Non-invasive biomagnetic assessment of gastrointestinal motility in a loperamide-induced constipation model

Constipation is a disorder of the gastrointestinal (GI) and some of the main etiological mechanisms are directly related to changes in GI physiology. The capacity to carry out paired assessments and measure GI parameters under the influence of constipation is a relevant point in selecting a suitable methodology. We aimed to perform a non-invasive investigation of gastrointestinal motility in constipated rats using the alternating current biosusceptometry system (ACB). The animals were split into two groups: the pre-induction stage (CONTROL) and post-induction loperamide stage (LOP). We assessed GI motility parameters using the ACB system. Colon morphometric and immunohistochemical analyses were performed for biomarkers (C-kit) for interstitial cells of Cajal (ICC). Our results showed a significant increase in gastrointestinal transit in the LOP group in addition to a reduction in the dominant frequency of gastric contraction and an arrhythmic profile. A change in colonic contractility profiles was observed, indicating colonic dysmotility in the LOP group. We found a reduction in the number of biomarkers for intestinal cells of Cajal (ICC) in the LOP group. The ACB system can evaluate transit irregularities and their degrees of severity, while also supporting research into novel, safer, and more efficient treatments for constipation.

Prevalence and Burden of Illness of Rome IV Chronic Idiopathic Constipation, Opioid-Induced Constipation, and Opioid-Exacerbated Constipation in the United States.

INTRODUCTION: Chronic idiopathic constipation (CIC) and opioid-induced constipation (OIC) are disorders that negatively affect quality of life. We sought to assess the prevalence, symptom severity, and medication use among people with Rome IV CIC, OIC, and opioid-exacerbated constipation (OEC) using a nationally representative data set with nearly 89,000 people in the United States. METHODS: From May 3, 2020, to June 24, 2020, we recruited a representative sample of people in the United States ≥ 18 years to complete an online national health survey. The survey guided participants through the Rome IV CIC and OIC questionnaires, Patient-Reported Outcome Measurement Information System gastrointestinal scales (percentile 0-100; higher = more severe), and medication questions. Individuals with OEC were identified by asking those with OIC whether they experienced constipation before starting an opioid and whether their symptoms worsened afterward. RESULTS: Among the 88,607 participants, 5,334 (6.0%) had Rome IV CIC, and 1,548 (1.7%) and 335 (0.4%) had Rome IV OIC and OEC, respectively. When compared with people with CIC (Patient-Reported Outcome Measurement Information System score, 53.9 ± 26.5; reference), those with OIC (62.7 ± 28.0; adjusted P < 0.001) and OEC (61.1 ± 25.8, adjusted P = 0.048) had more severe constipation symptoms. People with OIC (odds ratio 2.72, 95% confidence interval 2.04-3.62) and OEC (odds ratio 3.52, 95% confidence interval 2.22-5.59) were also more likely to be taking a prescription medication for their constipation vs those with CIC. DISCUSSION: In this nationwide US survey, we found that Rome IV CIC is common (6.0%) while Rome IV OIC (1.7%) and OEC (0.4%) are less prevalent. Individuals with OIC and OEC have a higher burden of illness with respect to symptom severity and prescription constipation medication use.

American Gastroenterological Association-American College of Gastroenterology Clinical Practice Guideline: Pharmacological Management of Chronic Idiopathic Constipation.

