Methodological issues in systematic reviews of headache trials: adapting historical diagnostic classifications and outcome measures to present-day standards

Effect of Galcanezumab on Total Pain Burden in Patients Who Had Previously Not Benefited from Migraine Preventive Medication (CONQUER Trial): A Post Hoc Analysis

INTRODUCTION

In evaluating therapies for migraine prevention, emphasis is placed on frequency and less attention is paid to duration or severity. Total pain burden (TPB) combines frequency, duration, and severity of migraine headache, and has the potential to further characterize the benefit of preventive treatment using a single composite measure. TPB was previously used to characterize response to galcanezumab (GMB) in patients with migraine. In this post hoc analysis we assessed the impact of GMB in lowering TPB in patients who had previously not benefited from two to four categories of migraine preventive medication.

METHODS

CONQUER trial patients (N = 462), 18-75 years old who had previously not benefited from two to four categories of migraine preventive medication, were randomized (1:1) to monthly placebo or GMB 120 mg with 240 mg loading dose. For each patient, monthly TPB in severity-weighted hours was calculated by multiplying migraine headache duration (hours) by maximum severity for each migraine headache day, then summing these daily scores over the month for the monthly score. Changes from baseline in monthly TPB across months 1-3 were analyzed. Spearman correlations between TPB and scores on the Migraine-Specific Quality-of-Life Questionnaire (MSQ) total and Migraine Disability Assessment Scale (MIDAS) were assessed at baseline.

RESULTS

Mean (SD) baseline monthly TPB was 192.1 (158.3) and 188.2 (197.4) severity-weighted hours for GMB-treated and placebo-treated patients, respectively. Across the 3-month double-blind period, GMB-treated patients experienced significantly greater mean reductions from baseline in monthly TPB compared with placebo-treated patients, both for mean change (GMB - 82.7, placebo - 15.8, p < 0.001) and percentage change (GMB - 38.6%, placebo 9.4%, p < 0.001). Furthermore, baseline TPB correlated with MSQ score (r = - 0.39) and MIDAS score (r = 0.40), suggesting good association of TPB with functional and disability outcomes.

CONCLUSION

GMB reduced mean TPB in patients who had previously not benefited from two to four categories of migraine preventive medication.

TRIAL REGISTRATION

NCT03559257.

Impact of galcanezumab on total pain burden: findings from phase 3 randomized, double-blind, placebo-controlled studies in patients with episodic or chronic migraine (EVOLVE-1, EVOLVE-2, and REGAIN trials)

Background

Focus on the frequency of migraine pain may undervalue the total burden of migraine as pain duration and severity may present unique, additive burden. A composite measure of total pain burden (TPB; frequency, severity, and duration) may provide a more comprehensive characterization of pain burden and treatment response in patients with episodic migraine (EM) or chronic migraine (CM). The impact of galcanezumab versus placebo on TPB among patients with EM or CM was analyzed.

Methods

Patients from randomized, double-blind, placebo-controlled episodic (two 6-month studies pooled) and chronic migraine (3-month) studies received once-monthly subcutaneous injection of galcanezumab 120 mg or placebo. A post hoc analysis of TPB for a given month was calculated as severity-weighted duration by multiplying duration (hours) and maximum pain severity (0 = none, 1 = mild, 2 = moderate, 3 = severe) of migraine for each day and summing these over the days in a month. Least square mean change from baseline in monthly TPB across Months 1–6 (EM, N = 444 galcanezumab, N = 894 placebo) and Months 1–3 (CM, N = 278 galcanezumab, N = 558 placebo) were compared using a mixed-model repeated measures model. Correlation of the Migraine Specific Quality of Life Questionnaire (MSQ) and Migraine Disability Assessment Scale (MIDAS) to TPB at baseline was assessed.

