Statins and risk of polyneuropathy: a case-control study

BACKGROUND

Several case reports and a single epidemiologic study indicate that use of statins occasionally may have a deleterious effect on the peripheral nervous system. The authors therefore performed a population-based study to estimate the relative risk of idiopathic polyneuropathy in users of statins.

METHOD

The authors used a population-based patient registry to identify first-time-ever cases of idiopathic polyneuropathy registered in the 5-year period 1994 to 1998. For each case, validated according to predefined criteria, 25 control subjects were randomly selected among subjects from the background population matched for age, sex, and calendar time. The authors used a prescription register to assess exposure to drugs and estimated the odds ratio of use of statins (ever and current use) in cases of idiopathic polyneuropathy compared with control subjects.

RESULTS

The authors verified a diagnosis of idiopathic polyneuropathy in 166 cases. The cases were classified as definite (35), probable (54), or possible (77). The odds ratio linking idiopathic polyneuropathy with statin use was 3.7 (95% CI 1.8 to 7.6) for all cases and 14.2 (5.3 to 38.0) for definite cases. The corresponding odds ratios in current users were 4.6 (2.1 to 10.0) for all cases and 16.1 (5.7 to 45.4) for definite cases. For patients treated with statins for 2 or more years the odds ratio of definite idiopathic polyneuropathy was 26.4 (7.8 to 45.4).

CONCLUSIONS

Long-term exposure to statins may substantially increase the risk of polyneuropathy.

[The BIFAP project: database for pharmaco-epidemiological research in primary care]

OBJECTIVES

To create a data base (BIFAP) with information provided by primary care doctors from the National Health System who use a computer at work, to evaluate its validity as a source of pharmaco-epidemiological information and to use it for the study of the efficacy and safety of medicines.

JUSTIFICATION

Some data bases, such as the British GPRD, have shown great efficiency in pharmaco-epidemiological research and in analysis of alarm signals in pharmacovigilance: primary care doctors are in a very good position to obtain clinical information from their patients. It is recommended that the impact of medicines on various populations is evaluated, including of course those medicines most used in Spain.

PILOT PHASE

January 2000-end of 2003. 300-500 doctors took part: a) monitoring of certain recommendations on recording; b) dispatch every 2 or 3 months to the Spanish Medicines Agency (AEM) of anonymous information with its origin encrypted (basic demographic details, morbidity, prescriptions, other data of epidemiological relevance), which are analysed by computer to check whether they meet adequate recording standards; c) despatch to the AEM of copies of anonymous clinical reports from small samples of patients (for BIFAP validation studies).

FEASIBILITY AND PERSPECTIVES

If BIFAP were viable, a standardised procedure for its use and protocols to support it as a research tool would be put in place.

Association between aspirin and upper gastrointestinal complications: systematic review of epidemiologic studies

AIMS

Because of the widespread use of aspirin for prevention of cardiovascular diseases, side-effects associated with thromboprophylactic doses are of interest. This study summarizes the relative risk (RR) for serious upper gastrointestinal complications (UGIC) associated with aspirin exposure in general and with specific aspirin doses and formulations in particular.

METHODS

After a systematic review, 17 original epidemiologic studies published between 1990 and 2001 were selected according to predefined criteria. Heterogeneity of effects was explored. Pooled estimates were calculated according to different study characteristics and patterns of aspirin use.

RESULTS

The overall relative risk of UGIC associated with aspirin use was 2.2 (95% confidence interval (CI): 2.1, 2.4) for cohort studies and nested case-control studies and 3.1 (95% CI: 2.8, 3.3) for non-nested case-control studies. Original studies found a dose-response relationship between UGIC and aspirin, although the risk was still elevated for doses lower or up to 300 mg day(-1). The summary RR was 2.6 (95% CI: 2.3, 2.9) for plain, 5.3 (95% CI: 3.0, 9.2) for buffered, and 2.4 (95% CI: 1.9, 2.9) for enteric-coated aspirin formulations.