INTRODUCTION: Chronic idiopathic constipation (CIC) is a common disorder associated with significant impairment in quality of life. This clinical practice guideline, jointly developed by the American Gastroenterological Association and the American College of Gastroenterology, aims to inform clinicians and patients by providing evidence-based practice recommendations for the pharmacological treatment of CIC in adults. METHODS: The American Gastroenterological Association and the American College of Gastroenterology formed a multidisciplinary guideline panel that conducted systematic reviews of the following agents: fiber, osmotic laxatives (polyethylene glycol, magnesium oxide, lactulose), stimulant laxatives (bisacodyl, sodium picosulfate, senna), secretagogues (lubiprostone, linaclotide, plecanatide), and serotonin type 4 agonist (prucalopride). The panel prioritized clinical questions and outcomes and used the Grading of Recommendations Assessment, Development, and Evaluation framework to assess the certainty of evidence for each intervention. The Evidence to Decision framework was used to develop clinical recommendations based on the balance between the desirable and undesirable effects, patient values, costs, and health equity considerations. RESULTS: The panel agreed on 10 recommendations for the pharmacological management of CIC in adults. Based on available evidence, the panel made strong recommendations for the use of polyethylene glycol, sodium picosulfate, linaclotide, plecanatide, and prucalopride for CIC in adults. Conditional recommendations were made for the use of fiber, lactulose, senna, magnesium oxide, and lubiprostone. DISCUSSION: This document provides a comprehensive outline of the various over-the-counter and prescription pharmacological agents available for the treatment of CIC. The guidelines are meant to provide a framework for approaching the management of CIC; clinical providers should engage in shared decision making based on patient preferences as well as medication cost and availability. Limitations and gaps in the evidence are highlighted to help guide future research opportunities and enhance the care of patients with chronic constipation.

Opioid-Induced Constipation: Cost Impact of Approved Medications in the Emergency Department.

INTRODUCTION: Opioid-induced constipation (OIC) prescription medications (OIC-Rx) like methylnaltrexone subcutaneous (SC) have shown efficacy in treating OIC in the emergency department (ED). This study aimed to describe and compare healthcare resource utilization (HRU) and healthcare costs in ED patients with OIC receiving OIC-Rx versus those not receiving OIC-Rx. METHODS: Adult patients with OIC during an ED encounter were identified from a hospital-based ED encounters database (2016-2019) and classified on the basis of receipt of OIC-Rx (OIC-Rx versus No OIC-Rx cohorts). Entropy balancing was used to reweight characteristics of the two cohorts. HRU and healthcare costs were measured and compared during the ED encounter and 30-day post-discharge period. RESULTS: Among 11,135 patients in the OIC-Rx cohort (21,474 in the No OIC-Rx cohort), 93% received methylnaltrexone SC. Patients in the OIC-Rx cohort had 0.7 fewer inpatient days per OIC ED encounter and 64% decreased odds of being hospitalized versus the No OIC-Rx cohort (both p < 0.001). During the post-discharge period, the OIC-Rx cohort had 35% decreased odds of any re-encounter (p < 0.001). The OIC-Rx cohort had a $732 reduction in costs per OIC ED encounter versus the No OIC-Rx cohort (p < 0.001), driven by larger hospitals and patients with Medicare or Commercial insurance. During the post-discharge period, the OIC-Rx cohort had a $421 reduction in costs associated with any re-encounter versus the No OIC-Rx cohort (p = 0.004). CONCLUSION: Patients receiving OIC-Rx in the ED had decreased odds of being hospitalized and fewer re-encounters in the 30-day post-discharge period versus patients who did not receive OIC-Rx, resulting in cost savings for insurance agencies and healthcare providers.

Characterization and Associated Costs of Constipation Relating to Exposure to Strong Opioids in England: An Observational Study.

