Utilization and safety of proton-pump inhibitors and histamine-2 receptor antagonists in children and adolescents: an observational cohort study

BACKGROUND

Little is known about the use of acid-suppressing treatments and related safety events in children.

OBJECTIVE

This study compared patient characteristics and safety outcomes among children prescribed acid-suppressing drugs for the first time.

METHODS

The Health Improvement Network was used to determine the characteristics of children prescribed a proton pump inhibitor (PPI; esomeprazole or another PPI) or a histamine-2 receptor antagonist (H₂RA) by UK primary care physicians between October 2009 and September 2012. Pre-defined safety outcomes were compared among the treatment groups in up to 18 months of follow-up.

RESULTS

The cohorts comprised 8,172 patients on PPIs (including 24 patients on esomeprazole) and 7,905 on H₂RAs. The baseline characteristics were similar between cohorts, although the children in the PPI cohorts tended to be older. No safety outcomes occurred in the esomeprazole cohort. In the other-PPIs cohort, 92 safety outcomes occurred, most commonly gastroenteritis (n = 36; 39.1%). In the H₂RAs cohort, 193 safety outcomes occurred, most commonly gastroenteritis (n = 62; 32.1%). The incidence of most safety outcomes was higher in the H₂RAs cohort than in the other-PPIs cohort, including failure to thrive (3.11 [95% confidence interval (CI) = 2.25-4.28] vs 0.49 per 1,000 person-years [95% CI = 0.22-1.07]) and gastroenteritis (5.27 [95% CI = 4.11-6.75] vs 3.04 per 1,000 person-years [95% CI = 2.20-4.20]).

CONCLUSION

Esomeprazole is rarely prescribed to children when they first require acid-suppressing medication, compared with other PPIs/H₂RAs. Overall, more safety outcomes occurred in the H₂RAs cohort than in the PPI cohorts.

Incidence of intracranial bleeds in new users of low-dose aspirin: a cohort study using The Health Improvement Network

Essentials Intracranial bleeds (ICB) are serious clinical events that have been associated with aspirin use. Incidence rates of ICB were calculated among new-users of low-dose aspirin in the UK (2000-2012). Over a median follow-up of 5.58 years, the incidence of ICB was 0.08 per 100 person-years. Our estimates are valuable for inclusion in risk-benefit assessments of low-dose aspirin use.

SUMMARY

Background Low-dose aspirin protects against both ischemic cardiovascular (CV) events and colorectal cancer (CRC). However, low-dose aspirin may be associated with a slightly increased risk of intracranial bleeds (ICBs). Objectives To obtain the incidence rates of ICBs overall and by patient subgroups among new users of low-dose aspirin. Patients/Methods Using The Health Improvement Network (THIN) UK primary-care database (2000-2012), we identified a cohort of new users of low-dose aspirin aged 40-84 years (N = 199 079; mean age at start of follow-up, 63.9 years) and followed them for up to 14 years (median 5.58 years). Incident ICB cases were identified and validated through linkage to hospitalization data and/or review of THIN records with free-text comments. Incidence rates with 95% confidence intervals (CIs) were calculated. Results Eight hundred and eighty-one incident ICBs cases were identified: 407 cases of intracerebral hemorrhage (ICH), 283 cases of subdural hematoma (SDH), and 191 cases of subarachnoid hemorrhage (SAH). Incidence rates per 100 person-years were 0.08 (95% CI 0.07-0.08) for all ICBs, 0.04 (95% CI 0.03-0.04) for ICH, 0.03 (95% CI 0.02-0.03) for SDH, and 0.02 (95% CI 0.01-0.02) for SAH. The ICB incidence rates per 100 person-years for individuals with an indication of primary CV disease prevention were 0.07 (95% CI 0.06-0.07) and 0.09 (95% CI 0.08-0.10) for secondary CV disease prevention. Incidence rates were higher in men for SDH, and higher in women for ICH and SAH. Conclusions Our results provide valuable estimates of the absolute ICB risk for incorporation into risk-benefit assessments of low-dose aspirin use.

