Isolated diastolic heart failure--what is it?

Epidemiological evidence suggests that 20 to 40% of all patients with heart failure have normal systolic function. Isolated diastolic dysfunction may be the principle pathophysiological mechanism in these patients. The diagnosis of isolated diastolic heart failure is problematic and not merely based on demonstrating normal systolic function. The prognosis in isolated diastolic heart failure is more favourable than in systolic heart failure. At the present time, there is no licensed treatment for isolated diastolic heart failure and treatment is largely empirical.

Drug exposure risk windows and unexposed comparator groups for cohort studies in pharmacoepidemiology

AIM

To determine the appropriate size of risk windows in both exposed and unexposed sub-cohorts.

METHOD

Data was taken from a previous study of upper gastrointestinal haemorrhage and perforation. The length of each prescription for NSAIDs was estimated. The risk was calculated for the duration of a prescription plus increments of -30, -25,..., +115, +120 (i.e. 31 increments). Ten unexposed groups were re-sampled for each increment (stratified for age and sex), using the same lengths of risk window as the exposed group. Mean risks and rate-ratios were calculated (per thousand person-years).

RESULTS

The NSAID risk rose from 3.52 at -30 days to a peak of 5.82 at -15 days, and then decreased gradually to 2.83 at +120 days. Unexposed risk was variable for the negative increments, and decreased gradually from 2.16 at +0 days to 1.54 at +120 days. The rate-ratio rose from 1.55 at -30 days to a peak of 2.85 at -5 days, and then decreased to 1.85 at +120 days.

CONCLUSION

Risk windows should be the same as (or slightly less than) the calculated length of a prescription. Lengthy windows should not be used for unexposed comparator groups (the exposed windows may be randomly allocated).

Diabetes and lower-limb amputations in the community. A retrospective cohort study. DARTS/MEMO Collaboration. Diabetes Audit and Research in Tayside Scotland/Medicines Monitoring Unit

OBJECTIVE

There are few U.K. data on the incidence rates of amputation in diabetic subjects compared with the nondiabetic population.

RESEARCH DESIGN AND METHODS

We performed a historical cohort study of first lower-extremity amputations based in Tayside, Scotland (population 364,880) from 1 January 1993 to 31 December 1994. The Diabetes Audit and Research in Tayside Scotland (DARTS) database was used to identify a prevalence cohort of 7,079 diabetic patients on 1 January 1993. We estimated age-specific and standardized incidence rates of lower-limb amputations in the diabetic and nondiabetic cohorts. Results were compared with a previous study that evaluated lower-extremity amputations in diabetic patients in Tayside in 1980-1982.

RESULTS

There were 221 subjects who underwent a total of 258 nontraumatic amputations. Of the 221 subjects, 60 (27%) patients were diabetic (93% NIDDM), and 63% were first amputations. The median duration of diabetes was 6 years (range: newly diagnosed to 41 years). Nonhealing ulceration (31%) and gangrene (29%) were the two main indications for amputation in the diabetic subjects. Of the 161 nondiabetic subjects, 140 (80%) underwent first amputations. The adjusted incidences in the diabetic and nondiabetic groups were 248 and 20 per 100,000 person-years, respectively. Tayside patients with diabetes thus had a 12.3-fold risk of an amputation compared with nondiabetic residents (95% CI 8.6-17.5). The estimated proportion of diabetic patients in the population rose from 0.81% in 1980-1982 to 1.94% in 1993-1994, whereas the absolute rate of amputation in diabetic subjects was unchanged from that in 1980-1982.

CONCLUSIONS

These population-based U.K. amputation data are similar to amputation rates in the U.S. Amputation rates appear to have decreased significantly since 1980-1982. The impact of diabetes education and prevention programs that target the processes leading to amputation can now be evaluated.

