James P Sheppard

Impact of age and sex on primary preventive treatment for cardiovascular disease in the West Midlands, UK: cross sectional study.

Objectives To establish the impact of age and sex on primary preventive treatment for cardiovascular disease in a typical primary care population. Design Cross sectional study of anonymised patient records. Participants All 41 250 records of patients aged ≥40 registered at 19 general practices in the West Midlands, United Kingdom, were extracted and analysed. Main outcome measures Patients’ demographics, risk factors for cardiovascular disease (blood pressure, total cholesterol concentration), and prescriptions for primary preventive drugs were extracted from patients’ records. Patients were subdivided into five year age bands up to 85 (patients aged ≥85 were analysed as one group) and prescribing trends across the population were assessed by estimating the proportion of patients prescribed with antihypertensive drug or statin drug, or both, in each group. Results Of the 41 250 records screened in this study, 36 679 (89%) patients did not have a history of cardiovascular disease and therefore could be considered for primary preventive treatment. The proportion receiving antihypertensive drugs increased with age (from 5% (378/6978) aged 40-44 to 57% (621/1092) aged ≥85) as did the proportion taking statins up to the age of 74 (from 3% (201/6978) aged 40-44 to 29% (675/2367) aged 70-74). In those aged 75 and above, the odds of a receiving prescription for a statin (relative to the 40-44 age group) decreased with every five year increment in age (odds ratio 12.9 (95% confidence interval 10.8 to 15.3) at age 75-79 to 5.7 (4.6 to 7.2) at age ≥85; P<0.001). There were no consistent differences in prescribing trends by sex. Conclusions Previously described undertreatment of women in secondary prevention of cardiovascular disease was not observed for primary prevention. Low use of statins in older people highlights the need for a stronger evidence base and clearer guidelines for people aged over 75.

Accuracy of ambulatory blood pressure monitors: A systematic review of validation studies

Background: Recent research and guidelines recommend the routine use of ambulatory blood pressure monitoring for the diagnosis of hypertension, so accuracy of such monitors is more important than ever. Aim: To systematically review the literature regarding the accuracy of ambulatory monitors currently in use. Methods: Medline, Embase, Cinahl, the Cochrane database, Medion and the dabl Educational Trust website were searched until February 2011. No language or publication date limits were applied. Data were extracted separately by two independent reviewers. Methodological quality was assessed by whether a validation protocol had been used and followed correctly. Results: From 5420 journal articles identified, 108 met the inclusion criteria. Excluding studies assessing monitors no longer in use, 40 relevant studies were found using 21 different monitors. Thirty-eight (95%) studies used a validation protocol of which 28 studies assessed a monitor in the general population. Of these, protocols were passed in 24 of 28 studies, but 12 of 24 (50%) found a difference of at least 5 mmHg systolic between the test device and the reference standard for 30% or more of the readings. Of the 10 studies conducted in special population groups (e.g. pregnancy, elderly people), only four devices passed the protocols. Only six (16%) studies correctly adhered to the protocols. Conclusion: Published validation studies assessed most ambulatory monitors as accurate, but many failed to adhere to the underlying protocols, undermining this conclusion and peer review standards. Furthermore, most monitors which ‘passed’ validation showed significant variation in blood pressure from the reference standard, highlighting inadequacies in older validation protocols. Future validation studies should use protocols with simpler methodologies but more rigorous accuracy criteria.

Prognostic Significance of the Morning Blood Pressure Surge in Clinical Practice: A Systematic Review

BACKGROUND An exaggerated morning blood pressure surge (MBPS) may be associated with stroke and other cardiovascular events, but the threshold at which an MBPS becomes pathological is unclear. This study aimed to systematically review the existing literature and establish the most appropriate definition of pathological MBPS. METHODS A MEDLINE search strategy was adapted for a range of literature databases to identify all prospective studies relating an exaggerated MBPS to cardiovascular endpoints. Hazard ratios (HRs) were extracted and synthesized using random-effects meta-analysis. RESULTS The search strategy identified 2,964 unique articles, of which 17 were eligible for the study. Seven different definitions of MBPS were identified; the most common was a prewaking surge (mean blood pressure for 2 hours after wake-up minus mean blood pressure for 2 hours before wake-up; n = 6 studies). Summary meta-analysis gave no clear evidence that prewaking MBPS (defined by a predetermined threshold: >25–55mm Hg) was associated with all cardiovascular events (n = 2 studies; HR = 0.94, 95% confidence interval (CI) = 0.39–2.28) or stroke (n = 2 studies; HR = 1.26, 95% CI = 0.92–1.71). However, using a continuous scale, which has more power to detect an association, there was evidence that a 10 mm Hg increase in MBPS was related to an increased risk of stroke (n = 3 studies; HR = 1.11, 95% CI = 1.03–1.20). CONCLUSIONS These findings suggest that when measured and analyzed as a continuous variable, increasing levels of MBPS may be associated with increased risk of stroke. Large, protocol-driven individual patient data analyses are needed to accurately define this relationship further.

