Economic evaluation of oral treatments for neuropathic pain

CDC Clinical Practice Guideline for Prescribing Opioids for Pain - United States, 2022

This guideline provides recommendations for clinicians providing pain care, including those prescribing opioids, for outpatients aged ≥18 years. It updates the CDC Guideline for Prescribing Opioids for Chronic Pain - United States, 2016 (MMWR Recomm Rep 2016;65[No. RR-1]:1-49) and includes recommendations for managing acute (duration of <1 month), subacute (duration of 1-3 months), and chronic (duration of >3 months) pain. The recommendations do not apply to pain related to sickle cell disease or cancer or to patients receiving palliative or end-of-life care. The guideline addresses the following four areas: 1) determining whether or not to initiate opioids for pain, 2) selecting opioids and determining opioid dosages, 3) deciding duration of initial opioid prescription and conducting follow-up, and 4) assessing risk and addressing potential harms of opioid use. CDC developed the guideline using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Recommendations are based on systematic reviews of the scientific evidence and reflect considerations of benefits and harms, patient and clinician values and preferences, and resource allocation. CDC obtained input from the Board of Scientific Counselors of the National Center for Injury Prevention and Control (a federally chartered advisory committee), the public, and peer reviewers. CDC recommends that persons with pain receive appropriate pain treatment, with careful consideration of the benefits and risks of all treatment options in the context of the patient's circumstances. Recommendations should not be applied as inflexible standards of care across patient populations. This clinical practice guideline is intended to improve communication between clinicians and patients about the benefits and risks of pain treatments, including opioid therapy; improve the effectiveness and safety of pain treatment; mitigate pain; improve function and quality of life for patients with pain; and reduce risks associated with opioid pain therapy, including opioid use disorder, overdose, and death.

A pharmacoeconomic evaluation of the pharmacotherapeutic options for painful diabetic neuropathy

INTRODUCTION

Painful diabetic neuropathy (PDN) is a high incidence and severe complication of diabetes mellitus, significantly compromising patients' quality of life and causing tremendous economic burden. Considering drug costs becomes part of treatment decisions, with the growing choice of monotherapy or combination treatment strategies for PDN treatment.

AREAS COVERED

This systematic review aims to identify the cost-effectiveness of pharmacotherapies in PDN, summarize key findings, and assess the quality of studies to inform healthcare resource allocation decisions and future research. Economic evaluations were identified by searching PubMed, Web of Science, Scopus and health technology assessment (HTA) databases, as well as screening reference lists of previously identified studies. Relevant data was extracted, and the CHEERS checklist was used to assess the quality of the studies.

EXPERT OPINION

Collectively, the findings indicate that more pharmacoeconomics research is urgently needed to directly compare high-quality research for PDN combination medication/sequential treatment, and which is performed from a societal perspective. Simultaneously, to strengthen the reliability of the analysis, metrics such as adherence, incidence of adverse drug reactions, and pain levels utility value should be examined to verify the robustness of the basic results.

Cost-Effectiveness of Treatment Options for Neuropathic Pain: a Systematic Review

BACKGROUND

Neuropathic pain significantly reduces an individual's quality of life and places a significant economic burden on society. As such, many cost-effectiveness analyses (CEAs) have been published for treatments available for neuropathic pain.

OBJECTIVES

The primary objective of this systematic review was to provide a detailed summary of the estimates of cost-effectiveness from published CEAs comparing available treatments for neuropathic pain. The secondary objectives were to identify the key drivers of cost-effectiveness and to assess the quality of published CEAs in neuropathic pain.

METHODS

We searched Embase, MEDLINE, Cochrane CENTRAL and seven other databases to identify CEAs reporting the costs, health benefits (e.g., quality-adjusted life-years or disability-adjusted life-years) and summary statistics, such as incremental cost-effectiveness ratios, of treatments for neuropathic pain. We excluded studies reporting diseases other than neuropathic pain, those for which the full text was not available (e.g., conference abstracts), studies not written in English or not published in peer-reviewed journals, and narrative reviews, editorials and opinion papers. Titles and abstract reviews, full-text reviews, and data extraction were all performed by two independent reviewers, with disagreement resolved by a third reviewer. Mean costs, health benefits, and summary statistics were reported and qualitatively compared across studies, stratified by time horizon. Drivers of cost-effectiveness were assessed using reported one-way sensitivity analyses. The quality of all included studies was evaluated using the Tufts CEA Registry Quality Score and study reporting using the CHEERS (Consolidated Health Economic Evaluation Reporting Standards) checklist.