Which drugs benefit diabetic patients for secondary prevention of myocardial infarction? DARTS/MEMO Collaboration

Diabetic patients have increased mortality following myocardial infarction. We review the evidence for benefit in diabetic patients, of the major drug groups used as secondary prevention. Beta blockers: meta-analyses suggest a reduction in mortality of 35% with beta blockers. Diabetic patients should receive beta blockers post myocardial infarction. In many patients, the benefits of beta blockers will outweigh relative contraindications. Aspirin: meta-analyses of antiplatelet therapy in high-risk subjects have shown substantial benefits. Aspirin should be prescribed for secondary prevention. Lipid lowering with statins: subgroup analyses of the major secondary prevention trials show substantial benefits across a wide range of baseline cholesterol and LDL levels. These drugs should be prescribed as secondary prevention to patients with diabetes whose total cholesterol is > 4.0 mmol(-1). Angiotensin converting enzyme inhibitors (ACEIs): the few subgroup analyses that exist from ACEI trials suggest that diabetic and non-diabetic patients derive similar benefits. Diabetic subjects who have systolic dysfunction after myocardial infarction should receive ACEIs. Treatment combination: data exist to suggest that most of these drugs produce benefit independently.

CONCLUSION

diabetic patients benefit from secondary prevention with drug treatment as much as, or more than, non-diabetic patients.

Safe withdrawal of monotherapy for hypertension is poorly effective and not likely to reduce health-care costs

OBJECTIVE

To carry out a population-based evaluation of withdrawal of treatment in primary care using repeated ambulatory blood pressure monitoring (ABPM) assessment to avoid subjecting patients to prolonged periods of excess risk.

METHOD

Patients from two community practices (total population 11 034 patients) being administered monotherapy for hypertension, were identified and invited to participate. Subjects were withdrawn from treatment if they had no significant co-morbidity and daytime ABPM blood pressure was < or = 150/90 mmHg. Antihypertensive therapy was restarted if daytime ABPM blood pressure was > 150/90 mmHg during weeks 4, 8, 12, 26, 39 and 52.

RESULTS

Of 126 eligible patients 53 had a co-morbidity and 37 declined to participate. Of the 36 patients who entered the study 10 were excluded because they had elevated ABPM blood pressures during treatment and one because they had echocardiographic left ventricular hypertrophy. Of the 25 patients from whom monotherapy was withdrawn, we restarted treatment of 19 before week 52. If clinic blood pressure monitoring had been used instead of ABPM, different decisions would have been taken in eight of 25 cases. The costs of the ABPM-determined withdrawal of treatment programme were greater than the expected savings in drug costs, even assuming that all six patients from whom treatment was withdrawn remained without treatment for a further 9 years. This conclusion was not sensitive to reducing the number of ABPM measurements and to inflation in study-drug costs. However, if all patients had been treated with the most expensive drug, then even the full ABPM programme could have saved money within 9 years.

CONCLUSIONS

Antihypertensive therapy could be withdrawn from only a small proportion of patients in the community on the basis of ABPM. The costs of the programme are likely to exceed savings unless the cost of drugs administered is substantially higher than that observed in this study.

Association of upper gastrointestinal toxicity of non-steroidal anti-inflammatory drugs with continued exposure: cohort study

OBJECTIVES

To determine the profile of risk of upper gastrointestinal toxicity during continuous treatment with, and after cessation of, non-steroidal anti-inflammatory drugs.

DESIGN

Cohort study with a prospectively constructed, population based, record linkage database containing details of exposure to all community dispensed non-steroidal anti-inflammatory drugs and also all admissions to hospital for upper gastrointestinal diagnoses.

SETTING

The population of Tayside, Scotland.

SUBJECTS

52,293 subjects aged 50 and over who received one or more non-steroidal anti-inflammatory between 1 January 1989 and 31 December 1991 and 73,792 subjects who did not receive one during the same period (controls).

MAIN OUTCOME MEASURES

Admission to hospital for upper gastrointestinal bleeding and perforation, and admission for other upper gastrointestinal diagnoses.

RESULTS

About 2% of the non-steroidal anti-inflammatory cohort were admitted with an upper gastrointestinal event during the study period compared with 1.4% of controls. The risk of admission for upper gastrointestinal haemorrhage and perforation was constant during continuous non-steroidal anti-inflammatory exposure and carried over after the end of exposure. The results were similar for admissions for all upper gastrointestinal events.

CONCLUSION

This study provides evidence that non-steroidal anti-inflammatory toxicity persists with continuous exposure. There seems to be carryover toxicity after the end of prescribing. These findings have implications for the management of patients requiring non-steroidal anti-inflammatory drugs.