Incidence rates and trends of hip/femur fractures in five European countries: comparison using e-healthcare records databases

Hip fractures represent a major public health challenge worldwide. Multinational studies using a common methodology are scarce. We aimed to estimate the incidence rates (IRs) and trends of hip/femur fractures over the period 2003-2009 in five European countries. The study was performed using seven electronic health-care records databases (DBs) from Denmark, The Netherlands, Germany, Spain, and the United Kingdom, based on the same protocol. Yearly IRs of hip/femur fractures were calculated for the general population and for those aged ≥50 years. Trends over time were evaluated using linear regression analysis for both crude and standardized IRs. Sex- and age-standardized IRs for the UK, Netherlands, and Spanish DBs varied from 9 to 11 per 10,000 person-years for the general population and from 22 to 26 for those ≥50 years old; the German DB showed slightly higher IRs (about 13 and 30, respectively), whereas the Danish DB yielded IRs twofold higher (19 and 52, respectively). IRs increased exponentially with age in both sexes. The ratio of females to males was ≥2 for patients aged ≥70-79 years in most DBs. Statistically significant trends over time were only shown for the UK DB (CPRD) (+0.7% per year, P < 0.01) and the Danish DB (-1.4% per year, P < 0.01). IRs of hip/femur fractures varied greatly across European countries. With the exception of Denmark, no decreasing trend was observed over the study period.

Use of prescription contraceptive methods in the UK general population: a primary care study

OBJECTIVE

To determine prescription contraceptive use in the UK.

DESIGN

Observational study using a primary care database.

SETTING

The Health Improvement Network (THIN).

POPULATION

Women in THIN aged 12-49 years in 2008, registered with their primary care doctor for at least 5 years, and with a prescription history of at least 1 year were included.

METHODS

THIN was searched using the Read and MULTILEX codes for the following methods: combined oral contraceptives (COCs), progestogen-only pills (POPs), copper intrauterine devices (Cu-IUDs), the levonorgestrel-releasing intrauterine system (LNG-IUS), progestogen-only implants, progestogen-only injections, and contraceptive patches.

MAIN OUTCOME MEASURES

Prevalence, switching, and duration of prescriptions.

RESULTS

A cohort of 194 054 women was identified. The prevalence of contraceptive use was: COCs, 16.2% (95% confidence interval, 95% CI 16.1-16.3%); POPs, 5.6% (95% CI 5.5-5.6%); Cu-IUD, 4.5% (95% CI 4.4-4.5%); LNG-IUS, 4.2% (95% CI 4.1-4.2%); progestogen-only implants, 1.5% (95% CI 1.5-1.6%); progestogen-only injections, 2.4% (95% CI 2.3-2.4%); and contraceptive patches, 0.1% (95% CI 0.1-0.2%). Within 1 year, 9.8% of new COC users switched to alternative COCs, and 9.0% changed to a different method. Among new COC users who did not switch method, 34.8% did not continue use beyond 3 months, and were no longer using a prescription contraceptive.

CONCLUSIONS

Among users of oral contraceptives who did not switch method, over one-third did not continue use beyond 3 months. This supports current UK guidelines recommending a follow-up consultation with a healthcare professional 3 months after the first prescription of COCs.

Characteristics and drug utilization patterns of new users of rosuvastatin and other statins in four countries

AIM

This study was undertaken to increase understanding of the utilization of a newly introduced statin through evaluation of characteristics of 'real-life' patients in a pharmacoepidemiology program in the USA, the Netherlands, the UK and Canada.

METHODS

This was an observational analysis of prospectively collected data from primary care patients classified as new users of rosuvastatin or any other statin. New users (naïve or switched initiators) of rosuvastatin were compared with initiators of other statins, as identified from automated healthcare databases in the first 1 to 2 years of rosuvastatin availability. Demographics, statin doses, previous statin use and other lipid-lowering therapies, and relevant comorbidities were recorded. The main outcome measure was proportion of naïve and non-naïve statin users in patients prescribed rosuvastatin or 'other statins'.

RESULTS

Among 346.547 new statin users identified in the cohorts, 46.838 (13.5%) were new users of rosuvastatin and most (84.1%) were statin-naïve. Patients receiving rosuvastatin were more likely to have been previously treated with another statin or non-statin lipid-lowering therapy and tended to be younger, compared with first users of other statins.