PURPOSE: Opioid use is associated with gastrointestinal adverse events, including nausea and constipation. We used a real-world dataset to characterize the health care burden associated with opioid-induced constipation (OIC) with particular emphasis on strong opioids. METHODS: This retrospective cohort study was conducted using the Clinical Practice Research Datalink, a large UK primary care dataset linked to hospital data. Patients prescribed opioids during 2016 were selected and episodes of opioid therapy constructed. Episodes with ≥84 days of exposure were classified as chronic, with date of first prescription as the index date. The main analysis focused on patients prescribed strong opioids who were laxative naive. Constipation was defined by ≥2 laxative prescriptions during the opioid episode. Patients for whom initial laxative therapy escalated by switch, augmentation, or dose were defined as OIC unstable, and the first 3 lines of OIC escalation were classified. Health care costs accrued in the first 12 months of the opioid episode were aggregated and compared. FINDINGS: A total of 27,629 opioid episodes were identified; 5916 (21.4%) involved a strong opioid for patients who were previously laxative naive. Of these patients, 2886 (48.8%) were defined as the OIC population; 941 (33.26%) were classified as stable. Of the 1945 (67.4%) episodes classified as unstable, 849 (43.7%), 360 (18.5%), and 736 (37.8%) had 1, 2, and ≥3 changes of laxative prescription, respectively. Patients without OIC had lower costs per patient year (£3822 [US$5160/€4242]) compared with OIC (£4786 [US$6461/€5312]). Costs increased as patients had multiple changes in therapy: £4696 (US$6340/€5213), £4749 (US$6411/€5271), and £4981 (US$6724/€5529) for 1, 2, and ≥3 changes, respectively. The adjusted cost ratio relative to non-OIC was 1.14 (95% CI, 1.09-1.32) for those classified as stable and 1.19 (95% CI, 1.09-1.32) for those with ≥3 laxative changes. Similar patterns were observed for patients taking anyopioid, with costs increased for those classified as having OIC (£3727 [US$5031/€4137] vs £2379 [US$3212 /€2641),and for those patients classified as unstable versus stable (£3931 [US$5307/€4363] vs £3432 [US$4633/€3810). Costs increased with each additional line of therapy from £3701 (US$4996/€4108), £3916 (US$5287/€4347), and £4318 (US$5829/€4793). IMPLICATIONS: OIC was a common adverse event of opioid treatment and was poorly controlled for a large number of patients. Poor control was associated with increased health care costs. The impact of OIC should be considered when prescribing opioids. These results should be interpreted with consideration of the caveats associated with the analysis of routine data.

Use of Peripheral µ-Opioid Receptor Antagonists for Treating Opioid-Induced Constipation among US Medicare Beneficiaries from 2014 to 2018.

Background: Opioid-induced constipation (OIC) remains the most common adverse event associated with opioid use. Treatment with more novel and costly agents (such as peripheral µ-opioid receptor antagonists [PAMORAs]) may be indicated in patients with laxative-refractory OIC. Three PAMORAs are U.S. Food and Drug Administration approved for managing OIC-methylnaltrexone (FDA approved in 2008), naloxegol (in 2014), and naldemedine (in 2017). These drugs are indicated only in limited scenarios. Their contemporary patterns of use and burden of spending remain unknown. Objective: To evaluate the trends in use and expenditures for the three PAMORAs approved for treating OIC. Design: Retrospective cross-sectional study using the 2014-2018 Medicare Part D Prescription Drug Event data and the 2018 Part D Prescriber Public Use File. Setting: Prescribers and beneficiaries using PAMORAs. Measurements: The annual spending, number of beneficiaries, number of claims, and spending per beneficiary and claim for each PAMORA. The distribution by prescriber specialty using PAMORA. Results: From 2014 to 2018, aggregate spending on PAMORAs increased, from $13.6 to $150.9 million, and use increased, from 4221 to 72,592 beneficiaries. After FDA approval in 2014, naloxegol overtook methylnaltrexone in the number of users in 2015 and spending in 2016. In 2018, 6989 unique prescribers used any PAMORA. Among them, the most common specialties/professions were family practice (20.2%), internal medicine (18.0%), and nurse practitioner (15.4%). Conclusions: Our findings-significant and increasing expenditure on PAMORAs, and broad use across specialties-serve as a call for defining and implementing appropriate use of PAMORAs.

Prevalence and management of constipation in pediatric acute lymphoblastic leukemia in U.S. children's hospitals.

