I am a biostatistician with extensive publications in the design and analysis of epidemiological studies and methodology, and textbooks in statistics for medical students and researchers in health.
The Author(s) 2014. This article is published with open access at Springerlink.com Abstract The g... more The Author(s) 2014. This article is published with open access at Springerlink.com Abstract The gekoTM device is a single-use, battery-powered, neuromuscular electrostimulation device that aims to reduce the risk of venous thromboembolism (VTE). The National Institute for Health and Care Excellence (NICE) selected the gekoTM device for eval-uation, and invited the manufacturer, Firstkind Ltd, to submit clinical and economic evidence. King’s Technol-ogy Evaluation Centre, an External Assessment Centre (EAC) commissioned by the NICE, independently asses-sed the evidence submitted. The sponsor submitted evi-dence related to the gekoTM device and, in addition, included studies of other related devices as further clinical evidence to support a link between increased blood flow and VTE prophylaxis. The EAC assessed this evidence,
The geko TM device is a single-use, battery- powered, neuromuscular electrostimulation device tha... more The geko TM device is a single-use, battery- powered, neuromuscular electrostimulation device that aims to reduce the risk of venous thromboembolism (VTE). The National Institute for Health and Care Excellence (NICE) selected the geko TM device for eval- uation, and invited the manufacturer, Firstkind Ltd, to submit clinical and economic evidence. King's Technol- ogy Evaluation Centre, an External Assessment Centre (EAC) commissioned by the NICE, independently asses- sed the evidence submitted. The sponsor submitted evi- dence related to the geko TM device and, in addition, included studies of other related devices as further clinical evidence to support a link between increased blood flow and VTE prophylaxis. The EAC assessed this evidence, conducted its own systematic review and concluded that there is currently limited direct evidence that geko TM prevents VTE. The sponsor's cost model is based on the assumption that patients with an underlying VTE risk and subsequently t...
BackgroundObservational studies suggest an increased risk of eczema in children living in hard ve... more BackgroundObservational studies suggest an increased risk of eczema in children living in hard versus soft water areas, and there is, therefore, an interest in knowing whether softening water may prevent eczema. We evaluated the feasibility of a parallel‐group assessor‐blinded pilot randomized controlled trial to test whether installing a domestic ion‐exchange water softener before birth in hard water areas reduces the risk of eczema in infants with a family history of atopy.MethodsPregnant women living in hard water areas (>250 mg/L calcium carbonate) in and around London UK, were randomized 1:1 antenatally to either have an ion‐exchange water softener installed in their home or not (ie to continue to receive usual domestic hard water). Infants were assessed at birth and followed up for 6 months. The main end‐points were around feasibility, the primary end‐point being the proportion of eligible families screened who were willing and able to be randomized. Clinical end‐points wer...
Background Reliable vascular access is essential for patients receiving haemodialysis. An arterio... more Background Reliable vascular access is essential for patients receiving haemodialysis. An arteriovenous fistula is the preferred option; however, these are prone to developing stenotic segments. These lesions are treated with angioplasty, but there is a high rate of recurrence. When the PAVE (Paclitaxel-assisted balloon Angioplasty of Venous stenosis in haEmodialysis access) trial was conceived, a number of small studies suggested that restenosis may be reduced by paclitaxel-coated balloons. Objective To test the efficacy of paclitaxel-coated balloons in arteriovenous fistulas. Design A randomised controlled trial. Setting Twenty UK centres. Participants Patients (aged ≥ 18 years) referred with a clinical indication for angioplasty of an arteriovenous fistula (212 patients in total, 106 per group). Interventions High-pressure plain balloon fistuloplasty was performed in all patients. In the intervention arm, the second component was insertion of a paclitaxel-coated balloon. In the c...
