Karen Barnett

Bio: Karen Barnett is an academic researcher from University of Dundee. The author has contributed to research in topics: Population & Health services research. The author has an hindex of 11, co-authored 23 publications receiving 4520 citations. Previous affiliations of Karen Barnett include University of Edinburgh.

High risk prescribing in primary care patients particularly vulnerable to adverse drug events: cross sectional population database analysis in Scottish general practice

Abstract: Objective To examine the prevalence and patterns of high risk prescribing, defined as potentially inappropriate prescribing of drugs to primary care patients particularly vulnerable to adverse drug events. Design Cross sectional population database analysis. Setting General practices in Scotland. Participants 315 Scottish general practices with 1.76 million registered patients, 139 404 (7.9%) of whom were defined as particularly vulnerable to adverse drug events because of age, comorbidity, or co-prescription. Main outcome measures How reliably each of 15 indicators—four each for non-steroidal anti-inflammatory drugs, co-prescription with warfarin, and prescribing in heart failure, two for dose instructions for methotrexate, and one for antipsychotic prescribing in dementia—and a composite of all 15 could distinguish practices in terms of their rates of high risk prescribing; and characteristics of patients and practices associated with high risk prescribing in a multilevel model. Results 19 308 of 139 404 (13.9%, 95% confidence interval 13.7% to 14.0%) patients had received at least one high risk prescription in the past year. This composite indicator was a reasonably reliable measure of practice rates of high risk prescribing (reliability >0.7 for 95.6% of practices, >0.8 for 88.2%). The patient characteristic most strongly associated with high risk prescribing was the number of drugs prescribed (>11 long term prescribed drugs v 0; odds ratio 7.90, 95% confidence interval 7.19 to 8.68). After adjustment for patient characteristics, rates of high risk prescribing varied by fourfold between practices, which was not explained by structural characteristics of the practices. Conclusions Almost 14% of patients defined as particularly vulnerable to adverse drug events were prescribed one or more high risk drugs. The composite indicator of high risk prescribing used could identify practices as having above average or below average high risk prescribing rates with reasonable confidence. After adjustment, only the number of drugs prescribed long term to patients was strongly associated with high risk prescribing, and considerable unexplained variation existed between practices. High risk prescribing will often be appropriate, but the large variation between practices suggests opportunities for improvement.

Prevalence and outcomes of use of potentially inappropriate medicines in older people: cohort study stratified by residence in nursing home or in the community

Abstract: Objectives To compare the prevalence of use of potentially inappropriate medicines (PIMs) between older patients living in their own homes versus those living in nursing or residential homes, and to test the association between exposure to PIMs and mortality. Design Cohort study stratified by place of residence. Setting Tayside, Scotland. Participants All people aged between 66 and 99 years who were resident or died in Tayside from 2005 to 2006. Main outcome measures The exposure variable was PIM use as defined by Beers' Criteria. All cause mortality was the main outcome measure. Results 70 299 people were enrolled in the cohort of whom 96% were exposed to any medicine and 31% received a PIM. Place of residence was not associated with overall risk of receiving PIMs, adjusted OR 0.94, 95% CI 0.87 to 1.01. Exposure to five of the PIMs (including long-acting benzodiazepines) was significantly higher in nursing homes whereas exposure to five other PIMs (including amitriptyline and NSAIDs) was significantly lower. Exposure to PIMs was similar (20–46%) across all 71 general practices in Tayside and was not associated with increased risk of mortality after adjustment for age, gender and polypharmacy (adjusted OR 0.98, 95% CI 0.92 to 1.05). Conclusions The authors question the validity of the full list of PIMs as an indicator of safety of medicines in older people because one-third of the population is exposed with little practice variation and no significant impact on mortality. Future studies should focus on management of a shorter list of genuinely high-risk medicines.

A 12-year follow-up study of all-cause and cardiovascular mortality among 10 532 people newly diagnosed with Type 2 diabetes in Tayside, Scotland.

Abstract: Diabet. Med. 27, 1124–1129 (2010) Abstract Aims To determine absolute and relative risks of all-cause and cardiovascular mortality among patients newly diagnosed with Type 2 diabetes. Methods In an observational cohort study using record-linkage databases, based in Tayside, Scotland, UK, we identified newly diagnosed patients with Type 2 diabetes in 1993–2004. We also identified a set of non-diabetic comparators from lists of patients registered with a general practice, individually matched to the diabetic patients by sex, age and deprivation. We followed up patients for mortality and cardiovascular mortality over a 12-year period and calculated hazard ratios using Cox regression. Results There were 10 532 patients with Type 2 diabetes and 21 056 non-diabetic comparators. Diabetic patients in every age/sex group had higher absolute mortality rates. Even taking deprivation into account, the hazard ratio for mortality was 1.32 (95% CI 1.25–1.40), decreasing to 1.15 (1.09–1.22) after adjusting for pre-existing cardiovascular disease. The hazard ratios for cardiovascular mortality were higher, decreasing from 1.51 (1.37–1.67) to 1.23 (1.11–1.36) after adjusting for pre-existing cardiovascular disease. The hazard ratios decreased with increasing age at diagnosis, although the difference in absolute rate of mortality increased slightly with age. Increased mortality risks were only evident 2 years after diagnosis and increased thereafter. Conclusions Patients with Type 2 diabetes have an increased risk of all-cause and cardiovascular mortality compared with non-diabetic comparators, although this is not observable immediately after diagnosis. Age at diagnosis and duration of the disease independently affect absolute and relative mortality risk.