BACKGROUND: Children with acute lymphoblastic leukemia (ALL) suffer from a litany of chemotherapy-induced side effects. Constipation secondary to vinca alkaloids, environmental changes, and opioid use is a common issue for children newly diagnosed with leukemia. PROCEDURE: We analyzed data from 48 children's hospitals in the Pediatric Health Information System, extracting patients 1-21 years of age with ALL hospitalized from October 2015 through September 2019. Our objective was to investigate the prevalence, risk factors, and treatment of constipation in hospitalized children with ALL. RESULTS: We identified 4647 unique patients with an ALL induction admission. Constipation was the most common gastrointestinal diagnosis with 1576 (33.9%; 95% confidence interval [CI]: 32.6%-35.3%) patients diagnosed during induction admission and 19.8% in post-induction admissions. The most commonly administered constipation medications were poly-ethyl glycol (n = 3385, 89.6%), followed by senna (n = 1240, 32.8%), lactulose (n = 916, 24.2%), and docusate (n = 914, 24.2%). Multivariate logistic regression revealed the following variables to be significantly associated with the presence of a constipation diagnosis: age < 6 years at induction (compared with those ≥12 years; odds ratios [OR] = 1.32 [95% CI: 1.13-1.55]; P = < 0.001), female sex (OR = 1.16 [95% CI: 1.02-1.31]; P = 0.024), increased length of hospitalization (OR = 1.03 [95% CI: 1.02-1.04]; P < 0.0001), use of non-fentanyl opioids for one or two days (OR = 1.28 [95% CI: 0.99-1.65]; P = 0.056), and use of non-fentanyl opioids > 2 days (OR = 1.53 [95% CI: 1.19-1.95]; P < 0.001). CONCLUSIONS: A large portion of hospitalized children with ALL experience constipation and required medications. Increased attention should be paid to constipation prophylaxis and treatment in ALL patients, particularly at the start of induction therapy.

Long-Term (3 Years) Outcomes of Ranolazine Therapy for Refractory Angina Pectoris (from the Ranolazine Refractory Registry).

Ranolazine is approved for patients with chronic stable angina but has not been formally studied in patients with refractory angina pectoris (RAP). Patients with RAP have limited therapeutic options and significant limitations in their quality of life. The Ranolazine Refractory Angina Registry was designed to evaluate the safety, tolerability, and effectiveness of ranolazine in RAP patients in order to expand treatment options for this challenging patient population. Using an extensive prospective database, we enrolled 158 consecutive patients evaluated in a dedicated RAP clinic. Angina class, medications, major adverse cardiac events including death, myocardial infarction, and revascularization were obtained at 12, 24, and 36 months. At 3 years, 95 (60%) patients remained on ranolazine. A ≥2 class improvement in angina was seen in 48% (38 of 80 patients with known Canadian Cardiovascular Society class) of those who remained on ranolazine. Discontinuation due to side effects, ineffectiveness, cost, and progression of disease were the principle reasons for discontinuation, but primarily occurred within the first year. In conclusion, ranolazine is an effective antianginal therapy at 3-year follow-up in patients with RAP and may reduce cardiac readmission.

Patients' Self-Assessment of the Symptoms and Impact of Opioid-Induced Constipation: Results From a Prospective Observational Cohort Study of Japanese Patients With Cancer.

CONTEXT: Many patients who have cancer consider opioid-induced constipation (OIC) to be a burdensome side effect of opioid treatment. OBJECTIVES: To evaluate patient-reported outcomes in Japanese patients with cancer pain and OIC. METHODS: This prospective observational study evaluated OIC incidence for two weeks in patients with cancer after they initiated strong opioid therapy. Rome IV diagnostic criteria, a physician's diagnosis, spontaneous bowel movements, Bowel Function Index score, and patients' daily self-assessments were used. Changes from baseline in Patient Assessment of Constipation Symptoms and Patient Assessment of Constipation Quality of Life (PAC-QOL) scores were compared between patients with and without OIC. Patients and health care providers (HCPs) completed study-specific questionnaires regarding OIC burden, treatment satisfaction, and patient-provider communications. RESULTS: Among 212 enrolled patients, the incidence of OIC was 47.6% by patients' self-assessments, with a cumulative incidence of 30.2% by Day 3 and 43.5% by Day 7. Patient Assessment of Constipation Symptoms and PAC-QOL overall scores from patients with OIC worsened significantly from baseline compared with patients without OIC by all diagnostic criteria, except for spontaneous bowel movement frequency for PAC-QOL. Patients and HCPs were generally satisfied with OIC treatment; however, 53.5% of patients and approximately 40.0% of HCPs reported that OIC affected pain management. Most patients and HCPs reported that OIC conditions were sufficiently or essentially communicated. CONCLUSION: After starting opioid therapy, patients recognized OIC onset and its impact on cancer pain management, highlighting the need for effective patient-provider communications, diagnosis, and treatment of OIC to improve QOL for patients with cancer receiving opioid analgesics.

