A Systematic Review of Observational Studies on the Effectiveness of Opioid Therapy for Cancer Pain

West Virginia University Hospitals, Morgantown, WV 26506, USA.
Pain physician (Impact Factor: 3.54). 03/2011; 14(2):E85-102.
Source: PubMed


The prevalence of cancer-related pain and residual pain in cancer survivors is high. Opioids serve as the gold standard for treating moderate to severe cancer pain. The evaluation of the effectiveness of opioids in chronic non-cancer pain has shown a lack of effectiveness, or rather weak evidence for some of the drugs. In contrast, in cancer pain, opioids are expected to be very effective. Due to the nature of the disease, there is evidence of a paucity of randomized trials investigating opioid effectiveness in cancer pain on a long-term basis. Consequently, the effectiveness of opioids in managing cancer-related pain warrants further evidence-based review beyond randomized trials, including observational studies and case reports.
The comprehensive literature search was conducted for the period 1996 through June 2010. Databases for the search included PubMed, EMBASE, Cochrane Reviews, and, along with reviews and cross references. Methodologic quality assessment of the observational studies managing chronic cancer pain with opioids was conducted utilizing the Agency for Healthcare Research and Quality (AHRQ) criteria for observational studies. Analysis of evidence included 5 levels of evidence developed by the United States Preventive Services Task Force (USPSTF) ranging from Level I to III with 3 subcategories in Level II. Grading recommendations were based on Guyatt et al's recommendations with 6 levels: 3 in the strong category and 3 in the weak category.
This evaluation is of 18 manuscripts considered for inclusion; 7 manuscripts met the inclusion criteria based on AHRQ quality assessment. Level of evidence for opioid therapy in cancer pain was Level II-3, and recommendations were 1C/strong recommendation based on observational studies, which could change based on future evidence.
This systematic review of observational studies indicates Level II-3 evidence for effectiveness of opioids in cancer pain therapy, with 1C/strong recommendation based on observational studies, which could change based on future evidence.

