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The Application of CO PC Principles in a Welsh Mining Village Graham Watt Glyncorrwg is a compact and isolated industrial village situated in the South Wales valleys. It is separated from the next village by 2~/' miles of road and from everywhere else by mountains. The last coal mine closed in 1970, and unemployment currently stands at 38 percent. There are 2,050 patients (about 97 percent of the population) registered at the health center with a single general practitioner, Dr. Julian Tudor Hart, who has been in practice since 1962. Patient consultation rates and hospital admission rates are 60 percent above the national average. This is typical of general practice in the South Wales valleys, where overall mortality is 30 percent above average. This burden of ill health is a legacy from the industrial period. In addition to coping with present illness, practice policy has been to develop an approach that anticipates ill health in the whole population served. There is also a busy research program. For the sake of brevity, these activities will be described in relation to a single clinical problem—the control of blood pressure. THE BLOOD PRESSURE PROGRAM Case-finding for high blood pressure began in 1968. At that time, before the results of the Veterans Administration Study were available, treatment of high blood pressure seemed the measure most likely to reduce the burden of morbidity and mortality from ischemic heart disease. Death rates from 243
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244 PART II: PRACTICAL APPLICATIONS this condition in men aged 35-44 were 70 percent above the national average at that time.) On reviewing the clinical notes, only half of the men aged 20-64 had had their blood pressure recorded during the previous 5 years. Rather than organize an intensive screening program, it was decided to collect the re- maining blood pressures on a casual basis, as patients attended the health center during the next 12 months. When 10 percent were still outstanding, letters were sent out asking patients to attend the health center, and a third complied. The remainder had their blood pressure measured at home. Ascertainment of the male population was complete after 15 months; as- certainment of the female population took a similar period. The process was described in Lcz~cet,2 showing that ascertainment had been completed without adding significantly tO the routine workload of the practice. The number of known hypertensives was increased from 15 tO 38, and 32 were started on or continued treatment. Only one man made a conditional refusal (that he would take part only if he became the sole nonrespondent); he had a diastolic pressure of 170 mrn/Hg at the age of 44 without symptoms. His blood pressure had never been taken before, and he is alive today after 14 years of treatment for his hypertension. Initial ascertainment is one problem; treatment and follow-up are quite another. The system we use is as follows. All patients have their blood pressure measured on the first occasion they consult after their twentieth birthday. A red sticker is then placed in their clinical notes indicating when the next measurement is due. For normotensives, it is not for another 5 years. For borderline hypertensives, it iS not for another 12 months. Patients on treatment have a red sticker put on the outside of their notes indicating that their blood pressure is due to be measured every 3 months. Whenever a patient consults, the receptionist notes when the blood pressure is due, and, if so, arranges for the practice nurse to measure it before the patient sees the doctor. All measurements are taken with a random zero sphyg- momanometer. Treatment is begun when the mean of three consecutive readings exceeds 105 mm Hg diastolic and/or 180 mm Hg systolic. Re- cently, patients have been trained to measure their blood pressure them- selves at home for a 2-week period in order to increase the amount of data on which decisions to treat are based. Initially all this work was incorporated into the normal practice routine, but since 1974 there has been a monthly evening hypertension clinic. About two-thirds of patients on treatment are reviewed at this clinic every 3 months, but a third are still seen at other times, indicating that for many patients hypertension is not their only medical problem. The follow-up of treated hypertensives was reviewed initially using a simple card-box system, indicating which patients were due to be seen each
