Sample Size

Publication Title: 
Trials

BACKGROUND: Recruiting to randomized controlled trials is fraught with challenges; with less than one third recruiting to their original target. In preparation for a trial evaluating the effectiveness of a blood test to screen for lung cancer (the ECLS trial), we conducted a qualitative study to explore the potential barriers and facilitators that would impact recruitment. METHODS: Thirty two people recruited from community settings took part in four focus groups in Glasgow and Dundee (UK). Thematic analysis was used to code the data and develop themes.

Author(s): 
das Nair, Roshan
Orr, Kate Skellington
Vedhara, Kavita
Kendrick, Denise
Publication Title: 
Statistics in Medicine

The analysis of data from matched pairs binary experiments, often performed with McNemar's test, presents a unique experimental design challenge in dealing with the effect of the discordance probability, p. Most approaches for determining size and power use point estimates or maximization, but this fails to account for the considerable variability across values of the nuisance parameter that occur for all common tests.

Author(s): 
Lennox, Kristin P.
Sherman, Michael
Publication Title: 
Acta Anaesthesiologica Scandinavica

BACKGROUND: The induction dose of hypnotic agents should be reduced in the elderly, but it is not well studied whether thiopental or propofol should be preferred in this group of patients. The aim of this study was to compare onset time, hypnosis level and the haemodynamic response after thiopental vs. propofol for induction of anaesthesia. Our primary hypothesis was that in the elderly, thiopental had a shorter onset time than propofol, defined as time to bispectral index (BIS) <50. METHODS: In this randomized and double-blinded study, we included 78 patients.

Author(s): 
Sørensen, M. K.
Dolven, T. L.
Rasmussen, L. S.
Publication Title: 
PloS One

The objective of this study was to determine the appropriate dose of artesunate for use in a fixed dose combination therapy with chlorproguanil-dapsone (CPG-DDS) for the treatment of uncomplicated falciparum malaria. METHODS: Open-label clinical trial comparing CPG-DDS alone or with artesunate 4, 2, or 1 mg/kg at medical centers in Blantyre, Malawi and Farafenni, The Gambia. The trial was conducted between June 2002 and February 2005, including 116 adults (median age 27 years) and 107 children (median age 38 months) with acute uncomplicated Plasmodium falciparum malaria.

Author(s): 
Wootton, Daniel G.
Opara, Hyginus
Biagini, Giancarlo A.
Kanjala, Maxwell K.
Duparc, Stephan
Kirby, Paula L.
Woessner, Mary
Neate, Colin
Nyirenda, Maggie
Blencowe, Hannah
Dube-Mbeye, Queen
Kanyok, Thomas
Ward, Stephen
Molyneux, Malcolm
Dunyo, Sam
Winstanley, Peter A.
Publication Title: 
Trials

BACKGROUND: Immediate injectable treatment is essential for severe malaria. Otherwise, the afflicted risk lifelong impairment or death. In rural areas of Africa and Asia, appropriate care is often miles away. In 2009, Melba Gomes and her colleagues published the findings of a randomized, placebo-controlled trial of rectal artesunate for suspected severe malaria in such remote areas.

Author(s): 
Hirji, Karim F.
Premji, Zulfiqarali G.
Publication Title: 
Implementation science: IS

BACKGROUND: Priority setting for artemisinin-based antimalarial drugs has become an integral part of malaria treatment policy change in malaria-endemic countries. Although these drugs are more efficacious, they are also more costly than the failing drugs. When Tanzania changed its National Malaria Treatment Policy in 2006, priority setting was an inevitable challenge. Artemether-lumefantrine was prioritised as the first-line drug for the management of uncomplicated malaria to be available at a subsidized price at public and faith-based healthcare facilities.

Author(s): 
Mori, Amani Thomas
Kaale, Eliangiringa Amos
Publication Title: 
BMJ (Clinical research ed.)

OBJECTIVE: To assess the impact of rapid diagnostic tests on the diagnostic accuracy and treatment of malaria and non-severe fever in an Asian setting. DESIGN: Patient randomised trial in primary level clinics. SETTING: Two areas of Afghanistan where Plasmodium vivax and Plasmodium falciparum are endemic; one area with moderate transmission (eastern region) and one with low transmission (northern region). PARTICIPANTS: 5794 patients of all ages with suspected malaria enrolled by 80 clinicians in 22 clinics.

Author(s): 
Leslie, Toby
Mikhail, Amy
Mayan, Ismail
Cundill, Bonnie
Anwar, Mohammed
Bakhtash, Sayed Habib
Mohammed, Nader
Rahman, Habib
Zekria, Rohullah
Whitty, Christopher J. M.
Rowland, Mark
Publication Title: 
Dementia and Geriatric Cognitive Disorders

BACKGROUND/AIMS: Behavioural and psychological symptoms (BPSD) are frequent in people with Alzheimer's disease and cause considerable stress to patients and their carers. Antipsychotics have been widely used as a first-line treatment, resulting in an estimated 1,800 excess strokes and 1,600 excess deaths in the UK alone. Safe and effective alternatives are urgently needed. Based upon preliminary evidence from clinical trials, aromatherapy with melissa oil may be such an alternative, but initial studies have been modest in size, and adequate blinding has been problematic.

Author(s): 
Burns, Alistair
Perry, Elaine
Holmes, Clive
Francis, Paul
Morris, Julie
Howes, Melanie-Jayne R.
Chazot, Paul
Lees, George
Ballard, Clive
Publication Title: 
Anesthesia and Analgesia

BACKGROUND: Postoperative nausea (PON) is a common complication of anesthesia and surgery. Antiemetic medication for higher-risk patients may reduce but does not reliably prevent PON. We examined aromatherapy as a treatment for patients experiencing PON after ambulatory surgery. Our primary hypothesis was that in comparison with inhaling a placebo, PON will be reduced significantly by aromatherapy with (1) essential oil of ginger, (2) a blend of essential oils of ginger, spearmint, peppermint, and cardamom, or (3) isopropyl alcohol.

Author(s): 
Hunt, Ronald
Dienemann, Jacqueline
Norton, H. James
Hartley, Wendy
Hudgens, Amanda
Stern, Thomas
Divine, George
Publication Title: 
Anesthesia and Analgesia

When a study uses an ordinal outcome measure with unknown differences in the anchors and a small range such as 4 or 7, use of the Wilcoxon rank sum test or the Wilcoxon signed rank test may be most appropriate. However, because nonparametric methods are at best indirect functions of standard measures of location such as means or medians, the choice of the most appropriate summary measure can be difficult. The issues underlying use of these tests are discussed.

Author(s): 
Divine, George
Norton, H. James
Hunt, Ronald
Dienemann, Jacqueline

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