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All Outputs (21)

The just-about-right pilot sample size to control the error margin (2023)
Journal Article
Obodo, S., Toher, D., & White, P. (2023). The just-about-right pilot sample size to control the error margin. International Journal of Statistics and Probability, 12(3), https://doi.org/10.5539/ijsp.v12n3p1

In practice, the required sample size for a two-arm randomised controlled trial cannot always be determined pre-study with great accuracy. This lack of accuracy has economic, ethical and scientific implications. The sample size for a pilot study is... Read More about The just-about-right pilot sample size to control the error margin.

Estimation of the two-group pilot sample size with a cautionary note on Browne’s formula (2021)
Journal Article
Obodo, S., Toher, D., & White, P. (2021). Estimation of the two-group pilot sample size with a cautionary note on Browne’s formula. Journal of Applied Quantitative Methods, 16(3),

Using data obtained from a pilot study, Browne (1995) proposed a procedure for estimating the sample size needed for a definitive two-arm randomised controlled trial when the minimal important difference is specified. Simulations confirm these findi... Read More about Estimation of the two-group pilot sample size with a cautionary note on Browne’s formula.

Ordinal Logistic Regression as an alternative analysis strategy for the comparison of two independent samples (2021)
Journal Article
Bilski, B., Derrick, B., Toher, D., & White, P. (2021). Ordinal Logistic Regression as an alternative analysis strategy for the comparison of two independent samples. Journal of Applied Quantitative Methods, 16(3),

The two group between subjects design is pervasive with analyses often performed using the Mann Whitney Rank Sum test or using the Welch variant of the t-test. Using simulation it is shown that a dummy variable ordinal logistic regression (OLR) mode... Read More about Ordinal Logistic Regression as an alternative analysis strategy for the comparison of two independent samples.

Parametric and non-parametric tests for the comparison of two samples which both include paired and unpaired observations (2019)
Journal Article
Derrick, B., White, P., & Toher, D. (2019). Parametric and non-parametric tests for the comparison of two samples which both include paired and unpaired observations. Journal of modern applied statistical methods : JMASM, 18(1), Article 9. https://doi.org/10.22237/jmasm/1556669520

Samples that include both independent and paired observations cause a dilemma for researchers that covers the full breadth of empirical research. Parametric approaches for the comparison of two samples using all available observations are considered,... Read More about Parametric and non-parametric tests for the comparison of two samples which both include paired and unpaired observations.

Young carers in England: Findings from the 2018 BBC survey on the prevalence and nature of caring among young people (2019)
Journal Article
Joseph, S., Kendall, C., Toher, D., Sempik, J., Holland, J., & Becker, S. (2019). Young carers in England: Findings from the 2018 BBC survey on the prevalence and nature of caring among young people. Child: Care, Health and Development, 45(4), 606-612. https://doi.org/10.1111/cch.12674

© 2019 John Wiley & Sons Ltd Background: Many young people are involved in caring for parents, siblings, or other relatives who have an illness or disability. The aim of this study was to estimate the prevalence of caring by young people in England... Read More about Young carers in England: Findings from the 2018 BBC survey on the prevalence and nature of caring among young people.

Feeding tube securement in critical illness: Implications for safety (2018)
Journal Article
Taylor, S. J., Allan, K., Clemente, R., Marsh, A., & Toher, D. (2018). Feeding tube securement in critical illness: Implications for safety. British Journal of Nursing, 27(18), 1036-1041. https://doi.org/10.12968/bjon.2018.27.18.1036

© 2018 MA Healthcare Ltd Over 50% of tape-secured feeding tubes are inadvertently lost. The impact of nasal bridle securement on nasogastric (NG) and nasointestinal (NI) tube loss, outcome and duration of use was determined from 1 October 2014 (NG) a... Read More about Feeding tube securement in critical illness: Implications for safety.

Time to Initial Debridement and wound Excision (TIDE) in severe open tibial fractures and related clinical outcome: A multi-centre study (2018)
Journal Article
Hendrickson, S. A., Wall, R. A., Manley, O., Gibson, W., Toher, D., Wallis, K., …Khan, U. (2018). Time to Initial Debridement and wound Excision (TIDE) in severe open tibial fractures and related clinical outcome: A multi-centre study. Injury, 49(10), 1922-1926. https://doi.org/10.1016/j.injury.2018.07.023

© 2018 Elsevier Ltd Background: Recent national (NICE) guidelines in England recommend that initial debridement and wound excision of open tibial fractures take place within 12 h of the time of injury, a change from the previous target of 24 h. This... Read More about Time to Initial Debridement and wound Excision (TIDE) in severe open tibial fractures and related clinical outcome: A multi-centre study.

