Robert G Newcombe

Cardiff University | CU · Department of Primary Care and Public Health

Objectives: Does a complex intervention of oral hygiene advice (OHA) delivered with intra-oral scanner images, anti-gingivitis toothpaste and motivational reminders, improve oral health more than a standard of care control arm of fluoride toothpaste, with OHA without scanner images? Methods: Adult participants with pre-existing gingivitis were r...

The lipid envelope of SARS-CoV-2 is an essential component of the virus; however, its molecular composition is undetermined. Addressing this knowledge gap could support the design of anti-viral agents, as well as further our understanding of viral-host protein interactions, infectivity, pathogenicity, and innate immune system clearance. Using lipid...

The lipid envelope of SARS-CoV2 is an essential component of the virus, however its molecular composition is unknown. Addressing this knowledge gap could support the design of anti-viral agents, and further understanding of viral interaction with extracellular host proteins, infectivity, pathogenicity, and innate immune system clearance. Lipidomics...

Introduction ACOSOG-Z0011(Z11) trial showed that axillary node clearance (ANC) may be omitted in women with ≤2 positive nodes undergoing breast conserving surgery (BCS) and whole breast radiotherapy (RT). A confirmatory study is needed to clarify the role of axillary treatment in women with ≤2 macrometastases undergoing BCS and groups that were not...

Objective To assess whether a weight management intervention for pregnant women with obesity was effective in reducing body mass index (BMI) 12 months after giving birth. Methods Pragmatic, cluster randomised controlled trial (RCT) with embedded cost-effectiveness analysis. 598 women with a BMI of ≥30 kg/m² (between 12 and 20 weeks gestation) were...

Objectives To determine whether a microneedle patch combined with 5% topical lidocaine reduces dental injection pain more than a patch without microneedles combined with 5% topical lidocaine. Methods This proof of principle randomised, two-treatment, double-blind, crossover split-unit design study in 16 healthy participants investigated levels of...

Objectives To determine the efficacy of a cosmetic aluminium lactate/potassium nitrate/hydroxylapatite toothpaste for the reduction of dentine hypersensitivity (DH) pain as compared to a control toothpaste containing potassium nitrate. Methods The study was a randomised, examiner-blind, two treatment arm, parallel controlled trial in healthy adult...

Objectives To compare gingival inflammation scores obtained chairside using the non-invasive modified gingival index (MGI) with MGI scores from an intraoral scan (IOS) captured at the clinical visit but viewed 10 days later. Methods Single visit, anterior teeth, observational, proof of concept study in healthy adult participants with a spectrum of...

Objectives To design and validate a new index to assess tooth wear (TW) in the cervical region and its association with gingival recession (GR), for use both in research studies and as resource in General Dental Practice, with focused prevention and management strategiesparticularly related to aetiology of dentine hypersensitivity provided for each...

Objectives: To compare the pain/discomfort experienced by patients in supportive periodontal therapy, following treatment with a piezoelectric ultrasonic scaler, designed for use with warmed water irrigation, and a magnetostrictive ultrasonic scaler. Methods: This was a single-centre, randomised, split mouth study with regard to side, and crosso...

Aims To determine patient awareness of periodontal health, dentine hypersensitivity and tooth wear, and their impact on oral health quality of life in patients attending NHS practices in South West England. Method In this cross-sectional, multi-centre epidemiological study 814 adult NHS patients completed an oral health questionnaire and then under...

Objectives: This study tested the efficacy of a toothpaste containing enzymes and proteins reflecting those naturally occurring in saliva which play an important role in maintaining bacterial balance to improve gingival health condition and reduce supra-gingival plaque formation over a period of 13 weeks as compared to a commercial control toothpa...

Objectives: Prevalence of gingival recession (GR) and associations with dentine hypersensitivity (DH), erosive toothwear (BEWE), gingival bleeding (BOP) and periodontal pocketing (PPD) in young European adults. Materials and methods: This is a secondary analysis using data collected from 350 UK participants enrolled in a European cross sectional...

Aim: To determine if the number of abnormal nodes seen on preoperative axillary ultrasound (AUS) is a predictor of the number of positive nodes at histology for women with needle-biopsy-proven positive nodes. Materials and methods: This prospective multicentre cohort study included consecutive patients with early breast cancer who had needle-bio...

Background:The trial aim was to determine if for women with needle biopsy proven positive node on preoperative axillary ultrasound(AUS), the number of abnormal nodes seen on AUS is a predictor of number of positive nodes at histology. Methods:This prospective multicentre cohort study included consecutive patients with early breast cancer who had ne...

Background: The sensitivity of axillary ultrasonography (AUS) has increased in recent years, enabling detection of even low-volume axillary nodal metastases. The aim here was to evaluate the axillary tumour burden in women with a fine-needle aspiration/core biopsy-proven positive node on AUS and in those with a positive sentinel node biopsy (SNB)....