CONCLUSIONS

Aspirin was associated with UGIC even when used at low doses or in buffered or enteric-coated formulations. The latter findings may be partially explained by channeling of susceptible patients to these formulations.

The effect of NSAIDs on the risk of coronary heart disease: fusion of clinical pharmacology and pharmacoepidemiologic data

The isozymes cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) catalyze the conversion of arachidonic acid to eicosanoids that play an important role in the maintenance of cardiovascular hemostasis. Thromboxane A2 (TxA2), which is primarily synthesized by platelet COX-1, causes irreversible platelet aggregation, vasoconstriction and smooth muscle proliferation, all of which are linked to coronary heart disease (CHD). In contrast, vascular prostaglandin I2 (PGI2), which appears to be synthesized by COX-2, counteracts most of these effects of TxA2. Inhibition of the COX isozymes by nonsteroidal anti-inflammatory drugs (NSAIDs) or COX-2 selective inhibitors may therefore influence hemostasis and the risk of CHD. Four epidemiologic studies with differing study designs and populations suggest no overall effect of traditional NSAIDs on the risk of CHD. No specific dose or duration response was found. The lack of cardiovascular protection associated with non-specific NSAIDs observed in these four studies leaves little room for an important cardioprotective class effect. In light of these findings, the potential minor cardiovascular effects of specific COX-2 inhibitors need to be evaluated in large populations.

Relative risk of upper gastrointestinal complications among users of acetaminophen and nonsteroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been associated with an increase in upper gastrointestinal complications. There is no agreement, however, on whether all conventional NSAIDs have a similar relative risk (RR), and epidemiologic data are limited on acetaminophen. We studied the association between these medications and the risk of upper gastrointestinal bleed/perforation in a population-based cohort of 958,397 persons in the United Kingdom between 1993 and 1998. Our nested case-control analysis included 2,105 cases and 11,500 controls. RR estimates were adjusted for several factors known to be associated with upper gastrointestinal bleed/perforation. Compared with non-users, users of acetaminophen at doses less than 2 gm did not have an increased risk of upper gastrointestinal complications. The adjusted RR for acetaminophen at doses greater than 2 gm was 3.6 [95% confidence interval (95% CI) = 2.6-5.1]. The corresponding RRs for low/medium and high doses of NSAIDs were 2.4 (95% CI = 1.9-3.1) and 4.9 (95% CI = 4.1-5.8). The RR was 3.1 (95% CI = 2.5, 3.8) for short plasma half-life, 4.5 (95% CI = 3.5-5.9) for long half-life, and 5.4 (95% CI = 4.0-7.1) for slow-release formulations of NSAIDs. After adjusting for daily dose, the differences in RR between individual NSAIDs tended to diminish except for apazone. Users of H2 receptor antagonists, omeprazole, and misoprostol had RRs of 1.4 (95% CI = 1.2-1.8), 0.6 (95% CI = 0.4-0.9), and 0.6 (95% CI = 0.4-1.0), respectively. Among NSAID users, use of nitrates was associated with an RR of 0.6 (95% CI = 0.4-1.0).

The risk of obstructive airways disease in a glaucoma population

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD), defined as obstructive airways disease (OAD), are two common chronic conditions especially in the elderly. Glaucoma is also a common disease in the elderly with a prevalence close to 5% among those older than 75 years. Most medical therapy for glaucoma is given as eye drops. It has been described that small amounts of systemically absorbed beta-blockers can produce significant respiratory adverse events in predisposed patients.

METHODS

Population-based cohort study with nested case-control analysis using the UK General Practice Research Database (GPRD). We studied the prevalence of OAD in a cohort of patients 60 to 85 years old with a first ever diagnosis of glaucoma and compared it to the prevalence in an age- and sex-matched cohort sampled from the general population. We also calculated the RR and 95% CI of worsening asthma in non-severe asthma patients among the two cohorts. Incidence of OAD was studied in a cohort of glaucoma patients 60 to 85 years old and in an age- and sex-matched cohort from the general population.