CONCLUSION

These findings suggest that rosuvastatin is preferentially prescribed to patients who have not responded satisfactorily to established treatment.

Uncomplicated peptic ulcer in the UK: trends from 1997 to 2005

BACKGROUND

Few studies have examined the incidence of uncomplicated peptic ulcer or the trends in factors affecting its incidence.

AIM

To estimate the incidence rate of uncomplicated peptic ulcer in the UK from 1997 to 2005 and report temporal changes in the main known preventive and risk factors.

METHODS

Population-based cohort study of 1 049 689 patients enrolled in The Health Improvement Network in the UK. We estimated the incidence rate of uncomplicated peptic ulcer and evaluated temporal trends in demographic characteristics and prescription patterns for various anti-inflammatory and gastroprotective agents.

RESULTS

Overall uncomplicated peptic ulcer incidence was 0.75 cases per 1000 persons-years, declining from 1.1 to 0.52 cases per 1000 person-years between 1997 and 2005. Distributions of age, gender and alcohol habits were similar in 1997 and 2005. The proportion of documented Helicobacter pylori-negative cases increased from 5% to 12%. Monthly prevalence of subjects with prescriptions for traditional non-aspirin NSAIDs changed from 7.7% to 6.8%, Coxibs from 0% to 0.7%, and proton pump inhibitors (PPIs) from 2.4% to 7.4%. The proportion of subjects on prescription NSAIDs on PPIs increased continuously over time.

CONCLUSION

A reduction in H. pylori-related peptic ulcers, changing patterns in NSAID use and increasing PPI use may have contributed to a decline in uncomplicated peptic ulcer incidence in the UK.

Use of antidepressants and the risk of Parkinson's disease: a prospective study

BACKGROUND

Individuals with depression have a higher risk of Parkinson's disease (PD) but the timing of the association is unknown. Therefore, the relationship between initiation of antidepressant therapy and PD risk was assessed in a large population based database from the UK and the timing of this association was explored.

METHODS

A case control study nested in the General Practice Research Database cohort, a large computerised database with clinical information from more than 3 million individuals in the UK, was conducted. Cases of PD were identified from the computer records from 1995 to 2001 and matched with up to 10 controls by age, sex and practice. Use of antidepressants was obtained from the computer records.

RESULTS

999 PD cases and 6261 controls were included. The rate ratio (RR) and 95% CI of PD in initiators of antidepressant therapy compared with non-initiators was 1.85 (1.25 to 2.75). The association was stronger during the first 2 years after initiation of medication use (RR 2.19; 95% CI 1.38 to 3.46) than later (RR 1.23; 95% CI 0.57 to 2.67). Results were similar for selective serotonin reuptake inhibitors and tricyclic antidepressants separately.

CONCLUSION

Initiation of any antidepressant therapy was associated with a higher risk of PD in the 2 years after the start of treatment, which suggests that depressive symptoms could be an early manifestation of PD, preceding motor dysfunction.

Trends in the prevalence and incidence of diabetes in the UK: 1996-2005

BACKGROUND

To estimate the incidence and prevalence of type 1 and type 2 diabetes in the UK general population from 1996 to 2005.

METHODS

Using the Health Improvement Network database, patients with type 1 or type 2 diabetes were identified who were 10-79 years old between 1996 and 2005. Prevalent cases (n = 49 999) were separated from incident cases (n = 42 642; type 1 = 1256, type 2 = 41 386). Data were collected on treatment patterns in incident cases, and on body mass index in prevalent and incident cases.

RESULTS

Diabetes prevalence increased from 2.8% in 1996 to 4.3% in 2005. The incidence of diabetes in the UK increased from 2.71 (2.58-2.85)/1000 person-years in 1996 to 4.42 (4.32-4.53)/1000 person-years in 2005. The incidence of type 1 diabetes remained relatively constant throughout the study period; however, the incidence of type 2 diabetes increased from 2.60 (2.47-2.74)/1000 person-years in 1996 to 4.31 (4.21-4.42)/1000 person-years in 2005. Between 1996 and 2005, the proportion of individuals newly diagnosed with type 2 diabetes who were obese increased from 46% to 56%. Treatment with metformin increased across the study period, while treatment with sulphonylureas decreased.

