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Dive into the research topics where Graeme MacLennan is active.

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Featured researches published by Graeme MacLennan.


The Lancet | 2005

Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial

Adrian Grant; Alison Avenell; Marion K Campbell; Alison McDonald; Graeme MacLennan; Gladys McPherson; F Anderson; C Cooper; Roger M. Francis; Cam Donaldson; W.J. Gillespie; C.M. Robinson; David Torgerson; W.A. Wallace

BACKGROUND Elderly people who have a fracture are at high risk of another. Vitamin D and calcium supplements are often recommended for fracture prevention. We aimed to assess whether vitamin D3 and calcium, either alone or in combination, were effective in prevention of secondary fractures. METHODS In a factorial-design trial, 5292 people aged 70 years or older (4481 [85%] of whom were women) who were mobile before developing a low-trauma fracture were randomly assigned 800 IU daily oral vitamin D3, 1000 mg calcium, oral vitamin D3 (800 IU per day) combined with calcium (1000 mg per day), or placebo. Participants who were recruited in 21 UK hospitals were followed up for between 24 months and 62 months. Analysis was by intention-to-treat and the primary outcome was new low-energy fractures. FINDINGS 698 (13%) of 5292 participants had a new low-trauma fracture, 183 (26%) of which were of the hip. The incidence of new, low-trauma fractures did not differ significantly between participants allocated calcium and those who were not (331 [12.6%] of 2617 vs 367 [13.7%] of 2675; hazard ratio (HR) 0.94 [95% CI 0.81-1.09]); between participants allocated vitamin D3 and those who were not (353 [13.3%] of 2649 vs 345 [13.1%] of 2643; 1.02 [0.88-1.19]); or between those allocated combination treatment and those assigned placebo (165 [12.6%] of 1306 vs 179 [13.4%] of 1332; HR for interaction term 1.01 [0.75-1.36]). The groups did not differ in the incidence of all-new fractures, fractures confirmed by radiography, hip fractures, death, number of falls, or quality of life. By 24 months, 2886 (54.5%) of 5292 were still taking tablets, 451 (8.5%) had died, 58 (1.1%) had withdrawn, and 1897 (35.8%) had stopped taking tablets but were still providing data for at least the main outcomes. Compliance with tablets containing calcium was significantly lower (difference: 9.4% [95% CI 6.6-12.2]), partly because of gastrointestinal symptoms. However, potentially serious adverse events were rare and did not differ between groups. INTERPRETATION The findings do not support routine oral supplementation with calcium and vitamin D3, either alone or in combination, for the prevention of further fractures in previously mobile elderly people.


BMJ | 2010

Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis

Mark J Bolland; Alison Avenell; John A. Baron; Andrew Grey; Graeme MacLennan; Greg Gamble; Ian R. Reid

Objective To investigate whether calcium supplements increase the risk of cardiovascular events. Design Patient level and trial level meta-analyses. Data sources Medline, Embase, and Cochrane Central Register of Controlled Trials (1966-March 2010), reference lists of meta-analyses of calcium supplements, and two clinical trial registries. Initial searches were carried out in November 2007, with electronic database searches repeated in March 2010. Study selection Eligible studies were randomised, placebo controlled trials of calcium supplements (≥500 mg/day), with 100 or more participants of mean age more than 40 years and study duration more than one year. The lead authors of eligible trials supplied data. Cardiovascular outcomes were obtained from self reports, hospital admissions, and death certificates. Results 15 trials were eligible for inclusion, five with patient level data (8151 participants, median follow-up 3.6 years, interquartile range 2.7-4.3 years) and 11 with trial level data (11 921 participants, mean duration 4.0 years). In the five studies contributing patient level data, 143 people allocated to calcium had a myocardial infarction compared with 111 allocated to placebo (hazard ratio 1.31, 95% confidence interval 1.02 to 1.67, P=0.035). Non-significant increases occurred in the incidence of stroke (1.20, 0.96 to 1.50, P=0.11), the composite end point of myocardial infarction, stroke, or sudden death (1.18, 1.00 to 1.39, P=0.057), and death (1.09, 0.96 to 1.23, P=0.18). The meta-analysis of trial level data showed similar results: 296 people had a myocardial infarction (166 allocated to calcium, 130 to placebo), with an increased incidence of myocardial infarction in those allocated to calcium (pooled relative risk 1.27, 95% confidence interval 1.01 to 1.59, P=0.038). Conclusions Calcium supplements (without coadministered vitamin D) are associated with an increased risk of myocardial infarction. As calcium supplements are widely used these modest increases in risk of cardiovascular disease might translate into a large burden of disease in the population. A reassessment of the role of calcium supplements in the management of osteoporosis is warranted.