Objectives: To investigate the abrasive effect of the tongue on human enamel loss with and without a prior dietary acid challenge in an in situ model. Methods: A single centre, single blind, randomly allocated, split mouth, four treatment regimen, in situ study in healthy adult volunteers was undertaken. Twenty four subjects wore two lower intra...

Unintended consequences are recognised as a potential risk for well-intentioned social marketing interventions and as a comparatively under-researched topic in the field. This case study uses an intervention tackling deliberate grassfires to explore the application of social marketing in a novel context, its potential effectiveness in demarketing a...

Confidence interval for U/mn modified for individually paired data

Confidence interval for the mean change divided by the baseline SD

Excel spreadsheet to obtain confidence interval for paired difference of proportions using score method (Tango, 1998)

Excel spreadsheet to calculate confidence interval for a variable taking the values 0, 1 and 2

Excel spreadsheet to produce a diagram comparing sensitivity and specificity simultaneously between two tests based on unpaired data

Excel spreadsheet to calculate a confidence interval for the generalised Mann-Whitney measure theta=U/mn

Excel spreadsheet to calculate and display positive and negative predictive values as functions of prevalence

Excel spreadsheet to calculate Bonett-Price confidence interval for a ratio of paired proportions or of sizes of overlapping groups

Excel spreadsheet to obtain confidence intervals for proportions and their differences. Spanish language version.

Excel spreadsheet to obtain confidence intervals for proportions and their differences

Excel spreadsheet to calculate confidence intervals for odds ratios and ratios of proportions

Excel spreadsheet to visualise the generalised Mann-Whitney measure theta=U/mn in terms of the corresponding standardised difference, delta

Excel spreadsheet to calculate a confidence interval for a difference between paired differences of proportions

Excel spreadsheet to produce a diagram comparing sensitivity and specificity simultaneously between two tests based on paired data

Excel spreadsheet to calculate a confidence interval for a difference between unpaired differences of proportions

Excel spreadsheet to obtain confidence intervals for proportions and their differences. Welsh language version.

Excel spreadsheet to obtain MOVER-R (MOVER for a ratio) confidence interval

Excel spreadsheet to obtain a rate difference from a baseline risk and relative risk, with a MOVER-R confidence interval

Excel spreadsheet to obtain MOVER-D (MOVER for a difference) confidence interval

Objective: To evaluate whether introducing tools, specifically designed for use in clinical encounters, namely Option Grids, into a clinical practice setting leads to higher levels of shared decision making. Methods: A stepped wedge trial design where 6 physiotherapists at an interface clinic in Oldham, UK, were sequentially instructed in how to...

Objective: To analyse the factors affecting the clinical performance and those influencing the survival of resin-retained bridgework provided at a UK dental teaching hospital between 1994 and 2001. Design: A prospective analysis of restorations provided at a single centre using case notes with all patients invited for review to corroborate findi...

Patient decision support interventions are not currently subject to standardized quality control. The current study aims to assess the feasibility of applying a proposed set of minimum standards (previously developed as part of a possible certification process) to a selection of existing patient decision support interventions. A convenience sample...

Herpes zoster reactivation, shingles, affects 0.2% of the population (1) and complications include: secondary bacterial infection, postherpetic neuralgia (PHN), ulceration and scarring, pneumonitis, hepatitis, Ramsey-Hunt syndrome, meningoencephalitis and paralysis. PHN occurs in 10 -15% of patients following an episode of shingles, with the greate...

The incidence of Human Papillomavirus (HPV)-associated tonsil cancer is increasing but the prevalence of HPV, and of premalignant precursors, in tonsil tissue is unknown. We aimed to assess prevalence of HPV infection in non-malignant tonsillar crypt epithelia and to histopathologically characterise positive samples. Formalin Fixed Paraffin Embedde...

Many research studies in health and social sciences generate before-and-after data on the same series of individuals. Appropriate non-parametric and parametric effect size measures to characterise the degree of change for such datasets are described.

Objective: To investigate the separate and combined effects of erosion and abrasion challenges to enamel samples using an in situ model. Method: This was a single centre, single blind (blinded to the person responsible for performing the sample analysis), randomised, split mouth, four treatment regimen, single period in situ study in healthy adul...

Background: Approximately 1 in 5 pregnant women in the United Kingdom are obese. In addition to being associated generally with poor health, obesity is known to be a contributing factor to pregnancy and birth complications and the retention of gestational weight can lead to long term obesity.This paper describes the protocol for a cluster randomis...

Despite policy interest, an ethical imperative, and evidence of the benefits of patient decision support tools, the adoption of shared decision making (SDM) in day-to-day clinical practice remains slow and is inhibited by barriers that include culture and attitudes; resources and time pressures. Patient decision support tools often require high lev...