Impact of opioid-induced constipation on healthcare resource utilization and costs for cancer pain patients receiving continuous opioid therapy.

PURPOSE: Opioid therapy is often associated with adverse effects, including opioid-induced constipation (OIC), in patients receiving opioids for cancer pain. This retrospective observational cohort study evaluated healthcare utilization and costs during the first year after initiating opioid therapy among cancer patients with (cohort 1) and without (cohort 2) constipation. METHODS: This study used administrative claims data from the HealthCore Integrated Research Environment between January 1, 2006, and April 30, 2014. Eligible patients included adults ≥ 18 years with a diagnosis of cancer who initiated continuous opioid therapy (≥ 30 days). Propensity scores were used to match patients with constipation in a 1:1 ratio to those without constipation. Generalized linear models were used to evaluate healthcare utilization and costs during the 12 months after initiating opioid therapy. RESULTS: After matching, 1369 patients were included in each cohort. Patients with constipation were more than twice as likely as those without constipation to have an all-cause inpatient hospitalization (odds ratio [95% confidence interval (CI)], 2.47 [2.11-2.90]), or pain-related hospitalization (2.15 [1.82-2.54]) during the 12 months after initiating therapy. Mean unadjusted overall healthcare costs during the first 12 months post-index were $21,629 (95% CI, $14,850-$29,018) higher for patients with constipation than for those without constipation. For patients with constipation, total mean (SD) constipation-related costs were $9196 ($26,896). CONCLUSIONS: These results suggest that OIC is associated with significantly increased healthcare and economic burden in cancer pain patients and that early and ongoing recognition and management of OIC are unmet needs in this population.

Development and preliminary testing of a brief clinical tool to enable daily monitoring of chemotherapy toxicity: The Daily Chemotherapy Toxicity self-Assessment Questionnaire.

Close monitoring of chemotherapy toxicity can be instrumental in ensuring prompt symptom management and quality care. Our aim was to develop a brief clinical tool to enable daily assessment of chemotherapy toxicity and investigate/establish its content validity, feasibility/applicability, internal consistency and stability. Development of the Daily Chemotherapy Toxicity self-Assessment Questionnaire (DCTAQ) was based on an initial item pool created from two scoping reviews. Expert panel review (n = 15) and cognitive debriefing with patients with cancer (n = 7) were used to establish content validity. Feasibility/acceptability, applicability (self-report vs. interview-like administration), internal consistency (KR-20) and test-retest reliability (at 1-hr intervals) of the DCTAQ were field-tested with 82 patients with breast or colorectal cancer receiving active chemotherapy at eight hospitals. Initial development/content validity stages enabled item revisions and re-wording that led to a final, 11-item DCTAQ version with 10 core symptom items plus one open-ended "any other symptom" item. Feasibility and acceptability were demonstrated through the absence of participant withdrawals, absence of missing data and no complaints about tool length. The DCTAQ was found to have modest internal consistency (KR-20 = 0.56), but very good test-retest reliability. The DCTAQ is a brief clinical tool that allows for rapid and accurate daily assessments of chemotherapy toxicity in clinical practice.

Treatment with Naloxegol Versus Placebo: Pain Assessment in Patients with Noncancer Pain and Opioid-Induced Constipation.

