Current evidence suggests that aerobic exercise may reduce the number of migraine days compared to no intervention or maintenance of normal activity; additional limited, low quality evidence also suggests that aerobic exercise may also reduce migraine pain intensity and migraine attack duration. However, these conclusions must be interpreted with caution, since several methodological weaknesses mean that relevant studies may have been missed. More high quality studies with standardised outcome measures and sufficiently intense training programmes are needed to fully address the review question.
Overall summary High risk of bias in the review
Studies were restricted based on date and language, only a limited number of databases were searched, and only search keywords were provided, meaning relevant studies may have been missed. Heterogeneity was found to be high for one outcome; this was not assessed further.
|A. Did the interpretation of findings address all of the concerns identified in Domains 1 to 4?||Probably no|
|B. Was the relevance of identified studies to the review's research question appropriately considered?||Probably yes|
|C. Did the reviewers avoid emphasizing results on the basis of their statistical significance?||Probably yes|
|Risk of bias in the review||High|
|Number of studies||6|
|Number of participants||357|
|Last search date||21st February 2018|
|Objective||To determine the value of aerobic exercise on the number of migraine days, duration and pain intensity in patients with migraine.|
|Population||Individuals with migraine (with or without aura) classified by the International Classification of Headache Disorders (ICHD-II).
Pregnant women were excluded.
|Interventions||Physical endurance, physical fitness, aerobic exercise or exercise therapy performed for at least 6 weeks.
Manual therapy, medication as a standalone treatment or no intervention (such as diagnosing or performing tests on patients) were excluded.
|Outcome||Number of migraine days, attack frequency, pain intensity or duration of migraine attacks.|
|Study design||Randomised controlled trials or clinical trials.
Cohort studies, case-control studies, case reports, reviews or meta-analyses were excluded.
In terms of the number of migraine days, pooled analysis reported that the number of migraine days was reduced with an aerobic exercise program compared to control therapy (no intervention, maintenance of normal activity, relaxiation of topiramate) after 10-12 weeks (mean difference [MD] -0.61, 95% confidence interval [CI] -1.14 to -0.09; 4 studies, n=176 participants).
In terms of pain intensity, three individual studies reported a reduction of 20% to 54% in pain intensity after aerobic exercise compared to no intervention, amitriptyline or maintenance of normal activity (1 study, n=16 participants; 1 study, n=50 participants; 1 study, n=72 participants, respectively).
In terms of migraine attack duration, three individual studies reported a decrease in attack duration of 20 to 27% after aerobic exercise compared to no intervention, amitriptyline or maintenance of normal activity (1 study, n=16 participants; 1 study, n=50 participants; 1 study, n=72 participants, respectively).
The research objective was clearly stated and appropriate inclusion criteria were defined. Studies were restricted based on date (2004 onwards) and language (only English, French and Dutch languages); these were considered inappropriate.
|1.1 Did the review adhere to pre-defined objectives and eligibility criteria?||Probably yes|
|1.2 Were the eligibility criteria appropriate for the review question?||Probably yes|
|1.3 Were eligibility criteria unambiguous?||Probably yes|
|1.4 Were all restrictions in eligibility criteria based on study characteristics appropriate (e.g. date, sample size, study quality, outcomes measured)?||Probably no|
|1.5 Were any restrictions in eligibility criteria based on sources of information appropriate (e.g. publication status or format, language, availability of data)?||Probably no|
|Concerns regarding specification of study eligibility criteria||High|
PubMed, the Cochrane Library for trials and Web of Science were searched to identify relevant articles. No additional efforts were made to search for relevant studies. Only search keywords were provided. Searches were restricted by date (only studies published after 2004 were included) and language (searches were restricted to English, French and Dutch languages), meaning relevant studies may have been missed. Two reviewers were independently involved in the study selection and disagreements were resolved by discussion with a third reviewer.
|2.1 Did the search include an appropriate range of databases/electronic sources for published and unpublished reports?||Probably no|
|2.2 Were methods additional to database searching used to identify relevant reports?||Probably no|
|2.3 Were the terms and structure of the search strategy likely to retrieve as many eligible studies as possible?||No|
|2.4 Were restrictions based on date, publication format, or language appropriate?||Probably no|
|2.5 Were efforts made to minimise error in selection of studies?||Yes|
|Concerns regarding methods used to identify and/or select studies||High|
Two reviewers were independently involved in the data extraction process. Sufficient study characteristics appear to have been extracted to allow interpretation of results. Relevant study results appear to have been extracted. Methodological quality assessment of included studies was performed using the Cochrane Risk of Bias Tool for randomised controlled trials. Two reviewers were independently involved in the risk of bias assessment and disagreements were resolved by consensus.
|3.1 Were efforts made to minimise error in data collection?||Yes|
|3.2 Were sufficient study characteristics considered for both review authors and readers to be able to interpret the results?||Probably yes|
|3.3 Were all relevant study results collected for use in the synthesis?||Probably yes|
|3.4 Was risk of bias (or methodological quality) formally assessed using appropriate criteria?||Probably yes|
|3.5 Were efforts made to minimise error in risk of bias assessment?||Yes|
|Concerns regarding methods used to collect data and appraise studies||Low|
The synthesis appeared to include all relevant studies. Analyses predefined in the methodology section were performed appropriately. Heterogeneity was assessed and found to be high for the number of migraine days outcome. The quality of individual studies was considered in the synthesis.
|4.1 Did the synthesis include all studies that it should?||Probably yes|
|4.2 Were all pre-defined analyses reported or departures explained?||Probably yes|
|4.3 Was the synthesis appropriate given the degree of similarity in the research questions, study designs and outcomes across included studies?||Probably yes|
|4.4 Was between-study variation minimal or addressed in the synthesis?||Probably no|
|4.5 Were the findings robust, e.g. as demonstrated through funnel plot or sensitivity analyses?||Probably no|
|4.6 Were biases in primary studies minimal or addressed in the synthesis?||Probably yes|
|Concerns regarding synthesis and findings||High|