PubMed Health⌕ Search

Biomedical subjects

Jesper Hallas

Publications and source records attributed to Jesper Hallas.

At least 19 recordsLinked to original sources
PubMed2006

Use of single and combined antithrombotic therapy and risk of serious upper gastrointestinal bleeding: population based case-control study.

OBJECTIVES: To assess the risk of serious upper gastrointestinal bleeding associated with the newer antithrombotic agents used alone or in combination with other antithrombotic drugs; to describe the trends in use of antithrombotic drugs in the background population. DESIGN: Population based case-control study. SETTING: Funen County, Denmark (population 470,000). SUBJECTS: 1443 cases of serious upper gastrointestinal bleeding identified during 2000-4; 57,720 age and sex matched controls. MAIN OUTCOME MEASURE: Exposure to low dose aspirin, clopidogrel, dipyridamole, vitamin K antagonists, and combined antithrombotic treatment. RESULTS: Adjusted odds ratios associating drug use with upper gastrointestinal bleeding were 1.8 (95% confidence interval 1.5 to 2.1) for low dose aspirin, 1.1 (0.6 to 2.1) for clopidogrel, 1.9 (1.3 to 2.8) for dipyridamole, and 1.8 (1.3 to 2.4) for vitamin K antagonists. Corresponding figures for combined use were 7.4 (3.5 to 15) for clopidogrel and aspirin, 5.3 (2.9 to 9.5) for vitamin K antagonists and aspirin, and 2.3 (1.7 to 3.3) for dipyridamole and aspirin. Other combinations were used too infrequently to allow estimation. The number of treatment years needed to produce one excess case varied from 124 for the clopidogrel-aspirin combination to 8800 for clopidogrel alone. During the study period, exposure to combined antithrombotic regimens increased by 425% in the background population. CONCLUSION: Antithrombotic treatment is becoming increasingly aggressive. Combined antithrombotic treatment confers particular risk and is associated with high incidence of gastrointestinal bleeding.

Aged↗
PubMed2006

[Is the use of selective serotonin reuptake inhibitors associated with an increased risk of bleeding?].

Recent studies have shown that there may be an increased risk of upper gastrointestinal tract bleeding when patients use selective serotonin reuptake inhibitors (SSRIs). We have reviewed the available epidemiological papers on this subject. There is apparently an increased risk of clinically significant bleeding episodes in patients treated with SSRIs. Two papers report a multiplicative interaction for combined treatment with non-steroidal anti-inflammatory drugs (NSAIDs) and SSRIs. We conclude that SSRIs should be used with caution in patients with an increased risk of bleeding.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2006

Complicated and uncomplicated peptic ulcers in a Danish county 1993-2002: a population-based cohort study.

UNLABELLED: Peptic ulcer epidemiology changes as the proportion of Helicobacter pylori infected people decreases, use of nonsteroidal anti-inflammatory drugs (NSAID) increases, and the proportion of elderly persons increases. OBJECTIVES: To describe incidence and prognosis of uncomplicated and complicated peptic ulcer patients in Funen County 1993-2002. METHODS: Data on endoscopies, gastric and duodenal operations, and related peptic ulcer diagnoses were extracted from four population-based databases covering a period from 1974 to 2002. All citizens of Funen County (population 470,000) who between 1993 and 2002 had a peptic ulcer diagnosed for the first time were identified. RESULTS: Between 1993 and 2002 the incidence of uncomplicated duodenal ulcer decreased from 0.55/1,000 person-years (95% CI 0.49-0.62) to 0.37 (0.31-0.43), uncomplicated gastric ulcer decreased from 0.56 (0.49-0.63) to 0.40 (0.34-0.46), and perforated ulcer decreased from 0.14 (0.11-0.18) to 0.08 (0.06-0.11). The incidence of bleeding peptic ulcer was stable with 0.55 (0.49-0.62) in 1993 and 0.57 (0.51-0.64) in 2002. The proportion of possible NSAID-related incident peptic ulcers increased from 320/827 (39%) in 1993 to 363/686 (53%) in 2002 (p < 0.01). A total of 3,233 patients with incident complicated peptic ulcer (9,927 person-years) and 4,421 patients with incident uncomplicated peptic ulcer (17,773 person-years) was followed for up to 10 yr. The first month following newly diagnosed complicated ulcer the standardized mortality rate was 37.1 (33.4-41.1) during the next 11 months it was 5.1 (4.6-5.6), and in the following years it was 2.6 (2.4-2.8). The corresponding figures for incident uncomplicated peptic ulcer was 11.6 (9.6-13.9), 4.0 (3.6-4.4), and 2.5 (2.3-2.7). CONCLUSION: During the period, incidence of peptic ulcers decreased and an increasing proportion was related to NSAID. Mortality is high.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2006

Esophagitis: incidence and risk of esophageal adenocarcinoma--a population-based cohort study.