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COPC in ~ Welsh Mining Village 245 month, and allowing rapid identification and outstanding pressures. More recently, the system has been computerized, and every blood pressure measurement taken at the health center or at home is recorded on a data sheet (along with other quantitative data, e.g., pulse, weight, number of cigarettes smoked, and peak flow rate). Every month the computer provides a printout indicating those patients whose pressures are outstanding in each of three categories treated hypertensives, borderline hypertensives' and normotensives. After 14 years the key question is, how effective has the blood pressure program been? We lack the numbers of patients and resources required to study this question in detail, but there are several indications that the program is working well. Figure 1 shows the number of patients aged 20- 64 treated for diastolic hypertension between 1968 and 19~32. It shows that 71 patients have been recruited to join the 32 who formed the treatment group in 1968. Of these 103 patients, 66 are alive, 34 dead, and 3 moved away. Diagnostic categories have not changed, and there is no evidence of an epidemic of high blood pressure in South Wales. We conclude that the steady enlargement of the treatment group is evidence that we are altering the natural history of high blood pressure in the Glyncorrwg population. Table 1 contains data on the adequacy of blood pressure control in 80 patients who were on treatment on February 1, 1982 (this includes some patients treated for systolic and borderline diastolic hypertension). It shows that 69 percent of patients had a diastolic pressure less than 90 mm Hg, and 59 percent had a systolic pressure less than 160 mm Hg. These figures compare favorably with mean pretreatment pressures of 114 mm Hg dia- astolic and 191 mm Hg systolic. The proportion with diastolic pressures Initial Ascertainment in 1968 32 Hypertensives Subsequent Recru itment 1968- 1 982 71 Hypertensives \ Total Number 103 Hypertensives Outcome 1982 66 Alive 34 Dead 3 Moved Away FUGUE 1 Number of patients treated for hypertension between 1968 and 1982, with diastolic pressures ~105 mm Hg (40-60 years), ~100 mm Hg (20-39 years).
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246 PART II: PRACTICAL APPLICATIONS TABLE 1 Control of Blood Pressure in 80 Patients as of February 1, 1982 . . . Diastolic Systolic Pressure Percent of Pressure Percent of Level Patients Level Patients ~105 mm Hg 1 ~200 mm Hg 4 100-104 mm Hg 11 180 - 199 mm Hg 6 95-99 mm Hg 10 16~179 mm Hg 31 90-94 mm Hg 9 <160 mm Hg 59 <90 mm Hg 69 less than 90 mm Hg also compares favorably with the figure of 38 percent reported in a recent study of hospital outpatients attending clinics of spe- cialists with an interest in hypertension.3 Table 2 shows the extent to which targets for blood pressure review were mer during the last 6 months of 1981. Patients are divided into three categories, according to their age and blood pressure level. Patients in Category 1 are on treatment and should be reviewed every 3 months. On average this target was met in 85 percent of cases. In practice this means that every month 10-12 patients have to be contacted and asked to attend the next hypertension clinic. This list involves a different set of patients every month, and, with an active policy of chasing outstanding pressures, follow-up of the treated group is kept virtually complete. Normotensives in Category 3 are meant to be reviewed every 5 years, and this target was met in approximately 90 percent of the cases. This result is in line with the observation that about 90 percent of the patients consult their general practitioner at least once during a 5-year period. The borderline hypertensive group, or Category 2, is meant to be re- viewed every year, but Table 2 shows that this target was met in less than 50 percent of cases. This poor performance is partly due to a lack of vigilance TABLE 2 Review of Ascertainment as of January 1, 1982 Percent of Planned Patients Blood Pressure Level Interval Date BP Category Age 40-64 Age 20-39 Readings Readings 1 ~05 mm Hg 3~00 mm Hg 3 months 85 2 ~ 90 mm Hg ~ ~5 mm Hg 1 year 45 3 < 90 mm Hg < S5 mm Hg 5 years 90
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COPC in a Welsh Mining Village 26~7 by doctors, receptionists, and nurses, but it is also the case that patients do not consult often enough for us to reach this target by measuring blood pressure only on a casual basis. Achieving higher levels of ascertainment in this group would require more active follow-up. A policy of treatment in this group would generate even more work, possibly more than could be managed under this system. The question of whether to treat and how to treat patients in this blood pressure range is currently under review. ANTICIPATORY CARE This approach to the control of high blood pressure in a whole community illustrates the principles on which a program of anticipatory care can be based. The approach can also be applied tO the immunization of babies, the care of pregnant women, screening for cervical cancer, child develop- ment, campaigns against smoking, and care of the elderly. Three other applications are the management of chronic disease; surveillance of long- term medication, including the contraceptive pill; and the collection of baseline clinical data in order to improve the quality of care. In each there must be commonly agreed definitions of the data to be collected or the treatment to be administered and a planned system for the collection, recording, and