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Dive into the research topics where Jocalyn Clark is active.

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Featured researches published by Jocalyn Clark.


BMJ | 2015

Firm action needed on predatory journals.

Jocalyn Clark; Richard Smith

They’re harming researchers in low and middle income countries most, but everyone must fight back


The Lancet | 2000

Rate of heart failure and 1-year survival for older people receiving low-dose β-blocker therapy after myocardial infarction

Paula A. Rochon; Jack V. Tu; Geoffrey M. Anderson; Jerry H. Gurwitz; Jocalyn Clark; Paula Lau; John Paul Szalai; Kathy Sykora; C. David Naylor

BACKGROUND Many older people do not receive beta-blocker therapy after myocardial infarction or receive doses lower than those tested in trials, perhaps because physicians fear that beta-blockers may precipitate heart failure. We examined the relation between use of beta-blockers, the dose used, and hospital admission for heart failure and 1-year survival in a cohort of all older patients surviving myocardial infarction in Ontario, Canada. METHODS We collected data on a cohort of 13,623 patients aged 66 years or older who were discharged from hospital after a myocardial infarction and who did not receive beta-blocker therapy or received low, standard, or high doses. We used Coxs proportional-hazards models to study the association of dose with admission for heart failure and survival with adjustment for factors including age, sex, and comorbidity. FINDINGS Among 8232 patients with no previous history of heart failure, dispensing of beta-blocker therapy was associated with a 43% reduction in subsequent admission for heart failure (adjusted risk ratio 0.57 [95% CI 0.48-0.69]) compared with patients not dispensed this therapy. Among the 4681 patients prescribed beta-blockers, the risk of admission was greater in the high-dose than in the low-dose group (1.53 [1.01-2.31]). Among all 13,623 patients in the cohort, 2326 (17.1%) died by 1 year. Compared with those not dispensed beta-blocker therapy, the adjusted risk ratio for mortality was lower for all three doses (low 0.40 [0.34-0.47], standard 0.36 [0.31-0.42], high 0.43 [0.33-0.56]). INTERPRETATION Compared with high-dose beta-blocker therapy, low-dose treatment is associated with a lower rate of hospital admission for heart failure and has a similar 1-year survival benefit. Our findings support the need for a randomised controlled trial comparing doses of beta-blocker therapy in elderly patients.


Canadian Medical Association Journal | 2004

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

Paula A. Rochon; Azad Mashari; Ariel Cohen; Anjali Misra; Dara Laxer; David L. Streiner; Julie M. Dergal; Jocalyn Clark; Jennifer L. Gold; Malcolm A. Binns

Background: More than two-thirds of the worlds 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.


PLOS Medicine | 2005

Five Futures for Academic Medicine

Shally Awasthi; Jil Beardmore; Jocalyn Clark; Philip Hadridge; Hardi Madani; Ana Marušić; Gretchen Purcell; Margaret Rhoads; Karen Sliwa-Hähnle; Richard Smith; Tessa Tan-Torres Edejer; Peter Tugwell; Timothy J. Underwood

The International Campaign to Revitalise Academic Medicine (ICRAM) considered current global instabilities and future drivers of change, and then created five scenarios of how academic medicine might look in 2025.


Accountability in Research | 2004

The Inclusion of Minority Groups in Clinical Trials: Problems of Under Representation and Under Reporting of Data

Paula A. Rochon; Azad Mashari; Ariel Cohen; Anjali Misra; Dara Laxer; David L. Streiner; Jocalyn Clark; Julie M. Dergal; Jennifer L. Gold

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%; χ2 = 20.9, p ≤ 0.001) and to include nonwhite participants (13.5% vs. 12.5%; χ2 = 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.


BMC Medicine | 2017

Potential predatory and legitimate biomedical journals: can you tell the difference? A cross-sectional comparison

Larissa Shamseer; David Moher; onyi maduekwe; Lucy Turner; Virginia Barbour; Rebecca C. Burch; Jocalyn Clark; James Galipeau; Jason R Roberts; Beverley Shea

BackgroundThe Internet has transformed scholarly publishing, most notably, by the introduction of open access publishing. Recently, there has been a rise of online journals characterized as ‘predatory’, which actively solicit manuscripts and charge publications fees without providing robust peer review and editorial services. We carried out a cross-sectional comparison of characteristics of potential predatory, legitimate open access, and legitimate subscription-based biomedical journals.MethodsOn July 10, 2014, scholarly journals from each of the following groups were identified – potential predatory journals (source: Beall’s List), presumed legitimate, fully open access journals (source: PubMed Central), and presumed legitimate subscription-based (including hybrid) journals (source: Abridged Index Medicus). MEDLINE journal inclusion criteria were used to screen and identify biomedical journals from within the potential predatory journals group. One hundred journals from each group were randomly selected. Journal characteristics (e.g., website integrity, look and feel, editors and staff, editorial/peer review process, instructions to authors, publication model, copyright and licensing, journal location, and contact) were collected by one assessor and verified by a second. Summary statistics were calculated.ResultsNinety-three predatory journals, 99 open access, and 100 subscription-based journals were analyzed; exclusions were due to website unavailability. Many more predatory journals’ homepages contained spelling errors (61/93, 66%) and distorted or potentially unauthorized images (59/93, 63%) compared to open access journals (6/99, 6% and 5/99, 5%, respectively) and subscription-based journals (3/100, 3% and 1/100, 1%, respectively). Thirty-one (33%) predatory journals promoted a bogus impact metric – the Index Copernicus Value – versus three (3%) open access journals and no subscription-based journals. Nearly three quarters (n = 66, 73%) of predatory journals had editors or editorial board members whose affiliation with the journal was unverified versus two (2%) open access journals and one (1%) subscription-based journal in which this was the case. Predatory journals charge a considerably smaller publication fee (median


BMJ | 2007

Performance measurement and equity

Arlene S. Bierman; Jocalyn Clark

100 USD, IQR


Journal of the American Geriatrics Society | 1999

Age- and gender-related use of low-dose drug therapy: the need to manufacture low-dose therapy and evaluate the minimum effective dose.

Paula A. Rochon; Geoffrey M. Anderson; Jack V. Tu; Jerry H. Gurwitz; Jocalyn Clark; Neil H. Shear; Paula Lau

63–


Global Health Action | 2014

Medicalization of global health 1: has the global health agenda become too medicalized?

Jocalyn Clark

150) than open access journals (


Journal of Bone and Joint Surgery, American Volume | 2009

Qualitative Research: A Review of Methods with Use of Examples from the Total Knee Replacement Literature

Dorcas E. Beaton; Jocalyn Clark

1865 USD, IQR

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Virginia Barbour

Queensland University of Technology

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Jerry H. Gurwitz

University of Massachusetts Medical School

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David Moher

Ottawa Hospital Research Institute

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Jack V. Tu

Sunnybrook Health Sciences Centre

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James Galipeau

Ottawa Hospital Research Institute

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