Adherence to insulin treatment, glycaemic control, and ketoacidosis in insulin-dependent diabetes mellitus. The DARTS/MEMO Collaboration. Diabetes Audit and Research in Tayside Scotland. Medicines Monitoring Unit

BACKGROUND

Intensive insulin treatment effectively delays the onset and slows the progression of microvascular complications in insulin-dependent diabetes mellitus (IDDM). Variable adherence to insulin treatment is thought to contribute to poor glycaemic control, diabetic ketoacidosis, and brittle diabetes in adolescents and young adults with IDDM. We assessed the association between the prescribed insulin dose and the amount dispensed from all community pharmacies with the Diabetes Audit and Research in Tayside Scotland (DARTS) database.

METHODS

We studied 89 patients, mean age 16 (SD 7) years, diabetes duration 8 (4) years, and glycosylated haemoglobin (HbA1c) 8.4 (1.9)%, who attended a teaching hospital paediatric or young-adult diabetes clinic in 1993 and 1994. The medically recommended insulin dose and cumulative volume of insulin prescriptions supplied were used to calculate the days of maximum possible insulin coverage per annum, expressed as the adherence index. Associations between glycaemic control (HbA1c), episodes of diabetic ketoacidosis, and all hospital admissions for acute complications and the adherence index were modelled.

FINDINGS

Insulin was prescribed at 48 (19) IU/day and mean insulin collected from pharmacies was 58 (25) IU/day, 25 (28%) of the 89 patients obtained less insulin than their prescribed dose (mean deficit 115 (68; range 9-246] insulin days/annum). There was a significant inverse association between HbA1c and the adherence index (R2 = 0.39; p < 0.001). In the top quartile (HbA1c > 10%), 14 (64%) of individuals had an adherence index suggestive of a missed dose of insulin (mean deficit 55 insulin days/annum). There were 36 admissions for complications related to diabetes. The adherence index was inversely related to hospital admissions for diabetic ketoacidosis (p < 0.001) and all hospital admissions related to acute diabetes complications (p = 0.008). The deterioration in glycaemic control observed in patients aged 10-20 years was associated with a significant reduction (p = 0.01) in the adherence index.

INTERPRETATION

We found direct evidence of poor compliance with insulin therapy in young patients with IDDM. We suggest that poor adherence to insulin treatment is the major factor that contributes to long-term poor glycaemic control and diabetic ketoacidosis in this age group.

Sample size for cohort studies in pharmacoepidemiology

OBJECT

Cohort studies in pharmacoepidemiology can result in a unique type of study, where subjects have complex types of exposure to drugs (with periods of non-exposure as well). The object of this paper is to explain how to calculate the sample size of such a study.

METHOD

It is assumed that adverse events follow Poisson distributions in the two study groups. The null hypothesis is that the two groups have equal rates of disease. Formulae are provided to calculate the sample size required to significantly reject the null hypothesis. Sample size is given as the number of events, rather than the number of subjects entered. In a Poisson study, it is the ratio of the amount of person-years exposure in the two groups that is important to calculate sample size, rather than the actual amounts of exposure (or number of subjects in the study). Some examples are included.

Influence of the angiotensin converting enzyme I/D gene polymorphisms on left ventricular diastolic filling in patients with essential hypertension

BACKGROUND

An insertion/deletion (I/D) polymorphism in the angiotensin converting enzyme (ACE) gene accounts for 50% of the variance in serum ACE activity. ACE is responsible for the generation of angiotensin II, which not only has pressor and mitogenic activities but also exerts effects on left ventricular diastolic performance.

OBJECTIVE

To investigate the contribution of genetic polymorphisms at the ACE gene to the development of diastolic functional abnormalities in 100 patients with essential hypertension.

METHODS AND RESULTS

The left ventricular mass (LVMI) of each patient was assessed echocardiographically. We calculated peak and integral early:late left ventricular diastolic filling ratios (E:AP, and E:AI, respectively) and determined the ACE genotype from leukocyte DNA. There was no significant difference in age, sex, blood pressure and LVMI among genotype groups. Analysis of covariance modelled for indices of diastolic function, adjusted for age, sex, heart rate and LVMI, demonstrated that the E:AP interacted with age (P < 0.0001), heart rate (P < 0.001) and ACE genotype (P = 0.018). Similarly, the E:AI interacted with age (P < 0.001), heart rate (P = 0.025) and ACE genotype (P = 0.047). There was a strong correlation between the E:AP and the LVMI for the DD group (r = -0.81, P < 0.0001) but not for the ID (r = -0.03, P = 0.83) and II (r = -0.23, P = 0.23) groups.