CONCLUSIONS

The prevalence and incidence of type 2 diabetes have increased in the UK over the past decade. This might be primarily explained by the changes in obesity prevalence. Also, there was a change in drug treatment pattern from sulphonylureas to metformin.

Proton pump inhibitors reduce the long-term risk of recurrent upper gastrointestinal bleeding: an observational study

BACKGROUND

Between 3% and 40% of patients surviving an episode of upper gastrointestinal bleeding (UGIB) experience a recurrence within 1 year. Aim To characterize further the recurrence rate of UGIB and to investigate the role of long-term acid suppressive therapy in its secondary prevention.

METHODS

Recurrent cases of UGIB were identified among patients registered in The Health Improvement Network in the UK. A nested case-control analysis provided relative risk (RR) estimates of factors associated with recurrence.

RESULTS

Of 1287 patients included, 67 (5.2%) were identified with a recurrent UGIB episode, corresponding to a recurrence rate of 17.5 per 1000 person-years during a mean follow-up of 3 years. The greatest risk of recurrence was in patients prescribed the oral anticoagulant warfarin (RR: 5.38; 95% confidence interval: 2.02-14.36). Use of a single proton pump inhibitor (PPIs) was associated with a reduced risk of recurrence (RR: 0.51; 95% confidence interval: 0.26-0.99), even in patients taking warfarin, while current use of H(2)-receptor antagonists was not. After the first episode of UGIB, use of nonsteroidal anti-inflammatory drugs and aspirin was greatly reduced, preventing estimation of the risk associated with these drugs.

CONCLUSION

Long-term PPI therapy reduces the risk of UGIB recurrence.

Endoscopic findings in a cohort of newly diagnosed gastroesophageal reflux disease patients registered in a UK primary care database

Gastroesophageal reflux disease (GERD) may be accompanied by erosive complications that are diagnosed by endoscopy. This study aimed to describe the characteristics of patients newly diagnosed with GERD who are referred for endoscopy, and the factors associated with esophageal endoscopic findings. This study included patients aged 2-79 years with a first recorded diagnosis of GERD in 1996, as identified in a previous cohort study in the UK General Practice Research Database. The rate and results of endoscopy were recorded. Unconditional logistic regression analysis was used to estimate the odds ratios and 95% confidence intervals for the relationship between a range of factors and endoscopy and its findings. Of the 7159 patients with a new GERD diagnosis, 805 (11%) underwent endoscopy close to the time of first consultation for GERD. Endoscopic findings indicative of esophageal damage were recorded in 73% of these patients. Esophageal endoscopic findings were significantly more likely in males, older patients, and individuals with a history of peptic ulcer disease or gastrointestinal bleeding. Use of acid-suppressive drugs, particularly proton pump inhibitors, was inversely associated with erosive endoscopic findings. Patients with erosive endoscopic findings were more likely to start a new course of treatment with a proton pump inhibitor. In conclusion, relatively few patients are referred for endoscopy close to the first consultation for GERD, and the majority of these individuals have esophageal findings. Male gender, increasing age and a history of bleeding were risk factors for esophageal complications.

Endoscopic findings in a cohort of newly diagnosed gastroesophageal reflux disease patients registered in a UK primary care database

Gastroesophageal reflux disease (GERD) may be accompanied by erosive complications that are diagnosed by endoscopy. This study aimed to describe the characteristics of patients newly diagnosed with GERD who are referred for endoscopy, and the factors associated with esophageal endoscopic findings. The study included patients aged 2-79 years with a first recorded diagnosis of GERD in 1996, as identified in a previous cohort study in the UK General Practice Research database. The rate and results of endoscopy were recorded. Unconditional logistic regression analysis was used to estimate the odds ratios and 95% confidence intervals for the relationship between a range of factors and endoscopy and its findings. Of the 7159 patients with a new GERD diagnosis, 805 (11%) underwent endoscopy close to the time of first consultation for GERD. Endoscopic findings indicative of esophageal damage were recorded in 73% of these patients. Esophageal endoscopic findings were significantly more likely in males, older patients, and individuals with a history of peptic ulcer disease or gastrointestinal bleeding. Use of acid-suppressive drugs, particularly proton pump inhibitors, was inversely associated with erosive endoscopic findings. Patients with erosive endoscopic findings were more likely to start a new course of treatment with a proton pump inhibitor. In conclusion, relatively few patients are referred for endoscopy close to the first consultation for GERD and the majority of these individuals have esophageal findings. Male gender, increasing age and a history of bleeding were risk factors for esophageal complications.