review of this information. Central to such review is the calculation of rates in which the denominator is the population at risk, and the numerator is the number of people ascertained. These rates not only provide a measure of how well or badly the program is running, but by subtracting the numerator from the denominator, they provide lists of patients who have not been included. A central feature of any program of anticipatory care is the ability to produce and respond to lists of this kind. The particular approach described here is only one way of organizing preventive care. The most noteworthy feature is its integration into the routine work of an ordinary general practice without the need for additional resources. Two-thirds of patients consult their general practitioner at least once a year, and 90 percent every 5 years. With simple methods of organ- ization and marginal redeployment of staff, three contacts can be used to build up profiles of risk factors and other data relevant to preventive pro- grams. RESEARCH Since 1978, the practice has been associated with the Epidemiology and Medical Care Unit of the British Medical Research Council. The parent unit provides additional resources for research and has commissioned a number of studies, mostly of a simple observational type, to which there
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248 PART II: PRACTICAL APPLICATIONS have been very high response rates. For example, in a prospective study of the etiology of large bowel cancer, subjects were asked to provide two stool specimens that were then frozen, to be analyzed later on a case-control basis as cases of bowel cancer presented. Eighty-one percent of the adult population aged 45-74 took part in this study. Our main current research study concerns the relationship between di- etary sodium intake, arterial pressure, and a family history of high blood pressure. Using the blood pressure profile of the population described above, it is possible to define groups of offspring whose parents belong either both to the top or both to the bottom third of the distribution of arterial pressure in their age group. Since these groups differ in their risk of developing high blood pressure, but only by a small amount in their actual blood pressure levels, differences between them can be attributed to the cause and not the consequences of high blood pressure. By comparing sodium restriction in offspring with and without a family history of hyper- tension. Similar studies can also planned on patients with blood pressures in the diastolic range 90-104 mm Hg. Future plans are to incorporate dietary sodium restriction in the blood pressure program as a first-line measure in the treatment of mild hypertension. The first of these studies is now complete. The field work involved the collection of seven consecutive 24-hour urine specimens from 115 free- living individuals aged 10-43. This figure represents a 90 percent response from the available offspring. The next stage will involve studies of dietary sodium restriction in offspring with and without a family history of hyper- tension. Similar studies can also planned on patients with blood pressures in the diastolic range 90-104 mm Hg. Future plans are tO incorporate dietary sodium restriction in the blood pressure program as a first-line measure in the treatment of mild hypertension. From within the structure of routine clinical work, it is posssible to develop a system of anticipatory care for the whole population. Within the setting of anticipatory care it is possible to develop a research program both dependent upon and complementary to the clinical work of the practice. The work I have described can be seen as a natural sequence: beginning with the clinical problem of deaths in young men from ischemic heart diseases, leading tO the development of a program for the control of blood pressure at a community level, using this blood pressure data to identify groups of offspring for etiological studies on hypertension, and applying research experience of dietary sodium restriction to the clinical care of patients. Primary prevention of high blood pressure by dietary intervention in families at high risk remains a future goal. This combination of clinical and epidemiologic practice within a single population is the hallmark of COPC.
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COPC in a Welsh Mining Village 249 The work described here was pioneered by Dr. Julian Tudor Hart. I am grateful to him for the experience of working in his practice. REFERENCES 1. Hart, J.T. (1970) The Distribution of Mortality From Coronary Heart Disease in South Wales.~. R. Coll. Gen. Pract. 19:258-68. 2. Hart, J.T. (1970) Semicontinuous Screening of a Whole Community for Hy- perrension. Lancet 2(August):223-26. 3. DHSS Hypertension Care Computing Project (1982) A Comparison of Blood Pressure Control in Hypertensive Patients Treated in Hospital Clinics and in General Practice. [. R. Coll. Gem. Pract. 32:98-102.
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