Anthony Matthews
University of London
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Featured researches published by Anthony Matthews.
BMJ | 2016
Anthony Matthews; Emily Herrett; Antonio Gasparrini; Tjeerd van Staa; Ben Goldacre; Liam Smeeth; Krishnan Bhaskaran
Objective To quantify how a period of intense media coverage of controversy over the risk:benefit balance of statins affected their use. Design Interrupted time series analysis of prospectively collected electronic data from primary care. Setting Clinical Practice Research Datalink (CPRD) in the United Kingdom. Participants Patients newly eligible for or currently taking statins for primary and secondary cardiovascular disease prevention in each month in January 2011-March 2015. Main outcome measures Adjusted odds ratios for starting/stopping taking statins after the media coverage (October 2013-March 2014). Results There was no evidence that the period of high media coverage was associated with changes in statin initiation among patients with a high recorded risk score for cardiovascular disease (primary prevention) or a recent cardiovascular event (secondary prevention) (odds ratio 0.99 (95% confidence interval 0.87 to 1.13; P=0.92) and 1.04 (0.92 to 1.18; P=0.54), respectively), though there was a decrease in the overall proportion of patients with a recorded risk score. Patients already taking statins were more likely to stop taking them for both primary and secondary prevention after the high media coverage period (1.11 (1.05 to 1.18; P<0.001) and 1.12 (1.04 to 1.21; P=0.003), respectively). Stratified analyses showed that older patients and those with a longer continuous prescription were more likely to stop taking statins after the media coverage. In post hoc analyses, the increased rates of cessation were no longer observed after six months. Conclusions A period of intense public discussion over the risks:benefit balance of statins, covered widely in the media, was followed by a transient rise in the proportion of people who stopped taking statins. This research highlights the potential for widely covered health stories in the lay media to impact on healthcare related behaviour.
PLOS Medicine | 2016
Anthony Matthews; Sinéad M. Langan; Ian J. Douglas; Liam Smeeth; Krishnan Bhaskaran
Background Laboratory evidence suggests that reduced phosphodiesterase type 5 (PDE5) expression increases the invasiveness of melanoma cells; hence, pharmacological inhibition of PDE5 could affect melanoma risk. Two major epidemiological studies have investigated this and come to differing conclusions. We therefore aimed to investigate whether PDE5 inhibitor use is associated with an increased risk of malignant melanoma, and whether any increase in risk is likely to represent a causal relationship. Methods and Findings We conducted a matched cohort study using primary care data from the UK Clinical Practice Research Datalink. All men initiating a PDE5 inhibitor and with no prior cancer diagnosis were identified and matched on age, diabetes status, and general practice to up to four unexposed controls. Ever use of a PDE5 inhibitor and time-updated cumulative number of PDE5 inhibitor prescriptions were investigated as exposures, and the primary outcome was malignant melanoma. Basal cell carcinoma, solar keratosis, and colorectal cancer were investigated as negative control outcomes to exclude bias. Hazard ratios (HRs) were estimated from Cox models stratified by matched set and adjusted for potential confounders. 145,104 men with ≥1 PDE5 inhibitor prescription, and 560,933 unexposed matched controls were included. In total, 1,315 incident malignant melanoma diagnoses were observed during 3.44 million person-years of follow-up (mean 4.9 y per person). After adjusting for potential confounders, there was weak evidence of a small positive association between PDE5 inhibitor use and melanoma risk (HR = 1.14, 95% CI 1.01–1.29, p = 0.04). A similar increase in risk was seen for the two negative control outcomes related to sun exposure (HR = 1.15, 95% CI 1.11–1.19, p < 0.001, for basal cell carcinoma; HR = 1.21, 95% CI 1.17–1.25, p < 0.001, for solar keratosis), but there was no increased risk for colorectal cancer (HR = 0.91, 95% CI 0.85–0.98, p = 0.01). There was no evidence that risk increased with number of prescriptions received (p-trend = 0.83). In a post hoc analysis, there was strong evidence that solar keratosis was associated with future PDE5 inhibitor use (odds ratio = 1.28, 95% CI 1.23–1.34, p < 0.001), suggesting that men with higher sun exposure were more likely to become PDE5 inhibitor users. However, a limitation of our study was that we did not have individual-level data on sun exposure, so we could not directly control for this in the primary analysis. Conclusions Our results were not consistent with PDE5 inhibitors being causally associated with melanoma risk, and strongly suggest that observed risk increases are driven by greater sun exposure among patients exposed to a PDE5 inhibitor.
British Journal of Dermatology | 2016
Anthony Matthews; M. Turkson; Harriet Forbes; Sinéad M. Langan; Liam Smeeth; Krishnan Bhaskaran
Statins are commonly prescribed worldwide and recent evidence suggests that they may increase the risk of herpes zoster (HZ).
