both types of clinics.

CONCLUSIONS

Supplementing the cost of a broad treatment repertoire enhances the enrollment of people with heroin use in MMTs. Further funding of human resources is vital for MMT clinics to keep up with the increasing numbers of participants and their retention.

External validation of machine learning algorithm predicting prolonged opioid prescriptions in opioid-naïve lumbar spine surgery patients using a Taiwanese cohort

BACKGROUND/PURPOSE

Identifying patients at risk of prolonged opioid use after surgery prompts appropriate prescription and personalized treatment plans. The Skeletal Oncology Research Group machine learning algorithm (SORG-MLA) was developed to predict the risk of prolonged opioid use in opioid-naive patients after lumbar spine surgery. However, its utility in a distinct country remains unknown.

METHODS

A Taiwanese cohort containing 2795 patients who were 20 years or older undergoing primary surgery for lumbar decompression from 2010 to 2018 were used to validate the SORG-MLA. Discrimination (area under receiver operating characteristic curve [AUROC] and area under precision-recall curve [AUPRC]), calibration, overall performance (Brier score), and decision curve analysis were applied.

RESULTS

Among 2795 patients, the prolonged opioid prescription rate was 5.2%. The validation cohort were older, more inpatient disposition, and more common pharmaceutical history of NSAIDs. Despite the differences, the SORG-MLA provided a good discriminative ability (AUROC of 0.71 and AURPC of 0.36), a good overall performance (Brier score of 0.044 compared to that of 0.039 in the developmental cohort). However, the probability of prolonged opioid prescription tended to be overestimated (calibration intercept of -0.07 and calibration slope of 1.45). Decision curve analysis suggested greater clinical net benefit in a wide range of clinical scenarios.

CONCLUSION

The SORG-MLA retained good discriminative abilities and overall performances in a geologically and medicolegally different region. It was suitable for predicting patients in risk of prolonged postoperative opioid use in Taiwan.

An analytical approach to determining pethidine: An investigation of 18 patients' urine

Pethidine (PET) is an opioid pain-relief medicine with high addiction potential, especially among health professionals. Pethidine is commonly prescribed in Turkey as a pain-relieving medication for operative purposes. Due to its accessibility, low cost, user-friendliness, and effectiveness, PET is often misused by both healthcare professionals and patients. For this reason, analytical determination methods for PET abuse are essential in terms of forensic toxicology. In this study, a fast, reliable, and accurate gas chromatography-mass spectrometry method was developed for the first time in Turkey for the simultaneous detection of PET and its main urinary metabolite norpethidine (NPET). The method was validated in terms of selectivity, linearity, the limit of detection (LOD), the limit of quantification (LOQ), trueness, and precision according to the Scientific Working Group for Forensic Toxicology guidelines. The linear range was between 0.125-25.00 μg/mL for PET and 1.00-20.00 μg/mL for NPET. The LOD values for PET and NPET were 0.05 µg/mL and 0.49 µg/mL, while the LOQ values were 0.125 µg/mL and 1.00 µg/mL, respectively. Extraction efficiencies were calculated as 113% for PET and 104% for NPET. The intra-assay and inter-assay precision results were within acceptable limits. In the presented study, the validated method was applied to the urine of 18 patients collected at the 1st and 3rd hours after receiving PET. All samples in the study were collected under patients' consent and in line with ethical guidelines.