RESULTS

The prevalence of OAD was the same between the glaucoma cohort and the general population (OR 1.1; 95% CI 0.9-1.4). The risk of worsening asthma associated with glaucoma was OR 1.2 (95% CI 0.5-2.8). The incidence of OAD was similar in both cohorts. Current users of ophthalmic drugs presented a RR of 1.2 (95% CI 0.8-1.9) of developing asthma compared to non-users in the glaucoma population. The risk in the first month of treatment with topical beta-blockers was 2.1 (95% CI 0.7-6.7).

DISCUSSION

We did not find an association between glaucoma and OAD. Use of topical glaucoma medication was not associated with a major increased risk of asthma.

Incidence of newly diagnosed heart failure in UK general practice

AIM

To estimate the incidence rate of heart failure in the general population and to assess risk factors associated with the occurrence of newly diagnosed heart failure.

METHODS

From the source population that was derived from the UK General Practice Research Database, we identified patients aged 40--84 years newly diagnosed with heart failure in 1996, and estimated incidence rates. We sent questionnaires to a random sample of heart failure patients (N=1200) and performed a nested case-control analysis to assess risk factors for heart failure.

RESULTS

The overall incidence rate for heart failure was 4.4 per 1000 person-years in men and 3.9 per 1000 person-years in women. The incidence increased steeply with age in both sexes. The relative risk of heart failure was 2.1 (95% C.I.: 1.7--2.6) among men compared with women less than 65 years old and 1.3 (95% C.I.: 1.2--1.4) above the age of 65. Slightly more than half of the cases were categorized in NYHA III--IV at the time of the first diagnosis. Within one month of initial diagnosis 62% of the men and 50% of the women were referred to specialists and/or hospitalized for heart failure. Smoking, hypertension, diabetes, obesity were independently associated with heart failure as well as history of distant dyspnoea. Coronary heart disease was the most common cause of heart failure with a greater relative prevalence in men than women.

CONCLUSION

Incident heart failure cases mainly comprised elderly men and women frequently burdened with several diseases in general practice. Women had a lower incidence of heart failure than men. However, traditional risk factors such as smoking, hypertension, obesity, diabetes and dyspnoea appeared to confer the same relative increase in heart failure risk among women and men.

Are users of lipid-lowering drugs at increased risk of peripheral neuropathy?

OBJECTIVE

To estimate the risk of peripheral neuropathy associated with use of lipid-lowering drugs.

METHODS

Population-based dynamic cohort study based on data from general practices in the United Kingdom from 1991 to 1997. Three cohorts of individuals aged 40-74 years were identified: a cohort of 17,219 persons who received at least one prescription for lipid-lowering drugs in the period; a second cohort of patients with a hyperlipidaemia diagnosis who had not been prescribed lipid-lowering drugs (n = 28,974) and a third cohort comprised of 50,000 individuals from the general population. The incidence rates of peripheral neuropathy in the three cohorts were calculated and the relative risk of peripheral neuropathy in users of lipid-lowering drugs was compared with non-users from the general population cohort.

RESULTS

The incidence rate of idiopathic peripheral neuropathy in users of lipid-lowering drugs was higher [0.73 per 10,000 person-years, 95% confidence interval (CI) 0.01-2.62] than in the hyperlipidaemia non-treated cohort (0.40 per 10,000 person-years, CI 0.05-1.46) and the general population cohort (0.46 per 10,000 person-years, CI 0.13-1.18). The raised risk of idiopathic peripheral neuropathy in users of lipid-lowering drugs was confined to current users of statins (relative risk 2.5, CI 0.3-14.2). These figures suggest one excess case of neuropathy for every 14,000 person-years of statin treatment.

CONCLUSIONS

Because of the wide CIs, these results are inconclusive and should be interpreted with caution. However, although peripheral neuropathy as an adverse effect of the use of lipid-lowering drugs cannot be excluded, the magnitude of this untoward effect appears to be small.

Are schizophrenia or antipsychotic drugs a risk factor for cataracts?

