Biomedical subjects

J Hallas

Publications and source records attributed to J Hallas.

At least 19 recordsLinked to original sources

PubMed2006

Prescribing of acid suppressive therapy: interactions between hospital and primary care.

BACKGROUND: Overuse of acid suppressive therapy in the hospital setting and in primary care is well documented. AIM: To describe interactions between prescriptions of acid suppressive therapy in hospital and in primary care. METHODS: All patients admitted to hospital over a 24-month period were identified. Details about prescription of acid suppressive therapy were retrieved. All prescriptions of acid suppressive therapy redeemed by these patients 12 months before and after discharge were retrieved from a prescription database. RESULTS: A total of 549 of 4477 patients (12.3%) were treated with acid suppressive therapy while in hospital, but acid suppressive therapy was prescribed de novo in only 192 (35%) of these cases. Information about indication for acid suppressive therapy and planned duration of therapy were given in the discharge letter in only 25% and 17% of the cases, respectively. Among patients treated with acid suppressive therapy during admission, prescriptions on acid suppressive therapy were redeemed by 67% in the year before admission and by 74% in the year after discharge. Among patients who had the acid suppressive therapy discontinued during admission (n = 67), 48% resumed acid suppressive therapy within the following 12 months. Of all subjects treated with acid suppressive therapy in the hospital catchment area, 7.8% were seen in our department. CONCLUSIONS: Decisions about acid suppressive therapy prescribing in hospital has little influence on prescribing in primary care.

Aged↗

PubMed2006

Trends in utilization of antiepileptic drugs in Denmark.

OBJECTIVES: To describe utilization of antiepileptic drugs (AEDs) in Denmark during 1993-2002, with special emphasis on oxcarbazepine, and to assess probable indications for AED use. MATERIALS AND METHODS: We retrieved prescription data from Odense University Pharmacoepidemiological Database, in Funen County, Denmark (population in 2002: 472,869). Within each calendar year we estimated period prevalence, incidence rate and monotherapy rate. Based on co-medication we defined 'epilepsy' when only AEDs were prescribed, 'pain' with co-prescription of opioids, and 'mood disorder' with co-prescription of antipsychotics or antidepressants. RESULTS: We identified 15,604 AED users. The prevalence of using AED increased from 9.3 (95% CI, 9-9.5) to 12.1 (11.8-12.4)/1000 persons. The incidence rate increased from 1.4 (1.3-1.6) to 1.7 (1.6-1.9)/1000 personyears. The monotherapy rate was 79-82%. AED use for 'epilepsy' declined by 19.7%, whereas the proportion of 'pain' and 'mood disorder' treatment increased by 11.2% and 8.4% respectively. CONCLUSIONS: Antiepileptic drug utilization increased during the study period, the increase probably caused by expanding use in areas other than epilepsy.

Adolescent↗

PubMed2004

Use of anti-secretory medication: a population-based cohort study.

BACKGROUND: Total use of anti-secretory medication (H2 blockers and proton pump inhibitors) is increasing rapidly, but knowledge of factors related to the increasing use is sparse. AIM: To describe development in the use of anti-secretory medication between 1993 and 2002 at a population level. METHODS: We extracted data on use of anti-secretory medication (H2-blockers and proton pump inhibitors) and ulcerogenic drugs, demographic data, and data on gastroscopy and endoscopically verified oesophagitis and peptic ulcer diagnoses, from three large population-based databases covering the County of Funen, Denmark 1990-2002 (population 470,000). RESULTS: Between 1993 and 2002 incidence of first time users was stable at 16.7/1000 persons/year. Total amount of consumed anti-secretory medication increased from 10.5 DDD/1000 persons/day to 25.2 DDD/1000 persons/day. Ninety per cent of the increase was related to long-term use of anti-secretory medication (> or = 180 DDD/patient/year). In 1993 21% of the anti-secretory medication was used by patients with oesophagitis, this increased to 28% in 2002. The proportion of medication used by peptic ulcer patients decreased from 29% in 1993 to 19% in 2002. CONCLUSIONS: Total use of anti-secretory medication increased as a result of more extensive long-term use, and most of the medication was used by patients without diagnosed peptic ulcer or oesophagitis.

Adult↗

PubMed2004

Appendicectomy has no beneficial effect on admission rates in patients with ulcerative colitis.