OBJECTIVE: To evaluate the associations of depressive symptoms and antidepressant use during preg... more OBJECTIVE: To evaluate the associations of depressive symptoms and antidepressant use during pregnancy with the risks of preterm birth, low birth weight, small for gestational age (SGA), and low Apgar scores. DATA SOURCES: MEDLINE, EMBASE, ClinicalTrials.gov, and PsycINFO up to June 2016. METHODS OF STUDY SELECTION: Data were sought from studies examining associations of depression, depressive symptoms, or use of antidepressants during pregnancy with gestational age, birth weight, SGA, or Apgar scores. Authors shared the raw data of their studies for incorporation into this individual participant data meta-analysis. TABULATION, INTEGRATION, AND RESULTS: We performed one-stage random-effects meta-analyses to estimate odds ratios (ORs) with 95% CIs. The 215 eligible articles resulted in 402,375 women derived from 27 study databases. Increased risks were observed for preterm birth among women with a clinical diagnosis of depression during pregnancy irrespective of antidepressant use (O...
IntroductionIt is increasingly recognized that type 2 diabetes (T2D) is a heterogenous disease wi... more IntroductionIt is increasingly recognized that type 2 diabetes (T2D) is a heterogenous disease with ethnic variations. Differences in insulin secretion, insulin resistance and ectopic fat are thought to contribute to these variations. Therefore, we aimed to compare postprandial insulin secretion and the relationships between insulin secretion, insulin sensitivity and pancreatic fat in men of black West African (BA) and white European (WE) ancestry.Research design and methodsA cross-sectional, observational study in which 23 WE and 23 BA men with normal glucose tolerance, matched for body mass index, underwent a mixed meal tolerance test with C peptide modeling to measure beta cell insulin secretion, an MRI to quantify intrapancreatic lipid (IPL), and a hyperinsulinemic-euglycemic clamp to measure whole-body insulin sensitivity.ResultsPostprandial insulin secretion was lower in BA versus WE men following adjustment for insulin sensitivity (estimated marginal means, BA vs WE: 40.5 (95...
AimTo investigate relationships between insulin clearance, insulin secretion, hepatic fat accumul... more AimTo investigate relationships between insulin clearance, insulin secretion, hepatic fat accumulation and insulin sensitivity in black African (BA) and white European (WE) men.MethodsTwenty‐three BA and twenty‐three WE men with normal glucose tolerance, matched for age and body mass index, underwent a hyperglycaemic clamp to measure insulin secretion and clearance, hyperinsulinaemic‐euglycaemic clamp with stable glucose isotope infusion to measure whole‐body and hepatic‐specific insulin sensitivity, and magnetic resonance imaging to quantify intrahepatic lipid (IHL).ResultsBA men had higher glucose‐stimulated peripheral insulin levels (48.1 [35.5, 65.2] × 103 vs. 29.9 [23.3, 38.4] × 103 pmol L−1 × min, P = .017) and lower endogeneous insulin clearance (771.6 [227.8] vs. 1381 [534.3] mL m−2 body surface area min −1, P < .001) compared with WE men. There were no ethnic differences in beta‐cell insulin secretion or beta‐cell responsivity to glucose, even after adjustment for prevai...
Objectives In men of black west African (BAM) and white European (WEM) ethnicity, we aimed to (1)... more Objectives In men of black west African (BAM) and white European (WEM) ethnicity, we aimed to (1) compare adipose tissue, peripheral and hepatic insulin sensitivity and (2) investigate associations between ectopic fat and insulin sensitivity by ethnicity. Design and methods In overweight BAM (n = 21) and WEM (n = 23) with normal glucose tolerance, we performed a two-step hyperinsulinaemic–euglycaemic clamp with infusion of [6,6 2H2]-glucose and [2H5]-glycerol to measure whole body, peripheral, hepatic and adipose tissue insulin sensitivity (lipolysis). Visceral adipose tissue (VAT), intrahepatic lipids (IHL) and intramyocellular (IMCL) lipids were measured using MRI and spectroscopy. Associations between insulin sensitivity and ectopic fat were assessed using Pearson’s correlation coefficient by ethnicity and regression analysis. Results There were no ethnic differences in whole body or tissue-specific insulin sensitivity (all P > 0.05). Suppression of lipolysis was inversely as...