RESULTS

A total of 22 studies were identified and included in this systematic review. Included studies were heterogeneous in the treatments compared, methodology and design, perspectives, and time horizons considered, making cross-study comparisons difficult. No single treatment was consistently the most cost-effective across all studies, but tricyclic antidepressants were the preferred treatment at a willingness-to-pay threshold of $US50,000 per quality-adjusted life-year in several studies with a short time horizon and a US payer perspective. Among the 14 studies reporting one-way sensitivity analyses, drivers of cost-effectiveness included utility values for health states and the likelihood of pain relief with treatment. The quality of the identified CEAs was moderate to high, and overall reporting largely met CHEERS recommendations.

LIMITATIONS

To assess drivers of cost-effectiveness and quality, we only included studies with the full text available and thus excluded some CEAs that reported cost-effectiveness results. The heterogeneity of the included studies meant that the study results could not be synthesized and comparison across studies was limited.

CONCLUSIONS

Though many pulished studies have evaluated the cost-effectiveness of treatments for neuropathic pain, significant heterogeneity between CEAs prevented synthesis of the results. Standardized methodology and improved reporting would allow for more reliable comparisons across studies.

Drug therapy for chronic idiopathic axonal polyneuropathy

BACKGROUND

Chronic idiopathic axonal polyneuropathy (CIAP) is an insidiously progressive sensory or sensorimotor polyneuropathy that affects elderly people. Although severe disability or handicap does not occur, CIAP reduces quality of life. CIAP is diagnosed in 10% to 25% of people referred for evaluation of polyneuropathy. There is a need to gather and review emerging evidence on treatments, as the number of people affected is likely to increase in ageing populations. This is an update of a review first published in 2004 and previously updated in 2006, 2008, 2011 and 2013.

OBJECTIVES

To assess the effects of drug therapy for chronic idiopathic axonal polyneuropathy for reducing disability and ameliorating neurological symptoms and associated impairments, and to assess any adverse effects of treatment.

SEARCH METHODS

In July 2016, we searched Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews in the Cochrane Library, MEDLINE, Embase, and the Web of Science. We searched two trials registries for ongoing trials. We also handsearched the reference lists of relevant articles, reviews and textbooks identified electronically, and we would have contacted authors and other experts in the field to identify additional studies if this seemed useful.

SELECTION CRITERIA

We sought all randomised or quasi-randomised (alternate or other systematic treatment allocation) trials that examined the effects of any drug therapy in people with CIAP at least one year after the onset of treatment. People with CIAP had to fulfil the following criteria: age 40 years or older, distal sensory or sensorimotor polyneuropathy, absence of systemic or other neurological disease, chronic clinical course not reaching a nadir in less than two months, exclusion of any recognised cause of the polyneuropathy by medical history taking, clinical or laboratory investigations, and electrophysiological studies in agreement with axonal polyneuropathy, without evidence of demyelinating features. The primary outcome was the proportion of participants with a significant improvement in disability. Secondary outcomes were change in the mean disability score, change in the proportion of participants who make use of walking aids, change in the mean Medical Research Council sum score, degree of pain relief and/or reduction of other positive sensory symptoms, change in the proportion of participants with pain or other positive sensory symptoms, and frequency of adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the results of the literature search and extracted details of trial methodology and outcome data of all potentially relevant trials.

MAIN RESULTS

We identified 39 studies and assessed them for possible inclusion in the review, but we excluded all of them because of insufficient quality or lack of relevance. We summarised evidence from non-randomised studies in the Discussion.

AUTHORS' CONCLUSIONS

Even though CIAP has been clearly described and delineated, no adequate randomised or quasi-randomised controlled clinical treatment trials have been performed. In their absence there is no proven efficacious drug therapy.

A systematic review of cost-effectiveness modeling of pharmaceutical therapies in neuropathic pain: variation in practice, key challenges, and recommendations for the future

OBJECTIVES

Complexities in the neuropathic-pain care pathway make the condition difficult to manage and difficult to capture in cost-effectiveness models. The aim of this study is to understand, through a systematic review of previous cost-effectiveness studies, some of the key strengths and limitations in data and modeling practices in neuropathic pain. Thus, the aim is to guide future research and practice to improve resource allocation decisions and encourage continued investment to find novel and effective treatments for patients with neuropathic pain.

METHODS

The search strategy was designed to identify peer-reviewed cost-effectiveness evaluations of non-surgical, pharmaceutical therapies for neuropathic pain published since January 2000, accessing five key databases. All identified publications were reviewed and screened according to pre-defined eligibility criteria. Data extraction was designed to reflect key data challenges and approaches to modeling in neuropathic pain and based on published guidelines.