CONCLUSIONS

These findings suggest that that the I/D polymorphism of the ACE gene influences the relationship between left ventricular mass and echocardiographic left ventricular diastolic filling abnormalities in patients with essential hypertension.

ACE inhibitor use is associated with hospitalization for severe hypoglycemia in patients with diabetes. DARTS/MEMO Collaboration. Diabetes Audit and Research in Tayside, Scotland. Medicines Monitoring Unit

OBJECTIVE

To evaluate the association between the use of ACE inhibitors and hospital admission for severe hypoglycemia and to explore the effects of potential confounding variables on this relationship.

RESEARCH DESIGN AND METHODS

The association between the use of ACE inhibitors and the incidence of hypoglycemia is controversial. A recent study reported that 14% of all hospital admissions for hypoglycemia might be attributable to ACE inhibitors. We performed a nested case-control study, using a cohort of 6,649 diabetic patients taking insulin or oral antidiabetic drugs, on the Diabetes Audit and Research in Tayside, Scotland (DARTS) database. From 1 January 1993 to 30 April 1994, we identified 64 patients who had been admitted to Tayside hospitals with hypoglycemia and selected 440 control patients from the same cohort.

RESULTS

Hypoglycemia was associated with the use of ACE inhibitors (odds ratio [OR] 3.2, 95% CI 1.2-8.3, P = 0.023), whereas use of beta-blockers and calcium antagonists was not associated with an increased risk of hospitalization for hypoglycemia with ORs of 0.9 (95% CI 0.3-3.3) and 1.7 (95% CI 0.2-2.1), respectively. There were significant differences between case and control patients in type of diabetes treatment, diabetes duration, place of routine diabetes care, and congestive cardiac failure. These differences did not confound the relationship between ACE inhibitors and hypoglycemia (adjusted OR 4.3, 95% CI 1.2-16.0).

CONCLUSIONS

The results show that the association between ACE inhibitor therapy and hospital admission for severe hypoglycemia is not explained by these confounding factors. Although ACE inhibitors have distinct advantages over other antihypertensive drugs in diabetes, the risk of hypoglycemia should be considered.

The diabetes audit and research in Tayside Scotland (DARTS) study: electronic record linkage to create a diabetes register. DARTS/MEMO Collaboration

OBJECTIVES

To identify all patients with diabetes in a community using electronic record linkage of multiple data sources and to compare this method of case ascertainment with registers of diabetic patients derived from primary care.

DESIGN

Electronic capture-recapture linkage of records included data on all patients attending hospital diabetes clinics, all encashed prescriptions for diabetes related drugs and monitoring equipment, all patients discharged from hospital, patients attending a mobile unit for eye screening, and results for glycated haemoglobin and plasma glucose concentrations from the regional biochemistry database. Diabetes registers from primary care were from a random sample of eight Tayside general practices. A detailed manual study of relevant records for the 35,144 patients registered with these eight general practices allowed for validation of the case ascertainment.

SETTING

Tayside region of Scotland, population 391,274 on 1 January 1996.

MAIN OUTCOME MEASURES

Prevalence of diabetes; population of patients identified by different data sources; sensitivity and positive predictive value of ascertainment methods.

RESULTS

Electronic record linkage identified 7596 diabetic patients, giving a prevalence of known diabetes of 1.94% (0.21% insulin dependent diabetes, 1.73% non-insulin dependent): 63% of patients had attended hospital diabetes clinics, 68% had encashed diabetes related prescriptions, 72% had attended the mobile eye screening unit, and 48% had biochemical results diagnostic of diabetes. A further 701 patients had isolated hyperglycaemia (plasma glucose > 11.1 mmol/l) but were not considered diabetic by general practitioners. Validation against the eight general practices (636 diabetic patients) showed electronic linkage to have a sensitivity of 0.96 and a positive predictive value of 0.95 for ascertainment of known diabetes. General practice lists had a sensitivity of 0.91 and a positive predictive value of 0.98.

CONCLUSIONS

Electronic record linkage was more sensitive than general practice registers in identifying diabetic subjects and identified an additional 0.18% of the population with a history of hyperglycaemia who might warrant screening for undiagnosed diabetes.