Data feedback and behavioural change intervention to improve primary care prescribing safety (EFIPPS): multicentre, three arm, cluster randomised controlled trial.

Abstract: We thank Jackie Caldwell, Iain Bishop, Grant Wyper, Kjersti Fergusson, and Martyn Ritchie in NHS National Services Scotland Information Services Division and all members of the Advisory Group for their contribution. Funding: The study was funded by Scottish Government Chief Scientist Office project grant CZH/3/17. The funder of the study had no role in study design, data collection, data analysis, data interpretation, or the writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication. ST works at the Health Services Research Unit, University of Aberdeen, which is funded by the Chief Scientist Office of the Scottish Government Health Directorates.

What is polypharmacy? A systematic review of definitions

Abstract: Multimorbidity and the associated use of multiple medicines (polypharmacy), is common in the older population. Despite this, there is no consensus definition for polypharmacy. A systematic review was conducted to identify and summarise polypharmacy definitions in existing literature. The reporting of this systematic review conforms to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) checklist. MEDLINE (Ovid), EMBASE and Cochrane were systematically searched, as well as grey literature, to identify articles which defined the term polypharmacy (without any limits on the types of definitions) and were in English, published between 1st January 2000 and 30th May 2016. Definitions were categorised as i. numerical only (using the number of medications to define polypharmacy), ii. numerical with an associated duration of therapy or healthcare setting (such as during hospital stay) or iii. Descriptive (using a brief description to define polypharmacy). A total of 1156 articles were identified and 110 articles met the inclusion criteria. Articles not only defined polypharmacy but associated terms such as minor and major polypharmacy. As a result, a total of 138 definitions of polypharmacy and associated terms were obtained. There were 111 numerical only definitions (80.4% of all definitions), 15 numerical definitions which incorporated a duration of therapy or healthcare setting (10.9%) and 12 descriptive definitions (8.7%). The most commonly reported definition of polypharmacy was the numerical definition of five or more medications daily (n = 51, 46.4% of articles), with definitions ranging from two or more to 11 or more medicines. Only 6.4% of articles classified the distinction between appropriate and inappropriate polypharmacy, using descriptive definitions to make this distinction. Polypharmacy definitions were variable. Numerical definitions of polypharmacy did not account for specific comorbidities present and make it difficult to assess safety and appropriateness of therapy in the clinical setting.

Racism and Health I: Pathways and Scientific Evidence

Abstract: This article reviews the scientific research that indicates that despite marked declines in public support for negative racial attitudes in the United States, racism, in its multiple forms, remains embedded in American society. The focus of the article is on the review of empirical research that suggests that racism adversely affects the health of nondominant racial populations in multiple ways. First, institutional racism developed policies and procedures that have reduced access to housing, neighborhood and educational quality, employment opportunities, and other desirable resources in society. Second, cultural racism, at the societal and individual level, negatively affects economic status and health by creating a policy environment hostile to egalitarian policies, triggering negative stereotypes and discrimination that are pathogenic and fostering health-damaging psychological responses, such as stereotype threat and internalized racism. Finally, a large and growing body of evidence indicates that experiences of racial discrimination are an important type of psychosocial stressor that can lead to adverse changes in health status and altered behavioral patterns that increase health risks.

Microglial priming in neurodegenerative disease.

Abstract: Under physiological conditions, the number and function of microglia--the resident macrophages of the CNS--is tightly controlled by the local microenvironment. In response to neurodegeneration and the accumulation of abnormally folded proteins, however, microglia multiply and adopt an activated state--a process referred to as priming. Studies using preclinical animal models have shown that priming of microglia is driven by changes in their microenvironment and the release of molecules that drive their proliferation. Priming makes the microglia susceptible to a secondary inflammatory stimulus, which can then trigger an exaggerated inflammatory response. The secondary stimulus can arise within the CNS, but in elderly individuals, the secondary stimulus most commonly arises from a systemic disease with an inflammatory component. The concept of microglial priming, and the subsequent exaggerated response of these cells to secondary systemic inflammation, opens the way to treat neurodegenerative diseases by targeting systemic disease or interrupting the signalling pathways that mediate the CNS response to systemic inflammation. Both lifestyle changes and pharmacological therapies could, therefore, provide efficient means to slow down or halt neurodegeneration.