OBJECTIVE: To summarize results from pain and opioid use assessments with naloxegol in adults with opioid-induced constipation (OIC) and chronic noncancer pain. METHODS: Two phase 3 randomized, double-blind, 12-week studies evaluated the efficacy and safety of oral naloxegol (12.5 or 25 mg daily) in adults (18 to < 85 years) with confirmed OIC and chronic noncancer pain: KODIAC-04 (NCT01309841) and KODIAC-05 (NCT01323790). Pain level was assessed daily (11-point numeric rating scale [NRS]; 0 = no pain, 10 = worst imaginable pain). Changes from baseline in mean weekly pain scores and opioid dose (weeks 1 through 12) were analyzed using mixed-model repeated measures. RESULTS: At baseline, mean daily NRS average pain scores ranged from 4.5 to 4.8 for all groups in KODIAC-04 (N = 652) and were 4.6 for each group in KODIAC-05 (N = 700). Respective mean ± SD changes from baseline average pain for placebo, naloxegol 12.5 mg, and naloxegol 25 mg were -0.2 ± 1.07, -0.3 ± 1.05 (P = 0.773 vs. placebo), and 0.2 ± 0.95 (P = 0.837 vs. placebo; KODIAC-04) and -0.1 ± 0.94, -0.1 ± 0.87 (P = 0.744), and 0.0 ± 1.18 (P = 0.572; KODIAC-05). At baseline, mean daily opioid doses ranged from 135.6 to 143.2 morphine equivalent units (MEUs)/day in KODIAC-04, and from 119.9 to 151.7 MEUs/day in KODIAC-05. Respective mean ± SD changes from baseline dose were -1.8 ± 30.19, -2.3 ± 20.52 (P = 0.724 vs. placebo), and 0.4 ± 13.01 (P = 0.188 vs. placebo; KODIAC-04) and -0.3 ± 17.14, -1.3 ± 17.11 (P = 0.669 vs. placebo), and 0.1 ± 8.54 (P = 0.863 vs. placebo; KODIAC-05). Changes in maintenance opioid dose were few; reasons for such changes were similar across treatment groups. CONCLUSION: Centrally mediated opioid analgesia was maintained during treatment with naloxegol in patients with noncancer pain and OIC.

Healthcare resource use and costs of opioid-induced constipation among non-cancer and cancer patients on opioid therapy: A nationwide register-based cohort study in Denmark.

BACKGROUND AND AIM: Opioid analgesics are often effective for pain management, but may cause constipation. The aim of this study was to determine healthcare resource use and costs in non-cancer and cancer patients with opioid-induced constipation (OIC). METHODS: This was a nationwide register-based cohort study including patients ≥18 years of age initiating ≥4 weeks opioid therapy (1998-2012) in Denmark. A measure of OIC was constructed based on data from Danish national health registries, and defined as ≥1 diagnosis of constipation, diverticulitis, mega colon, ileus/subileus, abdominal pain/acute abdomen or haemorrhoids and/or ≥2 subsequent prescription issues of laxatives. Total healthcare resource utilization and costs (including pharmacy dispense, inpatient-, outpatient-, emergency room- and primary care) were estimated according to OIC status, opioid treatment dosage and length, gender, age, marital status, and comorbidities using Generalised Linear Model. RESULTS: We identified 97169 eligible opioid users (77568 non-cancer and 19601 patients with a cancer diagnosis). Among non-cancer patients, 15% were classified with OIC, 10% had previous constipation, and 75% were without OIC. Patients characteristics of non-cancer OIC patients showed a higher frequency of strong opioid treatment (69% versus 41%), long-term opioid treatment (1189 days versus 584 days), advanced age (73 years versus 61 years), and cardiovascular disease (31% versus 19%) compared to those without OIC (P<0.001 for all comparisons). Non-cancer patients with OIC had 34% higher total healthcare costs compared to those without OIC (P<0.001) after adjusting for age, gender, opioid usage, marital status and comorbidities. Among cancer patients, 35% were classified with OIC, 14% had previous constipation, and 51% were without OIC. A higher proportion of cancer patients with OIC were continuous opioid users (85% versus 83%) and strong opioid users (97% versus 85%), compared to those without OIC (P<0.001 for both comparisons). Further, the mean number of days on opioids were higher for cancer patients with versus without OIC (329 days versus 238 days, P<0.001). Total healthcare costs were 25% higher for cancer patients with versus without OIC (P<0.001) after adjusting for age, gender, opioid usage, marital status and comorbidities. CONCLUSIONS: The results of this nationwide study based on real life data suggested that both non-cancer patients and cancer patients suffering from opioid-induced constipation (OIC) may have higher healthcare resource utilization and higher associated costs compared to those without OIC. IMPLICATIONS: Reducing the number of OIC patients has potential cost savings for the health care system. Special attention should be on patients at potential high risk of OIC, such as strong and long-term opioid treatment, advanced age, and concomitant cardiovascular disease.