RESULTS

The search strategy identified 20 cost-effectiveness analyses meeting the inclusion criteria, of which 14 had original model structures. Cost-effectiveness modeling in neuropathic pain is established and increasing across multiple jurisdictions; however, amongst these studies, there is substantial variation in modeling approach, and there are common limitations. Capturing the effect of treatments upon health outcomes, particularly health-related quality-of-life, is challenging, and the health effects of multiple lines of ineffective treatment, common for patients with neuropathic pain, have not been consistently or robustly modeled.

CONCLUSIONS

To improve future economic modeling in neuropathic pain, further research is suggested into the effect of multiple lines of treatment and treatment failure upon patient outcomes and subsequent treatment effectiveness; the impact of treatment-emergent adverse events upon patient outcomes; and consistent and appropriate pain measures to inform models. The authors further encourage transparent reporting of inputs used to inform cost-effectiveness models, with robust, comprehensive and clear uncertainty analysis and, where feasible, open-source modeling is encouraged.

The Economic Impact of Opioid Use in the Management of Chronic Nonmalignant Pain

Chronic nonmalignant pain (CNMP), defined as persistent pain that is not attributable to a potentially life-limiting condition and has a duration of at least 3 months, is widespread in the United States. Moderate-to-severe CNMP often is treated with opioid analgesics, and there is ongoing debate regarding appropriate allocation of opioids to treat CNMP because long-term treatment can result in problematic side effects, drug misuse, or abuse leading to detrimental medical, social, and economic consequences. Furthermore, therapeutic strategies arising from concerns about the misuse of opioids may impede the treatment of patients who require strong analgesics for adequate pain relief. While current CNMP management includes nonpharmacologic and pharmacologic approaches, including acetaminophen, nonsteroidal anti-inflammatory drugs, and opioids, there is debate regarding the risk-benefit profile of opioids for chronic pain treatment. Mitigation of opioid misuse and abuse and proper administration of opioid analgesics must be balanced against providing appropriate analgesia. To accomplish this, managed care policies could implement guidelines that focus on evaluating risk characteristics for opioid misuse and abuse, use opioid dose-sparing strategies, and encourage the use of alternative analgesics or nonpharmacologic therapy when appropriate. The purpose of this review is to examine challenges and costs associated with CNMP management using opioids and to summarize alternative therapeutic approaches.

Efficacy and tolerability of carbamazepine for the treatment of painful diabetic neuropathy in adults: a 12-week, open-label, multicenter study

Objective

Anticonvulsants are increasingly being used in the symptomatic management of several neuropathic pain disorders. The present observational study was designed to evaluate the efficacy, tolerability, and quality of life (QoL) of carbamazepine use for 12 weeks in patients with painful diabetic neuropathy, in Pakistan.

Methods

This was a 12-week, multicenter, open-label, uncontrolled trial in adult type 2 diabetic patients (aged 18–65 years) suffering from clinically confirmed neuropathic pain (Douleur Neuropathique en 4 [DN4] score ≥4). Change in neuropathic pain at week 12 compared with baseline was assessed using the Brief Pain Inventory Scale–Short Form (pain severity score and pain interference score). QoL was determined by the American Chronic Pain Association QoL scale. Safety was assessed based on patient reported adverse events (AEs) and serious AEs.

Results

Of the total 500 screened patients, 452 enrolled and completed the study. The mean (± standard deviation [SD]) pain interference score decreased from 4.5±2.0 at baseline to 3.1±1.9 at week 12 (P<0.001). The mean (± SD) pain severity score decreased from 5.8±2.0 at baseline to 3.6±2.2 at week 12 (P<0.001). There was a decrease of ≥30% in the pain severity score between visits. The mean (± SD) QoL scale score improved from 5.9±1.6 at baseline to 8.0±1.7 at week 12. A total of ten (2.2%) patients reported AEs during the study period. No patient discontinued the study due to AEs.

Conclusion

In this real-life experience study, carbamazepine, when prescribed for 12 weeks to adult diabetic patients suffering from neuropathic pain, showed pain-relief effect, with reduced mean pain severity and mean pain interference scores and with improved QoL and good tolerability profile.

Health economic evidence of 5% lidocaine medicated plaster in post-herpetic neuralgia

BACKGROUND

Post-herpetic neuralgia (PHN) is the most common and most debilitating complication of herpes zoster, and involves considerable associated costs.

OBJECTIVE

This paper presents results from nine health economic studies undertaken in eight European countries that compared lidocaine medicated plaster with gabapentin and/or pregabalin in PHN. It aims to support the increasing need for published cost-effectiveness data for health care decision-making processes in Europe.