This article considers confidence interval methods for differences between proportions. In line with well-known corresponding results for the single proportion, the simplest Wald confidence intervals perform poorly. Several better methods are described, and illustrated using data from two small clinical trials. Selected methods are readily implemen...

The purpose of this note is to show how the MOVER algorithm for a ratio of two independently estimated quantities, recently published by Donner and Zou,1 requires modification to cope with the general case in which the lower and upper confidence limits for the numerator can take either sign. The MOVER2 (Method Of Variance Estimates Recovery) algori...

Aim and Objectives: Web-based Prostate Specific Antigen (PSA) decision aids are known to promote informed decision-making. There is also some evidence that informed decision-making can result in reduced uptake of PSA testing, thus reducing subsequent costs related to urological intervention, specifically prostate biopsies. The aim of this study was...

The antiepileptic drug vigabatrin has been used widely since 1989, but has only been approved for use in the US since 2009. The risk:benefit of vigabatrin is generally predicated upon an assumed frequency of associated visual field loss (VAVFL) of approximately 31 %. This estimate is based upon relatively short-term usage (up to 4-5 years) and it i...

A key step in implementing the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system is the estimation of a risk difference based on estimates of the baseline risk and the relative risk estimated from different sources. In this paper we describe a simple and effective method to calculate confidence intervals (CIs) for the...

The IPDAS Collaboration has developed a checklist and an instrument (IPDASi v3.0) to assess the quality of patient decision aids (PDAs) in terms of their development process and shared decision-making design components. Certification of PDAs is of growing interest in the US and elsewhere. We report a modified Delphi consensus process to agree on IP...

The Wilcoxon matched-pairs signed-ranks test statistic can be re-expressed as a relative effect size measure psi ranging from -1 to +1. It is preferably formulated in terms of zero shifted ranks 0, 1, ..., n-1, without dropping zeros. Two inversion intervals based on shifted uniform and constrained quartic models are developed. Coverage and width p...

The inverse hyperbolic sine transformation can be used to shorten the standard delta logit interval for the odds ratio and the delta log interval for the relative risk. As it stands, this transformation does not provide sufficient coverage. A pseudo-frequency modification is suggested and evaluated. The modification achieves an improvement in cover...

Background The incidence of Human Papillomavirus (HPV) associated oropharyngeal cancer (OPC) is increasing. HPV-associated OPC appear to have better prognosis than HPV-negative OPC. The aim of this study was to robustly determine the prevalence of HPV-positive OPC in an unselected UK population and correlate HPV positivity with clinical outcome. M...

Clinical diagnosis based on the result of a test can utilise prior information on the patient as well as the test result. The present study was prompted by the observation that two pathologists differed diametrically in their views of the influence of prior information, and by comments by speech and language therapists in an earlier reliability stu...

This article presents a simple demonstration of Pythagoras' Theorem by tesselating an infinite plane into P-pentomino shapes.

Background: New Start, a structured, validated, multidisciplinary training programme in sentinel lymph node biopsy (SLNB), was established to allow the introduction and rapid transfer of appropriate knowledge and technical skills to ensure safe and competent practice across the UK. Methods: Multidisciplinary teams attended a theory/skills labora...

BACKGROUND: New Start, a structured, validated, multidisciplinary training programme in sentinel lymph node biopsy (SLNB), was established to allow the introduction and rapid transfer of appropriate knowledge and technical skills to ensure safe and competent practice across the UK. METHODS: Multidisciplinary teams attended a theory/skills laborator...

Ongoing professional education is essential for dental professionals to maintain and update their clinical skills and knowledge. There is a current trend towards mandatory Continuing Professional Development (CPD) for dentists within Europe and beyond. Mandatory CPD will ensure high professional standards and enable mobilisation of the dental workf...

Objectives: A product comparison study to compare the short term clinical efficacy of a strontium acetate/silica toothpaste with an arginine/calcium carbonate paste for pain reduction in dentine hypersensitivity. Methods: The study was examiner blind of two arm parallel design. Eighty healthy adult subjects from general dental practice with ≥2 s...

Prevalence surveillance methodology is the systematic observation of the occurrence and distribution of healthcare-associated infections (HCAIs) so that appropriate actions can be taken. The objectives of a prevalence survey with an international validated methodology were to determine the prevalence of HCAIs for the first time in Argentina, and to...

Objectives The aim of the study was to determine in situ the relative abilities of two desensitising toothpastes to occlude dentinal tubules with or without acid challenge. Materials and methods The study design was a single centre, randomised, split mouth crossover model examining four treatments over two periods. The primary outcome was the degre...

To evaluate a disinfection and decontamination dental postgraduate course run by the Wales Dental Postgraduate Deanery between 2008 and 2010. Pre- and post-course multiple choice questionnaires were completed by 1177 course attendees. Mean scores before and after participation on the training course were compared and analysed. Mean pre-course score...