Cost Effectiveness of Naloxegol for Opioid-Induced Constipation in the UK.

BACKGROUND AND OBJECTIVES: Opioid-induced constipation (OIC) is the most common adverse effect reported in patients receiving opioids to manage pain. Initial treatment with laxatives provides inadequate response in some patients. Naloxegol is a peripherally acting µ-opioid receptor antagonist used to treat patients with inadequate response to laxative(s) (laxative inadequate responder [LIR]). A cost-effectiveness model was constructed from the UK payer perspective to compare oral naloxegol 25 mg with placebo in non-cancer LIR patients receiving opioids for chronic pain, and a scenario analysis of naloxegol 25 mg with rescue laxatives compared with placebo with rescue laxatives in the same patient population. METHODS: The model comprised a decision tree for the first 4 weeks of treatment, followed by a Markov model with a 4-week cycle length and the following states: 'OIC', 'non-OIC (on treatment)', 'non-OIC (untreated)' and 'death'. Two phase III trials with a follow-up period of 12 weeks provided data on treatment efficacy, transition probabilities, adverse event frequency and patient utility. Resource utilisation data were sourced from a UK-based burden of illness study and physician surveys. A UK National Health Service and Personal Social Service perspective was adopted; costs and health-related quality of life gains were discounted at a rate of 3.5 %. The model was run over a time horizon of 5 years, reflecting the average period of opioid use. RESULTS: Naloxegol has an incremental cost-effectiveness ratio of £10,849 per quality-adjusted life-year gained versus placebo, and £11,179 when rescue laxatives are made available in both arms (2014 values). Model outcomes were only sensitive to variations in utility inputs. However, the probabilistic sensitivity analyses indicate that naloxegol has a 91 % probability of being cost effective at a £20,000 threshold when compared with placebo. CONCLUSIONS: Naloxegol is likely a cost-effective treatment option for LIR patients with OIC. This assessment should be supported by further work on the utility of patients with OIC, including how utility varies with more granular measures of OIC.

Cost-effectiveness analysis of oxycodone with naloxone versus oxycodone alone for the management of moderate-to-severe pain in patients with opioid-induced constipation in Canada.

BACKGROUND: Approximately 20-30% of Canadians suffer from chronic pain. Guidelines for the management of chronic pain support the use of controlled-release (CR) opioids to treat chronic pain. Although effective in managing chronic pain, oxycodone is associated with high rates of opioid-induced constipation (OIC). The cost-effectiveness of a combination of oxycodone for the management of pain and naloxone for the relief of OIC has not previously been evaluated for Canada. METHODS: A decision analytic model was developed to estimate the cost-utility of combination oxycodone/naloxone compared to oxycodone alone in four populations. Drug costs for managing pain and healthcare costs related to managing OIC were included in the analysis and the primary measure of effectiveness was quality adjusted life years (QALYs) derived from OIC rates observed in clinical trials. The analysis was conducted from a healthcare system perspective, used a 1-year time horizon, and results were expressed in 2015 Canadian dollars. RESULTS: In all four patient populations, there was a trade-off between slightly higher total expected costs for Targin treated patients compared to oxycodone treated patients, but also improved clinical benefits in terms of reduced OIC, which resulted in higher QALYs for patients. Although analgesic costs were found to be slightly higher for Targin treated patients, Targin also resulted in cost offsets to the healthcare system in terms of less rescue laxative drug use and other resources required for the management of OIC. The resulting 1-year cost-utility of Targin compared to oxycodone ranged from $2178-$7732 per QALY gained in the base case analysis, and it was found that these cost-utility results remained robust and at low values throughout a series of one-way deterministic analyses of uncertainty. CONCLUSION: The clinical effectiveness of oxycodone/naloxone in managing pain and OIC compared to CR oxycodone alone resulted in low cost-utility estimates.