BACKGROUND AND AIMS: Those who have had an appendicectomy have a reduced risk of developing ulcerative colitis. However, the effect of appendicectomy on disease activity in patients with ulcerative colitis has not been established. METHODS: We used the Danish National Patient Registry to identify all incident cases of ulcerative colitis in Denmark during the period 1981 to 1999. Of these, 202 had an appendicectomy after their first admission with ulcerative colitis. In these patients, we compared the incidence rate of hospitalisations with ulcerative colitis as first diagnosis during the period between the onset of ulcerative colitis and appendicectomy, with the rate of such hospitalisations after appendicectomy. To adjust for the clinical course of ulcerative colitis unrelated to appendicectomy, we extracted a reference cohort (n = 808), matched to the index subjects with respect to age, sex, and year of first admission, but with an intact appendix. RESULTS: The rate of admission with ulcerative colitis as first diagnosis decreased by 47% after appendicectomy (rate ratio 0.53 (95% confidence interval (CI) 0.36-0.80)). However, the reference cohort showed a similar decline in admission rate (rate ratio 0.51). Thus appendicectomy had no apparent beneficial effect on admission rate after adjustment for the clinical course of disease unrelated to appendicectomy (adjusted rate ratio 1.05 (95% CI 0.67-1.67)). CONCLUSIONS: Appendicectomy had no significant beneficial effect on admission rates in patients with ulcerative colitis.

Adult↗

PubMed2004

Helicobacter pylori test and eradicate versus prompt endoscopy for management of dyspeptic patients: 6.7 year follow up of a randomised trial.

BACKGROUND: Dyspepsia is a chronic disease with significant impact on the use of health care resources. A management strategy based on Helicobacter pylori testing has been recommended but the long term effect is unknown. AIM: To investigate the long term effect of a test and treat strategy compared with prompt endoscopy for management of dyspeptic patients in primary care. PATIENTS: A total of 500 patients presenting in primary care with dyspepsia were randomised to management by H pylori testing plus eradication therapy (n = 250) or by endoscopy (n = 250). Results of 12 month follow up have previously been presented. METHODS: Symptoms, quality of life, and patient satisfaction were recorded during a three month period, a median 6.7 years after randomisation (range 6.1-7.3 years). Number of endoscopies, antisecretory medication, H pylori treatments, and hospital visits were recorded from health care databases for the entire follow up period. RESULTS: Median age was 45 years; 28% were H pylori infected. Use of resources was registered in all 500 patients (3084 person years) of whom 312 completed diaries. We found no difference in symptoms between the two groups. Median proportion of days without symptoms was 0.52 (interquartile range 0.10-0.88) in the test and eradicate group versus 0.64 (0.14-0.90) in the prompt endoscopy group (p = 0.27) (mean difference 0.05 (95% confidence interval (CI) -0.03 to 0.14)). Compared with the prompt endoscopy group, the test and eradicate group underwent fewer endoscopies (mean difference 0.62 endoscopies/person (95% CI 0.38-0.86)) and used less antisecretory medication (mean difference 102 defined daily doses/person (95% CI -1 to 205)). CONCLUSION: On a long term basis, a H pylori test and eradicate strategy is as efficient as prompt endoscopy for management of dyspeptic patients in primary care and reduces the use of endoscopy and antisecretory medication.

Adolescent↗

PubMed2002

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.

Aged↗

PubMed2001

Conducting pharmacoepidemiologic research in Denmark.

Denmark has one of the worlds most comprehensive registration of its citizens' use of medical and social services. Most databases are population-based and of very high quality. Virtually all employ a mutual person identifier, which renders it technically possible to link any of them with others. There are two prescription registries of interest for research, the OPED and the NJPD, each covering 0.5 million persons. The content of these are described in brief. The most recent Danish data protection act can be viewed as a liberalization of prevailing registry practice. Our most important obstacles for performing record-linkage studies are costs, academic resources and a lack of generally accepted guidelines on the ethics of observational research.

Access to Information↗

PubMed2001

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.

Adult↗

PubMed2001

Drug prescribing among Danish children: a population-based study.

OBJECTIVES: To characterise the pattern of drug prescribing in Danish children below 19 years of age. METHODS: We used the Odense Pharmacoepidemiologic Database to identify all individual prescriptions for 0- to 19-year-olds in the County of Funen, Denmark, in 1998. The drug consumption was analysed by the defined daily dose methods and anatomical chemical classification system, using analytical templates for individual-based drug utilisation statistics. RESULTS: Of the examined population, 52.6% had one or more prescriptions issued. Overall, 10% of the children accounted for 67.5% of drug prescriptions. Approximately 40% of the children had a prescription issued before they were 1 year old. In 1- to 2-year-olds, 85% received a prescription. Thereafter, the 1-year prevalence of drug use declined to 40%. The total drug consumption was similar between boys and girls until the early teens; thereafter the girls had a prescription issued twice as often as boys. In all age groups, respiratory drugs dominated and drugs used in dermatology was the second largest group. The third largest group was systemic anti-infective agents for children below 12 years of age, whereas it was psychotropic drugs among the oldest children. CONCLUSION: There is the same skewness of drug consumption among Danish children as among Danish adults, but the types of medication differ. Drug use is most extensive among children below 2 years but drug prescribing was considerable in all age groups.