Unspecified abdominal pain in primary care: the role of gastrointestinal morbidity

BACKGROUND

Many patients with abdominal pain have no obvious cause for their symptoms and receive a diagnosis of unspecified abdominal pain.

AIM

The objective of this study was to ascertain risk factors and consequences of a diagnosis of unspecified abdominal pain in primary care.

METHODS

A population-based, case-control study was conducted using the UK General Practice Research Database. We identified 29,299 patients with a new diagnosis of abdominal pain, and 30,000 age- and sex-matched controls. Only diagnostic codes that did not specify the type or location of abdominal pain were included.

RESULTS AND DISCUSSION

The incidence of newly diagnosed unspecified abdominal pain was 22.3 per 1000 person-years. The incidence was higher in females than in males, and 29% of patients were below 20 years of age. Prior gastrointestinal morbidity was associated with abdominal pain, but high body mass index, smoking and alcohol intake were not. Patients newly diagnosed with abdominal pain were 16 to 27 times more likely than controls to receive a subsequent new diagnosis of gallbladder disease, diverticular disease, pancreatitis or appendicitis in the year after the diagnosis of abdominal pain. The likelihood of receiving other gastrointestinal diagnoses such as peptic ulcer disease, hiatus hernia, gastro-oesophageal reflux disease (GERD), irritable bowel syndrome (IBS) or dyspepsia was increased three- to 14-fold among patients consulting for abdominal pain.

CONCLUSION

When managing abdominal pain in primary care, morbidities such as GERD and IBS should be considered as diagnoses once potentially life-threatening problems have been excluded.

Gastric acid suppression and risk of oesophageal and gastric adenocarcinoma: a nested case control study in the UK

BACKGROUND

Gastric acid suppressing drugs (that is, histamine(2) receptor antagonists and proton pump inhibitors) could affect the risk of oesophageal or gastric adenocarcinoma but few studies are available.

AIMS

To study the association between long term treatment with acid suppressing drugs and the risk of oesophageal or gastric adenocarcinoma.

PATIENTS

Persons registered in the general practitioners research database in the UK and aged 40-84 years during the period 1994-2001.

METHODS

Population based nested case control study. Multivariable unconditional logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CI).

RESULTS

In 4 340 207 person years of follow up, 287 patients with oesophageal adenocarcinoma, 195 with gastric cardia adenocarcinoma, and 327 with gastric non-cardia adenocarcinoma were identified, and 10 000 control persons were randomly sampled. "Oesophageal" indication for long term acid suppression (that is, reflux symptoms, oesophagitis, Barrett's oesophagus, or hiatal hernia) rendered a fivefold increased risk of oesophageal adenocarcinoma (odds ratio (OR) 5.42 (95% confidence interval (CI) 3.13-9.39)) while no association was observed among users with a group of other indications, including peptic ulcer and "gastroduodenal symptoms" (that is, gastritis, dyspepsia, indigestion, and epigastric pain) (OR 1.74 (95% CI 0.90-3.34)). "Peptic ulcer" indication (that is, gastric ulcer, duodenal ulcer, or unspecified peptic ulcer) was associated with a greater than fourfold increased risk of gastric non-cardia adenocarcinoma among long term users (OR 4.66 (95% CI 2.42-8.97)) but no such association was found in those treated for a group of other indications (that is, "oesophageal" or "gastroduodenal symptoms") (OR 1.18 (95% CI 0.60-2.32)).

CONCLUSIONS

Long term pharmacological gastric acid suppression is a marker of increased risk of oesophageal and gastric adenocarcinoma. However, these associations are most likely explained by the underlying treatment indication being a risk factor for the cancer rather than an independent harmful effect of these agents per se.