Do trandolapril and indomethacin influence renal function and renal functional reserve in hypertensive patients?

AIMS

To assess the effect of trandolapril (2 mg once daily) and indomethacin (25 mg three times daily), alone and in combination, on renal function and renal functional reserve in hypertensive patients (DBP 95-115 mmHg) requiring regular non-steroidal anti-inflammatory drugs (NSAIDs).

METHODS

Randomized, double-blind, placebo-controlled, four way crossover design. After 3 weeks treatment renal plasma flow (RPF) and glomerular filtration rate (GFR) were measured using the p-aminohippurate (PAH) and inulin methods. Renal functional reserve was estimated by measuring RPF and GFR at the end of an intravenous infusion of dopamine 2 microg kg(-1) and 10% amino acid solution.

RESULTS

There was no significant difference in RPF between treatments: -22.79 ml min(-1) (95% CI -54.82, 9.24) for placebo and trandolapril, -10.37 ml min(-1) (95% CI -30.7, 9.96) for placebo and indomethacin, -14.78 ml min(-1) (95% CI -50.33, 20.77) for placebo and trandolapril with indomethacin. There was no significant difference in functional reserve RPF between treatments: -34.96 ml min(-1) (95% CI -119.8, 49.88) for placebo and trandolapril, 29.78 ml min(-1), -15.18, 74.74) for placebo and indomethacin, and -25.84 ml min(-1) (95% CI -87.62, 35.94) for placebo and trandolapril with indomethacin. There was no significant difference in GFR between treatments: -1.01 ml min(-1) (95% CI -7.45, 5.42) for placebo and trandolapril, -7.88 ml min(-1) (95% CI -15.08, -0.68) for placebo and indomethacin, and -0.36 ml min(-1) (95% CI -7.58, 6.86) for placebo and trandolapril with indomethacin. There was no significant difference in functional reserve GFR between treatments: 5.13 ml min(-1) (95% CI -4.97, 15.23) for placebo and trandolapril, 6.31 ml min(-1) (95% CI -1.88, 14.5) for placebo and indomethacin, 7.21 ml min(-1) (95% CI 1.26, 13.16) for placebo and trandolapril with indomethacin.

CONCLUSION

In hypertensives chronic treatment with NSAIDs or ACEI alone or in combination did not change RPF or GFR and did not change renal functional reserve capacity of RPF or GFR.

Non-steroidal anti-inflammatory drugs are associated with emergency admission to hospital for colitis due to inflammatory bowel disease

BACKGROUND

To evaluate the relation between non-steroidal anti-inflammatory drugs (NSAIDs) and colitis due to inflammatory bowel disease.

METHODS

A case-control study was conducted using a prospectively constructed, record linkage database containing hospital event and dispensed drug data (1989-93). The study population consisted of 319,465 people resident in Tayside in January 1989, and still resident (or dead) in October 1994.

RESULTS

Of the 785 patients admitted to hospital as emergencies with colitis between July 1989 and June 1993, 200 fulfilled the case criterion of colitis due to inflammatory bowel disease. A further 1198 persons were used as community controls. Odds ratios were calculated for three exposure periods (current, recent, and past exposure). The overall odds ratios (with 95% confidence intervals) for current and recent exposure to NSAIDs were 1.77 (1.01 to 3.10) and 1.93 (1.20 to 3.09) respectively. Current and recent exposure to NSAIDs was also associated for incident cases, with odds ratios of 2.96 (1.32 to 6.64) and 2.51 (1.13 to 5.55). There was a trend for recent exposure among non-incident cases.

CONCLUSION

The use of NSAIDs may be associated with an increased risk of emergency admission to hospital for colitis due to inflammatory bowel disease, particularly among patients with no previous history.

No association between non-steroidal anti-inflammatory drugs and acute appendicitis in a case-control study

BACKGROUND

A recent case-control study reported an association between non-steroidal anti-inflammatory drug (NSAID) use and acute appendicitis. This association was investigated in a case-control study of patients, aged 30 years and over, admitted as an emergency to hospitals in Tayside between 1989 and 1992, who had appendicectomy for acute appendicitis.

METHODS

A record-linkage database containing records of dispensed prescriptions and hospital admissions was used. A total of 223 patients were identified. The medical records of 161 were checked, of which 138 were valid cases, and information on white cell count and NSAID exposure was recorded. Community and hospital controls were generated.