METHODS

All studies were based on a similar core Markov model with data derived from clinical trials, local Delphi panels, and official national price and tariff lists. The main outcome measure was cost per quality-adjusted life year gained; time without pain or intolerable adverse events was also included as a secondary outcome measure. All studies focused on an elderly population of patients with PHN who had insufficient pain relief with standard analgesics and could not tolerate or had contraindications to tricyclic antidepressants.

RESULTS

Despite considerable differences in many of the variables used, the results showed remarkable similarity and suggested that use of lidocaine medicated plaster offered cost-savings in many of the countries studied, where it proved a highly cost-effective alternative to both gabapentin and pregabalin.

CONCLUSION

Lidocaine medicated plaster is a cost-effective alternative to gabapentin and pregabalin in the treatment of PHN. These savings are largely the result of the superior safety profile of the lidocaine medicated plaster.

Economic evaluation of duloxetine as a first-line treatment for painful diabetic peripheral neuropathy in Mexico

OBJECTIVE

To perform an economic evaluation of duloxetine, pregabalin, and both branded and generic gabapentin for managing pain in patients with painful diabetic peripheral neuropathy (PDPN) in Mexico.

RESEARCH DESIGN AND METHODS

The analysis was conducted using a 3-month decision model, which compares duloxetine 60 mg once daily (DUL), pregabalin 150 mg twice daily (PGB), and gabapentin 600 mg three-times daily (GBP) for PDPN patients with moderate-to-severe pain. A systematic review was performed and placebo-adjusted risk ratios for achieving good pain relief (GPR), adverse events (AE), and withdrawal owing to intolerable AE were calculated. Direct medical costs included drug acquisition and additional visits due to lack of efficacy (poor pain relief) or intolerable AE. Unit costs were taken from local sources. Adherence rates were used to estimate the expected drug costs. All costs are expressed in 2010 Mexican Pesos (MXN). Utility values drawn from published literature were applied to health states. The proportion of patients with GPR and quality-adjusted life years (QALY) were assessed.

RESULTS

Branded-GBP was dominated by all the other options. PGB was more costly and less effective than DUL. Compared with branded-GBP and PGB, DUL led to savings of 1.01 and 1.74 million MXN (per 1000 patients). The incremental cost per QALY gained with DUL used instead of generic-GBP was $102 433 MXN. This amount is slightly lower than the estimated gross domestic product per capita in Mexico for 2010. During a second-order Monte Carlo simulation, DUL had the highest probability of being cost-effective (61%), followed by generic-GBP (25%) and PGB (14%).

LIMITATIONS

Study limitations include a short timeframe and using data from different dosage schemes for GBP and PGB.

CONCLUSIONS

This study suggests that DUL provides overall savings and better health outcomes compared with branded-GBP and PGB. Administering DUL rather than generic-GBP is a cost-effective intervention to manage PDPN in Mexico.

Cost-effectiveness analysis of a new 8% capsaicin patch compared to existing therapies for postherpetic neuralgia

OBJECTIVE

The purpose of this study was to compare the cost effectiveness of a new 8% capsaicin patch, compared to the current treatments for postherpetic neuralgia (PHN), including tricyclic antidepressants (TCAs), topical lidocaine patches, duloxetine, gabapentin, and pregabalin.

METHODS

A 1-year Markov model was constructed for PHN with monthly cycles, including dose titration and management of adverse events. The perspective of the analysis was from a payer perspective, managed-care organization. Clinical trials were used to determine the proportion of patients achieving at least a 30% improvement in PHN pain, the efficacy parameter. The outcome was cost per quality-adjusted life-year (QALY); second-order probabilistic sensitivity analyses were conducted.

RESULTS

The effectiveness results indicated that 8% capsaicin patch and topical lidocaine patch were significantly more effective than the oral PHN products. TCAs were least costly and significantly less costly than duloxetine, pregabalin, topical lidocaine patch, 8% capsaicin patch, but not gabapentin. The incremental cost-effectiveness ratio for the 8% capsaicin patch overlapped with the topical lidocaine patch and was within the accepted threshold of cost per QALY gained compared to TCAs, duloxetine, gabapentin, and pregablin. The frequency of the 8% capsaicin patch retreatment assumption significantly impacts its cost-effectiveness results. There are several limitations to this analysis. Since no head-to-head studies were identified, this model used inputs from multiple clinical trials. Also, a last observation carried forward process was assumed to have continued for the duration of the model. Additionally, the trials with duloxetine may have over-predicted its efficacy in PHN. Although a 30% improvement in pain is often an endpoint in clinical trials, some patients may require greater or less improvement in pain to be considered a clinical success.