Journal of General Internal Medicine | 2006

Toward Evidence-Based Quality Improvement

Jeremy Grimshaw; Martin Eccles; Re Thomas; Graeme MacLennan; Craig Ramsay; Cynthia Fraser; Luke Vale

OBJECTIVES: To determine effectiveness and costs of different guideline dissemination and implementation strategies. DATA SOURCES: MEDLINE (1966 to 1998), HEALTH-STAR (1975 to 1998), Cochrane Controlled Trial Register (4th edn 1998), EMBASE (1980 to 1998), SIGLE (1980 to 1988), and the specialized register of the Cochrane Effective Practice and Organisation of Care group. REVIEW METHODS: INCLUSION CRITERIA: Randomized-controlled trials, controlled clinical trials, controlled before and after studies, and interrupted time series evaluating guideline dissemination and implementation strategies targeting medically qualified health care professionals that reported objective measures of provider behavior and/or patient outcome. Two reviewers independently abstracted data on the methodologic quality of the studies, characteristics of study setting, participants, targeted behaviors, and interventions. We derived single estimates of dichotomous process variables (e.g., proportion of patients receiving appropriate treatment) for each study comparison and reported the median and range of effect sizes observed by study group and other quality criteria. RESULTS: We included 309 comparisons derived from 235 studies. The overall quality of the studies was poor. Seventy-three percent of comparisons evaluated multi-faceted interventions. Overall, the majority of comparisons (86.6%) observed improvements in care; for example, the median absolute improvement in performance across interventions ranged from 14.1% in 14 cluster-randomized comparisons of reminders, 8.1% in 4 cluster-randomized comparisons of dissemination of educational materials, 7.0% in 5 cluster-randomized comparisons of audit and feedback, and 6.0% in 13 cluster-randomized comparisons of multifaceted interventions involving educational outreach. We found no relationship between the number of components and the effects of multifaceted interventions. Only 29.4% of comparisons reported any economic data. CONCLUSIONS: Current guideline dissemination and implementation strategies can lead to improvements in care within the context of rigorous evaluative studies. However, there is an imperfect evidence base to support decisions about which guideline dissemination and implementation strategies are likely to be efficient under different circumstances. Decision makers need to use considerable judgment about how best to use the limited resources they have for quality improvement activities.


Health Psychology Review | 2012

Identifying active ingredients in complex behavioural interventions for obese adults with obesity-related co-morbidities or additional risk factors for co-morbidities: a systematic review

Stephan U Dombrowski; Falko F. Sniehotta; Alison Avenell; Marie Johnston; Graeme MacLennan; Vera Araujo-Soares

Abstract Reducing obesity is an important preventive strategy for people who are at increased risk of major disabling or life-threatening conditions. Behavioural treatments for obesity are complex and involve several components aiming to facilitate behaviour change. Systematic reviews need to assess the components that moderate intervention effects. Electronic databases and journals were searched for randomised controlled trials of behavioural interventions targeting dietary and/or physical activity change for obese adults (mean BMI≥30, mean age≥40 years) with risk factors and follow-up data≥12 weeks. A reliable taxonomy of theory-congruent behaviour change techniques (BCTs; Abraham & Michie, 2008) was used to identify programme components. Meta-regression suggested that increasing numbers of identified BCTs are not necessarily associated with better outcomes. The BCTs provision of instructions (β =− 2.69, p=0.02), self-monitoring (β = − 3.37, p<0.001), relapse prevention (β = − 2.63, p=0.02) and prompting practice (β = − 3.63, p<0.001) could be linked to more successful interventions. Studies including more BCTs aimed at dietary change that are congruent with Control Theory were associated with greater weight loss (β = − 1.13, p=0.04). Post-hoc ratings of intervention components in published trials can lead to the identification of components and theories for behaviour change practice and research.