RESULTS

Some 9.0 per cent of patients were prescribed NSAIDs within 90 days of hospitalization, compared with 7.6 per cent of community controls and 11.5 per cent of hospital controls. The odds ratio was 1.21 (95 per cent confidence interval 0.73-2.01) and 0.75 (0.43-1.32) respectively. There was no significant difference in white cell count between exposed and non-exposed cases. No increased risk of appendicectomy was associated with aspirin use: odds ratio 1.67 (0.52-5.30) and 0.37 (0.12-1.13) using community and hospital controls respectively.

CONCLUSION

Appendicectomy for acute appendicitis is not associated with increased prior use of NSAIDs.

Helicobacter pylori infection status in relation to antibiotic and non-steroidal prescribing in patients on maintenance treatment for chronic duodenal ulcer

It has been suggested that establishing Helicobacter pylori infection status is irrelevant prior to H. pylori eradication treatment in chronic duodenal ulcer, as virtually all may benefit from therapy.

OBJECTIVE

The aim of the present study was (i) to determine the prevalence of active H. pylori infection in patients with proven chronic duodenal ulcer on long-term H2-antagonist prophylactic treatment and whether knowledge of this would influence the use of eradication therapy and (ii) to assess other factors which might influence the clinical diagnosis or H. pylori status, such as non-steroidal and antibiotic use.

METHODS

One hundred and forty-five patients receiving long-term H2-antagonists for chronic duodenal ulcer were recruited. Their case records and a prescribing database were reviewed. Patients underwent endoscopy with biopsies for rapid urease test, histology and H. pylori culture. Serum was immunoblotted and an enzyme-linked immunosorbent assay for H. pylori was performed.

RESULTS

Of the 145 patients, 128 (88%) were H. pylori biopsy positive. Twelve of the 17 H. pylori biopsy-negative patients had anti-H. pylori immunoglobulin G (IgG) antibodies and 10 of the 17 H. pylori-negative patients had previously received antibiotics for other indications. Nine patients were exposed to non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) and one had additional aspirin exposure.

CONCLUSION

Only 11.7% of patients on maintenance treatment for chronic duodenal ulcer had no current infection with H. pylori, although more than 70% of these had serological evidence of previous infection. Confirmation of active infection may be indicated where there is a history of NSAID or antibiotic exposure and may result in more precise targeting of eradication therapy, thus avoiding unnecessary and potentially hazardous treatment.

A cohort study (with re-sampled comparator groups) to measure the association between new NSAID prescribing and upper gastrointestinal hemorrhage and perforation

This cohort study examined the relationship between newly prescribed NSAIDs (none in the previous six months) and upper gastrointestinal hemorrhage and perforation in Tayside, Scotland. Exposure was classified by prescription duration. The study population consisted of the population of Tayside. A Comparator Group was chosen at random (within age and sex strata). Two hundred re-sampled comparator groups were created. Statistical analyses were carried out by Poisson regression (repeated for each of the re-samples). The analyses controlled for age, sex, prior hospitalization for upper gastrointestinal events, prior endoscopy, and the use of ulcer healing drugs. There were 78,191 subjects in the NSAID group, and 78,207 in each of the comparator groups. The increased risk with NSAIDs was only apparent for subjects without a history of upper gastrointestinal events; univariate rate ratio = 2.76 (1.90, 4.01). The final, re-sampled estimate of NSAID risk was rate ratio = 2.48 (1.87, 3.29).

Demand for warfarin anticoagulation monitoring in Tayside, Scotland

AIM

The aim of this study was to assess the demand for warfarin prescribing and monitoring, and to identify patients with atrial fibrillation who might benefit from warfarin therapy. The study was carried out in the population of Tayside, Scotland (400,000 people) using patient-specific dispensed prescribing and hospitalisation data from the Medicines Monitoring Unit at the University of Dundee.

METHODS

The incidence and prevalence of digoxin and warfarin prescribing were calculated between 1989 and 1993. Patients dispensed digoxin in 1993 were assumed to have atrial fibrillation and they were stratified into high risk groups for an adverse thromboembolic event based on past medical history. The numbers of patients at high risk who were judged to be possible candidates for warfarin were calculated.