CONCLUSIONS

The effectiveness results demonstrated that 8% capsaicin and topical lidocaine patches had significantly higher effectiveness rates than the oral agents used to treat PHN. In addition, this cost-effectiveness analysis found that the 8% capsaicin patch was similar to topical lidocaine patch and within an accepted cost per QALY gained threshold compared to the oral products.

A cost-consequences analysis of the effect of pregabalin in the treatment of peripheral neuropathic pain in routine medical practice in primary care settings

Background

Neuropathic pain (NeP) is a common symptom of a group of a variety of conditions, including diabetic neuropathy, trigeminal neuralgia, or postherpetic neuralgia. Prevalence of NeP has been estimated to range between 5-7.5%, and produces up to 25% of pain clinics consultations. Due to its severity, chronic evolution, and associated co-morbidities, NeP has an important individual and social impact. The objective was to analyze the effect of pregabalin (PGB) on pain alleviation and longitudinal health and non-health resources utilization and derived costs in peripheral refractory NeP in routine medical practice in primary care settings (PCS) in Spain.

Methods

Subjects from PCS were older than 18 years, with peripheral NeP (diabetic neuropathy, post-herpetic neuralgia or trigeminal neuralgia), refractory to at least one previous analgesic, and included in a prospective, real world, and 12-week two-visit cost-of-illness study. Measurement of resources utilization included both direct healthcare and indirect expenditures. Pain severity was measured by the Short Form-McGill Pain Questionnaire (SF-MPQ).

Results

One-thousand-three-hundred-fifty-four PGB-naive patients [58.8% women, 59.5 (12.7) years old] were found eligible for this secondary analysis: 598 (44%) switched from previous therapy to PGB given in monotherapy (PGBm), 589 (44%) received PGB as add-on therapy (PGB add-on), and 167 (12%) patients changed previous treatments to others different than PGB (non-PGB). Reductions of pain severity were higher in both PGBm and PGB add-on groups (54% and 51%, respectively) than in non-PGB group (34%), p < 0.001. Incremental drug costs, particularly in PGB subgroups [€34.6 (80.3), €160.7 (123.9) and €154.5 (133.0), for non-PGB, PGBm and PGBadd-on, respectively (p < 0.001)], were off-set by higher significant reductions in all other components of health costs yielding to a greater total cost reductions: -€1,045.3 (1,989.6),-€1,312.9 (1,543.0), and -€1,565.5 (2,004.1), for the three groups respectively (p = 0.03).

Conclusion

In Spanish primary care settings, PGB given either add-on or in monotherapy in routine medical practice was associated with pain alleviation leading to significant longitudinal reductions in resource use and total costs during the 12-week period of the study compared with non-PGB-therapy of patients with chronic NeP of peripheral origin. The use of non-appropriate analgesic therapies for neuropathic pain in a portion of subjects in non-PGB group could explain partially such findings.

Guidelines for the diagnosis and management of neuropathic pain: consensus of a group of Latin American experts

These consensus guidelines have been developed by a group of Latin American experts in pain management, to point out patterns and make practical recommendations to guide the diagnosis, identify warning signs (yellow and red flags), and establish comprehensive medical management (pharmacologic and nonpharmacologic treatment) and monitoring plans for patients enduring neuropathic pain. From the viewpoint of pharmacologic management, drugs are classified into groups according to efficacy, availability/accessibility, and safety criteria. Drugs are recommended for use depending on the disease and particular circumstances of each patient, with an approach that favors multimodal treatment while taking into consideration the idiosyncrasies of medical practice in Latin America.

Impact of postherpetic neuralgia and painful diabetic peripheral neuropathy on health care costs

Knowledge of the health care costs associated with neuropathic pain is limited. Existing studies have not directly compared the health care costs of different neuropathic pain conditions, and patients with neuropathic pain have not been compared with control subjects with the same underlying conditions (for example, diabetes). To determine health care costs associated with postherpetic neuralgia (PHN) and painful diabetic peripheral neuropathy (DPN), patients with these conditions were selected from 2 different administrative databases of health care claims and respectively matched to control subjects who had a diagnosis of herpes zoster without persisting pain or a diagnosis of diabetes without neurological complications using propensity scores for demographic and clinical factors. Total excess health care costs attributable to PHN and painful DPN and excess costs for inpatient care, outpatient/professional services, and pharmacy expenses were calculated. The results indicated that the annual excess health care costs associated with peripheral neuropathic pain in patients of all ages range from approximately $1600 to $7000, depending on the specific pain condition. Total excess health care costs associated with painful DPN were substantially greater than those associated with PHN, which might reflect the great medical comorbidity associated with DPN.