Tests for equality of variances between two samples which contain both paired observations and independent observations (2018)
Journal Article
Derrick, B., Ruck, A., Toher, D., & White, P. (2018). Tests for equality of variances between two samples which contain both paired observations and independent observations. Journal of Applied Quantitative Methods, 13(2),

Tests for equality of variances between two samples which contain both paired observations and independent observations are explored using simulation. New solutions which make use of all of the available data are put forward. These new approaches are... Read More about Tests for equality of variances between two samples which contain both paired observations and independent observations.

Challenges for police leadership: Identity, experience, legitimacy and direct entry (2018)
Journal Article
Hoggett, J., Redford, P., Toher, D., & White, P. (2019). Challenges for police leadership: Identity, experience, legitimacy and direct entry. Journal of Police and Criminal Psychology, 34(2), 145-155. https://doi.org/10.1007/s11896-018-9264-2

© 2018, The Author(s). The police service in England and Wales has developed a new approach to police leadership where individuals from outside of the police service can now enter directly to leadership ranks. Previous research identified that office... Read More about Challenges for police leadership: Identity, experience, legitimacy and direct entry.

The impact of an extreme observation in a paired samples design (2017)
Journal Article
Derrick, B., Broad, A., Toher, D., & White, P. (2017). The impact of an extreme observation in a paired samples design

The effect of systematically altering the value of a single observation within a paired differences design is considered. A paradox is observed for the paired samples t-test, where increasing the value of an observation in the direction of the true m... Read More about The impact of an extreme observation in a paired samples design.

Stroke: Ineffective tube securement reduces nutrition and drug treatment (2017)
Journal Article
Taylor, S. J., Brazier, S., Allan, K., Clemente, R., & Toher, D. (2017). Stroke: Ineffective tube securement reduces nutrition and drug treatment. British Journal of Nursing, 26(12), 656-663. https://doi.org/10.12968/bjon.2017.26.12.656

© 2017 MA Healthcare Ltd. Stroke patients with dysphagia often depend on nutrition, hydration and medication via nasogastric (NG) feeding tubes. Securing tubes using tape is associated with repeated tube loss. In this study, the authors determined ca... Read More about Stroke: Ineffective tube securement reduces nutrition and drug treatment.

Test statistics for the comparison of means for two samples that include both paired and independent observations (2017)
Journal Article
Derrick, B., Russ, B., Toher, D., & White, P. (2017). Test statistics for the comparison of means for two samples that include both paired and independent observations. Journal of modern applied statistical methods : JMASM, 16(1), 137-157. https://doi.org/10.22237/jmasm/1493597280

©2017 JMASM, Inc. Standard approaches for analyzing the difference in two means, where partially overlapping samples are present, are less than desirable. Here are introduced two test statistics, making reference to the t-distribution. It is shown th... Read More about Test statistics for the comparison of means for two samples that include both paired and independent observations.

How to compare the means of two samples that include paired observations and independent observations: A companion to Derrick, Russ, Toher and White (2017) (2017)
Journal Article
Derrick, B., Toher, D., & White, P. (2017). How to compare the means of two samples that include paired observations and independent observations: A companion to Derrick, Russ, Toher and White (2017). Quantitative Methods for Psychology, 13(2), 120-126. https://doi.org/10.20982/tqmp.13.2.p120

Standard approaches for comparing the means of two samples, comprising both paired observations and independent observations, involve the discarding of valuable information. An alternative test which uses all of the available data, is the partially o... Read More about How to compare the means of two samples that include paired observations and independent observations: A companion to Derrick, Russ, Toher and White (2017).

