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Thorax 67:1052-1060 doi:10.1136/thoraxjnl-2012-202093
  • Original articles
    • Asthma

The at-risk registers in severe asthma (ARRISA) study: a cluster-randomised controlled trial examining effectiveness and costs in primary care

  1. Andrew M Wilson1
  1. 1Norwich Medical School, University of East Anglia, Norwich, UK
  2. 2Acle Medical Centre, Acle, Norfolk, UK
  3. 3School of Nursing Sciences, University of East Anglia, Norwich, UK
  4. 4Research in Real Life Ltd, Cawston, Norfolk, UK
  1. Correspondence to Dr Jane Rebecca Smith, Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, UK; j.r.smith{at}uea.ac.uk
  1. Contributors All authors had full access to all of the data (including statistical reports and tables) in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis. JRS was a joint principal investigator. She was involved in the pilot study, contributed to the original protocol design, led the funding application and co-ordinated the overall running of the project. She oversaw the outcome and cost analyses, contributed to interpretation of findings and drafted and edited the paper. MJN led the pilot study, contributed to protocol design, led the design and delivery of the intervention, advised on data collection and coding, contributed to interpretation of findings, drafted sections on the intervention in the methods and commented on drafts. SM was responsible for day-to-day project management, undertook practice recruitment and liaison, was involved in data collection, coding and management, drafted sections on recruitment, data collection and coding in the methods, contributed to interpretation of findings and commented on drafts. JM undertook practice recruitment and liaison, was involved in data collection, coding and management, drafted sections on data collection and coding in the methods, and commented on drafts. GMP oversaw randomisation, planned and conducted outcomes analyses, contributed to interpretation of findings, drafted sections/tables on the outcomes analyses in the methods and results, and commented on drafts. GRB conducted and interpreted the cost analyses, drafted sections on costs in the methods and results, and commented on drafts. JW was involved in the pilot study, contributed to intervention design and delivery, and commented on drafts. RH contributed to protocol design and the funding application, advised on analyses, and commented on drafts. BDWH contributed to protocol design, advised on data coding, contributed to interpretation of findings, and commented on drafts. AH commented on the funding application, advised on intervention design and delivery, and commented on drafts. DBP advised on data collection, coding and management, and commented on drafts. IH commented on protocol design, advised on analyses, and commented on drafts. AMW was a joint principal investigator. He contributed to the original protocol design and funding application, and gained ethical and regulatory approvals. He chaired the trial steering group meetings, was involved with the analysis plan, commented on drafts and edited the final paper.

  • Received 27 April 2012
  • Accepted 15 July 2012
  • Published Online First 31 August 2012

Abstract

Background Patients at risk of severe exacerbations contribute disproportionally to asthma mortality, morbidity and costs. We evaluated the effectiveness and costs of using ‘asthma risk registers’ for these patients in primary care.

Methods In a cluster-randomised trial, 29 primary care practices identified 911 at-risk asthma patients using British asthma guideline criteria (severe asthma plus adverse psychosocial characteristics). Intervention practices added electronic alerts to identified patients' records to flag their at-risk status and received practice-based training about using the alerts to improve patient access and opportunistic management. Control practices continued routine care. Numbers of patients experiencing the primary outcome of a moderate-severe exacerbation (resulting in death, hospitalisation, accident and emergency attendance, out-of-hours contact, or a course/boost in oral prednisolone for asthma), other healthcare and medication usage, and costs over 1 year were derived from practice-based records.

Results There was no significant effect on exacerbations (control: 46.5%; intervention: 53.6%, OR, 95% CI 1.30, 0.93 to 1.80). However, this composite outcome masked relative reductions in intervention patients experiencing hospitalisations (OR 0.50, 95% CI 0.26 to 0.94), accident and emergency (OR 0.74, 95% CI 0.42 to 1.31) and out-of-hours contacts (OR 0.79, 95% CI 0.45 to 1.37); and a relative increase in prednisolone prescription for exacerbations (OR 1.31, 95% CI 0.92 to 1.85). Furthermore, prescription of nebulised short-acting β-agonists reduced and long-acting β-agonists increased for intervention relative to control patients. The adjusted mean per patient healthcare cost was £138.21 lower (p=0.837) among intervention practices.

Conclusion Using asthma risk registers in primary care did not reduce treated exacerbations, but reduced hospitalisations and increased prescriptions of recommended preventative therapies without increasing costs.

Footnotes

  • Funding This study was funded by Asthma UK (Project no. 06/047). Neither the funder nor sponsor had a role in the design, data collection, analysis, interpretation, writing up, or decision to submit for publication, responsibility for which rested solely with the authors.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by Norfolk Research Ethics Committee (reference number 06/Q0101/200).

  • Provenance and peer review Not commissioned; externally peer reviewed.