PERSPECTIVE

The data demonstrate that the health care costs associated with 1 peripheral neuropathic pain condition cannot be extrapolated to other neuropathic pain conditions. The results also increase understanding of the economic burden of PHN and painful DPN and provide a basis for evaluating the impact on health care costs of new interventions for their treatment and prevention.

Psychiatric issues in chronic pain

Chronic pain requires comprehensive care. While interdisciplinary approaches are recommended, the role of psychiatrists is often misunderstood. Psychiatrists should be involved with the care of patients with chronic pain as early as possible to maximize outcome. Psychiatrists offer an expertise that specifically addresses important deficiencies in the care of patients with chronic pain: 1) the lack of a detailed formulation, 2) the lumping of all psychopathology, and 3) the failure to effectively use psychopharmacologic treatments. This review provides a framework for formulating the diagnoses and treatments of patients with chronic pain.

Neuropathic pain: quality-of-life impact, costs and cost effectiveness of therapy

A number of different diseases or injuries can damage the central or peripheral nervous system and produce neuropathic pain (NP), which seems to be more difficult to treat than many other types of chronic pain. As a group, patients with NP have greater medical co-morbidity burden than age- and sex-adjusted controls, which makes determining the humanistic and economic burden attributable to NP challenging. Health-related quality of life (HR-QOL) is substantially impaired among patients with NP. Patients describe pain-related interference in multiple HR-QOL and functional domains, as well as reduced ability to work and reduced mobility due to their pain. In addition, the spouses of NP patients have been shown to experience adverse social consequences related to NP. In randomized controlled trials, several medications have been shown to improve various measures of HR-QOL. Changes in HR-QOL appear to be tightly linked to pain relief, but not to the development of adverse effects. However, in cross-sectional studies, many patients continue to have moderate or severe pain and markedly impaired HR-QOL, despite taking medications prescribed for NP. The quality of NP treatment appears to be poor, with few patients receiving recommended medications in efficacious dosages. The substantial costs to society of NP derive from direct medical costs, loss of the ability to work, loss of caregivers' ability to work and possibly greater need for institutionalization or other living assistance. No single study has measured all of these costs to society for chronic NP. The cost effectiveness of various interventions for the treatment or prevention of different types of NP has been assessed in several different studies. The most-studied diseases are post-herpetic neuralgia and painful diabetic neuropathy, for which tricyclic antidepressants (both amitriptyline and desipramine) have been found to be either cost effective or dominant relative to other strategies. Increasing the use of cost-effective therapies such as tricyclic antidepressants for post-herpetic neuralgia and painful diabetic neuropathy may improve the HR-QOL of patients and decrease societal costs. Head-to-head clinical trials comparing NP therapies are needed to help assess the relative clinical efficacy of treatments, ideally using HR-QOL and utility outcomes. The full costs to society of NP, including productivity loss costs, have not been determined for chronic NP. Improved relative efficacy, utility and cost estimates would facilitate future cost-effectiveness research in NP.

Post-surgical neuropathic pain

Surgeons and anaesthetists are involved in Pain Medicine, as they have a responsibility to contribute to postoperative pain management and are often consulted about longer-term pain problems as well. A large component of persistent pain after surgery can be defined as neuropathic pain (NP). Nerves are injured during surgery and pain can persist after the surgical wound has healed. NP is because of a primary lesion or dysfunction of the peripheral or central nervous system. Prevalence estimates indicate that 2-3% of the population in the developed world experience NP. Persistent post-surgical NP is a mostly unrecognized clinical problem. The chronicity and persistence of post-surgical NP is often severely debilitating and impinges on the psychosocial, physical, economic and emotional well-being of patients. Options for treatment of any neuropathic factors are based on understanding the pain mechanisms involved. The current understandings of the mechanisms involved are presented. There is reasonable evidence for the efficacy of pharmacological management for NP. The aim of this article was to appraise the prevention, diagnostic work-up, the physical and particularly the pharmacological management of post-surgical NP and to provide a glimpse of advances in the field. It is a practical approach to post-surgical NP for all surgeons and anaesthetists. The take-home message is that prevention is better than waiting for post-surgical NP to become persistent.

Healthcare costs of acute and chronic pain associated with a diagnosis of herpes zoster

OBJECTIVES

To determine the healthcare costs of acute and chronic pain associated with herpes zoster.

DESIGN

Retrospective cohort analysis.

SETTING

Inpatient and outpatient care.

PARTICIPANTS

Patients were selected from Medicare, commercial insurance, and Medicaid claims databases if they had a diagnosis of herpes zoster or postherpetic neuralgia (PHN) or were prescribed analgesics after a diagnosis of herpes zoster (possible PHN) and were matched to controls for demographic and clinical factors using propensity scores.

