Using electronic data from primary care to inform decision making for hypertension in the elderly

Mitchell, Elizabeth Dumigan (2004) Using electronic data from primary care to inform decision making for hypertension in the elderly. PhD thesis, University of Glasgow.

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Hypertension is a major risk factor for cardiovascular disease and the main risk factor for stroke. Previous research has demonstrated that treatment of hypertension significantly reduces cardiovascular risk and the incidence of cardiovascular events. Since the prevalence of hypertension increases with age, so the absolute reduction in risk associated with treatment and its resultant benefits are greater in the elderly population. Despite this, a situation known as the rale of halves has been shown to exist. This indicates that half of the hypertensive population are not known, half of those known are not treated and half of those treated are not controlled. Addressing this anomaly requires information on all potentially at risk patients and accessing the large amounts of data held in general practice computer systems is one of the best ways of generating such information. However, whilst practitioners can access the information required to inform management of individual patients, the data required to inform strategic decision making are not as readily available. The research described in this thesis evaluates the provision of different levels of feedback, developed from computerized data, on identification, treatment and control of hypertension in the elderly. This was done by means of a randomised controlled trial. Fifty two Scottish general practices were recruited and randomised to three groups. A Control group which received no intervention, an Audit group which received feedback of audit data and a Strategic group which received audit feedback plus data prioritising patients by absolute risk of death from stroke. Electronic data on demography, morbidity and prescribing were extracted from practice computer systems annually from 1999-2001 and used to develop feedback. Participants represented both urban and rural practice and a range of practice size, list size and deprivation level. The data presented demonstrate that over the period of study, the proportion of 65-79 years olds with a blood pressure recorded increased, with the largest improvement seen in the Audit group. At the outset, 30-40% of the patients whose blood pressure was 160/90 mm Hg had been identified as being hypertensive. This improved in all three groups, the improvement made in the Audit and Control groups being two to three times that made in the Strategic group. The majority of diagnosed hypertensives were initially receiving treatment and this increased to more than 90% in all three groups. The greatest improvement was seen in the Strategic group. Around 40% of treated patients in each group had controlled high blood pressure at the outset of the study and this rose by around 10%. The lowest mean systolic blood pressure was found in the Strategic group, whilst the greatest proportions of controlled hypertensive patients were found in the Strategic and Control groups. However, after adjusting for clustering, patient and practice effects, there was a significant difference in the level of control in the Strategic group compared with the other two groups. Absolute risk was reduced for between 10-20% of patients in each group, with the largest reduction found in the Strategic group. More than 80% of the patients in that group had their blood pressure record updated compared with only half of the patients in the Audit and Control groups. In addition, twice as many patients in the Strategic group had their record changed to reflect that they did not smoke and fewer patients in that group were newly recorded as smokers. There was no significant difference in the numbers of patients in each group who had a stroke during the study period. Improvements were demonstrated in all aspects of the rule of halves, a finding supported by other studies in this area. Whilst 60%> of all hypertensive patients and 40% of treated hypertensives were still not controlled at the end of the study, the results suggest that providing practices with patient specific, strategic feedback can impact on identification and management of hypertension in the elderly, producing a consequent increase in blood pressure control. The study also demonstrates the utility of electronic primary care data and highlights the importance of practice organisation in the management of chronic disease.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Keywords: Medicine.
Colleges/Schools: College of Medical Veterinary and Life Sciences
Supervisor's Name: Watt, Prof. Graham
Date of Award: 2004
Depositing User: Enlighten Team
Unique ID: glathesis:2004-71174
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 10 May 2019 10:49
Last Modified: 17 Aug 2021 08:47
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