Relation between randomized controlled trials published in leading general medical journals and the global burden of disease.

BACKGROUND: More than two-thirds of the world's population live in low-income countries, where health priorities are different from those of people living in more affluent parts of the world. We evaluated the relation between the global burden of disease and conditions or diseases studied in randomized controlled trials (RCTs) published in general medical journals. METHODS: A MEDLINE search identified 373 RCTs that had been published in 6 international peer-reviewed general medical journals in 1999. Manual review excluded non-RCTs, brief reports and trials in which the unit of randomization was not the patient; 286 RCTs remained eligible for analysis. We identified the RCTs that studied any of the 40 leading causes of the global burden of disease. Five of these conditions were considered unsuitable for study with an RCT design and were excluded from subsequent analysis. To provide a practical perspective, we asked 12 experts working with international health organizations to rate the relevance to global health of the articles that studied any of the top 10 causes of the global burden of disease, as measured by disability-adjusted life years (DALYs) and mortality, using a 5-point Likert scale. RESULTS: Among the 286 RCTs in our sample, 124 (43.4%) addressed 1 of the 35 leading causes of the global burden of disease. Of these, ischemic heart disease, HIV/AIDS and cerebrovascular disease were the most commonly studied conditions. Ninety articles (31.5%) studied 1 of the top 10 causes of the global burden of disease. The mean rating (and standard deviation) for international health relevance assigned by experts was 2.6 (1.5) out of 5. Only 14 (16%) of the 90 trials received a rating of 4 or greater, indicating high relevance to international health. Almost half of the 40 leading causes of the global burden of disease were not studied by any trial. INTERPRETATION: Many conditions or diseases common internationally are underrepresented in RCTs published in leading general medical journals. Trials published in these journals that studied one of these high-priority conditions were generally rated as being of little relevance to international health.

The inclusion of minority groups in clinical trials: problems of under representation and under reporting of data.

OBJECTIVE: To evaluate the representation of minority groups in randomized control trials (RCTs), and the frequency with which this information is reported. STUDY DESIGN: Reviewers collected data on the racial/ethnic composition of study samples from all RCTs published in six leading medical journals in 1999. RESULTS: Of the 280 RCTs, most (204, 71.3%) provided no information on the race/ethnicity of participants. Of the 89 U.S.-based RCTs, 50 (56.1%) reported their minority distribution. Relative to other trials, those funded by the National Institute of Health (NIH) (n = 52) were more likely to report race/ethnicity data (55.8% vs. 23.7%; x2 = 20.9, p <_0.001) and to include nonwhite participants (13.5 % vs. 12.5%; x2=22.7, p<_0.001). CONCLUSION: Minority groups are currently under-represented in clinical trials. Information on the race and ethnicity of clinical trial participants is currently underreported in six leading medical journals. Reporting of minority group information was significantly better only in NIH funded trials, which also were more likely to include nonwhite participants. This suggests that mandatory reporting policies may have a positive effect on both reporting and representation.

Potential interactions between herbal medicines and conventional drug therapies used by older adults attending a memory clinic.

OBJECTIVE: Herbal medicines and conventional drug therapies are often taken in combination. The objective of our study was to identify the range of natural health products and conventional drug therapies used by older adults (aged 65 years and over) attending a memory clinic, and to specifically evaluate the frequency of potential interactions between herbal medicines and conventional drug therapies. DESIGN: We interviewed consecutive patients attending the Memory Disorders Clinic at the Baycrest Centre for Geriatric Care, a University of Toronto teaching hospital, between 4 July and 15 August 2000. Patients were asked to bring to their appointment all natural health products (i.e. herbal medicines, vitamins and minerals) and conventional drug therapies (i.e. prescription and over-the-counter) they were currently using. We collected information on current and previously used natural health products and current conventional drug therapies. Patients were classified as having the potential for an interaction if they were using a current herbal medicine in combination with a conventional drug therapy and the interaction had been reported previously in the medical literature. PARTICIPANTS: We interviewed 195 consecutive patients attending the Memory Disorders Clinic at the Baycrest Centre for Geriatric Care, Toronto, Ontario, Canada. RESULTS: Of the 195 patients in our sample, 33 (17%) were 'current users', 19 (10%) were 'past users', and 143 (73%) were 'never users' of herbal medicines. Among the 52 patients who were 'current or past users', the most frequently used herbal medicines were ginkgo (Ginkgo biloba) [39 users], garlic (n = 10), glucosamine sulphate (n = 9) and echinacea (n = 8). Among the 33 patients who were current users, the most commonly used herbal medicines were Ginkgo biloba (n = 22), glucosamine sulphate (n = 8) and garlic (n = 6). Among the 33 current users, we identified 11 potential herb-drug interactions in nine patients. The 11 herb-drug interactions we identified were between ginkgo and aspirin (acetylsalicylic acid) [n = 8], ginkgo and trazodone (n = 1), ginseng and amlodipine (n = 1) and valerian and lorazepam (n = 1). CONCLUSIONS: Herbal medicines are widely used. Almost one-third of current users of herbal medicines were at risk of a herb-drug interaction. The most common potential herb-drug interaction was between ginkgo and aspirin. This finding has important potential implications because both of these products are regularly used by older people. Physicians and other healthcare providers should be aware of potential herb-drug interactions and should monitor and inform their patients accordingly.

Comparison of review articles published in peer-reviewed and throwaway journals.

CONTEXT: To compare the quality, presentation, readability, and clinical relevance of review articles published in peer-reviewed and "throwaway" journals. METHODS: We reviewed articles that focused on the diagnosis or treatment of a medical condition published between January 1 and December 31, 1998, in the 5 leading peer-reviewed general medical journals and high-circulation throwaway journals. Reviewers independently assessed the methodologic and reporting quality, and evaluated each article's presentation and readability. Clinical relevance was evaluated independently by 6 physicians. RESULTS: Of the 394 articles in our sample, 16 (4.1%) were peer-reviewed systematic reviews, 135 (34.3%) were peer-reviewed nonsystematic reviews, and 243 (61.7%) were nonsystematic reviews published in throwaway journals. The mean (SD) quality scores were highest for peer-reviewed articles (0.94 [0.09] for systematic reviews and 0.30 [0.19] for nonsystematic reviews) compared with throwaway journal articles (0.23 [0.03], F(2,391) = 280.8, P<.001). Throwaway journal articles used more tables (P =.02), figures (P =.01), photographs (P<.001), color (P<.001), and larger font sizes (P<.001) compared with peer-reviewed articles. Readability scores were more often in the college or higher range for peer-reviewed journals compared with the throwaway journal articles (104 [77.0%] vs 156 [64.2%]; P =.01). Peer-reviewed article titles were judged less relevant to clinical practice than throwaway journal article titles (P<.001). CONCLUSIONS: Although lower in methodologic and reporting quality, review articles published in throwaway journals have characteristics that appeal to physician readers.