OBJECTIVES: Although symptoms of reflux are common, our knowledge of the epidemiology and natural history of gastroesophageal reflux disease is sparse. The risk of esophageal adenocarcinoma is increased among patients with acid reflux, but the contribution of Barrett's lesions is unknown. METHODS: With the aim to estimate the incidence of diagnosed endoscopic esophagitis lesions and the risk of esophageal adenocarcinoma among patients with previously diagnosed esophagitis, we extracted data on endoscopies, esophagitis diagnoses, and gastroesophageal cancer diagnoses from five population-based databases covering the period from 1974 to 2002, and covering all citizens in Funen County (population 470,000). RESULTS: In 2002, the incidence of esophagitis lesions was 2.4 per 1,000 person-years (95% confidence interval 2.3-2.6), 18.3 per 1,000 persons (17.9-18.7) had previously diagnosed esophagitis. Incidence increased by calendar year and age, was higher among males than among females, and was closely related to rate of endoscopy. Among 11,129 patients with previously diagnosed esophagitis, 15 had esophageal adenocarcinoma during 58,322 person-years of follow-up (26 per 100,000 person-years). The expected number was 2.79 and the standardized incidence ratio was 5.38 (3.01-8.87). Ten of the 15 patients with esophageal adenocarcinoma had previously diagnosed Barrett's esophagus. CONCLUSION: The risk of esophageal adenocarcinoma is increased fivefold in patients with previously diagnosed esophagitis, but most of the adenocarcinomas occurred among patients with Barrett's esophagus.

Adenocarcinoma↗
PubMed2006

Templates for analysis of individual-level prescription data.

The advent of large population-based prescription databases has enabled us to study drug use with the individual user as our unit of analysis. This review presents three non-specific analytic templates that may be applied to individual-level prescription data. The ratio of prevalence odds to incidence rate can estimate the average duration for drug use. Limitations and pitfalls are discussed. Although it should be cautiously interpreted, it provides a reasonable ranking of drugs with respect to their retention in users. The Lorenz curve is an analytic tool to express skewness in drug use. It shows the proportion of drug use that is accounted for by percentiles of drug users, ranked according to their volume of drug intake. It may express the extent of heavy users as well as sporadic small-volume users and may, for example, be used to screen for an unsuspected abuse potential of a drug. The waiting-time distribution is a frequency distribution of first occurrences of drug use within a time-window. It forms the basis for a theoretical model for robust estimates of prevalence and incidence rate. On an intuitive level, it displays visual correlates of epidemiological prescribing parameters such as period prevalence, point prevalence, incidence rate, duration, prescription renewal rate, relapse of treatments and seasonality. Each measure may be incorporated into an integral matrix that reflects various traits in utilization of every drug or drug class, thereby possibly finding abnormalities that suggest sub-optimal prescribing.

Data Interpretation, Statistical↗
PubMed2005

Antibiotics active against Chlamydia do not reduce the risk of myocardial infarction.

OBJECTIVE: There is evidence that Chlamydia pneumoniae (CP) is involved in the aetiology of myocardial infarction (MI). Randomised trials do not support a beneficial effect of antibiotics in secondary prevention of MI, but the evidence for an effect on primary prevention is conflicting. We investigated if past use of antibiotics active against CP is associated with a decreased risk of developing MI. METHODS: We conducted a population-based case-control study of 4166 patients hospitalised due to MI from 1 January 1994 to 1 September 1999 in the County of Funen, Denmark. Controls (n=16,664) were a random sample of inhabitants, matched for age and sex. Confounders controlled for in the analysis were gender, age, obstructive pulmonary disease, diabetes, previous MI and known atherosclerotic antecedents. Previous use of antibiotics active against CP (macrolides, tetracyclines and quinolones) and of antibiotics not active against CP (penicillins) was analysed among the cases and controls. RESULTS: The risk of MI was not associated with previous exposure to macrolides (OR: 1.0; CI: 0.9-1.1), tetracyclines (OR: 1.0; CI: 0.9-1.2) or quinolones (OR: 1.0; CI: 0.9-1.2) or combinations of the three drugs (OR: 1.0; CI: 0.9-1.1). There was no sign of a protective effect in subgroups defined by high cumulative doses of antibiotics, various time-windows of exposure, risk factors of MI or other co-morbidity. OR was 1.1 (0.9-1.3) in persons with no atherosclerotic antecedents. CONCLUSION: The study does not support the hypothesis of a decreased risk of MI in patients exposed to antibiotics active against CP.