No association of postoperative opioid usage with long-term surgery outcomes in patients with liver cancer: a population-based retrospective cohort study

ABSTRACT

Hepatocellular carcinoma (HCC) is a fatal cancer worldwide, and surgical resection remains the standard treatment. Postoperative opioid prescription has been believed to affect cancer recurrence through complex biological pathways. We conducted a retrospective cohort study using the Longitudinal Health Insurance Database of Taiwan to evaluate the relationship between postoperative opioid use and long-term surgical outcomes of patients with HCC. This study had a retrospective cohort design. In total, 812 patients older than 20 years who underwent hepatectomy because of HCC were included. The exposure group comprised patients who used opioids during hospitalization postoperatively. The comparison group included those who never used opioids during hospitalization postoperatively. A Cox proportional hazards model was used to evaluate the overall survival or recurrence-free survival rate between the opioid group and the nonopioid group. A total of 530 patients received opioids postoperatively and 282 patients did not. The hazard ratios of overall survival and recurrence-free survival were 1.10 (95% confidence interval [CI], 0.85-1.41) and 1.15 (95% CI, 0.91-1.46), respectively. Total postoperative opioids were converted into oral morphine milligram equivalents and then divided into 3 equal subgroups: low dose, <40 mg; medium dose, 40 to 144 mg; and high dose, ≥145 mg. The hazard ratios of overall survival were 0.88 (95% CI, 0.63-1.24) for the low-dose group, 1.27 (95% CI, 0.92-1.74) for the medium-dose group, and 1.14 (95% CI, 0.83-1.58) for the high-dose group. Postoperative opioids do not affect overall and recurrence-free survival in patients undergoing hepatectomy or liver transplantation because of HCC. Cancer recurrence should not be a clinical concern regarding postoperative opioid prescription.

Transdermal buprenorphine improves overall quality of life and symptom severity in cancer patients with pain

AIM AND OBJECTIVES

This study explored the effect of transdermal buprenorphine on quality of life and six symptoms in cancer patients with pain.

BACKGROUND

Transdermal opioids offer advantages over traditional routes of administration. The impact of transdermal buprenorphine on quality of life for patients with cancer in Asian populations is unknown.

DESIGN

This study employed a single-arm observational repeated measures design. Cancer patients with pain were evaluated prior to treatment (baseline). Over a 4-week treatment period, quality of life and symptoms were assessed at 2 and 4 weeks. This study adhered to the recommendations of STROBE guidelines.

METHODS

This multi-site study was conducted in six hospitals located across northern, middle and southern Taiwan. Adult cancer patients whose pain was previously stable with opioid analgesics and, based on clinical judgement, were able to convert to transdermal buprenorphine treatment were invited to participate. Quality of life was measured with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30).

RESULTS

Generalised estimating equations showed participants who completed at least one follow-up measurement (N = 80) over 4-weeks had a significant improvement in overall quality of life. Functional status only improved for social functioning. However, symptom severity decreased significantly for nausea/vomiting, pain, insomnia and constipation.

CONCLUSIONS

The study provides initial evidence supporting transdermal buprenorphine for providing beneficial effects of improving quality of life and reducing severity of symptoms in Asian patients with cancer.

RELEVANCE TO CLINICAL PRACTICE

The findings of this study can inform the clinical practice that the use of transdermal buprenorphine in cancer patients with pain may also reduce the severity of other symptoms and improve overall quality of life.

TRIAL REGISTRATION DETAILS

This study was registered in ClinicalTrials.gov. Identifier: NCT04315831.

A nationwide study on consumption of opioid analgesics in Iran from 2000 to 2018

BACKGROUND

Opioid analgesics play a unique role in pain management. National opioid consumption studies could provide indirect evidence of pain management in a country. National, regional, and global opioid consumption have been studied in other countries so far; however, conducting a focused study to illuminate the consumption of opioid analgesics over the past decades in Iran seemed necessary.

AIM

The main objective of this study was to determine the consumption of opioid analgesics and explore the trend of their use during 19 years in Iran.

METHOD

Iran pharmaceutical wholesale data were used to extract the annual consumption figures of the opioid analgesics in group N02A of the World Health Organization (WHO) Anatomical Therapeutic Chemical classification and were available in Iran (morphine, fentanyl, pethidine, and oxycodone as strong opioids and, tramadol and pentazocine as weak opioids), from 2000 to 2018. Using Defined Daily Dose (DDD) by WHO and Oral Morphine Equivalent (OMEQ), the amount of annual consumption was determined in DDD/1000 inhabitants/Day (DID) and OMEQ (mg)/1000 inhabitants/Day (OID).

