Published in PLoS One on December 26, 2013
Micronutrients in HIV: a Bayesian meta-analysis. PLoS One (2015) 1.45
Development of an algorithm to provide awareness in choosing study designs for inclusion in systematic reviews of healthcare interventions: a method study. BMJ Open (2015) 0.75
Oral hypoglycemic agents: do the ends justify the means? Matern Health Neonatol Perinatol (2015) 0.75
Adding non-randomised studies to a Cochrane review brings complementary information for healthcare stakeholders: an augmented systematic review and meta-analysis. BMC Health Serv Res (2016) 0.75
A systematic literature review on the efficacy-effectiveness gap: comparison of randomized controlled trials and observational studies of glucose-lowering drugs. Clin Epidemiol (2017) 0.75
Randomized, controlled trials, observational studies, and the hierarchy of research designs. N Engl J Med (2000) 19.56
Why we need observational studies to evaluate the effectiveness of health care. BMJ (1996) 17.27
A comparison of observational studies and randomized, controlled trials. N Engl J Med (2000) 14.11
Contradicted and initially stronger effects in highly cited clinical research. JAMA (2005) 11.15
Evaluating non-randomised intervention studies. Health Technol Assess (2003) 9.69
Evidence-based public health: moving beyond randomized trials. Am J Public Health (2004) 8.61
Effect of aspirin on long-term risk of colorectal cancer: consistent evidence from randomised and observational studies. Lancet (2007) 7.11
Can it work? Does it work? Is it worth it? The testing of healthcareinterventions is evolving. BMJ (1999) 6.63
Those confounded vitamins: what can we learn from the differences between observational versus randomised trial evidence? Lancet (2004) 6.37
When are observational studies as credible as randomised trials? Lancet (2004) 6.19
Comparison of evidence of treatment effects in randomized and nonrandomized studies. JAMA (2001) 5.96
The unpredictability paradox: review of empirical comparisons of randomised and non-randomised clinical trials. BMJ (1998) 5.05
Observational research, randomised trials, and two views of medical science. PLoS Med (2008) 4.02
How study design affects outcomes in comparisons of therapy. I: Medical. Stat Med (1989) 3.84
Influence of reported study design characteristics on intervention effect estimates from randomized, controlled trials. Ann Intern Med (2012) 3.63
Effects of regular aspirin on long-term cancer incidence and metastasis: a systematic comparison of evidence from observational studies versus randomised trials. Lancet Oncol (2012) 3.37
Comparative effectiveness of prostate cancer treatments: evaluating statistical adjustments for confounding in observational data. J Natl Cancer Inst (2010) 3.24
Should meta-analyses of interventions include observational studies in addition to randomized controlled trials? A critical examination of underlying principles. Am J Epidemiol (2007) 2.64
Comparison of predictions based on observational data with the results of randomized controlled clinical trials of coronary artery bypass surgery. J Am Coll Cardiol (1988) 2.59
Study designs for effectiveness and translation research :identifying trade-offs. Am J Prev Med (2007) 2.53
Choosing between randomised and non-randomised studies: a systematic review. Health Technol Assess (1998) 2.49
Comparison of evidence on harms of medical interventions in randomized and nonrandomized studies. CMAJ (2006) 2.40
Randomisation to protect against selection bias in healthcare trials. Cochrane Database Syst Rev (2007) 2.19
The effect of randomization to weight loss on total mortality in older overweight and obese adults: the ADAPT Study. J Gerontol A Biol Sci Med Sci (2010) 2.12
Meta-analyses of adverse effects data derived from randomised controlled trials as compared to observational studies: methodological overview. PLoS Med (2011) 2.06
From randomized controlled trials to observational studies. Am J Med (2009) 2.03
Systematic reviews of health effects of social interventions: 2. Best available evidence: how low should you go? J Epidemiol Community Health (2005) 2.01
Prognostic effect size of cardiovascular biomarkers in datasets from observational studies versus randomised trials: meta-epidemiology study. BMJ (2011) 1.97
A systematic review of comparisons of effect sizes derived from randomised and non-randomised studies. Health Technol Assess (2000) 1.96
Reported effects in randomized controlled trials were compared with those of nonrandomized trials in cholecystectomy. J Clin Epidemiol (2010) 1.95