Critical Care | 2010

Quality of life in the five years after intensive care: a cohort study

Brian H. Cuthbertson; Sian Roughton; David Jenkinson; Graeme MacLennan; Luke Vale

IntroductionData on quality of life beyond 2 years after intensive care discharge are limited and we aimed to explore this area further. Our objective was to quantify quality of life and health utilities in the 5 years after intensive care discharge.MethodsA prospective longitudinal cohort study in a University Hospital in the UK. Quality of life was assessed from the period before ICU admission until 5 years and quality adjusted life years calculated.Results300 level 3 intensive care patients of median age 60.5 years and median length of stay 6.7 days, were recruited. Physical quality of life fell to 3 months (P = 0.003), rose back to pre-morbid levels at 12 months then fell again from 2.5 to 5 years after intensive care (P = 0.002). Mean physical scores were below the population norm at all time points but the mean mental scores after 6 months were similar to those population norms. The utility value measured using the EuroQOL-5D quality of life assessment tool (EQ-5D) at 5 years was 0.677. During the five years after intensive care unit, the cumulative quality adjusted life years were significantly lower than that expected for the general population (P < 0.001).ConclusionsIntensive care unit admission is associated with a high mortality, a poor physical quality of life and a low quality adjusted life years gained compared to the general population for 5 years after discharge. In this group, critical illness associated with ICU admission should be treated as a life time diagnosis with associated excess mortality, morbidity and the requirement for ongoing health care support.


British Journal of Obstetrics and Gynaecology | 2008

Efficacy and safety of using mesh or grafts in surgery for anterior and/or posterior vaginal wall prolapse: systematic review and meta‐analysis

Xueli Jia; C Glazener; G Mowatt; Graeme MacLennan; Christine Bain; Cynthia Fraser; Jennifer Burr

Background  The efficacy and safety of mesh/graft in surgery for anterior or posterior pelvic organ prolapse is uncertain.


International Journal of Technology Assessment in Health Care | 2005

Effectiveness and efficiency of guideline dissemination and implementation strategies

Jeremy Grimshaw; Re Thomas; Graeme MacLennan; Cynthia Fraser; Craig Ramsay; Luke Vale; Paula Whitty; Martin Eccles; L. Matowe; L. Shirran; M.J.P. Wensing; R.F. Dijkstra; Cam Donaldson

Objectives: A systematic review of the effectiveness and costs of different guideline development, dissemination, and implementation strategies wasundertaken. The resource implications of these strategies was estimated, and a framework for deciding when it is efficient to develop and introduce clinical guidelines was developed.


Computers in Biology and Medicine | 2004

Sample size calculator for cluster randomized trials

Marion K Campbell; Sean Thomson; Craig Ramsay; Graeme MacLennan; Jeremy Grimshaw

Cluster randomized trials, where individuals are randomized in groups are increasingly being used in healthcare evaluation. The adoption of a clustered design has implications for design, conduct and analysis of studies. In particular, standard sample sizes have to be inflated for cluster designs, as outcomes for individuals within clusters may be correlated; inflation can be achieved either by increasing the cluster size or by increasing the number of clusters in the study. A sample size calculator is presented for calculating appropriate sample sizes for cluster trials, whilst allowing the implications of both methods of inflation to be considered.


The Journal of Clinical Endocrinology and Metabolism | 2012

Long-Term Follow-Up for Mortality and Cancer in a Randomized Placebo-Controlled Trial of Vitamin D3 and/or Calcium (RECORD Trial)

Alison Avenell; Graeme MacLennan; David Jenkinson; Gladys McPherson; Alison McDonald; Puspa R. Pant; Adrian Grant; Marion K Campbell; F Anderson; C Cooper; Roger M. Francis; William J. Gillespie; C. Michael Robinson; David Torgerson; W. Angus Wallace