RESULTS

Total opioid analgesic utilization based on DID and OID increased 31.12-fold (from 0.0196 to 0.61) and 21.06-fold (from 1.97 to 41.5 mg) over 19 years, respectively with a significant sharp increase from 2003 to 2006 (ß = 1.78 (DID), P value < 0.001). Medications that constituted 70% of annual opioid analgesics utilization were morphine in 2000, compared to tramadol in 2018. The annual weak and strong opioids share were 86.7% and 13.2% in 2018, respectively.

CONCLUSION

Despite considerable growth in the consumption of opioid analgesics in Iran over nearly two decades, the consumption amount remained low, which might signal sub-optimal pain management. On the other hand, misuse and abuse seem to be the main reason behind significant increases in the consumption of opioid analgesics with less controlled distribution.

Long-term opioid use and mortality in patients with chronic non-cancer pain: Ten-year follow-up study in South Korea from 2010 through 2019

BACKGROUND

We aimed to investigate the prevalence and factors associated with long-term opioid use among patients with chronic non-cancer pain (CNCP).

METHODS

We extracted data from the National Health Insurance Service (NHIS) database in South Korea. As a nationwide database, the NHIS database contains information regarding all disease diagnoses and prescriptions for any drug and/or procedures. A total of 2.5% of adult patients (≥20 years of age) who were diagnosed with musculoskeletal diseases and CNCP from 2010 to 2019 were selected using a stratified random sampling technique and included in the analysis. Patients who were prescribed opioids continuously for ≥90 days were classified as long-term opioid users.

FINDINGS

A total of 19,645,161 patients with CNCP were included in the final analysis. The prevalence of long-term opioid use was 0.47% (95% confidence interval [CI]: 0.46%, 0.48%; 8421/1,808,043) in 2010, which gradually increased to 2.63% (95% CI: 2.61%, 2.66%; 49,846/1,892,913) in 2019. Among the 2010 cohort (n = 1,804,019), in multivariable logistic regression: old age, underlying disability, increased Charlson comorbidity index, use of benzodiazepine or Z-drug, rheumatoid arthritis, osteoarthritis, and low back pain were associated with an increased prevalence of long-term opioid use among patients with CNCP. In a multivariable Cox regression, the 10-year all-cause mortality in long-term opioid users was found to be 1·21-fold (hazard ratio: 1.21, 95% CI: 1.13, 1.31; P<0·001) higher than that in opioid-naive patients with CNCP.

INTERPRETATION

Long-term opioid use increased in patients with CNCP in South Korea from 2010 to 2019. Certain factors were potential risk factors for long-term opioid use. Moreover, long-term opioid use was associated with increased 10-year all-cause mortality among patients with CNCP.

FUNDING

None.

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/.

Prevalence of opioid prescriptions in Taiwan (2008-2018)

BACKGROUND

Opioids are effective for severe pain; however, the safety issue is also a primary concern. To better understand the opioid use in Taiwan, we conducted this study.

METHODS

Data on patients with opioid prescriptions, including morphine, fentanyl, pethidine, codeine, oxycodone, hydromorphone, and buprenorphine were collected using the Taiwan National Health Insurance Database (NHID).

RESULTS

Our analysis of opioid prescriptions from 2008 to 2018 in Taiwan indicated that (1) A slow increase in prevalence of opioid prescription was found during the study period. Among the drugs studied, morphine accounted for the majority of the prescriptions written, with a gradual increase annually. Pethidine prescriptions showed a significant and rapid decline over the years; (2) medical centers prescribed the largest number of opioids, followed by regional hospitals, local hospitals, and clinics; (3) the number of prescriptions per year per capita in cancer group was much higher than that in noncancer group. In noncancer group, most of the prescriptions were used in acute pain service (98.7%); and (4) use of opioids increased with age in both cancer and noncancer patients.