From efficacy to effectiveness in the face of uncertainty: indication creep and prevention creep. JAMA (2011) 1.92
Workload and surgeon's specialty for outcome after colorectal cancer surgery. Cochrane Database Syst Rev (2012) 1.91
Outcomes of patients who participate in randomized controlled trials compared to similar patients receiving similar interventions who do not participate. Cochrane Database Syst Rev (2008) 1.86
Worldwide collaborative observational study and meta-analysis on allogenic leukocyte immunotherapy for recurrent spontaneous abortion. Recurrent Miscarriage Immunotherapy Trialists Group. Am J Reprod Immunol (1994) 1.84
Randomisation to protect against selection bias in healthcare trials. Cochrane Database Syst Rev (2011) 1.82
Explanatory models are needed to integrate RCT and observational data with the patient's unique biology. J R Soc Med (2012) 1.77
Methodological quality and homogeneity influenced agreement between randomized trials and nonrandomized studies of the same intervention for back pain. J Clin Epidemiol (2008) 1.62
Randomized clinical trials and observational studies: guidelines for assessing respective strengths and limitations. JACC Cardiovasc Interv (2008) 1.62
The HRT controversy: observational studies and RCTs fall in line. Lancet (2009) 1.60
AHRQ series paper 4: assessing harms when comparing medical interventions: AHRQ and the effective health-care program. J Clin Epidemiol (2008) 1.57
Randomized trials versus observational studies in adolescent pregnancy prevention. J Clin Epidemiol (2000) 1.52
Does mesh offer an advantage over tissue in the open repair of umbilical hernias? A systematic review and meta-analysis. Hernia (2010) 1.51
Randomization is important in studies with pain outcomes: systematic review of transcutaneous electrical nerve stimulation in acute postoperative pain. Br J Anaesth (1996) 1.49
Hierarchy of evidence: where observational studies fit in and why we need them. J Bone Joint Surg Am (2009) 1.46
Selection bias in clinical trials. J Clin Oncol (1985) 1.42
Observational research and evidence-based medicine: What should we teach young physicians? J Clin Epidemiol (1998) 1.38
The effectiveness of pneumococcal polysaccharide vaccines in adults: a systematic review of observational studies and comparison with results from randomised controlled trials. Vaccine (2004) 1.34
Observational methods in comparative effectiveness research. Am J Med (2010) 1.33
Effectiveness of exposure and ritual prevention for obsessive-compulsive disorder: randomized compared with nonrandomized samples. J Consult Clin Psychol (2000) 1.27
The nature of the scientific evidence leading to drug withdrawals for pharmacovigilance reasons in France. Pharmacoepidemiol Drug Saf (2006) 1.20
Comparison of effects in randomized controlled trials with observational studies in digestive surgery. Ann Surg (2006) 1.19
Meta-analysis of well-designed nonrandomized comparative studies of surgical procedures is as good as randomized controlled trials. J Clin Epidemiol (2009) 1.18
Rare diseases and the assessment of intervention: what sorts of clinical trials can we use? J Inherit Metab Dis (2001) 1.14
Why results of clinical trials and observational studies of antitumour necrosis factor (anti-TNF) therapy differ: methodological and interpretive issues. Ann Rheum Dis (2004) 1.14
Where do we find the best evidence? Plast Reconstr Surg (2008) 1.10
Coronary artery surgery study (CASS): a randomized trial of coronary artery bypass surgery. Comparability of entry characteristics and survival in randomized patients and nonrandomized patients meeting randomization criteria. J Am Coll Cardiol (1984) 1.10
Challenges in systematic reviews of therapeutic devices and procedures. Ann Intern Med (2005) 1.09
Using routine data to complement and enhance the results of randomised controlled trials. Health Technol Assess (2000) 1.08
Evidence from nonrandomized studies: a case study on the estimation of causal effects. Am J Epidemiol (2008) 1.07
Not only randomized controlled trials, but also case series should be considered in systematic reviews of rapidly developing technologies. J Clin Epidemiol (2009) 1.06
Treatments effects from randomized trials and propensity score analyses were similar in similar populations in an example from cardiac surgery. J Clin Epidemiol (2011) 1.05
Creating and synthesizing evidence with decision makers in mind: integrating evidence from clinical trials and other study designs. Med Care (2007) 1.05
Challenges in using nonrandomized studies in systematic reviews of treatment interventions. Ann Intern Med (2005) 1.05