IntroductionWalking exercise is a recommended but underused treatment for intermittent claudicati... more IntroductionWalking exercise is a recommended but underused treatment for intermittent claudication caused by peripheral arterial disease (PAD). Addressing the factors that influence walking exercise may increase patient uptake of and adherence to recommended walking. The primary aim of this randomised controlled trial (RCT) is to evaluate the efficacy of a physiotherapist-led behavioural change intervention on walking ability in adults with intermittent claudication (MOtivating Structured walking Activity in people with Intermittent Claudication (MOSAIC)) in comparison with usual care.Methods and analysisThe MOSAIC trial is a two-arm, parallel-group, single-blind RCT. 192 adults will be recruited from six National Health Service Hospital Trusts. Inclusion criteria are: aged ≥50 years, PAD (Ankle Brachial Pressure Index ≤0.90, radiographic evidence or clinician report) and intermittent claudication (San Diego Claudication Questionnaire), being able and willing to participate and pro...
AimTo test the hypothesis that men of black (West) African ethnicity (black African men [BAM]) wi... more AimTo test the hypothesis that men of black (West) African ethnicity (black African men [BAM]) with early type 2 diabetes (T2D) would have greater insulin secretory deficits compared with white European men (WEM), following prediabetic hypersecretion.MethodsIn 19 BAM and 15 WEM, matched for age, body mass index and duration of diabetes, we assessed and modelled insulin secretory responses to hyperglycaemia stimulated intravenously (hyperglycaemic clamp) and orally (meal tolerance test).ResultsWith similar post‐challenge glucose responses, BAM had lower second‐phase C‐peptide responses to intravenous glucose (BAM 70.6 vs WEM 115.1 nmol/L/min [ratio of geometric mean 0.55, 95% confidence interval {CI} 0.37, 0.83]; P = .006) and to oral glucose (BAM 65.4 vs WEM 88.5 nmol/L/min [mean difference −23.2, 95% CI −40.0, −6.3]; P = .009). Peripheral insulin response in BAM to oral glucose was preserved (BAM 47.4 vs WEM 59.4 nmol/L/min [ratio of geometric mean 0.89, 95% CI 0.59, 1.35]; P = .56...
The Author(s) 2014. This article is published with open access at Springerlink.com Abstract The g... more The Author(s) 2014. This article is published with open access at Springerlink.com Abstract The gekoTM device is a single-use, battery-powered, neuromuscular electrostimulation device that aims to reduce the risk of venous thromboembolism (VTE). The National Institute for Health and Care Excellence (NICE) selected the gekoTM device for eval-uation, and invited the manufacturer, Firstkind Ltd, to submit clinical and economic evidence. King’s Technol-ogy Evaluation Centre, an External Assessment Centre (EAC) commissioned by the NICE, independently asses-sed the evidence submitted. The sponsor submitted evi-dence related to the gekoTM device and, in addition, included studies of other related devices as further clinical evidence to support a link between increased blood flow and VTE prophylaxis. The EAC assessed this evidence,
The geko TM device is a single-use, battery- powered, neuromuscular electrostimulation device tha... more The geko TM device is a single-use, battery- powered, neuromuscular electrostimulation device that aims to reduce the risk of venous thromboembolism (VTE). The National Institute for Health and Care Excellence (NICE) selected the geko TM device for eval- uation, and invited the manufacturer, Firstkind Ltd, to submit clinical and economic evidence. King's Technol- ogy Evaluation Centre, an External Assessment Centre (EAC) commissioned by the NICE, independently asses- sed the evidence submitted. The sponsor submitted evi- dence related to the geko TM device and, in addition, included studies of other related devices as further clinical evidence to support a link between increased blood flow and VTE prophylaxis. The EAC assessed this evidence, conducted its own systematic review and concluded that there is currently limited direct evidence that geko TM prevents VTE. The sponsor's cost model is based on the assumption that patients with an underlying VTE risk and subsequently t...