Lens changes and ocular disturbances have been reported in conjunction with the use of antipsychotic drugs. We estimated the incidence rate of a clinical diagnosis of cataract in patients with a psychotic disorder, schizophrenia, and compared it with the rate in the general population. Among the schizophrenic patients, we also examined the role of dose and duration of antipsychotic drugs on the risk of cataract development. We followed up two cohorts of patients 30-85 years of age who were included in the United Kingdom General Practice Research Database. Patients in one group had a diagnosis of schizophrenia (N = 4,209). The other group was an age- and sex-matched cohort of 10,000 patients sampled from the source population. The incidence of cataracts was 4.5 per 1,000 person-years among the general population and 3.5 in the schizophrenia population. Overall, antipsychotic drug use was not associated with the occurrence of cataracts. Nevertheless, among long-term users of chlorpromazine at daily doses of 300 mg or greater, and among users of prochlorperazine, the relative risks were 8.8 (95% confidence interval = 3.1-25.1) and 4.0 (95% confidence interval = 0.8-20.7), respectively. There is no indication that schizophrenia per se is associated with an increased risk of developing cataracts.

Differential effects of aspirin and non-aspirin nonsteroidal antiinflammatory drugs in the primary prevention of myocardial infarction in postmenopausal women

The antiplatelet effect of aspirin reduces the risk of clinical manifestations of atherothrombosis by approximately 25% in secondary prevention settings. Data are limited in primary prevention of coronary heart disease, and even more in women. Here, we estimate the effects of aspirin and non-aspirin nonsteroidal antiinflammatory drugs in the primary prevention of myocardial infarction in postmenopausal women. We followed a cohort of 164,769 women, 50-74 years of age, registered in the General Practice Research Database in the United Kingdom, from January 1991 through December 1995. For aspirin and non-aspirin nonsteroidal antiinflammatory drugs, the risk of myocardial infarction associated with current use was compared with risk in non-users, using a nested case-control analysis. Overall, the relative risk of myocardial infarction associated with current use of aspirin of more than 1 month's duration was 0.56 [95% confidence interval (95% CI) = 0.26-1.21], and that of nonfatal myocardial infarction was 0.28 (95% CI = 0.08-0.91). Chronic use of nonsteroidal antiinflammatory drugs was not associated with a protective effect (relative risk = 1.32; 95% CI = 0.97-1.81). These findings indicate that incomplete and reversible inhibition of platelet cyclooxygenase by non-aspirin nonsteroidal antiinflammatory drugs is not sufficient to produce clinically detectable cardiovascular protection comparable with that achieved by low-dose aspirin through irreversible inactivation of platelet cyclooxygenase.

Reduced incidence of colorectal adenoma among long-term users of nonsteroidal antiinflammatory drugs: a pooled analysis of published studies and a new population-based study

Chronic treatment with nonsteroidal antiinflammatory drugs (NSAIDs) has been associated with a reduced risk of colorectal cancer, but less information is available on the relationship between NSAIDs and colorectal adenoma. We carried out a population-based cohort study with nested case-control analysis to determine the association between the use of aspirin and individual NSAIDs and the risk of colorectal adenoma. The General Practice Research Database in the United Kingdom was the source population. We followed 943,903 persons who were 40-79 years of age and free of colorectal adenoma or other cancer at baseline, which varied between January 1994 and September 1997. There were 1,864 incident cases of colorectal adenoma, for an incidence rate of 6.8 per 10,000 person-years. Compared with non-users, long-term users (1 year and more) of nonaspirin NSAIDs had a 40% decreased risk of colorectal adenoma (relative risk = 0.6; 95% confidence interval = 0.4-0.9). Long-term NSAID use was still associated with a reduced risk 1 year after stopping NSAID treatment. Use of most individual NSAIDs conferred a reduced risk. The risk of developing colorectal adenoma was reduced in long-term users of aspirin at doses of 300 mg daily (relative risk = 0.6; 95% confidence interval = 0.4-1.0), but reduced risk was not evident with daily doses of 75 and 150 mg aspirin. These results add further support to the value of NSAIDs as a candidate for primary prevention of colorectal tumors.