MEASUREMENTS

One-year excess healthcare expenditures attributable to herpes zoster pain or PHN were calculated for inpatient, outpatient, and prescription drug services.

RESULTS

For the Medicare cohort, the average excess cost per patient was $1,300 in the year after a diagnosis of herpes zoster with 30 days or fewer of analgesic use and ranged from $2,200 to $2,300 per patient with PHN or possible PHN. Patients with possible PHN were 53% more prevalent than patients with PHN in the Medicare cohort and accounted for half of all excess expenditures. Findings were similar in the younger cohorts with commercial insurance and Medicaid except that costs attributable to PHN and possible PHN were higher, and patients with possible PHN were three to five times as prevalent as patients with PHN.

CONCLUSION

Healthcare costs associated with PHN were substantially greater than those associated with herpes zoster pain that resolved within 30 days. The data suggest that as many as 80% of patients with PHN may not be diagnosed with PHN and that these patients account for at least half of PHN expenditures.

A Cost-Effectiveness Comparison of Desipramine, Gabapentin, and Pregabalin for Treating Postherpetic Neuralgia

OBJECTIVES

To compare the net health effects and costs resulting from treatment with different first-line postherpetic neuralgia (PHN) medications.

DESIGN

Cost-utility analysis using published literature.

PARTICIPANTS

Hypothetical cohort of patients aged 60 to 80 with PHN.

INTERVENTIONS

Desipramine 100 mg/d, gabapentin 1,800 mg/d, and pregabalin 450 mg/d.

MEASUREMENTS

A decision model was designed to describe possible treatment outcomes, including different combinations of analgesia and side effects, during the first 3 months of therapy for moderate to severe PHN. The main outcome was cost per quality-adjusted life-year (QALY) gained. Costs were estimated using the perspective of a third-party payer. Multivariate, univariate, and probabilistic sensitivity analyses were performed, and the time frame of the model was varied to 1-month and 6-month horizons.

RESULTS

Desipramine was more effective and less expensive than gabapentin or pregabalin (dominant) under all conditions tested. Gabapentin was more effective than pregabalin but at an incremental cost of $216,000/QALY. Below $140/month, gabapentin became more cost-effective than pregabalin at a threshold of $50,000/QALY, and below $115/month gabapentin dominated pregabalin.

CONCLUSION

Desipramine appears to be more effective and less expensive than gabapentin or pregabalin for the treatment of older patients with PHN in whom it is not contraindicated. After its price falls, generic gabapentin will likely be more cost-effective than pregabalin.

The Application of Economic Evaluation Methods in the Chronic Pain Medicine Literature

BACKGROUND

The relative efficiency of a health care intervention or health status improvement realized for a given amount of resources expended can be determined using cost-effectiveness analysis or cost-utility analysis.

METHODS

An extensive chronic pain-focused search was undertaken of the MEDLINE, EMBASE, and SCI-EXPANDED databases. A total of 1822 unique citations were generated, with 142 studies subsequently categorized as incorporating one of seven recognized types of health care economic evaluation.

RESULTS

Of the 142 identified chronic pain-related economic evaluations published between 1988 and 2006, 30 incorporated a cost-effectiveness analysis and 29 incorporated a cost-utility analysis. The data are consistent with the previously reported chronological pattern of an increased overall diffusion of cost-utility analysis studies from the general medical and health services research literature into the medical subspecialty journals. However, only a few studies combined the economic analysis alongside a randomized controlled trial, the economic end-points in the trials had limited time horizons, and there was failure to address the protracted costs versus benefits of treating long-term and often recurrent chronic pain conditions.

CONCLUSIONS

Although it would appear worthwhile for researchers and clinicians to consider cost-effectiveness analysis and cost-utility analysis in their trial designs and treatment algorithms for chronic pain conditions, methodological improvements can be made in trial designs.

Sequential medication strategies for postherpetic neuralgia: a cost-effectiveness analysis

Several medications are recommended for relief of postherpetic neuralgia (PHN). A sequential treatment algorithm has been suggested, but its cost-effectiveness is unclear. We developed a decision model to estimate the cost-effectiveness of this algorithm compared with other sequential medication strategies in 70-year-olds with PHN, using literature data to model medication-related PHN relief while also accounting for severe medication side effects. Hypothetical patients with and without coronary artery disease (CAD) were considered separately, with and without localized pain. Sequential medication switches occurred as the result of inadequate relief or intolerable side effects. Probabilistic sensitivity analyses were performed to estimate the favorability of each medication early in treatment sequences. In patients without CAD, tricyclic and gabapentin were equally favored as initial therapy if mortality with tricyclic use was not increased, but gabapentin was strongly favored if it was. In patients with CAD, gabapentin was overwhelmingly favored. In either patient group, opioids, pregabalin, and tramadol were not favored as initial therapy but were sensible choices later in treatment sequences. The lidocaine patch was a reasonable first choice in patients with localized PHN. Our analysis supports the suggested treatment algorithm, with cost-effectiveness ratios within acceptable ranges for medications given sequentially, based on literature-based estimates of effectiveness and tolerability.

