Background: Diversity of treatments used for headache, and varied quality of research conduct and reporting make it difficult to accurately assess the literature and to determine the
best treatment(s) for patients.
Objectives: To compare the quality of available research evidence describing the effects and
outcomes of conventional, and complementary and alternative medicine (CAM) approaches
to treating primary (migraine, tension, and/or cluster-type) headache.
Study Design: A systematic review of quality of research studies of conventional and alternative treatment(s) of primary headache.
Methods: Randomized, controlled clinical trials (RCTs) of treatment(s) of chronic primary
headache (in English between 1979 to June 2004) were searched through MEDLINE, PsycInfo, EMBASE, Cochrane Library, and the NIH databases. Studies were evaluated using standard approaches for assessing and analyzing quality indicators.
Results: 125 studies of conventional, and 121 CAM treatments met inclusion criteria. 80%
of studies of conventional treatment(s) reported positive effects (P<0.05), versus 73% of
studies of CAM approaches (chi2
= 3.798, 1 df, p=0.051). Overall, the literature addressing
the treatment of primary headache received a mean Jadad score of 2.72 out of 5 (SD 1.1).
The mean Jadad score for studies of conventional therapeutics was significantly better than
for those studies of CAM approaches: 3.21 ± 0.9 vs 2.23 ± 1.1 (t=7.72, 246 df, mean difference 0.98, p < 0.0005).
Conclusions: Studies of conventional treatments scored higher on reporting quality than
studies of CAM approaches. It is possible that these differences may reflect distinctions in
1) methodologic integrity, 2) therapeutic paradigm(s), and/or 3) bias(es) in the approach(es)
used to evaluate certain types of therapies. Each of these possibilities — and the implications
— is addressed and considered.
Key words: chronic headache, complementary and alternative medicine, research quality,
randomized controlled trial, Jadad scores
Systematic Assessment of the Quality of
Research Studies of Conventional and
Alternative Treatment(s) of Primary Headache
State of the Data at the Mid-Point of the Decade of
Pain Control and Research