Detection of colorectal tumor and inflammatory bowel disease during follow-up of patients with initial diagnosis of irritable bowel syndrome

BACKGROUND

We wanted to estimate the incidence of irritable bowel syndrome (IBS) and functional dyspepsia (FD) in the general population, and the detection of colorectal tumor (CRT) and inflammatory bowel disease (IBD) after the diagnosis of IBS and FD.

METHODS

Patients aged 20-79 years newly diagnosed with IBS (N = 2956) or FD (N = 9900), together with a comparison cohort randomly sampled from the general source population, were followed-up during a mean time of 3 years.

RESULTS

We found an overall incidence of 10.3 per 1000 person-years for FD and 2.6 per 1000 person-years for IBS. There was a greater prevalence of depression, stress, fatigue, and pain disorders among IBS and FD patients than in the general population. During the 1st year after a diagnosis of IBS the cumulative risk of detecting CRT was close to 1% in IBS patients. After the 1st year the risk of CRT in IBS patients was close to that in the general population. We found a significantly increased risk of detecting IBD among patients initially diagnosed as having IBS (relative risk (RR), 16.3; 95% confidence interval (CI), 6.6-40.7), which was constant during all the follow-up period. No association was found between dyspepsia and CRT, or IBD.

CONCLUSION

IBS and FD shared some comorbidity features, yet demographics and incidence rates were different. Unlike the detection of colorectal tumor, the excess risk of IBD after an initial diagnosis of IBS was cumulatively increased during all the follow-up period. The continuously increased risk of IBD detection in IBS patients favors a true association between IBS and IBD.

Overall mortality among patients surviving an episode of peptic ulcer bleeding

STUDY OBJECTIVE

The authors investigated whether patients who have survived an acute episode of peptic ulcer bleeding (PUB) have an excess long term all cause mortality compared with the general population free of PUB.

DESIGN

Follow up study of previously identified cohort of patients with a PUB episode and a general population cohort.

SETTING

The source population included all people aged 30 to 89 years, registered with general practitioners in the United Kingdom.

PATIENTS

All patients alive one month after the PUB episode constituted the cohort of PUB patients (n = 978). A control group of 5000 people was randomly sampled from the source population. The same eligibility criteria as for patients with PUB were applied to the control series. Also, controls had to be free of PUB before start date.

MAIN RESULTS

Relative risk of mortality among PUB patients was 2.1, 95% CI: 1.7, 2.6) compared with the general population. This increased mortality risk occurred mainly in the patients less than 60 years old. No difference was observed between men and women. The excess mortality was not only circumscribed to deaths attributable to recurrent gastrointestinal bleed, but also cardiovascular, cancer and other causes.

CONCLUSIONS

People who have survived an acute episode of PUB have a reduced long term survival compared with the general population. This reduction was stronger among middle age patients than in the elderly.

A cohort study on the risk of acute liver injury among users of ketoconazole and other antifungal drugs

AIMS

The aim of this cohort study was to estimate the risk of clinical acute liver injury among users of oral antifungals identified in the general population of the General Practice Research Database in UK.

METHODS

The cohort included 69 830 patients, 20-79 years old, free of liver and systemic disease, who had received at least one prescription for either oral fluconazole, griseofulvin, itraconazole, ketoconazole, or terbinafine between 1991 and 1996.

RESULTS

Sixteen cases of acute liver injury were identified and validated. Ten cases occurred during nonuse of oral antifungals with a background rate of 0.6 per 100,000 person-months (95% confidence interval 0.3,1.1). Five cases occurred during current use of oral antifungals. Two were using ketoconazole, another two itraconazole, and one terbinafine. Incidence rates of acute liver injury were 134.1 per 100 000 person-months (36.8,488.0) for ketoconazole, 10.4 (2.9-38.1) for itraconazole, and 2.5 (0.4,13. 9) for terbinafine. The remaining case was associated with past use of fluconazole. Ketoconazole was the antifungal associated with the highest relative risk, 228.0 (95% confidence interval 33.9,933.0), when compared with the risk among nonusers, followed by itraconazole and terbinafine with relative risks of 17.7 (2.6,72.6) and 4.2 (0.2, 24.9), respectively.