Results

At baseline, the duration of migraine on a given migraine headache day accounted for the greatest unique proportion of variability (EM, 57.4% and CM, 61.1%) to TPB after adjusting for frequency of migraine headache days and maximum pain severity. The decrease from baseline in monthly TPB was greater with galcanezumab than placebo for patients with EM (68.6 versus 36.2) and CM (102.6 versus 44.4). The average percent reduction of TPB from baseline was significantly greater with galcanezumab compared with placebo in patients with EM (50.8% versus 17.2%) and CM (29.7% versus 11.0%). In patients with EM and CM, TPB correlated with MSQ total score (r = − 0.35 and r = − 0.37) and MIDAS (r = 0.34 and r = 0.32).

Conclusions

Greater reduction in TPB was seen in patients with EM and CM treated with galcanezumab 120 mg once-monthly injection relative to placebo. Discussing TPB supports patient-centric conversations regarding treatment expectations when clinicians are evaluating options for migraine prevention.

Trial registration

ClinicalTrials.gov: #NCT02614183 (I5Q-MC-CGAG; EVOLVE-1), #NCT02614196 (I5Q-MC-CGAH; EVOLVE-2), and #NCT02614261 (I5Q-MC-CGAI; REGAIN) – all 3 trials were registered on 23 November 2015.

Assessing the impact of headaches and the outcomes of treatment: A systematic review of patient-reported outcome measures (PROMs)

Aims To critically appraise, compare and synthesise the quality and acceptability of multi-item patient reported outcome measures for adults with chronic or episodic headache. Methods Systematic literature searches of major databases (1980-2016) to identify published evidence of PROM measurement and practical properties. Data on study quality (COSMIN), measurement and practical properties per measure were extracted and assessed against accepted standards to inform an evidence synthesis. Results From 10,903 reviewed abstracts, 103 articles were assessed in full; 46 provided evidence for 23 PROMs: Eleven specific to the health-related impact of migraine (n = 5) or headache (n = 6); six assessed migraine-specific treatment response/satisfaction; six were generic measures. Evidence for measurement validity and score interpretation was strongest for two measures of impact, Migraine-Specific Quality of Life Questionnaire (MSQ v2.1) and Headache Impact Test 6-item (HIT-6), and one of treatment response, the Patient Perception of Migraine Questionnaire (PPMQ-R). Evidence of reliability was limited, but acceptable for the HIT-6. Responsiveness was rarely evaluated. Evidence for the remaining measures was limited. Patient involvement was limited and poorly reported. Conclusion While evidence is limited, three measures have acceptable evidence of reliability and validity: HIT-6, MSQ v2.1 and PPMQ-R. Only the HIT-6 has acceptable evidence supporting its completion by all "headache" populations.

Spinal rehabilitative exercise or manual treatment for the prevention of cervicogenic headache in adults

This is the protocol for a review and there is no abstract. The objectives are as follows: To quantify and compare the short- and long-term effects of manual treatment and spinal rehabilitative exercise for cervicogenic headache, classified according to the International Headache Society's (IHS) diagnostic criteria, with an active or placebo/sham comparison or wait-list control.

Spinal rehabilitative exercise or manual treatment for the prevention of tension-type headache in adults

This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the short- and long-term effects of manual treatment and spinal rehabilitative exercise for the prevention of tension-type headache in adults.

Responsiveness of efficacy endpoints in clinical trials with over the counter analgesics for headache

AIM

To quantify and compare the responsiveness within the meaning of clinical relevance of efficacy endpoints in a clinical trial with over the counter (OTC) analgesics for headache. Efficacy endpoints and observed differences in clinical trials need to be clinically meaningful and mirror the change in the clinical status of a patient. This must be demonstrated for the specific disease indication and the particular patient population based on the application of treatments with proven efficacy.

METHODS

Patient's global efficacy assessment during two study phases (pre-phase and treatment phase) was used to classify patients as satisfied or non-satisfied with the efficacy of their medication. The analysis is based on 1734 patients included in the efficacy analysis of a randomized, placebo-controlled, double-blind, multi-centre parallel group trial with six treatment arms. Based on this classification and the pain intensity recorded by the patients on a 100 mm visual analogue scale, group differences by assessment categories and receiver operating characteristic (ROC) curve methods were used to quantify responsiveness of the efficacy endpoints 'time to 50% pain relief', 'time until reduction of pain intensity to 10 mm', 'weighted sum of pain intensity difference' (%SPIDweighted), 'pain intensity difference (PID) relative to baseline at 2 hours', and 'pain-free at 2 hours'.