Aged↗
PubMed2005

Cancer patients' first treatment episode with opioids: a pharmaco-epidemiological perspective.

GOAL: The factors underlying the choice of opioids for cancer patients in primary care are largely unknown. Our aim was to describe cancer patients' first treatment episode with opioids in relation to disease characteristics and clinical course. PATIENTS AND METHODS: During 1997 and 1998, a population-based cohort of 4,006 incident cancer patients from a Danish county was identified. The patients were followed up from diagnosis to death or until 31 December 2003, and data on their use of opioids were obtained from a prescription database. MAIN RESULTS: Eventually, 54% of the cancer patients became incident users of opioids. Opioid treatment was initiated close to the diagnosis date in 20% of the patients. Most incident users (57%) were not terminal when they began using opioids, and 44% survived the first treatment episode. Of those who died, 70% received opioids in their terminal phase. The incidence rates of new opioid users were inversely related to the 5-year cancer survival period. A weak opioid was the first choice in 64% of the non-terminal users and in 43% of the terminal ones. No statistically significant differences in opioid use were found between men and women. CONCLUSIONS: Opioid use in cancer patients was not confined to the terminal course. Treatment with opioids should be viewed as a dynamic condition, with patients shifting between periods of use and non-use. The aggressiveness of the cancer and the presence of metastases were characteristics found to be strong determinants of opioid use.

Aged↗
PubMed2005

[Pharmacoepidemiology].

Explore the source record for details and available documents.

Adverse Drug Reaction Reporting Systems↗
PubMed2005

Drug utilization statistics for individual-level pharmacy dispensing data.

The emergence of large, computerized pharmacoepidemiologic databases has enabled us to study drug utilization with the individual user as the unit of analysis. A recurrent problem in such analyses, however, is the overwhelming volume and complexity of data. This paper reviews the methods to estimate basic epidemiologic measures of drug utilization and some methods to screen for aberrant prescribing patterns. It also presents the basis and application of the waiting time distributions that can provide information about the period prevalence, point prevalence, incidence, duration of use, seasonality and rate of prescription renewal or relapse for specific drugs. If analyzed regularly, these measures can disclose subtle trends in clinical drug use that would not be evident from the wholesale figures. In specific situations, pharmacy dispensing data without diagnostic information can be used to assess the association between drug use and adverse effects in a prescription symmetry design.

Age Factors↗
PubMed2005

Use of opioids in a Danish population-based cohort of cancer patients.

Until recently, Denmark has had the highest use of strong opioids per capita in the world. Our aim was to analyze cancer patients' use of opioids in this population by linkage between the Danish Cancer Register and a prescription database. The changes in opioid use from 1994 to 1998 in the entire cohort of cancer patients (n=24,190) in a Danish county (n approximately 470,000) were analyzed. The overall consumption of opioids increased from 20 kg to 37 kg oral morphine equivalents (omeq) per year. The average consumption increased from 7.6 to 10.7 g omeq/opioid user/year. The annual proportion of users increased from 17% to 20%. The proportion of patients who were alive 2 years after their first opioid prescription increased from 38% to 55%. Increased awareness towards pain treatment, with earlier initiation of opioid treatment and higher doses to the cancer patients, could be major explanations for the increase in the cancer patients' use of opioids.

Aged↗
PubMed2005

The risk of missed gastroesophageal cancer diagnoses in users and nonusers of antisecretory medication.

BACKGROUND & AIMS: Some patients with early gastroesophageal cancer may appear to "heal" because of antisecretory medication, but the risk of a missed diagnosis is unknown. The aim of the study was to estimate the incidence of gastroesophageal cancer with or without pre-endoscopic treatment with antisecretory medication. METHODS: We extracted data on use of endoscopies, gastroesophageal cancer diagnoses, death, migration, and use of antisecretory medication (H(2) blockers and proton pump inhibitors) from 5 population-based registries covering 1974-2002. We included all citizens in Funen County (population, 470,000) who between 1993 and 2002 were investigated by endoscopy for the first time. The patients were followed up until death, emigration, or the end of the study period. RESULTS: Among 27,829 patients with a first endoscopy (mean age, 56 years; 48% male, 115,804 person-years of follow-up), 461 had gastroesophageal cancer diagnosed at the first endoscopy and 52 were diagnosed during a median follow-up of 2.7 years after the first endoscopy. The incidence during follow-up was similar to the background population (standardized incidence ratio, 1.24; 95% confidence interval, 0.81-1.91), increased with age, and was higher in male patients. The incidence of gastroesophageal cancer during follow-up was 46 per 100,000 person-years in users of antisecretory medication the last 180 days before the first endoscopy compared with 44 per 100,000 person-years in nonusers (age and sex standardized difference, 4 per 100,000 person-years; 95% confidence interval, -14 to 22). CONCLUSIONS: Very few cancers are missed at endoscopy. The risk seems similar in users and nonusers of antisecretory medication before endoscopy.