RESULTS

The prevalence of warfarin prescribing is increasing in Tayside and is mainly for elderly patients. There were also many patients assumed to have atrial fibrillation who were at particularly high risk for an adverse thromboembolic event, who had no record of warfarin prescribing. Only 35% received warfarin. Even given the methodological limitations of this study, and the use of aspirin as an alternative prophylactic agent, it is likely that these patients have been a source of increased prevalence of warfarin prescribing since 1993 and will be in the future. Other indications for warfarin prescribing are also increasing.

CONCLUSION

It is anticipated that there will be increasing demands for anticoagulant monitoring, which will need to be met either by increasing the capacity of existing clinics, or by increasing the role of primary care.

The impact on community benzodiazepine prescribing of hospitalization

To assess the impact of both general and psychiatric hospitalization on the community prescribing of benzodiazepines, we carried out an observational study using record linkage of prescribing prior to and following hospitalization along with a review of hospital case records at four Tayside General Practices. In a population of 29,672 subjects, 2628 general hospital and 254 psychiatric hospitalizations were studied. The main outcome measure was the change in community benzodiazepine prescribing following hospitalization. We found that admission to a general hospital resulted in 59 of the 2628 subjects (2.2%) commencing and 45 subjects (1.7%) discontinuing benzodiazepines. Admission to a psychiatric hospital resulted in 17 of 254 subjects (6.7%) commencing and 40 (16.7%) discontinuing benzodiazepines. When compared to benzodiazepine prescribing in the study population these effects were trivial. We conclude that hospitalization in both general and psychiatric hospitals had a minor effect on total community prescribing of benzodiazepines. In this study general hospital admission resulted in a small net increase and psychiatric hospitalization a small net decrease in benzodiazepine prescribing.

Indomethacin does not attenuate the hypotensive effect of trandolapril

This is a randomised, double-blind, placebo-controlled, four-way crossover study to determine if indomethacin attenuates the hypotensive effect of trandolapril. Twenty-three hypertensive patients (diastolic blood pressure (DBP) 95-115) requiring NSAID were recruited. Seventeen completed the study. Three week treatment periods: trandolapril 2 mg od and indomethacin 25 mg tds, trandolapril 2 mg and placebo, indomethacin and placebo, placebo and placebo. Clinic and ambulatory BP after 3 weeks of each treatment. Study had 85% power to detect a 5 mm Hg difference in BP (s.d. 7 mm Hg). End of treatment clinic BPs were: 152.9/98 mm Hg (95% CI 147.2, 158.6/95.8, 101.4) with placebo and placebo; 150.4/94.9 mm Hg (95% CI 144.7, 156.1/92.1, 97.7) with trandolapril and indomethacin; 148.2/96.5 mm Hg (95% CI 142.5, 153.9/93.7, 99.3) with trandolapril and placebo; and 156.6/97.4 mm Hg (95% CI 150.9, 162.3/94.6, 100.2) with indomethacin and placebo. There were no significant interactions between trandolapril and indomethacin for clinic systolic BP (SBP) (P = 0.79) or clinic DBP (P = 0.87). When trandolapril treatments (placebo or with indomethacin) were compared to treatments without trandolapril (placebo or indomethacin), trandolapril lowered clinic SBP by 5.4 mm Hg (P = 0.047) and DBP by 2.3 mm Hg (P = 0.08). Mean ambulatory BP was: 140.6/88.2 mm Hg (trandolapril and placebo); 142.8/89.7 mm Hg (trandolapril and indomethacin); 149.6/95.0 mm Hg, (indomethacin and placebo); 147.7/94.0 mm Hg (placebo and placebo). Compared with placebo, trandolapril and placebo lowered BP by 6.5/7.5 mm Hg (P < 0.001, SBP; P < 0.001, DBP). Compared with indomethacin, trandolapril and indomethacin lowered BP by 5.0/5.5 mm Hg (P = 0.001, SBP; P < 0.001, DBP). In the present study trandolapril 2 mg lowered clinic SBP and ambulatory BP, but indomethacin did not attenuate this. Indomethacin had no significant effect on either clinic or ambulatory BP. The antihypertensive effects of trandolapril in this study were modest. Patient selection factors may have contributed to the observed responses, but it seems unlikely from these data that a clinically important drug interaction has occurred.