RESULTS

Clinically relevant differences between patients satisfied and non-satisfied with the treatment were observed for all efficacy endpoints. Patients with the highest rating of efficacy had the fastest and strongest pain relief. In comparison, patients assessing efficacy as 'less good' reached a 50% pain relief on average nearly an hour later than those scoring efficacy as at least 'good'. Simultaneously, their extent of pain relief was only half as great 2 hours after medication intake. Patients scoring efficacy as 'poor' experienced practically no pain relief within the 4 hour observation interval. ROC curve calculations confirmed an adequate responsiveness for all continuous endpoints. The following cut-off points for differentiating between satisfied and non-satisfied patients were deduced from the data in the pre- and treatment phase, respectively: 'time to 50% pain relief' 1:10 and 1:31 h:min, 'time until reduction of pain intensity to 10 mm' 2:40 and 3:00 h:min, '%SPIDweighted' 68 and 64%, 'PID at 2 hours' 35 and 35 mm. The sensitivity and specificity based on these cut-off points ranged from 70 to 79%. The binary endpoint 'pain-free at 2 hours' showed a clearly higher specificity (80 and 87%) than sensitivity (65 and 61%) in the pre- and treatment phase, respectively.

CONCLUSIONS

When global assessment of efficacy by the patient was used as external criterion, ROC curve calculations confirmed a high responsiveness for all efficacy endpoints included in this study. Clinically relevant differences between patients satisfied and non-satisfied with the treatment were observed. The endpoint '%SPIDweighted' proved slightly but consistently superior to the other endpoints. SPID and %SPIDweighted are not easy to interpret and the time course of pain reduction is of high importance for the patients in the treatment of acute pain, including headache. The endpoint 'pain-free at 2 hours' showed the expected high specificity, but at the cost of a concurrently low sensitivity and clearly makes less use of the available information than the endpoint 'time to 50% pain reduction', which combines the highly relevant aspects of time course and extent of pain reduction. Responsiveness, the ability of an outcome measure to detect clinically important changes in a specific condition of a patient, should be added in future revisions of IHS guidelines for clinical trials in headache disorders.

Clinical relevance of efficacy endpoints in OTC headache trials

OBJECTIVE

This analysis evaluates and ranks efficacy endpoints often used in headache trials concerning their clinical relevance in relation to the patient-related criterion "global assessment of overall efficacy" based on data gained in a large trial investigating different over-the-counter drugs in the treatment of headache.

BACKGROUND

The original study showed a significant superiority of the fixed combination of acetylsalicylic acid+paracetamol+caffeine over the combination without caffeine, the single preparations, and placebo in the treatment of headache.

METHODS

For 1734 patients included in the efficacy analysis we investigated the correlation of patient's global efficacy assessment with the endpoints "time to 50% pain relief" (primary endpoint), "time to be pain-free," pain intensity difference, sum of pain intensity difference, and extent of impairment of daily activities. Patients recorded pain intensity on a visual analog scale. Efficacy, tolerability, and extent of impairment of daily activity were assessed on verbal rating scales.A logistic regression, proportional odds model was adapted to the time to event data.

RESULTS

The highest correlation with patient's global efficacy assessment was demonstrated for the primary endpoint time to 50% pain relief (r = 0.6727) and the sum of pain intensity difference (r = 0.7037). The frequency distribution of patient's global efficacy assessment depended primarily on the time to 50% pain relief and similarly, but to a somewhat lesser extent, on the reduction of pain intensity to 10 mm as assessed on the visual analog scale. More than 86% of the patients assessed efficacy as very good or good when their pain was reduced by 50% at least within 1 hour after drug intake. The patients accept a longer time span than 2 hours for reaching no pain to give a positive global evaluation of efficacy.