CONTEXT Vitamin D or calcium supplementation may have effects on vascular disease and cancer. OBJECTIVE Our objective was to investigate whether vitamin D or calcium supplementation affects mortality, vascular disease, and cancer in older people. DESIGN AND SETTING The study included long-term follow-up of participants in a two by two factorial, randomized controlled trial from 21 orthopedic centers in the United Kingdom. PARTICIPANTS Participants were 5292 people (85% women) aged at least 70 yr with previous low-trauma fracture. INTERVENTIONS Participants were randomly allocated to daily vitamin D(3) (800 IU), calcium (1000 mg), both, or placebo for 24-62 months, with a follow-up of 3 yr after intervention. MAIN OUTCOME MEASURES All-cause mortality, vascular disease mortality, cancer mortality, and cancer incidence were evaluated. RESULTS In intention-to-treat analyses, mortality [hazard ratio (HR) = 0.93; 95% confidence interval (CI) = 0.85-1.02], vascular disease mortality (HR = 0.91; 95% CI = 0.79-1.05), cancer mortality (HR = 0.85; 95% CI = 0.68-1.06), and cancer incidence (HR = 1.07; 95% CI = 0.92-1.25) did not differ significantly between participants allocated vitamin D and those not. All-cause mortality (HR = 1.03; 95% CI = 0.94-1.13), vascular disease mortality (HR = 1.07; 95% CI = 0.92-1.24), cancer mortality (HR = 1.13; 95% CI = 0.91-1.40), and cancer incidence (HR = 1.06; 95% CI = 0.91-1.23) also did not differ significantly between participants allocated calcium and those not. In a post hoc statistical analysis adjusting for compliance, thus with fewer participants, trends for reduced mortality with vitamin D and increased mortality with calcium were accentuated, although all results remain nonsignificant. CONCLUSIONS Daily vitamin D or calcium supplementation did not affect mortality, vascular disease, cancer mortality, or cancer incidence.


European Urology | 2012

Systematic review of oncological outcomes following surgical management of localised renal cancer.

Steven MacLennan; Mari Imamura; Marie Carmela M Lapitan; Muhammad Imran Omar; Thomas Lam; Ana M. Hilvano-Cabungcal; Pamela Royle; Fiona Stewart; Graeme MacLennan; Sara MacLennan; Steven E. Canfield; Sam McClinton; T.R. Leyshon Griffiths; Börje Ljungberg; James N'Dow

CONTEXT Renal cell carcinoma (RCC) accounts for 2-3% of adult malignancies. There remain uncertainties over the oncological outcomes for the surgical management of localised RCC. OBJECTIVE Systematically review relevant literature comparing oncological outcomes of surgical management of localised RCC (T1-2N0M0). EVIDENCE ACQUISITION Relevant databases including Medline, Embase, and the Cochrane Library were searched up to October 2010, and an updated scoping search was performed up to January 2012. Randomised controlled trials (RCTs) or quasi-RCTs, prospective observational studies with controls, retrospective matched-pair studies, and comparative studies from well-defined registries/databases were included. The main outcomes were overall survival, cancer-specific survival, recurrence, and metastases. The Cochrane risk of bias tool was used to assess RCTs, and an extended version was used to assess nonrandomised studies (NRSs). The quality of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). EVIDENCE SYNTHESIS A total of 4580 abstracts and 389 full-text articles were assessed. Thirty-four studies met the inclusion criteria (6 RCTs and 28 NRSs). Meta-analyses were planned but were deemed inappropriate due to data heterogeneity. There were high risks of bias and low-quality evidence across the evidence base. Open radical nephrectomy and open partial nephrectomy showed similar cancer-specific and overall survival, but when both open and laparoscopic approaches are considered together, the evidence showed improved survival for partial nephrectomy for tumours ≤4cm. The overall evidence suggests either equivalent or better survival with partial nephrectomy. Laparoscopic radical nephrectomy offered equivalent survival to open radical nephrectomy, and all laparoscopic approaches achieved equivalent survival. Open and laparoscopic partial nephrectomy achieved equivalent survival. The issue of ipsilateral adrenalectomy or complete lymph node dissection with radical nephrectomy or partial nephrectomy remains unresolved. CONCLUSIONS The evidence base suggests localised RCCs are best managed by nephron-sparing surgery where technically feasible. However, the current evidence base has significant limitations due to studies of low methodological quality marked by high risks of bias.

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John Norrie

University of Aberdeen

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Jeremy Grimshaw

Ottawa Hospital Research Institute

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Re Thomas

University of Aberdeen

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James N'Dow

University of Aberdeen

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