Adrenergic beta-Antagonists↗
PubMed2005

First-time endoscopy and use of antisecretory medication: a population-based cohort study.

OBJECTIVE: Endoscopy is the gold standard for diagnostic evaluation of upper gastrointestinal symptoms. The relation between endoscopy and use of antisecretory medication on a population level is unknown. The aim of this study was to describe development in the number of patients undergoing first-time endoscopies and their use of antisecretory medication. MATERIAL AND METHODS: Data on the use of endoscopies and antisecretory medication (H2 blockers and proton-pump inhibitors) were extracted from five population-based databases and included all citizens in Funen County (population 470,000) who had first-time endoscopies between 1993 and 2002. RESULTS: A total of 27,829 first-time endoscopy patients were identified. In 2002 the number of first-time endoscopies was 5.6/1000 persons. The proportion that had redeemed prescription(s) on antisecretory medication the last year before endoscopy increased from 33% (1095/3286) in 1993 to 41% (1012/2445) in 2002 (p = 0.000). Following endoscopy, average use of antisecretory medication increased by 90 defined daily doses (DDD)/patient/year (95% CI 84-96) in patients with oesophagitis (N = 4850), by 59 DDD/patient/year (95% CI 54-64) in peptic ulcer patients (N = 4373) and by 18 DDD/patient/year (95% CI 16-20) in patients with normal endoscopies (N = 16,400). CONCLUSIONS: An increasing proportion of patients are treated with antisecretory medication before endoscopy. Following endoscopy, use of antisecretory medication increases irrespective of the diagnostic findings.

Adult↗
PubMed2005

The antiplatelet effect of clopidogrel is not attenuated by statin treatment in stable patients with ischemic heart disease.

Recent studies suggest that cytochrome P450 (CYP) 3A4 metabolized statins attenuate the antiaggregatory effect of clopidogrel. We evaluated how CYP3A4 metabolized statins and non-CYP3A4 metabolized statins influence platelet aggregation when given concomitantly with clopidogrel. Sixty-six stable patients with ischemic heart disease were included in this parallel group study. All patients were on clopidogrel and aspirin. Thirty-three patients received a CYP3A4 metabolized statin (simvastatin or atorvastatin), and 33 were treated with a non-CYP3A4 metabolized statin (pravastatin). The antiplatelet effect of clopidogrel was assessed at inclusion and 21 days after statin discontinuation. Platelet function was evaluated by two methods 1) optical platelet aggregometry after stimulation with 20 and 30 microM ADP, and 2 and 4 mg/l collagen, respectively, 2) a Platelet FunctionAnalyzer-100. The primary effect measure was final platelet aggregation after stimulation with 20 microM ADP. No difference was observed between patients treated with a CYP3A4 metabolized statin and patients receiving a non-CYP3A4 metabolized statin (30% point (7-42) versus 20% point (9-32), p = 0.83). Platelet aggregation was not improved by discontinuation of statins for 21 days. Indeed, we found that statin treatment given concomitantly with clopidogrel resulted in an improved platelet inhibition when compared to clopidogrel given alone. The antiplatelet effect of clopidogrel is not attenuated by concomitant treatment with a CYP3A4 metabolized statin in patients with clinical stable ischemic heart disease.

Aged↗
PubMed2004

Cancer patients' share in a population's use of opioids. A linkage study between a prescription database and the Danish Cancer Registry.

The aim of this study was to 1) assess cancer patients' share in a population's use of opioids and how much it influences the total use, and 2) analyze trends in the population's use of "weak" and "strong" opioids during a five-year period. Person-identifiable data on opioid prescriptions and cancer diagnoses from a Danish county (n approximately 470,000) were retrieved from a prescription database, OPED, and The Danish Cancer Registry from 1993-1997 (identifying 23,843 cancer patients). In a given year, 14% of the population's opioid users were cancer patients, and they received 23% of the total opioid consumption. Over time, the number of patients using weak opioids increased and the number using strong opioids decreased among both cancer patients and non-cancer patients. Cancer patients' consumption of strong opioids increased dramatically in 1996-1997, almost accounting for the entire increase in the whole population's consumption of strong opioids.

Data Collection↗