    • "CDC, Center for Disease Control; CI, confidence interval; OR, odds ratio; SSI, surgical site infection. Note: Adopted with permission from Colson et al. [23]. Modified based on Reisch et al. [24], West et al. [21], and von Elm et al. [22]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Risk factors for surgical site infection (SSI) in children derived from studies in the adult population are potentially misleading due to differences in pathophysiology and management. This systematic review addresses the key question: What are the risk factors for SSI in pediatric patients undergoing scoliosis surgery? This is a qualitative systematic literature review. Retrospective and observational trials of children undergoing scoliosis surgery that reported on the occurrence of risk factors for SSI and the occurrence of SSI. Pubmed (Medline), EBMR reviews, Scopus and CINAHL were searched electronically for relevant articles in all languages between 1991 and August 2012 and cross-references were checked. Two independent reviewers identified articles and appraised quality with the Agency for Healthcare Research and Quality (AHRQ) criteria based on a weighted scoring of 0 to 100. Our search identified 135 abstracts and 14 studies meeting the inclusion criteria. AHRQ grading showed that five articles were high-quality with a score of > 67 and five articles were moderate-quality with a score between 50 and 67. The percent agreement between the two independent reviewers was 84% and kappa agreement score was 0.91 (95% confidence interval 0.78-1.03). There were 76 risk factors identified, of which 22 factors were reported in more than one study. Odds ratios and 95% confidence intervals were reported inconsistently. Pooled p analysis of high- and moderate-quality articles identified five risk factors predictive of SSI: inappropriate antibiotic use (p = 0.001), neuromuscular scoliosis (p = 0.014), instrumentation (p = 0.023), increased hospital stay days (p = 0.003), and residual postoperative curve (p = 0.003). The systematic review identified inappropriate antibiotic use, neuromuscular scoliosis, instrumentation, increased hospital stay days, and residual postoperative curve as risk factors for SSI following pediatric scoliosis surgery. Copyright © 2015 Elsevier Inc. All rights reserved.
    No preview · Article · Mar 2015 · The spine journal: official journal of the North American Spine Society
  • [Show abstract] [Hide abstract]
    ABSTRACT: Treatment of chronic non-cancer pain with opioid therapy has escalated in recent years, resulting in exploding therapeutic use and misuse of prescription opioids and multiple adverse drug events. Breakthrough pain is defined as a transient exacerbation of pain experienced by individuals who have relatively stable and adequately controlled baseline cancer pain. Further, the definition of breakthrough pain, prevalence, characteristics, implications, and treatment modalities have been extensively described for chronic cancer pain. However, the literature for breakthrough pain in chronic non-cancer pain including its terminology, prevalence, relevance, characteristics, and treatments, have been poorly described and continue to be debated. The philosophy of breakthrough pain in chronic non-cancer pain raises multiple issues leading almost all patients to be on high dose long-acting opioids, followed by supplementing with short-acting drugs, instead of treating the patients with only short-acting drugs as required. Consequently, the subject of breakthrough pain in chronic non-cancer pain is looked at with suspicion due to the lack of evidence and inherent bias associated with its evaluation, followed by escalating use and abuse of opioids. Multiple issues related to the concept of breakthrough pain in chronic non-cancer pain evolve around extensive use, overuse, misuse, and abuse of opioids. In the era of eliminating opioids or significantly curtailing their use to only appropriate indications, the concept of breakthrough pain raises multiple questions without any scientific evidence. This review illustrates that there is no significant evidence for any type of breakthrough pain in chronic non-cancer pain based on available literature, methodology utilized, and response to opioids in chronic non-cancer pain. The advocacy for increased usage of opioids in the treatment of chronic pain dates back to the liberalization of laws governing opioid prescription for the treatment of chronic non-cancer pain by state medical boards in the late 1990s, and is exploding with new pain management standards for inpatient and outpatient medical care implemented by the Joint Commission on Accreditation of Health Care Organizations in 2000, and the advocacy by many physicians and organizations for increased use of opioids. This comprehensive review critically evaluates the available evidence of breakthrough pain in chronic non-cancer pain including its existence, prevalence, and managing symptoms which are described as breakthrough pain or episodic pain.
    No preview · Article · Nov 2010 · Pain physician
  • [Show abstract] [Hide abstract]
    ABSTRACT: Use of opioids for chronic non-cancer pain (CNCP) has increased in recent years because this pain had been undertreated. There was also a simultaneous increase in misuse and abuse of opioids. Deaths due to such abuse and misuse also have risen as seen in the many reports published every day in local papers as well as in the medical literature. So, it is imperative that patients who are prescribed these medications be monitored for adherence so misuse and abuse can be curtailed and opioids are available to those who genuinely need them for chronic pain control. There are various screening tools available to monitor such adherence, and there is an abundance of literature about it in addiction and psychiatric medicine. There is, though, a paucity of such literature as applied to pain medicine. Our objectives for this review were twofold. We wanted to identify which screening tools are available to monitor opioid adherence and we wanted to see if there were prospective comparative studies of these tools to identify a single best tool that can be applied to all chronic non-cancer pain patients managed with opioids. We did a review of the current literature about monitoring of opioid adherence. We also looked at their use, validity, and comparative studies. We performed a literature search using PubMed, EMBASE, and the Cochrane library. The search was conducted using the terms opioids, non-cancer pain, monitoring, and adherence. The databases from 1996 to November 2010 were reviewed. The search included prospective and retrospective studies, review articles, and FDA records. Bibliographies and cross references were reviewed when deemed appropriate. We found 52 publications, of which 22 met the criteria to be included in this manuscript. We found only one study that was prospective, and compared the various screening tools that are available to monitor opioid adherence. In the majority of the studies the number treated was small. There was not a single screening tool that can be applied universally to all patients who are on opioid therapy for chronic non-cancer pain.
    No preview · Article · Nov 2010 · Pain physician
Show more