Non-steroidal anti-inflammatory drugs and risk of first hospital admission for heart failure in the general population

OBJECTIVES

To estimate the risk of a first hospital admission for heart failure (HF) associated with the use of non-steroidal anti-inflammatory drugs (NSAIDs).

METHODS

Cohort study with a nested case-control analysis based on the UK General Practice Research Database. Overall, 1396 cases of first hospital admission for non-fatal HF were identified (January 1997 to December 2000) and compared with a random sample of 5000 controls.

RESULTS

The incidence rate was 2.7/1000 person years. Prior clinical diagnosis of HF was the main independent risk factor triggering a first HF hospitalisation (relative risk 7.3, 95% confidence interval (CI) 6.1 to 8.8). The risk of a first hospital admission for HF associated with current use of NSAIDs was 1.3 (95% CI 1.1 to 1.6) after controlling for major confounding factors. No effects of dose and duration were found. The relative risk in current users of NSAIDs with prior HF was 8.6 (95% CI 5.3 to 13.8) compared with patients who did not use NSAIDs and without prior clinical diagnosis of HF.

CONCLUSION

Use of NSAIDs was associated with a small increase in risk of a first hospitalisation for HF. In patients with prior clinical diagnosis of HF, the use of NSAIDs may lead to worsening of pre-existing HF that triggers their hospital admission. This increased risk, although small, may result in considerable public health impact, particularly among the elderly.

Hormone replacement therapy and risks of oesophageal and gastric adenocarcinomas

Oesophageal and gastric adenocarcinoma share an unexplained male predominance, which would be explained by the hypothesis that oestrogens are protective in this respect. We carried out a nested case–control study of hormone replacement therapy (HRT) among 299 women with oesophageal cancer, 313 with gastric cancer, and 3191 randomly selected control women, frequency matched by age and calendar year in the General Practitioners Research Database in the United Kingdom. Data were adjusted for age, calendar year, tobacco smoking, alcohol consumption, body mass index, hysterectomy, and upper gastrointestinal disorders. Among 1 619 563 person-years of follow-up, more than 50% reduced risk of gastric adenocarcinoma was found among users of HRT compared to nonusers (odds ratio (OR), 0.48, 95% confidence interval (CI) 0.29–0.79). This inverse association appeared to be stronger for gastric noncardia (OR 0.34, 95% CI 0.14–0.78) and weaker for gastric cardia tumours (OR 0.68, 95% CI 0.23–2.01). There was no association between HRT and oesophageal adenocarcinoma (OR 1.17, 95% CI 0.41–3.32).

Prostate Cancer Risk Among Men with Diabetes Mellitus (Spain)

OBJECTIVE

Observational studies have associated diabetes with a decreased risk of prostate cancer. We aimed to evaluate this association using the General Practitioner Research Database in the UK.

METHODS

Population based case-control study nested in a cohort.

RESULTS

We identified 2,183 incident cases of prostate cancer between January 1995 and December 2001. We found that diabetic patients had a decreased risk of prostate cancer (OR = 0.72; 95% CI: 0.59-0.87). This association was observed among treated diabetics (OR = 0.63; 95% CI: 0.50-0.80) but not among untreated diabetics (OR = 1.01; 95% CI: 0.73-1.40). Our results suggest that the observed reduced risk could be restricted to users of insulin or sulphonylureas.

CONCLUSION

Patients with diabetes have a decreased risk of prostate cancer. The role of antidiabetic treatment in this association warrants further research.

Risk factors for inflammatory bowel disease in the general population

BACKGROUND

The aetiology of inflammatory bowel disease remains largely unknown.

AIM

We performed a comprehensive assessment of potential risk factors associated with the occurrence of inflammatory bowel disease.

METHODS

We identified a cohort of patients 20-84 years old between 1995 and 1997 registered in the General Practitioner Research Database in the UK. A total of 444 incident cases of IBD were ascertained and validated with the general practitioner. We performed a nested case-control analysis using all cases and a random sample of 10 000 frequency-matched controls.

