Is screening for AF worthwhile? Stroke risk in a screened population from the SAFE study.

INTRODUCTION: Atrial fibrillation (AF) is an important independent risk factor for stroke and oral anticoagulation therapy provides a highly effective treatment to reduce this risk. Active screening strategies improve detection of AF in comparison with routine care; however, whether screen-detected patients have stroke risk profiles favouring anticoagulation is unclear. Using data derived from the screening for AF in the elderly (SAFE) study, the aim of this article was to determine if patients with AF detected via active screening have stroke risk profiles that warrant prophylactic anticoagulation. METHODS: Secondary analysis of data derived from 25 general practices within which cohorts of 200 patients were randomly allocated to opportunistic [pulse and electrocardiogram (ECG)] or systematic screening (postal invitation for ECG). Stroke risk assessment was undertaken using baseline data extracted from medical records and CHADS2 criteria. CHADS2 scores were compared between the screening groups. RESULTS: One hundred and forty-nine new cases of AF were detected, 75 via opportunistic screening and 74 via systematic screening. CHADS2 scores were ≥1 in 83% [95% confidence interval (CI) 72.6-89.6] of patients detected via opportunistic screening and 78% (95% CI 67.7-86.2) detected via systematic screening. There were no significant differences in stroke risk profiles of patients detected via opportunistic and systematic screenings. CONCLUSION: Stroke risk profiles of patients detected via opportunistic and systematic screenings were similar. Data derived from the SAFE study suggest that active screening for AF in patients aged ≥65 years in primary care is a useful screening programme with 78-83% of patients identified eligible for anticoagulation treatment according to the CHADS2 criteria.

External quality assessment for warfarin dosing using computerised decision support software.

AIM: To establish and evaluate an external quality assessment scheme for warfarin dosing for users of a computerised decision support system, BAP-PC. DESIGN: Analysis of 12 months of clinical data from 10 primary care centres using BAP-PC within an oral anticoagulation clinic. Data were analysed for individual centres and compared with aggregated data for all practices. Individual feedback forms were provided to participating centres. RESULTS: A total patient population of 367 (range, 17-65/centre) was analysed. On average, patients spent 69% of time in the therapeutic range (range, 60-76%). Patients were seen on average every 27 days (range, 24-30). The average point prevalence was 86% (range, 76-100%). In total, 33 adverse events were reported (0-13/practice). Serious adverse events ranged from 0 to 1 for each practice. This translates into a serious adverse event rate of 1.6/100 patient years. CONCLUSIONS: Practices were successful in maintaining good therapeutic international normalised ratio control, with centres achieving 60% or higher time in range. There are some doubts about the quality of data collection at a practice level because there were no reported events in half of the participating centres. The observed event rates do concur with previously reported data, however. Further cycles of the scheme are necessary to establish it as a useful research and benchmarking tool.

Patient self management of oral anticoagulation in routine care in the UK.

BACKGROUND: Self management of anticoagulation: a randomised trial (SMART) was the first large scale UK trial to assess clinical and cost effectiveness of patient self management (PSM) of oral anticoagulation therapy compared to routine care. SMART showed that while PSM was as clinically effective as routine care, it was not as cost effective. SMART adds to the growing body of trial data to support PSM; however there are no data on clinical effectiveness and cost of PSM in routine care. AIM: To evaluate clinical effectiveness of PSM compared to routine care outside trial conditions. METHODS: A retrospective multicentre matched control study. 63 PSM patients from primary care in the West Midlands were matched by age and international normalised ratio (INR) target with controls. INR results were collected for the period 1 July 2003-30 June 2004. The primary outcome measure was INR control. RESULTS: 38 PSM and 40 control patients were recruited. INR percentage time in range was 70% PSM vs 64% controls. 60% PSM were having a regular clinical review, 45% were performing an internal quality control (IQC) test and 82% were performing external quality assurance (EQA) on a regular basis. CONCLUSION: PSM outside trial conditions is as clinically effective as routine UK care.

Self management of oral anticoagulation: randomised trial.

OBJECTIVE: To determine the clinical effectiveness of self management compared with routine care in patients on long term oral anticoagulants. DESIGN: Multicentre open randomised controlled trial. SETTING: Midlands region of the UK. PARTICIPANTS: 617 patients aged over 18 and receiving warfarin randomised to intervention (n = 337) and routine care (n = from 2470 invited; 193/337 (57%) completed the 12 month intervention. INTERVENTION: Intervention patients used a point of care device to measure international normalised ratio twice a week and a simple dosing chart to interpret their dose of warfarin. MAIN OUTCOME MEASURE: Percentage of time spent within the therapeutic range of international normalised ratio. RESULTS: No significant differences were found in percentage of time in the therapeutic range between self management and routine care (70% v 68%). Self managed patients with poor control before the study showed an improvement in control that was not seen in the routine care group. Nine patients (2.8/100 patient years) had serious adverse events in the self managed group, compared with seven (2.7/100 patient years) in the routine care arm (chi2(df = 1) = 0.02, P = 0.89). CONCLUSION: With appropriate training, self management is safe and reliable for a sizeable proportion of patients receiving oral anticoagulation treatment. It may improve the time spent the therapeutic range for patients with initially poor control. Trial registration ISRCTN 19313375.