CONCLUSION

The total number of opioid prescriptions in Taiwan gradually increased annually, among which morphine was the most commonly used opioid. Cancer patients consumed more opioid prescriptions than noncancer patients and most of the prescriptions in noncancer patients were used in acute pain service. The number of prescriptions increased with the age of the patients in both cancer and noncancer patients. The low prescription rate of opioids in chronic pain in Taiwan is not similar as those in high opioid-consuming countries, such as United States.

Recent trends in opioid consumption in Korea from 2002 to 2015, based on the Korean NHIS-NSC cohort

Objectives

Opioids are prescribed to treat moderate-to-severe pain. We aimed to investigate the recent trends in opioid (morphine, oxycodone, fentanyl, and hydromorphone) consumption using data from the Korean National Health Insurance Service-National Sample Cohort between 2002 and 2015.

Methods

Morphine milligram equivalent (MME) was calculated to standardize the relative potency of the opioids. The number (cases) or amount (MME) of annual opioid prescription per 10,000 registrants was computed to analyze trends of consumption of opioids after age standardization. Joinpoint regression analysis was conducted to calculate the annual percentage change and average annual percentage change (AAPC).

Results

The number (cases) of prescriptions per 10,000 registrants increased from 0.07 in 2002 to 41.23 in 2015 (AAPC [95% CIs], 76.0% [61.6-91.7%]). The MME per 10,000 registrants increased from 15.06 in 2002 to 40,727.80 in 2015 (AAPC [95% CIs], 103.0% [78.2-131.3%]). The highest AAPC of prescriptions and MME per 10,000 registrants were observed in the elderly (60-69 years) and at general hospitals. Fentanyl prescription increased most rapidly among four opioids.

Conclusion

Consumption of opioids greatly increased in South Korea over 14 years.

Population-Based Study on the All-Cause and Cause-Specific Risks of Mortality among Long-Term Opioid Analgesics Users without Cancer in Taiwan

(1) Background: The prevalence of opioid use in Taiwan increased by 41% between 2002 and 2014. However, little is known regarding the risk of mortality among long-term opioid analgesics users who do not have cancer. This study investigated this mortality risk with an emphasis on the calendar year and patients’ age and sex. (2) Methods: This retrospective cohort study included 12,990 adult individuals without cancer who were long-term users of opioid analgesics and were randomly selected from the data set of Taiwan’s National Health Insurance program from 2000 to 2012. They were then followed up through 2013. Information on the underlying causes of death was retrieved from the Taiwan Death Registry. Age, sex, and calendar year-standardized mortality ratios (SMRs) of all-cause and cause-specific mortality were calculated with reference to those of the general population. (3) Results: With up to 14 years of follow-up, 558 individuals had all-cause mortality in 48,020 person-years (cumulative mortality: 4.3%, mortality rate: 11.62 per 1000 person-years). Compared with the general population, the all-cause SMR of 4.30 (95% confidence interval (95% CI): 3.95–4.66) was significantly higher: it was higher in men than in women, declined with calendar year and age, and was significantly higher for both natural (4.15, 95% CI: 3.78–4.53) and unnatural (5.04, 95% CI: 3.88–6.45) causes. (4) Conclusions: Long-term opioid analgesics use among individuals without cancer in Taiwan was associated with a significantly increased risk of mortality. The notably increased mortality in younger adults warrants attention. Strategies to reduce long-term opioid analgesics use, especially their overuse or misuse, are in an urgent need.

Cost-Effectiveness of an Opioid Abuse-Prevention Program Using the Narcotics Information Management System in South Korea

OBJECTIVES

To assess the cost-effectiveness of an opioid abuse-prevention program embedded in the Narcotics Information Management System ("the Network System to Prevent Doctor-Shopping for Narcotics") in South Korea.