Diagnostic Performance of Self-Assessment for Constipation in Patients With Long-Term Opioid Treatment.

Constipation is a prevalent comorbidity affecting ∼50% of patients with long-term opioid therapy. In clinical routine different diagnostic instruments are in use to identify patients under risk. The aim of this study was to assess the diagnostic performance of an 11-item Likert scale for constipation used as a self-assessment in opioid-treated patients. This trial was conducted as a retrospective cohort study in Berlin, Germany. Patients with long-term opioid therapy treated in 2 university-affiliated outpatient pain facilities at the Charité hospital were included from January 2013 to August 2013. Constipation was rated in a self-assessment using a numeric rating scale from 0 to 10 (Con-NRS) and compared with results from a structured assessment based on ROME-III criteria. Altogether, 171 patients were included. Incidence of constipation was 49% of patients. The receiver-operating characteristic of Con-NRS achieved an area under the curve of 0.814 (AUC 95% confidence interval 0.748-0.880, P < 0.001). Con-NRS ≥ 1 achieved sensitivity and specificity of 79.7% and 77.2%, respectively. The positive predictive value and the negative predictive value were 70.3% and 81.6%, respectively. Overall diagnostic performance of a concise 11-item Likert scale for constipation was moderate. Although patients with long-term opioid therapy are familiar with numeric rating scales, a significant number of patients with constipation were not identified. The instrument may be additionally useful to facilitate individualized therapeutic decision making and to control therapeutic success when measured repetitively.

Consensus Recommendations on Initiating Prescription Therapies for Opioid-Induced Constipation.

OBJECTIVE: Aims of this consensus panel were to determine (1) an optimal symptom-based method for assessing opioid-induced constipation in clinical practice and (2) a threshold of symptom severity to prompt consideration of prescription therapy. METHODS: A multidisciplinary panel of 10 experts with extensive knowledge/experience with opioid-associated adverse events convened to discuss the literature on assessment methods used for opioid-induced constipation and reach consensus on each objective using the nominal group technique. RESULTS: Five validated assessment tools were evaluated: the Patient Assessment of Constipation-Symptoms (PAC-SYM), Patient Assessment of Constipation-Quality of Life (PAC-QOL), Stool Symptom Screener (SSS), Bowel Function Index (BFI), and Bowel Function Diary (BF-Diary). The 3-item BFI and 4-item SSS, both clinician administered, are the shortest tools. In published trials, the BFI and 12-item PAC-SYM are most commonly used. The 11-item BF-Diary is highly relevant in opioid-induced constipation and was developed and validated in accordance with US Food and Drug Administration guidelines. However, the panel believes that the complex scoring for this tool and the SSS, PAC-SYM, and 28-item PAC-QOL may be unfeasible for clinical practice. The BFI is psychometrically validated and responsive to changes in symptom severity; scores range from 0 to 100, with higher scores indicating greater severity and scores >28.8 points indicating constipation. CONCLUSIONS: The BFI is a simple assessment tool with a validated threshold of clinically significant constipation. Prescription treatments for opioid-induced constipation should be considered for patients who have a BFI score of ≥30 points and an inadequate response to first-line interventions.