Selection Bias

Publication Title: 
PloS One

BACKGROUND: Bias in randomized controlled trials (RCTs) of complementary therapy interventions seems to be associated with specific factors and to potentially distort the studies' conclusions. This systematic review assessed associated factors of risk of bias and consequences for the studies' conclusions in RCTs of yoga as one of the most commonly used complementary therapies. METHODS: Medline/PubMed, Scopus, IndMED and the Cochrane Library were searched through February 2014 for yoga RCTs.

Author(s): 
Cramer, Holger
Langhorst, Jost
Dobos, Gustav
Lauche, Romy
Publication Title: 
Critical Care Medicine

OBJECTIVE: Because the results of a meta-analysis are used to formulate the highest level recommendation in clinical practice guidelines, clinicians should be mindful of problems inherent in this technique. Rather than reviewing meta-analysis in abstract, general terms, we believe readers can gain a more concrete understanding of the problems through a detailed examination of one meta-analysis.

Author(s): 
Tobin, Martin J.
Jubran, Amal
Publication Title: 
International Journal of Epidemiology

Results of 14 randomized controlled trials of acupuncture for chronic pain were pooled in a meta-analysis and analysed in three subgroups according to site of pain; and in two subgroups each according to type to trial, type of treatment, type of control, 'blindness' of participating agents, trial size, and type of journal in which results were published. While few individual trials had statistically significant results, pooled results of many subgroups attained statistical significance in favour of acupuncture.

Author(s): 
Patel, M.
Gutzwiller, F.
Paccaud, F.
Marazzi, A.
Publication Title: 
European Journal of Pain (London, England)

AIMS: This systematic review summarises the existing evidence on acupuncture for cancer-related pain. METHODS: Literature searches were conducted in seven databases. All clinical studies of acupuncture, electroacupuncture and ear acupuncture in cancer patients with the main outcome measure of pain were included. Data were extracted according to pre-defined criteria by two independent reviewers and methodological quality was assessed using the Jadad scale.

Author(s): 
Lee, Hyangsook
Schmidt, Katja
Ernst, Edzard
Publication Title: 
European Journal of Pain (London, England)

AIMS: This systematic review summarises the existing evidence on acupuncture for cancer-related pain. METHODS: Literature searches were conducted in seven databases. All clinical studies of acupuncture, electroacupuncture and ear acupuncture in cancer patients with the main outcome measure of pain were included. Data were extracted according to pre-defined criteria by two independent reviewers and methodological quality was assessed using the Jadad scale.

Author(s): 
Lee, Hyangsook
Schmidt, Katja
Ernst, Edzard
Publication Title: 
The Cochrane Database of Systematic Reviews

BACKGROUND: Acne is a chronic skin disease characterised by inflamed spots and blackheads on the face, neck, back, and chest. Cysts and scarring can also occur, especially in more severe disease. People with acne often turn to complementary and alternative medicine (CAM), such as herbal medicine, acupuncture, and dietary modifications, because of their concerns about the adverse effects of conventional medicines. However, evidence for CAM therapies has not been systematically assessed. OBJECTIVES: To assess the effects and safety of any complementary therapies in people with acne vulgaris.

Author(s): 
Cao, Huijuan
Yang, Guoyan
Wang, Yuyi
Liu, Jian Ping
Smith, Caroline A.
Luo, Hui
Liu, Yueming
Publication Title: 
The Rand Journal of Economics

This article identifies the impact of managed-care reforms on the utilization of medical services within the military health-services system. The data come from a recent demonstration project that substituted an HMO and PPO for traditional FFS arrangements. Results from a semiparametric model indicate that the generosity of benefits in the HMO increased demand for ambulatory services. Unlike the private-sector experience with managed care, aggressive utilization review did not significantly curtail inpatient stays.

Author(s): 
Goldman, D. P.
Publication Title: 
The Journal of School Health

Retaining school-aged study participants poses a major challenge in any longitudinal research study. Dropouts produce bias in the remaining sample and this loss may affect study findings and their interpretation. Dominant factors that influence retention in pediatric research studies include family versus individual participation, patient management strategies of study personnel, knowledge about the condition or therapy, age and gender factors, credibility within the community, monetary incentives, and altruism.

Author(s): 
Frank, Gail C.
Nader, Philip R.
Zive, Michelle Murphy
Broyles, Shelia L.
Brennan, Jesse J.
Publication Title: 
Personality & Social Psychology Bulletin

The authors investigated whether students who selectively volunteer for a study of prison life possess dispositions associated with behaving abusively. Students were recruited for a psychological study of prison life using a virtually identical newspaper ad as used in the Stanford Prison Experiment (SPE; Haney, Banks & Zimbardo, 1973) or for a psychological study, an identical ad minus the words of prison life.

Author(s): 
Carnahan, Thomas
McFarland, Sam
Publication Title: 
Ethnicity & Disease

OBJECTIVE: Historically, researchers have experienced difficulties with the recruitment of underrepresented populations, especially for women and minorities to cancer clinical trials. This has lead to marked health disparities among these groups. The purpose of this literature review is to investigate barriers and facilitators that provide explanations for the low participation rate of women and minorities in clinical trials. METHODS: A search was conducted for published work in medical and social research from 1995 to 2008 using computerized databases: PubMed, CINAHL, and PsyclNFO.

Author(s): 
Schmotzer, Geri L.

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