In a randomised crossover study, 60 ambulance paramedics attempted tracheal intubation of a manikin model of a Cormack and Lehane grade 3/4 view using a Portex stylet, Portex and Frova single-use bougies, and a Portex reusable bougie. Tracheal intubation within 30 s was achieved by 34/60 (57%) using the stylet, 18/60 (30%) using a Portex single-use...

Purpose: IPDAS developed an instrument (IPDASi) to assess the quality of patient decision aids (PDAs). There have been calls in the US for these tools to be certified. The aims were to: (1) correlate IPDASi scores with outcome measurements in RCTs (included in Cochrane systematic review of PDAs); (2) conduct a Delphi consensus process for expert ag...

The Propagating Imprecision (PropImp) approach is a general, easily implemented method for calculating confidence intervals for a function of two or more parameters which are estimated separately. It extends the single-parameter substitution method of Daly (1998) and is very flexible and widely applicable. It does not assume linearity, but normally...

Testosterone levels are commonly lowered in men with diabetes, but it is unclear how these relate to symptoms of hypogonadism and quality of life. We sought to investigate the relationship between testosterone levels, symptoms of androgen deficiency, erectile function and quality of life in men with type 1 and type 2 diabetes. Cross-sectional study...

This study examined the effect of a community-based intervention on the natural rise with age of the Framingham 10-year risk score. Patients in the 45-64-year-old age group from 10 general practices were sent an invite card including five self-screening questions. Those with any of the prescribed risk factors were invited to arrange an appointment...

To evaluate medium-term knowledge retention of dental personnel following attendance at a postgraduate course in radiation protection. Knowledge was measured using identical pre- and post-course validated single best-answer multiple-choice instruments, administered immediately before and after training and at follow-up at 6 or 12 months. These comp...

Florence and colleagues found that systematic collection, analysis, and use of anonymised emergency department recorded information on violence significantly reduced violence related hospital admissions.1 Although violence has long been a public health matter, there is ambivalence in making it a health priority. After all, crime reduction is the r...

In conclusion, likelihood-based intervals, including the Miettinen-Nurminen (MN) method, have gained a well deserved place as appropriate tools for useful application in epidemiologic and medical research practice. We call for a wider availability of these procedures in statistical software, including StatXact, based on a correct test statistic tha...

This study compared the staining potential of two experimental amine fluoride/stannous fluoride mouth rinses (A and B), a phenolic/essential oil rinse (C) and a negative control, water, rinse (D). The study was a single centre, randomized, single-blind, four treatment crossover study design among healthy participants. Prior to each study period, pa...

Numerous methods have been developed to calculate confidence intervals for the binomial proportion π. Boundedness and discreteness of the sample space imply that none achieves exactly the nominal α/2 left and right non coverage. We consider whether intervals calculated by a particular method tend to be located too close to, or too far out from, the...

Mounting evidence supports incorporation of HPV testing into cervical screening; however, the optimal test format and target population have yet to be confirmed. Assessment of the potential benefits of type-specific testing requires estimation of the risk associated with infection with individual HPV types. However, the risk posed by individual HPV...

Current models of the medical consultation emphasize shared decision-making (SDM), whereby the expertise of both the doctor and the patient are recognised and seen to equally contribute to the consultation. The evidence regarding the desirability and effectiveness of the SDM approach is often conflicting. It is proposed that the conflicts are due t...

Objectives: To investigate the survival characteristics of 771 resin-retained bridges provided in a UK teaching hospital between 1994 and 2001. Methods: Records were kept of patients provided with resin-retained bridgework by all grades of staff and undergraduate students at Bristol Dental Hospital & School between 1994 and 2001. These patients wer...

Background Intravenous morphine is the preferred drug for the treatment of moderate to severe pain by paramedics. Nausea and vomiting are believed to be frequent side-effects and routine co-administration of metoclopramide is common. In the absence of pre-hospital data to support this practice, we sought to determine the incidence of peri-opiate na...

Background Intravenous morphine is the preferred drug for the treatment of moderate to severe pain by paramedics. Nausea and vomiting are believed to be frequent side-effects and routine co-administration of metoclopramide is common. In the absence of pre-hospital data to support this practice, we sought to determine the incidence of peri-opiate na...

A recent article (Santner et al., 2007) asserted that a score interval for a difference of independent binomial proportions (Miettinen and Nurminen, 1985) may have inadequate coverage. We re-visit the properties of score intervals for binomial proportions and their differences. Published data indicate these methods produce mean coverage slightly ab...

This paper presents a case study of a social marketing intervention, developed as an action research project, which applied marketing principles and practices to the public policy challenge of reducing the incidence of deliberate countryside fire-setting in certain communities. This represented an interesting and challenging application of social m...