PERSPECTIVE

This article examines the cost-effectiveness of recommended sequential treatment strategies for postherpetic neuralgia. This decision analysis-based synthesis of effectiveness and cost data found that recommended treatment algorithms are also economically reasonable.

Evidence-Based Scientific Data Documenting the Treatment and Cost-Effectiveness of Comprehensive Pain Programs for Chronic Nonmalignant Pain

Chronic pain is one of the most prevalent and costly problems in the United States today. Traditional medical treatments for it, though, have not been consistently efficacious or cost-effective. In contrast, more recent comprehensive pain programs (CPPs) have been shown to be both therapeutically efficacious and cost-effective. The present study reviews available evidence demonstrating the therapeutic efficacy and cost-effectiveness of CPPs, relative to conventional medical treatment. Searches of the chronic pain treatment literature during the past decade were conducted for this purpose, using MEDLINE and PSYCHLIT. Studies reporting treatment outcome results for patients with chronic pain were selected, and data on the major outcome variables of self-reported pain, function, healthcare utilization and cost, medication use, work factors, and insurance claims were evaluated. When available, conventional medical treatments were used as the benchmark against which CPPs were evaluated. This review clearly demonstrates that CPPs offer the most efficacious and cost-effective, evidence-based treatment for persons with chronic pain. Unfortunately, such programs are not being taken advantage of because of short-sighted cost-containment policies of third-party payers.

PERSPECTIVE

A comprehensive review was conducted of all studies in the scientific literature reporting treatment outcomes for patients with chronic pain. This review clearly revealed that CPPs offer the most efficacious and cost-effective treatment for persons with chronic pain, relative to a host of widely used conventional medical treatment.

Drug therapy for chronic idiopathic axonal polyneuropathy

BACKGROUND

Chronic idiopathic axonal polyneuropathy is an insidiously progressive sensory or sensorimotor polyneuropathy that affects elderly people. Although severe disability or handicap does not occur, it reduces quality of life.

OBJECTIVES

To assess whether drug therapy for chronic idiopathic axonal polyneuropathy reduces disability, ameliorates neurological symptoms and associated impairments, and whether treatment is safe.

SEARCH STRATEGY

We searched Cochrane Library (Cochrane Neuromuscular Disease Review Group Register, Cochrane Database of Systematic Reviews, Cochrane Database of Abstracts of Reviews of Effectiveness, and the Cochrane Central Register of Controlled Trials), MEDLINE, EMBASE, ISI, and ACP Journal Club's Best Evidence, from 1981 until December 2002. We also hand searched the reference lists of relevant articles, reviews and textbooks identified electronically, and contacted authors and other experts in the field to identify additional studies.

SELECTION CRITERIA

We sought all randomised or quasi-randomised (alternate or other systematic treatment allocation), unconfounded trials that examined the effects of any drug therapy in patients with chronic idiopathic axonal polyneuropathy at least one year after the onset of treatment. Patients with chronic idiopathic axonal polyneuropathy had to fulfil the following criteria: age 40 years or older, distal sensory or sensorimotor polyneuropathy, absence of systemic or other neurological disease, chronic clinical course not reaching a nadir in less than two months, exclusion of any recognised cause of the polyneuropathy by medical history taking, clinical or laboratory investigations, electrophysiological studies in agreement with axonal polyneuropathy without evidence of demyelinating features. The primary outcome was the proportion of patients with a significant improvement in disability. Secondary outcomes were change in the mean disability score, change in the proportion of patients who make use of walking aids, change in the mean Medical Research Council sum score, degree of pain relief and/or reduction of other positive sensory symptoms, change in the proportion of patients with pain or other positive sensory symptoms, and frequency of adverse effects.

DATA COLLECTION AND ANALYSIS

Two reviewers independently reviewed and extracted details of trial methodology and outcome data of all potentially relevant trials.

MAIN RESULTS

Eighteen studies were identified and assessed for possible inclusion in the review, but all were excluded because of insufficient quality or lack of relevance.

REVIEWERS' CONCLUSIONS

Even though chronic idiopathic axonal polyneuropathy has been clearly described and delineated, no adequate randomised or quasi-randomised controlled clinical treatment trials have been performed. In their absence there is no proven efficacious drug therapy.