CONCLUSIONS

Ketoconazole and itraconazole were the two oral antifungal associated with a marked increase of clinical acute liver injury. The risk associated with ketoconazole should be taken into account when prescribing it as initial treatment for uncomplicated fungal infections.

Health resource utilization and drug treatment pattern in a cohort of patients with a first episode of gastroesophageal reflux disease

PURPOSE

To describe the demographics, comorbidity, and health care resource utilization, as well as treatment patterns among gastroesophageal reflux disease (GORD) patients.

METHODS

We identified a population-based cohort of newly diagnosed GORD patients receiving cimetidine, ranitidine or omeprazole. Our final study population consisted of 1193 patients, who were followed up for 1 year.

RESULTS

Mild symptoms were reported in 44% of cases, moderate in 52%, and 4% had a severe episode. Moderate and severe cases were more likely to undergo endoscopy and to be hospitalized for GORD than mild cases. They also had a higher probability of receiving long-term continuous treatment and to start initial treatment with omeprazole rather than with cimetidine or ranitidine. Initial treatment failure was greater among severe cases and in patients started on H(2)-blockers.

CONCLUSION

This study has shown that severity of initial GORD episode is significantly associated with an increased use of health resources, and is the major determinant of initial treatment failure. Patients started on H(2)-blockers also had a greater risk of initial treatment failure compared to patients started on omeprazole.

Use of cimetidine, omeprazole, and ranitidine in pregnant women and pregnancy outcomes

Evidence documenting the safety of acid-suppressing drugs in pregnancy is very limited. The authors assessed the prevalence of congenital malformations in first trimester-exposed pregnancies to cimetidine, omeprazole, and ranitidine and compared it with nonexposed pregnancies between 1991 and 1996. Two different sources were used, the United Kingdom General Practice Research Database and the Italian Friuli-Venezia Giulia Health Database. The final study cohort included 1,179 pregnancies from the United Kingdom and 1,057 from Italy. Abortions or ectopic pregnancies were not included. There were 20 stillbirths and 2,261 live-born babies in both cohorts combined, with 100 offspring identified with a malformation. The overall malformation rate was 4.4%. The relative risks for nongenetic congenital malformations associated with the use of cimetidine, omeprazole, and ranitidine were 1.2 (95% confidence interval (CI): 0.6, 2.3), 0.9 (95% CI: 0.3, 2.2), and 1.4 (95% CI: 0.8, 2.4), respectively, compared with the nonexposed. No specific grouping in the distribution of malformations was observed in any of the three exposed groups. Moreover, no relation was found between drug exposure and preterm delivery or growth retardation. These findings suggest that the use of acid-suppressing drugs during the first trimester of pregnancy is not associated with a major teratogenic risk.

One-year follow-up of newly diagnosed irritable bowel syndrome patients

BACKGROUND

Irritable bowel syndrome is the most common functional gastrointestinal disorder seen by general physicians.

METHODS

We followed up a population-based cohort of newly diagnosed irritable bowel syndrome patients aged 20-79 years, to examine patterns of treatment, comorbidity and healthcare utilization. We used the UK General Practice Research Database as the source population. Individuals with other gastrointestinal diseases, cancer and pregnant women were not included. There were 2956 patients in our final cohort.

RESULTS

Irritable bowel syndrome patients were mainly young and middle-aged; only 12% were 60 years or older. The majority of patients were women (74%). There were no marked differences in terms of use of healthcare services or comorbidity status in the year before irritable bowel syndrome diagnosis as compared to the year after. Fourteen per cent of irritable bowel syndrome patients received no drug treatment at all. Among those treated, the first choice was an antispasmodic. Elderly patients (>60 years old) were more likely to receive drug treatment. Females had a slightly higher probability of being treated than men, except for the category of anti-diarrhoeal drugs.