Outcome Measurement in Behavioral Headache Research: Headache Parameters and Psychosocial Outcomes

The experience of pain is complex and includes multiple dimensions or aspects, such as sensory and affective (among others). Headache includes not only pain, but also associated symptoms that can further diversify the relevant dimensions. Subjective ratings of head pain, sampled daily, have come to be regarded as the "gold standard" in behavioral headache research. Primary measures of headache include the attack frequency or headache days per month. Secondary measures of headache may include headache activity/index, headache duration, peak headache severity, and/or frequency of severe headaches per month. Secondary measures of disability and quality of life include Migraine Disability Assessment (MIDAS), Headache Impact Test (HIT), Headache Disability Inventory (HDI). Secondary nonheadache measures include medication consumption, psychiatric symptoms, stress and coping, treatment satisfaction and preference, side effects, and others. Researchers should include not only primary measures of headache, but also secondary measures, disability and quality of life, and nonheadache measures. All measures should be clearly defined and reported. A baseline period that is adequate for each measure needs inclusion and a minimum of 4 weeks is recommended for primary headache measures. Specific suggestions for future research directions are provided.

Guidelines for Trials of Behavioral Treatments for Recurrent Headache, First Edition: American Headache Society Behavioral Clinical Trials Workgroup

Guidelines for design of clinical trials evaluating behavioral headache treatments were developed to facilitate production of quality research evaluating behavioral therapies for management of primary headache disorders. These guidelines were produced by a Workgroup of headache researchers under auspices of the American Headache Society. The guidelines are complementary to and modeled after guidelines for pharmacological trials published by the International Headache Society, but they address methodologic considerations unique to behavioral and other nonpharmacological treatments. Explicit guidelines for evaluating behavioral headache therapies are needed as the optimal methodology for behavioral (and other nonpharmacologic) trials necessarily differs from the preferred methodology for drug trials. In addition, trials comparing and integrating drug and behavioral therapies present methodological challenges not addressed by guidelines for pharmacologic research. These guidelines address patient selection, trial design for behavioral treatments and for comparisons across multiple treatment modalities (eg, behavioral vs pharmacologic), evaluation of results, and research ethics. Although developed specifically for behavioral therapies, the guidelines may apply to the design of clinical trials evaluating many forms of nonpharmacologic therapies for headache.

Behavioral Headache Treatment: History, Review of the Empirical Literature, and Methodological Critique

Theoretical developments and burgeoning research on stress and illness in the mid-20th century yielded the foundations necessary to conceptualize headache as a psychophysiological disorder and eventually to develop and apply contemporary behavioral headache treatments. Over the past three decades, these behavioral headache treatments (relaxation training, biofeedback, cognitive-behavioral therapy, and stress-management training) have amassed a sizeable evidence base. Meta-analytic reviews of the literature consistently have shown behavioral interventions to yield 35% to 55% improvements in migraine and tension-type headache and that these outcomes are significantly superior to control conditions. The strength of the evidence has lead many professional practice organizations to recommend use of behavioral headache treatments alongside pharmacologic treatments for primary headache. The present overview was prepared as a companion article to and intended to provide a background for the Guidelines for Trials of Behavioral Treatments for Recurrent Headache also published within this journal supplement. This article begins with a synopsis of key historical developments leading to our current conceptualization of migraine and tension-type headache as psychophysiological disorders amenable to behavioral intervention. The evolution of the behavioral headache literature is discussed, exemplified by publication trends in the journal Headache. Leading empirically-based behavioral headache interventions are described, and meta-analytic reviews examining the migraine and tension-type headache literatures are summarized, compared, and contrasted. A critique of the methodological quality of the clinical trials literature is presented, highlighting the strengths and weaknesses in relation to recruitment and selection of patients, sample size and statistical power, the use of a credible control, and the reproducibility of the study interventions in clinical practice.