title: Point-of-care cluster randomized trial in stroke secondary prevention using electronic health records.
abstract: OBJECTIVE
  The aim of this study was to evaluate whether the remote introduction of electronic decision support tools into family practices improves risk factor control after first stroke. This study also aimed to develop methods to implement cluster randomized trials in stroke using electronic health records.
  
  
  METHODS
  Family practices were recruited from the UK Clinical Practice Research Datalink and allocated to intervention and control trial arms by minimization. Remotely installed, electronic decision support tools promoted intensified secondary prevention for 12 months with last measure of systolic blood pressure as the primary outcome. Outcome data from electronic health records were analyzed using marginal models.
  
  
  RESULTS
  There were 106 Clinical Practice Research Datalink family practices allocated (intervention, 53; control, 53), with 11 391 (control, 5516; intervention, 5875) participants with acute stroke ever diagnosed. Participants at trial practices had similar characteristics as 47,887 patients with stroke at nontrial practices. During the intervention period, blood pressure values were recorded in the electronic health records for 90% and cholesterol values for 84% of participants. After intervention, the latest mean systolic blood pressure was 131.7 (SD, 16.8) mm Hg in the control trial arm and 131.4 (16.7) mm Hg in the intervention trial arm, and adjusted mean difference was -0.56 mm Hg (95% confidence interval, -1.38 to 0.26; P=0.183). The financial cost of the trial was approximately US $22 per participant, or US $2400 per family practice allocated.
  
  
  CONCLUSIONS
  Large pragmatic intervention studies may be implemented at low cost by using electronic health records. The intervention used in this trial was not found to be effective, and further research is needed to develop more effective intervention strategies.
  
  
  BACKGROUND
  http://www.controlled-trials.com. Current Controlled Trials identifier: ISRCTN35701810.
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Alex
authors.initials: A
authors.lastname: Dregan
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Tjeerd P
authors.initials: TP
authors.lastname: van Staa
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Lisa
authors.initials: L
authors.lastname: McDermott
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Gerard
authors.initials: G
authors.lastname: McCann
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Mark
authors.initials: M
authors.lastname: Ashworth
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Judith
authors.initials: J
authors.lastname: Charlton
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Charles D A
authors.initials: CD
authors.lastname: Wolfe
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Anthony
authors.initials: A
authors.lastname: Rudd
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.).
authors.forename: Lucy
authors.initials: L
authors.lastname: Yardley
authors.affiliation: From the Department of Primary Care and Public Health Sciences, King's College London, London, United Kingdom (A.D., L.M., M.A., J.C., C.D.A.W., A.R., M.C.G.); NIHR Biomedical Research Centre at Guy's and St Thomas' Hospital London, London, United Kingdom (A.D., C.D.A.W., A.R., M.C.G.); Clinical Practice Research Datalink (CPRD), Medicines and Healthcare Products Regulatory Agency, London, United Kingdom (T.P.v.S., G.M.); London School of Hygiene & Tropical Medicine, London, United Kingdom (T.P.v.S.); and Division of Community Clinical Sciences, University of Southampton, Southampton, United Kingdom (L.M., L.Y.). martin.gulliford@kcl.ac.uk.
authors.forename: Martin C
authors.initials: MC
authors.lastname: Gulliford
authors.lastname: Trial Steering Committee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D057286:Electronic Health Records / Q000706:statistics & numerical data; D005194:Family Practice / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D016032:Randomized Controlled Trials as Topic / Q000191:economics / Q000592:standards / Q000706:statistics & numerical data; D020521:Stroke / Q000191:economics / Q000503:physiopathology / Q000517:prevention & control* / Q000628:therapy; D006113:United Kingdom
keywords: blood pressure; cholesterol; electronic health records; intervention studies; secondary prevention; stroke