The association between prehospital care and in-hospital treatment decisions in acute stroke: a cohort study

Background Hospital prealerting in acute stroke improves the timeliness of subsequent treatment, but little is known about the impact of prehospital assessments on in-hospital care. Objective Examine the association between prehospital assessments and notification by emergency medical service staff on the subsequent acute stroke care pathway. Methods This was a cohort study of linked patient medical records. Consenting patients with a diagnosis of stroke were recruited from two urban hospitals. Data from patient medical records were extracted and entered into a Cox regression analysis to investigate the association between time to CT request and recording of onset time, stroke recognition (using the Face Arm Speech Test (FAST)) and sending of a prealert message. Results 151 patients (aged 71±15 years) travelled to hospital via ambulance and were eligible for this analysis. Time of symptom onset was recorded in 61 (40%) cases, the FAST test was positive in 114 (75%) and a prealert message was sent in 65 (44%). Following adjustment for confounding, patients who had time of onset recorded (HR 0.73, 95% CI 0.52 to 1.03), were FAST-positive (HR 0.54, 95% CI 0.37 to 0.80) or were prealerted (HR 0.26, 95% CI 0.18 to 0.38), were more likely to receive a timely CT request in hospital. Conclusions This study highlights the importance of hospital prealerting, accurate stroke recognition, and recording of onset time. Those not recognised with stroke in a prehospital setting appear to be excluded from the possibility of rapid treatment in hospital, even before they have been seen by a specialist.

Predicting out-of-office blood pressure level using repeated measurements in the clinic: an observational cohort study.

Objectives: Identification of people with lower (white-coat effect) or higher (masked effect) blood pressure at home compared to the clinic usually requires ambulatory or home monitoring. This study assessed whether changes in SBP with repeated measurement at a single clinic predict subsequent differences between clinic and home measurements. Methods: This study used an observational cohort design and included 220 individuals aged 35–84 years, receiving treatment for hypertension, but whose SBP was not controlled. The characteristics of change in SBP over six clinic readings were defined as the SBP drop, the slope and the quadratic coefficient using polynomial regression modelling. The predictive abilities of these characteristics for lower or higher home SBP readings were investigated with logistic regression and repeated operating characteristic analysis. Results: The single clinic SBP drop was predictive of the white-coat effect with a sensitivity of 90%, specificity of 50%, positive predictive value of 56% and negative predictive value of 88%. Predictive values for the masked effect and those of the slope and quadratic coefficient were slightly lower, but when the slope and quadratic variables were combined, the sensitivity, specificity, positive and negative predictive values for the masked effect were improved to 91, 48, 24 and 97%, respectively. Conclusion: Characteristics obtainable from multiple SBP measurements in a single clinic in patients with treated hypertension appear to reasonably predict those unlikely to have a large white-coat or masked effect, potentially allowing better targeting of out-of-office monitoring in routine clinical practice.

Predictors of the Home-Clinic Blood Pressure Difference: A Systematic Review and Meta-Analysis

BACKGROUND Patients may have lower (white coat hypertension) or higher (masked hypertension) blood pressure (BP) at home compared to the clinic, resulting in misdiagnosis and suboptimal management of hypertension. This study aimed to systematically review the literature and establish the most important predictors of the home-clinic BP difference. METHODS A systematic review was conducted using a MEDLINE search strategy, adapted for use in 6 literature databases. Studies examining factors that predict the home-clinic BP difference were included in the review. Odds ratios (ORs) describing the association between patient characteristics and white coat or masked hypertension were extracted and entered into a random-effects meta-analysis. RESULTS The search strategy identified 3,743 articles of which 70 were eligible for this review. Studies examined a total of 86,167 patients (47% female) and reported a total of 60 significant predictors of the home-clinic BP difference. Masked hypertension was associated with male sex (OR 1.47, 95% confidence interval (CI) 1.18–1.75), body mass index (BMI, per kg/m2 increase, OR 1.07, 95% CI 1.01–1.14), current smoking status (OR 1.32, 95% CI 1.13–1.50), and systolic clinic BP (per mm Hg increase, OR 1.10, 95% CI 1.01–1.19). Female sex was the only significant predictor of white coat hypertension (OR 3.38, 95% CI 1.64–6.96). CONCLUSIONS There are a number of common patient characteristics that predict the home-clinic BP difference, in particular for people with masked hypertension. There is scope to incorporate such predictors into a clinical prediction tool which could be used to identify those patients displaying a significant masked or white coat effect in routine clinical practice.

Cost-Effectiveness of Optimizing Acute Stroke Care Services for Thrombolysis

Background and Purpose— Thrombolysis in acute stroke is effective up to 4.5 hours after symptom onset but relies on early recognition, prompt arrival in hospital, and timely brain scanning. This study aimed to establish the cost-effectiveness of increasing thrombolysis rates through a series of hypothetical change strategies designed to optimize the acute care pathway for stroke. Methods— A decision-tree model was constructed, which relates the acute management of patients with suspected stroke from symptom onset to outcome. Current practice was modeled and compared with 7 change strategies designed to facilitate wider eligibility for thrombolysis. The model basecase consisted of data from consenting patients following the acute stroke pathway recruited in participating hospitals with data on effectiveness of treatment and costs from published sources. Results— All change strategies were cost saving while increasing quality-adjusted life years gained. Using realistic estimates of effectiveness, the change strategy with the largest potential benefit was that of better recording of onset time, which resulted in 3.3 additional quality-adjusted life years and a cost saving of US

Movement-based estimation and visualization of space use in 3D for wildlife ecology and conservation

46 000 per 100 000 population. All strategies increased the number of thrombolysed patients and the number requiring urgent brain imaging (by 9% to 21% dependent on the scenario). Assuming a willingness-to-pay of US

Predicting Out-of-Office Blood Pressure in the Clinic (PROOF-BP): Derivation and Validation of a Tool to Improve the Accuracy of Blood Pressure Measurement in Clinical Practice

30 000 per quality-adjusted life year gained, the potential budget available to deliver the interventions in each strategy ranged from US

Modern Management and Diagnosis of Hypertension in the United Kingdom: Home Care and Self-care.

50 000 to US