BackgroundObservational studies suggest an increased risk of eczema in children living in hard ve... more BackgroundObservational studies suggest an increased risk of eczema in children living in hard versus soft water areas, and there is, therefore, an interest in knowing whether softening water may prevent eczema. We evaluated the feasibility of a parallel‐group assessor‐blinded pilot randomized controlled trial to test whether installing a domestic ion‐exchange water softener before birth in hard water areas reduces the risk of eczema in infants with a family history of atopy.MethodsPregnant women living in hard water areas (>250 mg/L calcium carbonate) in and around London UK, were randomized 1:1 antenatally to either have an ion‐exchange water softener installed in their home or not (ie to continue to receive usual domestic hard water). Infants were assessed at birth and followed up for 6 months. The main end‐points were around feasibility, the primary end‐point being the proportion of eligible families screened who were willing and able to be randomized. Clinical end‐points wer...
Background Reliable vascular access is essential for patients receiving haemodialysis. An arterio... more Background Reliable vascular access is essential for patients receiving haemodialysis. An arteriovenous fistula is the preferred option; however, these are prone to developing stenotic segments. These lesions are treated with angioplasty, but there is a high rate of recurrence. When the PAVE (Paclitaxel-assisted balloon Angioplasty of Venous stenosis in haEmodialysis access) trial was conceived, a number of small studies suggested that restenosis may be reduced by paclitaxel-coated balloons. Objective To test the efficacy of paclitaxel-coated balloons in arteriovenous fistulas. Design A randomised controlled trial. Setting Twenty UK centres. Participants Patients (aged ≥ 18 years) referred with a clinical indication for angioplasty of an arteriovenous fistula (212 patients in total, 106 per group). Interventions High-pressure plain balloon fistuloplasty was performed in all patients. In the intervention arm, the second component was insertion of a paclitaxel-coated balloon. In the c...
OBJECTIVE: To evaluate the associations of depressive symptoms and antidepressant use during preg... more OBJECTIVE: To evaluate the associations of depressive symptoms and antidepressant use during pregnancy with the risks of preterm birth, low birth weight, small for gestational age (SGA), and low Apgar scores. DATA SOURCES: MEDLINE, EMBASE, ClinicalTrials.gov, and PsycINFO up to June 2016. METHODS OF STUDY SELECTION: Data were sought from studies examining associations of depression, depressive symptoms, or use of antidepressants during pregnancy with gestational age, birth weight, SGA, or Apgar scores. Authors shared the raw data of their studies for incorporation into this individual participant data meta-analysis. TABULATION, INTEGRATION, AND RESULTS: We performed one-stage random-effects meta-analyses to estimate odds ratios (ORs) with 95% CIs. The 215 eligible articles resulted in 402,375 women derived from 27 study databases. Increased risks were observed for preterm birth among women with a clinical diagnosis of depression during pregnancy irrespective of antidepressant use (O...
IntroductionIt is increasingly recognized that type 2 diabetes (T2D) is a heterogenous disease wi... more IntroductionIt is increasingly recognized that type 2 diabetes (T2D) is a heterogenous disease with ethnic variations. Differences in insulin secretion, insulin resistance and ectopic fat are thought to contribute to these variations. Therefore, we aimed to compare postprandial insulin secretion and the relationships between insulin secretion, insulin sensitivity and pancreatic fat in men of black West African (BA) and white European (WE) ancestry.Research design and methodsA cross-sectional, observational study in which 23 WE and 23 BA men with normal glucose tolerance, matched for body mass index, underwent a mixed meal tolerance test with C peptide modeling to measure beta cell insulin secretion, an MRI to quantify intrapancreatic lipid (IPL), and a hyperinsulinemic-euglycemic clamp to measure whole-body insulin sensitivity.ResultsPostprandial insulin secretion was lower in BA versus WE men following adjustment for insulin sensitivity (estimated marginal means, BA vs WE: 40.5 (95...
