Research design considerations for chronic pain prevention clinical trials: IMMPACT recommendations.

Although certain risk factors can identify individuals who are most likely to develop chronic pain, few interventions to prevent chronic pain have been identified. To facilitate the identification of preventive interventions, an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain. We present general design considerations for prevention trials in populations that are at relatively high risk for developing chronic pain. Specific design considerations included subject identification, timing and duration of treatment, outcomes, timing of assessment, and adjusting for risk factors in the analyses. We provide a detailed examination of 4 models of chronic pain prevention (ie, chronic postsurgical pain, postherpetic neuralgia, chronic low back pain, and painful chemotherapy-induced peripheral neuropathy). The issues discussed can, in many instances, be extrapolated to other chronic pain conditions. These examples were selected because they are representative models of primary and secondary prevention, reflect persistent pain resulting from multiple insults (ie, surgery, viral infection, injury, and toxic or noxious element exposure), and are chronically painful conditions that are treated with a range of interventions. Improvements in the design of chronic pain prevention trials could improve assay sensitivity and thus accelerate the identification of efficacious interventions. Such interventions would have the potential to reduce the prevalence of chronic pain in the population. Additionally, standardization of outcomes in prevention clinical trials will facilitate meta-analyses and systematic reviews and improve detection of preventive strategies emerging from clinical trials.

Chemotherapy-induced peripheral neuropathy clinical trials: Review and recommendations.

OBJECTIVE: To assess the design characteristics and reporting quality of published randomized controlled trials (RCTs) for treatments of chemotherapy-induced peripheral neuropathy (CIPN) initiated before or during chemotherapy. METHODS: In this systematic review of RCTs of preventive or symptomatic pharmacologic treatments for CIPN initiated before or during chemotherapy treatment, articles were identified by updating the PubMed search utilized in the CIPN treatment guidelines published in the Journal of Clinical Oncology in 2014. RESULTS: Thirty-eight articles were identified. The majority included only patients receiving platinum therapies (61%) and used a placebo control (79%). Common exclusion criteria were preexisting neuropathy (84%), diabetes (55%), and receiving treatments that could potentially improve neuropathy symptoms (45%). Ninety-five percent of studies initiated the experimental treatment before CIPN symptoms occurred. Although 58% of articles identified a primary outcome measure (POM), only 32% specified a primary analysis. Approximately half (54%) of the POMs were patient-reported outcome measures of symptoms and functional impairment. Other POMs included composite measures of symptoms and clinician-rated signs (23%) and vibration tests (14%). Only 32% of articles indicated how data from participants who prematurely discontinued chemotherapy were analyzed, and 21% and 29% reported the number of participants who discontinued chemotherapy due to neuropathy or other/unspecified reasons, respectively. CONCLUSIONS: These data identify reporting practices that could be improved in order to enhance readers' ability to critically evaluate RCTs of CIPN treatments and use the findings to inform the design of future studies and clinical practice. Reporting recommendations are provided.

Reporting of Design Features and Analysis Details in Randomized Clinical Trials of Procedural Treatments for Cancer Pain: An ACTTION Systematic Review.

BACKGROUND AND OBJECTIVES: The objective of this study was to assess the reporting of randomized clinical trials investigating procedural treatments (eg, nerve blocks, targeted drug delivery) for cancer pain, with a focus on aspects that are particularly challenging in these trials. METHODS: This article presents results from a systematic review of reporting of randomized clinical trials of procedural interventions for cancer pain. Articles were identified by searching PubMed from 1966 to June 2014. Data related to quality of reporting are presented for early (1985-2004) and late periods (2005-2014). RESULTS: A total of 35 published trials were included. Approximately two-thirds of the articles clearly indicated the level of blinding. Only 26% reported a primary outcome measure. Less than half explicitly reported the number of patients who completed the trial, and only 1 reported a method that was used to accommodate missing data. Almost one-third of articles included a responder analysis, all of which specified the definition of a responder. CONCLUSIONS: The goal of highlighting these deficiencies in reporting is to promote transparent reporting of details affecting the completion and interpretation of procedural cancer pain trials so that their quality can be more easily evaluated.

Participant Preferences for Pharmacologic Chronic Pain Treatment Trial Characteristics: An ACTTION Adaptive Choice-Based Conjoint Study.

Barriers to clinical trial recruitment can delay study completion, potentially resulting in increased costs and an unrepresentative sample. In the current study of 150 participants with chronic pain, we used a computerized adaptive choice-based conjoint survey that included 8 characteristics that may affect enrollment in pharmacologic pain treatment trials (ie, treatment allocation, frequency of pain ratings, treatment administration method, current medications, number of study visits, availability of evening and weekend visits, invasiveness of laboratory procedures, payment). These data were analyzed using Sawtooth Software ver. 8.4.8 (Sawtooth Software, Inc, Orem, UT), which identifies the characteristics that dominate participants' decisions across multiple sets of potential trials. Three characteristics had the largest relative importance in participants' trial preferences: 1) invasiveness of required laboratory procedures (ie, 22%), with no procedures or blood tests preferred over ice-water sensory testing or skin biopsy; 2) ability to continue current pain medications (21%); and 3) payment for study participation (21%), with higher payment preferred. The fourth most important characteristic was number of study visits (13%), with participants preferring fewer in-person visits and more phone contacts. Understanding the preferences of potential participants is an important step toward enhancing enrollment in pain treatment trials. PERSPECTIVE: This article presents the preferences of individuals with chronic pain conditions regarding modifiable pain treatment trial characteristics (eg, number of study visits, payment, treatment allocation). These findings may help to improve enrollment into analgesic clinical trials and in turn accelerate the development of new pain treatments.

Research design considerations for chronic pain prevention clinical trials: IMMPACT recommendations.

Although certain risk factors can identify individuals who are most likely to develop chronic pain, few interventions to prevent chronic pain have been identified. To facilitate the identification of preventive interventions, an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain. We present general design considerations for prevention trials in populations that are at relatively high risk for developing chronic pain. Specific design considerations included subject identification, timing and duration of treatment, outcomes, timing of assessment, and adjusting for risk factors in the analyses. We provide a detailed examination of 4 models of chronic pain prevention (ie, chronic postsurgical pain, postherpetic neuralgia, chronic low back pain, and painful chemotherapy-induced peripheral neuropathy). The issues discussed can, in many instances, be extrapolated to other chronic pain conditions. These examples were selected because they are representative models of primary and secondary prevention, reflect persistent pain resulting from multiple insults (ie, surgery, viral infection, injury, and toxic or noxious element exposure), and are chronically painful conditions that are treated with a range of interventions. Improvements in the design of chronic pain prevention trials could improve assay sensitivity and thus accelerate the identification of efficacious interventions. Such interventions would have the potential to reduce the prevalence of chronic pain in the population. Additionally, standardization of outcomes in prevention clinical trials will facilitate meta-analyses and systematic reviews and improve detection of preventive strategies emerging from clinical trials.