CONCLUSION

This study has shown that irritable bowel syndrome patients are mainly young and female. We also found that treatment pattern varied according to age and gender. Elderly patients and females were at a higher risk of receiving drug treatment.

Positive predictive value of ICD-9th codes for upper gastrointestinal bleeding and perforation in the Sistema Informativo Sanitario Regionale database

We identified patients whose records in the Sistema Informativo Sanitario Regionale database in the Italian region of Friuli-Venezia Giulia showed a code of upper gastrointestinal bleeding (UGIB) and perforation according to codes of the International Classification of Diseases (ICD)-9th revision. The validity of site- and lesion-specific codes (531 to 534) and nonspecific codes (5780, 5781, and 5789) was ascertained through manual review of hospital clinical records. The initial group was made of 1779 potential cases of UGIB identified with one of these codes recorded. First, the positive predictive values (PPV) were calculated in a random sample. As a result of the observed high PPV of 531 and 532 codes, additional hospital charts were solely requested for all remaining potential cases with 533, 534, and 578 ICD-9 codes. The overall PPV reached a high of 97% for 531 and 532 site-specific codes, 84% for 534 site-specific codes, and 80% for 533 lesion-specific codes, and a low of 59% for nonspecific codes. These data suggest a considerable research potential for this new computerized health care database in Southern Europe.

Secondary prevention of upper gastrointestinal bleeding associated with maintenance acid-suppressing treatment in patients with peptic ulcer bleed

We studied the recurrence of upper gastrointestinal bleeding (UGIB) in a cohort of patients who had an episode of peptic ulcer bleed, and we investigated the effect of maintenance treatment with cimetidine, omeprazole, and ranitidine. We identified 952 patients with a hospitalization for an episode of peptic ulcer bleed by searching the General Practice Research Database in the United Kingdom. The mean follow-up time was 33 months. Less than 10% of the cohort presented with a new episode of UGIB. We calculated incidence rates of recurrent UGIB and estimated the relative risk (RR) of UGIB associated with use of the various acid-suppressing drugs. The greatest protection for recurrent UGIB associated with maintenance acid-suppressing treatment was seen with omeprazole (relative risk 0.2; 95% CI, 0.02-1.0). The corresponding estimates with cimetidine and ranitidine were 0.9 (0.3-2.3) and 0.9 (0.5-1.8). Among nonsteroidal anti-inflammatory drug users, concomitant use of omeprazole afforded protection against a new bleed (RR 0.0; 0.0-1.0), and there was a suggestion of a protective effect with misoprostol, 0.4 (0.01-3.2). The degree of lowered risk of recurrent UGIB in patients on omeprazole maintenance therapy compared with cimetidine or ranitidine therapy is comparable with the protection provided through profound reduction of gastric acidity achieved with proton-pump inhibitors.

Antiepileptics and blood dyscrasias: a cohort study

We conducted a cohort study to investigate the frequency of serious blood dyscrasias in patients age 10-74 years, taking antiepileptic drugs between January 1, 1990, and October 31, 1994. Main outcome measures were validated diagnoses of neutropenia, agranulocytosis, hemolytic anemia, thrombocytopenia, bicytopenia, pancytopenia, or aplastic anemia. A total of 29,357 recipients of antiepileptic therapy received 684,706 prescriptions. Among them there were 21 cases of serious blood dyscrasia of which only 18 could be considered to have a temporal relationship to drug use. Seventeen cases occurred in current users of carbamazepine, phenobarbital, phenytoin or valproate, and 7 in patients taking two or more drugs. Twenty of the 21 patients recovered. The overall rate of blood dyscrasias was 3-4/100,000 prescriptions. The rate in those age less than 60 years was 2.0 (range 0.9-3.6)/100,000 prescriptions compared with 4.0 (range 1.6-8.2) for those age 60 or older. The overall rate of neutropenia was 1.2 (0.5-2.3)/100,000 prescriptions, compared with 0.9 (0.3-1.9) for thrombocytopenia and 0.4 (0.1-1.3) for hemolytic anemia. Rates did not differ among the four drugs. Serious blood dyscrasias are rare in patients taking antiepileptic agents.