RESULTS

Incidence rates for ulcerative colitis, Crohn's disease, and indeterminate colitis were 11, 8, and 2 cases per 100 000 person-years, respectively. Among women, we found that long-term users of oral contraceptives were at increased risk of developing UC (OR: 2.35; 95% CI: 0.89-6.22) and CD (OR: 3.15; 95% CI: 1.24-7.99). Similarly, long-term users of HRT had an increased risk of CD (OR: 2.60; 95% CI: 1.04-6.49) but not UC. Current smokers experienced a reduced risk of UC along with an increased risk of CD. Prior appendectomy was associated with a decreased the risk of UC (OR: 0.37; 95% CI: 0.14-1.00).

CONCLUSIONS

Our results support the hypothesis of an increased risk of inflammatory bowel disease associated with oral contraceptives use and suggest a similar effect of hormone replacement therapy on CD. We also confirmed the effects of smoking and appendectomy on inflammatory bowel disease.

Use of antibiotics and risk of breast cancer

A recent nested case-control study found that increasing use of antibiotics was associated with a significantly elevated risk of breast cancer. The authors attempted to replicate this finding with a similar study design using the General Practice Research Database in the United Kingdom. Women aged 30-79 years who were registered in the database between January 1995 and December 2001 comprised the study cohort. A total of 3,708 women with incident cases of breast cancer and 20,000 frequency-matched controls were entered into a nested case-control analysis. Use of antibiotics was not associated with an increased risk of breast cancer. For categories of increasing cumulative days of use (1-50, 51-100, 101-500, and >or=501 days), the corresponding odds ratios were 1.0 (95% confidence interval (CI): 0.9, 1.1), 1.0 (95% CI: 0.8, 1.1), 0.9 (95% CI: 0.7, 1.0), and 1.2 (95% CI: 0.9, 1.6) (p = 0.31 for trend). On the basis of these results, antibiotic use does not appear to be a major determinant of breast cancer risk.

Natural history of gastro-oesophageal reflux disease diagnosed in general practice

BACKGROUND

Cross-sectional studies indicate that gastro-oesophageal reflux disease symptoms have a prevalence of 10-20% in Western countries and are associated with obesity, smoking, oesophagitis, chest pain and respiratory disease.

AIM

To determine the natural history of gastro-oesophageal reflux disease presenting in primary care in the UK.

METHODS

Patients with a first diagnosis of gastro-oesophageal reflux disease during 1996 were identified in the UK General Practice Research Database and compared with age- and sex-matched controls. We investigated the incidence of gastro-oesophageal reflux disease, potential risk factors and comorbidities, and relative risk for subsequent oesophageal complications and mortality.

RESULTS

The incidence of a gastro-oesophageal reflux disease diagnosis was 4.5 per 1000 person-years (95% confidence interval: 4.4-4.7). Prior use of non-steroidal anti-inflammatory drugs, smoking, excess body weight and gastrointestinal and cardiac conditions were associated with an increased risk of gastro-oesophageal reflux disease diagnosis. Subjects with gastro-oesophageal reflux disease had an increased risk of respiratory problems, chest pain and angina in the year after diagnosis, and had a relative risk of 11.5 (95% confidence interval: 5.9-22.3) of being diagnosed with an oesophageal complication. There was an increase in mortality in the gastro-oesophageal reflux disease cohort only in the year following the diagnosis.

CONCLUSIONS

Gastro-oesophageal reflux disease is a disease associated with a range of potentially serious oesophageal complications and extra-oesophageal diseases.

Risk of breast cancer among users of aspirin and other anti-inflammatory drugs

We conducted a cohort study with a nested case-control analysis to evaluate the effect of anti-inflammatory drugs in breast cancer incidence using the General Practice Research Database. Women taking aspirin and paracetamol for 1 year or longer had an odds ratio (OR) of 0.77 (95 percent confidence interval (95% CI): 0.62,0.95) and 0.76 (95% CI: 0.65,0.88), respectively, compared to nonusers. Daily doses of aspirin (75 mg) and paracetamol (up to 2000 mg) showed the greatest reduced risk. Use of non-aspirin nonsteroidal anti-inflammatory drugs for more than 1 year was not associated with a reduced risk of breast cancer (OR=1.00 (95% CI: 0.84, 1.17), and the corresponding estimate among users with at least 2 years duration was similar. Our findings suggest that aspirin at cardioprophylactic doses as well as paracetamol at analgesic doses is associated with a reduced risk of breast cancer.