Observational studies versus randomized controlled trials: avenues to causal inference in nephrology. Adv Chronic Kidney Dis (2012) 1.04
Why do the results of randomised and observational studies differ? BMJ (2011) 1.04
Are there roles for observational database studies and structured quantification of expert opinion to answer therapy controversies in transplants? Bone Marrow Transplant (2009) 1.02
Should systematic reviews include non-randomized and uncontrolled studies? The case of acupuncture for chronic headache. J Clin Epidemiol (2002) 1.00
Observational studies in systematic [corrected] reviews of comparative effectiveness: AHRQ and the Effective Health Care Program. J Clin Epidemiol (2011) 0.99
Bisphosphonates and osteoporotic fractures: a cross-design synthesis of results among compliant/persistent postmenopausal women in clinical practice versus randomized controlled trials. Osteoporos Int (2009) 0.97
Systematic reviews incorporating evidence from nonrandomized study designs: reasons for caution when estimating health effects. Eur J Clin Nutr (2005) 0.95
Examining heterogeneity in meta-analysis: comparing results of randomized trials and nonrandomized studies of interventions for low back pain. Spine (Phila Pa 1976) (2008) 0.95
Identifying observational studies of surgical interventions in MEDLINE and EMBASE. BMC Med Res Methodol (2006) 0.94
Bridging case-control studies and randomized trials. Curr Control Trials Cardiovasc Med (2001) 0.93
Generalizability of trial results based on randomized versus nonrandomized allocation of OME infants to ventilation tubes or watchful waiting. J Clin Epidemiol (2001) 0.93
Asymptomatic cervical bruit and abnormal ocular pneumoplethysmography: a prospective study comparing two approaches to management. Surgery (1984) 0.92
Investigating outcomes associated with medication use during pregnancy: a review of methodological challenges and observational study designs. Reprod Toxicol (2012) 0.88
Hierarchy of evidence: differences in results between non-randomized studies and randomized trials in patients with femoral neck fractures. Arch Orthop Trauma Surg (2003) 0.86
Controversy over "contradiction": Should randomized trials always trump observational studies? Am J Ophthalmol (2009) 0.86
Randomized controlled trials in evidence-based mental health care: getting the right answer to the right question. Schizophr Bull (2003) 0.85
Recommendations for research design of telehealth studies. Telemed J E Health (2008) 0.85
Implications of the principle of question propagation for comparative-effectiveness and "data mining" research. JAMA (2011) 0.84
Antidepressant response in major depressive disorder: a meta-regression comparison of randomized controlled trials and observational studies. PLoS One (2011) 0.84
Practice-based evidence for clinical practice improvement: an alternative study design for evidence-based medicine. Stud Health Technol Inform (2010) 0.84
Comparative effectiveness research: what kind of studies do we need? J Investig Med (2010) 0.83
Can observational studies provide a realistic alternative to randomized controlled trials in palliative care? J Pain Palliat Care Pharmacother (2009) 0.82
Surfactant lavage therapy for meconium aspiration syndrome: a systematic review and meta-analysis. Neonatology (2011) 0.82
Common pitfalls in the conduct of clinical research. Med Princ Pract (2006) 0.82
When a randomised controlled trial is needed to assess drug safety. The case of paediatric ibuprofen. Drug Saf (1995) 0.81
Overall survival in the intervention arm of a randomized controlled screening trial for prostate cancer compared with a clinically diagnosed cohort. Eur Urol (2007) 0.80
The generalizability of observational data to elderly patients was dependent on the research question in a systematic review. J Clin Epidemiol (2005) 0.80
Measurement of long-term outcomes in observational and randomised controlled trials. Br J Psychiatry Suppl (2007) 0.79
Are pacifiers associated with early weaning from breastfeeding? Adv Neonatal Care (2002) 0.78
Evaluation of interventions. J Clin Epidemiol (2002) 0.78
Laparoscopic vs. open cholecystectomy for cirrhotic patients: a systematic review and meta-analysis. Hepatogastroenterology (2012) 0.77
Use of non-randomised evidence alongside randomised trials in a systematic review of endovascular aneurysm repair: strengths and limitations. Eur J Vasc Endovasc Surg (2009) 0.76
Meta-analytic comparison of randomized and nonrandomized studies of breast cancer surgery. Can J Surg (2012) 0.76