Presence of diabetes related complication at the time of NIDDM diagnosis: an important prognostic factor

We studied the short-term natural history of patients with newly diagnosed non-insulin dependent diabetes mellitus (NIDDM), and the prognostic role of history of NIDDM related complication at the time of first NIDDM diagnosis in relation to the development of a new complication or death. We performed a cohort study using data from the General Practice Research Database in the UK. We identified patients aged 30 to 74 years with a newly diagnosed NIDDM between 1990 and 1992 and followed them from the day of NIDDM diagnosis until June 1995. Among the 1077 patients identified, 437 (41%) developed a NIDDM complication during the follow-up. NIDDM complications were more frequent among males and in the elderly. Sixty-seven percent of the study cohort was initially free of any complication while the remaining 360 patients presented already one or more NIDDM complication at the time of their NIDDM diagnosis. History of diabetic related complication was associated with an increased risk of developing a new NIDDM complication (RR: 1.8; 95% CI: 1.5-2.2). Mortality was also greater among patients with history of NIDDM complication (RR: 1.5; 95% CI: 1.0-2.2). Patients with a history of any disorder related to diabetes before their clinical diagnosis of NIDDM are at increased risk of developing a NIDDM complication after the NIDDM diagnosis, as well as at increased risk of dying compared to diabetic patients with no history.

Comparison of mortality from peptic ulcer bleed between patients with or without peptic ulcer antecedents

We studied mortality related to peptic ulcer bleed in a well defined cohort of patients in the month after the episode of peptic ulcer bleed. Our objective was to assess the contribution of peptic ulcer antecedents and other predictive factors on the risk of dying. The study cohort comprised 1,020 patients hospitalized for an episode of peptic ulcer bleed between January 1991 and March 1994 and identified in the General Practice Research Database in the United Kingdom. Six hundred twenty-three patients had no prior episode of peptic ulcer disease, and 384 had peptic ulcer antecedents; for 13 patients, information was not available. Forty-five patients died (mortality rate = 4.4 per 100 person-months; 95% confidence interval = 3.3-5.9) within 1 month of the peptic ulcer bleed. Patients with no peptic ulcer antecedent faced a greater risk of dying than patients with antecedents (relative risk = 3.0; 95% confidence interval = 1.2-7.1). Elderly patients, those undergoing surgery, and current users of acid-suppressing drugs or nonsteroidal antiinflammatory drugs all had an increased mortality risk. Patients presenting with their first-ever episode of peptic ulcer bleed have a higher case fatality rate than those with previous episodes of peptic ulcer.

Use of the UK General Practice Research Database for pharmacoepidemiology

The last decade has seen a surge in the use of computerized health care data for pharmacoepidemiology. Of all European databases, the General Practice Research Database (GPRD) in the UK, has been the most widely used for pharmacoepidemiological research. Since 1994, this database has belonged to the UK Department of Health, and is maintained by the Office of National Statistics (ONS). Currently, around 1500 general practitioners with a population coverage in excess of 3 million, systematically provide their computerized medical data anonymously to ONS. Validation studies of the GPRD have documented the recording of medical data into general practitioners' computers to be near to complete. The GPRD collects truly population-based data, has a size that makes it possible to follow-up large cohorts of users of specific drugs, and includes both outpatient and inpatient clinical information. The access to original medical records is excellent. Desirable improvements to the GPRD would be additional computerized information on certain variables and linkage to other health care databases. Most published studies to date have been in the area of drug safety. The General Practice Research Database has proved that valuable data can be collected in a general practice setting. The full potential of this rich computerized database has yet to come. This experience should serve to encourage others to develop similar population-based data in other countries.