METHODS

Using a Markov model with a 1-year cycle length and 30-year time horizon, we estimated the incremental cost-utility ratio (ICUR) of implementing an opioid abuse-prevention program in patients prescribed outpatient opioids from a Korean healthcare payer's perspective. The model has 6 health states: no opioid use, therapeutic opioid use, opioid abuse, overdose, overdose death, and all-cause death. Patient characteristics, healthcare costs, and transition probabilities were estimated from national population-based data and published literature. Age- and sex-specific utilities of the general Korean population were used for the no-use state, whereas the other health-state utilities were obtained from published studies. Costs (in 2019 US dollars) included the expenses of the program, opioids, and overdoses. An annual 5% discount rate was applied to the costs and quality-adjusted life-years (QALYs). Parameter uncertainties were explored via deterministic and probabilistic sensitivity analyses.

RESULTS

The program was associated with 2.27 fewer overdoses per 100 000 person-years, with an ICUR of $227/QALY. The ICURs were generally robust to parameter changes, although the program's effect on abuse reduction was the most influential parameter. Probabilistic sensitivity analysis showed that the program reached a 100% probability of cost-effectiveness at a willingness-to-pay threshold of $900/QALY.

CONCLUSIONS

The opioid abuse-prevention program appears to be cost-effective in South Korea. Mandatory use of the program should be considered to maximize clinical and economic benefits of the program.

Frailty modifies the association between opioid use and mortality in chronic kidney disease patients with diabetes: a population-based cohort study

The prevalence of chronic pain in patients with chronic kidney disease (CKD) and diabetes mellitus is high and correlates with higher frailty risk, but satisfactory pain control frequently fails, necessitating opioid initiation. We aimed to examine whether opioid use affected their outcomes and whether such a relationship was modified by frailty. From the longitudinal cohort of diabetes patients (n = 840,000), we identified opioid users with CKD (n = 26,029) and propensity score-matched them to opioid-naïve patients in a 1:1 ratio. We analyzed the associations between opioid use and long-term mortality according to baseline frailty status, defined by the modified FRAIL scale. Among all, 20.3% did not have any FRAIL items, while 57.2%, 20.6%, and 1.9% had 1, 2, and at least 3 positive FRAIL items, respectively. After 4.2 years, 16.4% died. Cox proportional hazard regression showed that opioid users exhibited an 18% higher mortality risk (HR 1.183, 95% CI 1.13-1.24) with a dose- and duration-responsive relationship, compared to opioid-naive ones. Furthermore, the mortality risk posed by opioids was observed only in CKD patients without frailty but not in those with frailty. In conclusion, opioid use increased mortality among patients with CKD, while this negative outcome influence was not observed among frail ones.

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

BACKGROUND/PURPOSE

Prescribing of opioids to patients with non-cancer pain is strictly regulated in Taiwan, but tramadol is not included in the regulation on chronic opioid prescribing. This study aims to identify the utilization trend of prescribing tramadol and other opioid analgesics and investigate the influence of government regulation on opioid prescribing in Taiwan.

METHODS

This cross-sectional study used the Taiwan National Health Insurance claims database and the cancer registry from 2001 through 2016. The annual number of adult opioid users, opioid utilization (Defined Daily Doses [DDDs]/1000 registrants) and the number of supply days were enumerated for each calendar year and stratified by cancer or non-cancer patients. Descriptive statistics were used to report the trends in utilization for each calendar year.

RESULTS

The regulation strictly limited persistent use of opioids for patients with non-cancer pain, of which only a small proportion of fentanyl (20%) and morphine (<2%) users were prescribed with an annual number of supply days greater than 28 days. The annual utilization of morphine (6.4-53.5 vs. 1.1 to 9.6 DDD/1000 registrants) and fentanyl (8.3-37.0 vs. 0.16 to 1.8 DDD/1000 registrants) to patients with cancer was consistently higher than patients without cancer. In contrast to morphine and fentanyl, the utilization of tramadol prescribed to patients without cancer increased 92.2-fold (3.7-341.2 DDD/1000 registrants) from 2002 to 2016.