Is there any association between myocardial infarction, gastro-oesophageal reflux disease and acid-suppressing drugs?

BACKGROUND

A link between gastro-oesophageal reflux disease and coronary heart disease has been suggested.

AIM

To estimate the incidence of myocardial infarction in patients with newly diagnosed gastro-oesophageal reflux disease in comparison with that in the general population.

METHODS

A population-based cohort study was performed in the UK. Patients aged 18-79 years with a first diagnosis of gastro-oesophageal reflux disease (n = 7084) were identified and a group of 10,000 patients free of gastro-oesophageal reflux disease were sampled. A nested case-control analysis was performed to assess the risk factors for myocardial infarction.

RESULTS

The incidence of myocardial infarction in the general population was 4.0 per 1,000 person-years [95% confidence interval (CI), 3.2-4.9] and 5.1 per 1,000 person-years (95% CI, 4.1-6.4) in patients with gastro-oesophageal reflux disease. The relative risk of myocardial infarction in patients with gastro-oesophageal reflux disease was 1.4 (95% CI, 1.0-1.9). The increased risk of myocardial infarction was limited to the immediate days after the diagnosis of gastro-oesophageal reflux disease. Previous chest pain was an important predictor of myocardial infarction in patients free of gastro-oesophageal reflux disease. No association was found between the use of acid-suppressing drugs and the risk of myocardial infarction.

CONCLUSION

Our results suggest that gastro-oesophageal reflux disease is not an independent predictor of myocardial infarction. Rather, the increased risk of myocardial infarction in patients with gastro-oesophageal reflux disease in the immediate days after diagnosis indicates that prodromal ischaemic symptoms were misinterpreted as reflux symptoms.

Respiratory medications and risk of asthma death

BACKGROUND

The effect of respiratory medications on risk of asthma death in the UK was studied using the General Practice Research Database.

METHODS

A total of 96 258 individuals with a diagnosis of asthma were identified, 43 of whom had died as a result of their asthma. For each case 20 controls were selected. Relative risk (RR) estimates and 95% confidence intervals (CI) were computed for each respiratory drug category controlling for effects of age, sex, body mass index, smoking, frequency of visits to the GP, hospital admissions for asthma, and visits to a specialist.

RESULTS

The strongest associations were found for at least 13 prescriptions of short acting beta agonists during the previous year (RR=51.6, 95% CI 7.9 to 345) and 7-12 prescriptions of short acting beta agonists (RR=16.2, 95% CI 2.6 to 101). Short acting beta agonists and inhaled steroids tended to be prescribed most frequently to the same patients. In patients who received more than one prescription per month of short acting beta agonists during the previous year, regular use of inhaled steroids was associated with a 60% reduced risk of asthma death (RR=0.4, 95% CI 0.2 to 1.0).

CONCLUSIONS

Regular use of inhaled steroids is associated with a decreased risk of asthma death, and excessive use of short acting beta agonists is associated with a markedly increased risk of asthma death.

Gender and drug treatment as determinants of mortality in a cohort of heart failure patients

AIM

We assessed gender differences in the risk of mortality in heart failure (HF) patients and evaluated the association between HF drug treatment and mortality.

METHODS AND RESULTS

We identified a cohort of 820 patients with newly diagnosed HF in 1996 in UK general practices. The diagnosis of HF was confirmed by the general practitioner. Fifty per cent were females and 27% were less than 70 years old. During a mean follow-up of 2 years, 172 patients died. We used computerized records to assess risk factors and drugs prescribed as treatment. The information on severity was assessed through a questionnaire. We performed a nested case-control analysis, and observed that men had twice the risk of dying than females, however the effect of age on mortality was stronger in females than males. We found a similar interaction between HF severity and sex. Data on use of some cardiovascular drugs such as diuretics, beta-blockers ACE-inhibitors and calcium channel blockers were suggestive of a reduced mortality risk. Current use of nitrates and glycosides carried an increased risk.

CONCLUSION

Older age, male sex and severity of HF were the main predictors of mortality among HF patients. Long-term use of beta-blockers was associated with a significantly reduced risk of mortality.

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.