A randomised controlled trial and cost-effectiveness study of systematic screening (targeted and total population screening) versus routine practice for the detection of atrial fibrillation in people aged 65 and over. The SAFE study

Hobbs F D R, Fitzmaurice D A, Mant J, Murray E, Jowett S, Bryan S, Raftery J, Davies M, Lip G
Record ID 32005001182
English
Authors' objectives:

The aim of this report was to determine the most cost-effective method of screening for atrial fibrillation (AF) in the population aged 65 years and over, as well as its prevalence and incidence in this age group, and also to evaluate the relative cost-effectiveness of different methods of recording and interpreting the electrocardiogram (ECG) within a screening programme.

Authors' results and conclusions: Baseline prevalence of AF was 7.2%, with a higher prevalence in males (7.8%) and patients aged 75 years and over (10.3%). The control population demonstrated higher baseline prevalence (7.9%) than either the systematic (6.9%) or opportunistic (6.9%) intervention population. In the control population 47 new cases were detected (incidence 1.04% per year). In the opportunistic arm 243 patients without a baseline diagnosis of AF were found to have an irregular pulse, with 177 having an ECG, yielding 31 new cases (incidence 0.69% per year). A further 44 cases were detected outside the screening programme (overall incidence 1.64% per year). In the systematic arm 2357 patients had an ECG yielding 52 new cases (incidence 1.1% per year). Of these, 31 were detected by targeted screening and a further 21 by total population screening. A further 22 cases were detected outside the screening programme (overall incidence 1.62% per year). In terms of ECG interpretation, computerised decision support software (CDSS) gave a sensitivity of 87.3%, a specificity of 99.1% and a positive predictive value (PPV) of 89.5% compared with the gold standard (cardiologist reporting). GPs and practice nurses performed less well. The only difference in performance between intervention populations and controls was that practice nurses from the control arm performed less well than with intervention practice nurses on interpretation of limb-lead (PPV 38.8% versus 20.8%) and single-lead (PPV 37.7% versus 24.0%) ECGs.
Authors' recommendations: The results of the study indicated that in terms of a screening programme for atrial fibrillation in patients 65 and over, the only strategy that improved on routine practice was opportunistic screening, model-based analyses indicated that there was a probability of approximately 60% of annual opportunistic screening being cost effective. It is suggested that the following topics are worthy of further investigation: the effect of the implementation of a screening programme for AF on the uptake and maintenance of anticoagulation in patients aged 65 years and over; an evaluation of the role of CDSS in the diagnosis of cardiac arrythmias; the best method for routinely detecting paroxysmal AF; ways of improving healthcare professionals- performance in ECG interpretation; development of a robust economic model to incorporate data on new therapeutic agents for use as thromboprophylactic agents for patients with AF, and an evaluation of the relative risk of stroke for patients with incident as opposed to prevalent AF.
Authors' methods: Randomised controlled trial
Details
Project Status: Completed
URL for project: http://www.hta.ac.uk/1129
Year Published: 2005
English language abstract: An English language summary is available
Publication Type: Not Assigned
Country: England, United Kingdom
MeSH Terms
  • Aged
  • Atrial Fibrillation
  • Costs and Cost Analysis
  • Mass Screening
Contact
Organisation Name: NIHR Health Technology Assessment programme
Contact Address: NIHR Journals Library, National Institute for Health and Care Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK
Contact Name: journals.library@nihr.ac.uk
Contact Email: journals.library@nihr.ac.uk
Copyright: 2009 Queen's Printer and Controller of HMSO
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