CONCLUSION

The regulation in Taiwan limited the prescribing of selective opioids for patients with non-cancer pain and the substitution of tramadol for other opioids may have safety implications.

Chronic Opioid Use and Risk of Cancer in Patients with Chronic Noncancer Pain: A Nationwide Historical Cohort Study

BACKGROUND

To investigate whether chronic opioid therapy is associated with a higher risk of cancer among noncancer patients with chronic pain.

METHODS

A population-based historical cohort study of the South Korean adult population was conducted using data from the National Health Insurance Service. We included patients registered with a diagnostic code of M00-M99 (musculoskeletal system and connective tissue diseases) according to the International Classification of Diseases, 10th revision, in 2010. Patients prescribed a continuous supply of any opioid drug for ≥90 days were defined as chronic opioid users.

RESULTS

A total of 351,701 patients were analyzed. Among them, 25,153 (7.2%) were chronic opioid users. Using a multivariate time-dependent Cox regression model, the risk of cancer in chronic opioid users was 1.20-fold higher than that in controls [HR, 1.20; 95% confidence interval (CI), 1.15-1.25; P < 0.001]. On subgroup analysis according to opioid potency, the cancer risk in chronic weak and strong opioid users was 1.18-fold (HR, 1.18; 95% CI, 1.13-1.23; P < 0.001) and 1.32-fold (HR, 1.32; 95% CI, 1.10-1.59; P = 0.003) higher than that in controls, respectively.

CONCLUSIONS

Chronic opioid therapy was associated with an increased risk of cancer among noncancer patients with chronic pain. This association was more evident in chronic strong opioid users. However, as unmeasured and potential confounders may have affected the results, the relationship between chronic opioid use and cancer risk should be evaluated with caution.

IMPACT

Chronic opioid therapy was associated with an increased risk of cancer among noncancer patients.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Chronic pain and use of analgesics in the elderly: a nationwide population-based study

INTRODUCTION

Chronic pain may cause many comorbidities in the elderly; however, nationwide data about this issue remain insufficient. We conducted this study to address the data gap.

MATERIAL AND METHODS

We identified geriatric participants (≥ 65 years) with chronic pain between 2000 and 2013 from the Taiwan National Health Insurance Research Database. The causes of chronic pain and use of analgesics between two sexes and among three age subgroups were compared.

RESULTS

A total of 21,018 participants were identified with the mean age (standard deviation) of 72.7 years (5.6) and the female percentage of 50.8%. The prevalence of chronic pain in the elderly was 21.5%, and it was higher in the females than males. The proportions of each age subgroup were 65-74 (66.8%), 75-84 (29.4%), and ≥ 85 years (3.8%). Common causes of chronic pain were osteoarthritis (21.9%), spinal disorders (19.0%), peripheral vascular diseases (12.4%), and osteoporosis (11.4%). Non-steroidal anti-inflammatory drugs were the most common medication, followed by acetaminophen and opioids. The most commonly used opioid was morphine. The use of opioids increased with age.

CONCLUSIONS

This study delineated the causes of chronic pain and use of analgesics in a geriatric population, which may help further studies about this issue in the future.

Endogenous opiates and behavior: 2017

This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Trends in chronic opioid use and association with five-year survival in South Korea: a population-based cohort study

BACKGROUND

The Korean National Health Insurance Service (NHIS) was developed to provide population data for medical research. The aim of this study was to estimate trends in prescription opioid use in South Korea, and to determine the association between chronic opioid use and 5-yr mortality in cancer and non-cancer patients.