AimTo investigate relationships between insulin clearance, insulin secretion, hepatic fat accumul... more AimTo investigate relationships between insulin clearance, insulin secretion, hepatic fat accumulation and insulin sensitivity in black African (BA) and white European (WE) men.MethodsTwenty‐three BA and twenty‐three WE men with normal glucose tolerance, matched for age and body mass index, underwent a hyperglycaemic clamp to measure insulin secretion and clearance, hyperinsulinaemic‐euglycaemic clamp with stable glucose isotope infusion to measure whole‐body and hepatic‐specific insulin sensitivity, and magnetic resonance imaging to quantify intrahepatic lipid (IHL).ResultsBA men had higher glucose‐stimulated peripheral insulin levels (48.1 [35.5, 65.2] × 103 vs. 29.9 [23.3, 38.4] × 103 pmol L−1 × min, P = .017) and lower endogeneous insulin clearance (771.6 [227.8] vs. 1381 [534.3] mL m−2 body surface area min −1, P < .001) compared with WE men. There were no ethnic differences in beta‐cell insulin secretion or beta‐cell responsivity to glucose, even after adjustment for prevai...
Objectives In men of black west African (BAM) and white European (WEM) ethnicity, we aimed to (1)... more Objectives In men of black west African (BAM) and white European (WEM) ethnicity, we aimed to (1) compare adipose tissue, peripheral and hepatic insulin sensitivity and (2) investigate associations between ectopic fat and insulin sensitivity by ethnicity. Design and methods In overweight BAM (n = 21) and WEM (n = 23) with normal glucose tolerance, we performed a two-step hyperinsulinaemic–euglycaemic clamp with infusion of [6,6 2H2]-glucose and [2H5]-glycerol to measure whole body, peripheral, hepatic and adipose tissue insulin sensitivity (lipolysis). Visceral adipose tissue (VAT), intrahepatic lipids (IHL) and intramyocellular (IMCL) lipids were measured using MRI and spectroscopy. Associations between insulin sensitivity and ectopic fat were assessed using Pearson’s correlation coefficient by ethnicity and regression analysis. Results There were no ethnic differences in whole body or tissue-specific insulin sensitivity (all P > 0.05). Suppression of lipolysis was inversely as...
IntroductionWalking exercise is a recommended but underused treatment for intermittent claudicati... more IntroductionWalking exercise is a recommended but underused treatment for intermittent claudication caused by peripheral arterial disease (PAD). Addressing the factors that influence walking exercise may increase patient uptake of and adherence to recommended walking. The primary aim of this randomised controlled trial (RCT) is to evaluate the efficacy of a physiotherapist-led behavioural change intervention on walking ability in adults with intermittent claudication (MOtivating Structured walking Activity in people with Intermittent Claudication (MOSAIC)) in comparison with usual care.Methods and analysisThe MOSAIC trial is a two-arm, parallel-group, single-blind RCT. 192 adults will be recruited from six National Health Service Hospital Trusts. Inclusion criteria are: aged ≥50 years, PAD (Ankle Brachial Pressure Index ≤0.90, radiographic evidence or clinician report) and intermittent claudication (San Diego Claudication Questionnaire), being able and willing to participate and pro...
AimTo test the hypothesis that men of black (West) African ethnicity (black African men [BAM]) wi... more AimTo test the hypothesis that men of black (West) African ethnicity (black African men [BAM]) with early type 2 diabetes (T2D) would have greater insulin secretory deficits compared with white European men (WEM), following prediabetic hypersecretion.MethodsIn 19 BAM and 15 WEM, matched for age, body mass index and duration of diabetes, we assessed and modelled insulin secretory responses to hyperglycaemia stimulated intravenously (hyperglycaemic clamp) and orally (meal tolerance test).ResultsWith similar post‐challenge glucose responses, BAM had lower second‐phase C‐peptide responses to intravenous glucose (BAM 70.6 vs WEM 115.1 nmol/L/min [ratio of geometric mean 0.55, 95% confidence interval {CI} 0.37, 0.83]; P = .006) and to oral glucose (BAM 65.4 vs WEM 88.5 nmol/L/min [mean difference −23.2, 95% CI −40.0, −6.3]; P = .009). Peripheral insulin response in BAM to oral glucose was preserved (BAM 47.4 vs WEM 59.4 nmol/L/min [ratio of geometric mean 0.89, 95% CI 0.59, 1.35]; P = .56...
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Papers by Janet Peacock