BMJ | 2018
Anthony Matthews; Liam Donaldson; Stephen Evans; Sinéad M. Langan
Inadequate surveillance threatens patient safety and public health
BMJ | 2018
Anthony Matthews; Susannah Stanway; Ruth Farmer; Helen Strongman; Sara L Thomas; Alexander R. Lyon; Liam Smeeth; Krishnan Bhaskaran
Abstract Objective To investigate the effect of endocrine therapies on a wide range of specific clinical cardiovascular disease outcomes in women with a history of non-metastatic breast cancer. Design Systematic review and meta-analysis of randomised controlled trials and observational studies. Data sources Medline and Embase up until June 2018. Eligibility criteria for selecting studies Studies were included if they investigated the risk of a specific cardiovascular disease outcome associated with use of either tamoxifen or an aromatase inhibitor, or compared the two treatments, in women with a history of non-metastatic breast cancer. Appraisal and data extraction Relevant studies were originally identified and results extracted by one researcher, with a full replication of the study identification process by a combination of two other researchers. The Cochrane Collaboration’s tool for assessing risk of bias was used to assess risk of bias in randomised controlled trials, and this tool was adapted to assess risk of bias in observational studies. Results 26 studies were identified, with results for seven specific cardiovascular disease outcomes (venous thromboembolism, myocardial infarction, stroke, angina, heart failure, arrhythmia, and peripheral vascular disease). Results suggested an increased risk of venous thromboembolism in tamoxifen users compared with both non-users and aromatase inhibitor users. Results were also consistent with a higher risk of the vascular diseases myocardial infarction and angina in aromatase inhibitor users compared with tamoxifen users, but there was also a suggestion that this may be partly driven by a protective effect of tamoxifen on these outcomes. Data were limited, and evidence was generally inconsistent for all other cardiovascular disease outcomes. Conclusion This review has collated substantial randomised controlled trial and observational evidence on the effect of endocrine therapies on several specific cardiovascular disease outcomes including venous thromboembolism and myocardial infarction, progressing knowledge. Although the choice of aromatase inhibitor or tamoxifen will primarily be based on the effectiveness against the recurrence of breast cancer, this review shows that the individual patient’s risk of venous or arterial vascular disease should be an important secondary consideration. Systematic review registration Prospero CRD42017065944.
BMC Cancer | 2018
Kendal Chidwick; Helen Strongman; Anthony Matthews; Susannah Stanway; Alexander R. Lyon; Liam Smeeth; Krishnan Bhaskaran
BackgroundCancer survivors may be at increased risk of cardiovascular diseases, but little is known about whether prescribing guidelines for the primary prevention of cardiovascular disease are adequately implemented in these patients. We compared levels of statin initiation and cessation among cancer survivors compared to the general population to determine differences in uptake of pharmaceutical cardiovascular risk prevention measures in these groups.MethodsThe study population included individuals aged ≥40 during 2005–13 within the UK Clinical Practice Research Datalink primary care database. Within this population we identified cancer survivors who were alive and under follow-up at least 1 year after diagnosis, and controls with no cancer history. Follow-up time prior to cancer diagnosis was included in the control cohort. Using logistic regression, we compared these groups with respect to uptake of statins within 1 month of a first high recorded cardiovascular risk score. Then, we used Cox modelling to compare persistence on statin therapy (time to statin cessation) between cancer survivors and controls from the main study population who had initiated on a statin.ResultsAmong 4202 cancer survivors and 113,035 controls with a record indicating a high cardiovascular risk score, 23.0% and 23.5% respectively initiated a statin within 1 month (adjusted odds ratio 0.98 [91.8–1.05], p = 0.626). Cancer survivors appeared more likely to discontinue statin treatment than controls (adjusted hazard ratio 1.07 [1.01–1.12], p = 0.02). This greater risk of discontinuing was only evident after the first year of therapy (p-interaction < 0.001).InterpretationAlthough cardiovascular risk is thought to be higher in cancer survivors compared to the general population, cancer survivors were no more likely to receive statins, and marginally more likely to cease long-term therapy, than general population controls. There may be an opportunity to mitigate the suspected higher cardiovascular risk in the growing population of cancer survivors by improving uptake of lipid-lowering treatment and persistence on therapy.
Blood | 2016
Luca Mazzarella; Edoardo Botteri; Anthony Matthews; Davide Disalvatore; Vincenzo Bagnardi; Massimo Breccia; Pau Montesinos; Teresa Bernal; Cristina Gil; Timothy J. Ley; Miguel A. Sanz; Krishnan Bhaskaran; Francesco Lo Coco; Pier Giuseppe Pelicci
Archive | 2017
Anthony Matthews; Krishnan Bhaskaran
Archive | 2017
Anthony Matthews; Krishnan Bhaskaran
Archive | 2017
Anthony Matthews; Krishnan Bhaskaran