METHODS

A population-based cohort study was conducted amongst the South Korean adult population using data from the NHIS. Those prescribed a continuous supply of opioids for ≥90 days were defined as chronic opioid users. Multivariable Cox regression analysis was used to assess the association between chronic opioid use and 5-yr mortality.

RESULTS

The proportion of chronic weak opioid users increased from 1.03% in 2002 to 9.62% in 2015. The proportion of chronic strong opioid users increased from 0.04% in 2002 to 0.24% in 2015. In the 2010 cohort (n=822 214), compared with non-users, chronic weak opioid users had a significantly lower 5-yr mortality (hazard ratio [HR]: 0.93; 95% confidence interval [CI]: 0.89-0.96; P<0.001), and chronic strong opioid users had a significantly higher 5-yr mortality (HR: 1.45; 95% CI: 1.28-1.63; P<0.001). Similar results were observed in non-cancer patients, but chronic weak opioid users were not significantly associated with 5-yr mortality in cancer patients (P=0.063).

CONCLUSIONS

In South Korea, chronic opioid use has increased since 2002. Chronic strong opioid use was associated with a higher 5-yr mortality, and chronic weak opioid use was associated with a slightly lower 5-yr mortality. However, the findings regarding chronic weak opioid users should be interpreted carefully because there might be residual confounders in this study. Further study is needed to confirm these retrospective findings.

Strong opioid prescription in cancer patients in their final year of life: A population-based analysis using a Taiwanese health insurance database

AIM

Pain assessment and management have been important criteria in hospital accreditation in Taiwan since 2007. We used a Taiwanese health insurance database to determine factors influencing patterns of strong opioid use in cancer patients in their final 12 months of life.

METHODS

Data from patients with cancer in Taiwan outpatient clinics with cancer-related deaths between 2008 and 2011 were included in the analysis. Strong opioid prescription data from the last 12 months of each patient's life, as well as patient, physician, and hospital characteristics, were collected from the National Health Insurance Research Database.

RESULTS

Among 162 679 patients, more were male (63.6%) than female (36.4%) and almost half (49.3%) were ≥70 years old. Most (44.9%) patients had gastrointestinal cancer. More than one-third (35.4%) of patients were prescribed strong opioids during the 12 months before death, and more than half (53.2%) of those prescribed opioids received them in the 3 months before death. Median duration of strong opioid use was 81 days before death. Patients with head/neck cancer (52.8%) or who were treated in hematology and oncology departments (45.8%) were most likely, and patients with gastrointestinal cancer (hazard ratio = 0.65; 95% confidence interval, 0.64-0.67) or treated in gastroenterology departments (hazard ratio = 0.88; 95% confidence interval, 0.84-0.93) were least likely to be prescribed strong opioids.

CONCLUSION

Strong opioid prescriptions varied among patients with different cancer diagnoses and physicians. Information from this study can guide efforts to improve patient and physician education about cancer pain management.

Transdermal buprenorphine and fentanyl patches in cancer pain: a network systematic review

Treatment of cancer pain is generally based on the three-step World Health Organization (WHO) pain relief ladder, which utilizes a sequential approach with drugs of increasing potency. Goals of pain management include optimization of analgesia, optimization of activities of daily living, minimization of adverse effects, and avoidance of aberrant drug taking. In addition, it is recommended that analgesic regimens are individualized and simplified to help ensure patient compliance and should provide the least invasive, easiest, and safest route of opioid administration to ensure adequate analgesia. Buprenorphine and fentanyl are two opioids available for the relief of moderate-to-severe cancer pain. Available clinical data regarding the transdermal (TD) formulations of these opioids and the extent to which they fulfill the recommendations mentioned earlier are systematically reviewed, with the aim of providing additional information for oncologists and pain specialists regarding their comparative use. Due to lack of studies directly comparing TD buprenorphine with TD fentanyl, data comparing these with other step-3 opioids are also evaluated in a network fashion.