A randomised controlled feasibility and proof-of-concept trial in delayedgastric emptying when metoclopramide fails: We should revisitnasointestinal feeding versus dual prokinetic treatment: Achieving goal nutrition in critical illness and delayed gastric emptying: Trial of nasointestinal feeding versus nasogastric feeding plus prokinetics (2016)
Journal Article
Taylor, S. J., Allan, K., McWilliam, H., Manara, A., Brown, J., Greenwood, R., & Toher, D. (2016). A randomised controlled feasibility and proof-of-concept trial in delayedgastric emptying when metoclopramide fails: We should revisitnasointestinal feeding versus dual prokinetic treatment: Achieving goal nutrition in critical illness and delayed gastric emptying: Trial of nasointestinal feeding versus nasogastric feeding plus prokinetics. Clinical nutrition ESPEN, 14, 1-8. https://doi.org/10.1016/j.clnesp.2016.04.020

© 2016 European Society for Clinical Nutrition and Metabolism Background & aims Delayed gastric emptying (DGE) commonly limits the use of enteral nutrition (EN) and may increase ventilator-associated pneumonia. Nasointestinal feeding has not been tes... Read More about A randomised controlled feasibility and proof-of-concept trial in delayedgastric emptying when metoclopramide fails: We should revisitnasointestinal feeding versus dual prokinetic treatment: Achieving goal nutrition in critical illness and delayed gastric emptying: Trial of nasointestinal feeding versus nasogastric feeding plus prokinetics.

Why Welch’s test is Type I error robust (2016)
Journal Article
Derrick, B., Toher, D., & White, P. (2016). Why Welch’s test is Type I error robust. Quantitative Methods for Psychology, 12(1), 30-38

The comparison of two means is one of the most commonly applied statistical procedures in psychology. The independent samples t-test corrected for unequal variances is commonly known as Welch’s test, and is widely considered to be a robust alternativ... Read More about Why Welch’s test is Type I error robust.

Test statistics for comparing two proportions with partially overlapping samples (2015)
Journal Article
Derrick, B., Dobson-Mckittrick, A., Toher, D., & White, P. (2015). Test statistics for comparing two proportions with partially overlapping samples. Journal of Applied Quantitative Methods, 10(3),

Standard tests for comparing two sample proportions of a dichotomous dependent variable where there is a combination of paired and unpaired samples are considered. Four new tests are introduced and compared against standard tests and an alternative p... Read More about Test statistics for comparing two proportions with partially overlapping samples.

Confirming nasogastric tube position with electromagnetic tracking versus pH or X-ray and tube radio-opacity (2014)
Journal Article
Taylor, S., Allan, K., McWilliam, H., Manara, A., Brown, J., Toher, D., & Rayner, W. (2014). Confirming nasogastric tube position with electromagnetic tracking versus pH or X-ray and tube radio-opacity. British Journal of Nursing, 23(7), 352-358. https://doi.org/10.12968/bjon.2014.23.7.352

Recent evidence suggests official statistics greatly underestimate the occurrence of complications from misplaced nasogastric (NG) tubes, even when detected. Current methods of confirming tube position do not provide adequate protection from misplace... Read More about Confirming nasogastric tube position with electromagnetic tracking versus pH or X-ray and tube radio-opacity.

Nasogastric tube depth: The 'NEX' guideline is incorrect (2014)
Journal Article
Taylor, S. J., Allan, K., McWilliam, H., & Toher, D. (2014). Nasogastric tube depth: The 'NEX' guideline is incorrect. British Journal of Nursing, 23(12), 641-644. https://doi.org/10.12968/bjon.2014.23.12.641

© 2014 MA Healthcare Ltd. Misplacing 17-23% of nasogastric (NG) tubes above the stomach (Rollins et al, 2012; Rayner, 2013) represents a serious risk in terms of aspiration, further invasive (tube) procedures, irradiation from failed X-ray confirmati... Read More about Nasogastric tube depth: The 'NEX' guideline is incorrect.

Infrared Spectroscopic Studies of Cells and Tissues: Triple Helix Proteins as a Potential Biomarker for Tumors (2013)
Journal Article
Stelling, A. L., Toher, D., Uckermann, O., Tavkin, J., Leipnitz, E., Schweizer, J., …Kirsch, M. (2013). Infrared Spectroscopic Studies of Cells and Tissues: Triple Helix Proteins as a Potential Biomarker for Tumors. PLoS ONE, 8(3), https://doi.org/10.1371/journal.pone.0058332

In this work, the infrared (IR) spectra of living neural cells in suspension, native brain tissue, and native brain tumor tissue were investigated. Methods were developed to overcome the strong IR signal of liquid water so that the signal from the ce... Read More about Infrared Spectroscopic Studies of Cells and Tissues: Triple Helix Proteins as a Potential Biomarker for Tumors.