Adolescent↗

PubMed2001

Antiepileptic drug utilization: a Danish prescription database analysis.

OBJECTIVES: The purpose of the study was to use prescription data from a Danish database to analyse and evaluate antiepileptic drug (AED) utilization, and compare with other prevalence studies. METHODS: A Danish research database covering outpatient prescription data from a population of 471,873 persons was used. Prescription records on all patients prescribed AEDs during 1998 were retrieved. A cohort was extracted from the group of AED users. RESULTS: We identified 5426 AED users. A total of 3756 of the 5426 AED users were included in our cohort. Of the subjects in the cohort 74% were on monotherapy, 19% used two AEDs and only 7% used three or more AEDs. The eight most frequent regimens were all monotherapy: carbamazepine, oxcarbazepine, phenobarbital, valproic acid, lamotrigine, clonazepam, phenytoin and primidon in that order. The estimated crude 1-year prevalence of AED use was 0.77% for women and 0.83% for men (P<0.001), and it increased with age for both genders. CONCLUSIONS: The prescription pattern reported here is in accordance with the general guidelines for the treatment of epilepsy in Denmark, except for a surprisingly extensive use of phenobarbital. With specific reservations the figures appear to be reasonable estimates of the prevalence of epilepsy.

Adolescent↗

PubMed2001

Lipid-lowering drugs and risk of myopathy: a population-based follow-up study.

We conducted a population-based cohort study to estimate the risk of myopathy associated with use of lipid-lowering drugs. Using data from general practices in the United Kingdom in 1991 through 1997, we identified three cohorts of individuals 40 to 74 years of age. One cohort comprised 17,219 persons who had received at least one prescription for lipid-lowering drugs in the period; a second cohort consisted of patients with a hyperlipidemia diagnosis who had not been prescribed lipid-lowering drugs (N = 28,974); and a third cohort comprised 50,000 individuals from the general population with no diagnosis of hyperlipidemia. The incidence rate of myopathy in the cohort of users of lipid-lowering drugs was 2.3 per 10,000 person-years [95% confidence interval (95% CI) = 1.2-4.4], which exceeded the incidence rates observed in the nontreated hyperlipidemia cohort [0 per 10,000 person-years (95% CI = 0.0-0.4)] and the general population [0.2 per 10,000 person-years (95% CI = 0.1-0.4)]. The relative risks of myopathy in current users of fibrates and statins compared with nonusers were 42.4 (95% CI = 11.6-170.5) and 7.6 (95% CI = 1.4-41.3), respectively. Potential risk factors other than drug use could not explain our findings in the nested case-control analysis. We conclude that use of lipid-lowering drugs is associated with a substantially greater risk of myopathy, which is most pronounced for fibrates. The absolute risk of myopathy in users of lipid-lowering drugs is, however, small.

Adult↗

PubMed2000

[Big differences in the frequency of polypharmacy between physicians].

Polypharmacy, the simultaneous use of multiple drugs, is associated with adverse drug reactions, medication errors, and increased risk of hospitalisation. When the number of drugs is five or more (major polypharmacy), a significant risk may be present. We analysed the prevalence of major polypharmacy among listed patients, and identified possible predictors of major polypharmacy related to the practice. Prescription data were retrieved from the Odense Pharmaco-epidemiological Database and the age and sex standardised prevalence rate of major polypharmacy was calculated for each practice (n = 173). Possible predictors of major polypharmacy related to the GPs were analysed by backward stepwise linear multiple regression. A six-fold variation between practices in the prevalence of major polypharmacy was found, i.e. from 16 to 96 per 1000 listed patients (median: 42). Predictors related to the practice structure, workload, clinical work profile, and prescribing profile could explain 56% of the variation.

Adult↗

PubMed2000

Pharmacovigilance based on prescription databases.

Prescription databases are indispensible in drug safety research and surveillance. For suspected rare serious adverse drug reactions, the confirmation and quantitative risk assessment requires proper epidemiological studies. Often prescription databases provide the information on drug exposure for such studies. Aberrant drug utilization in terms of overuse, underuse, polypharmacy etc. may be a threat to the health of the patient, and these aspects can best be studied by prescription databases. In cases of international drug safety alerts, prescription databases may provide information required for rational actions to be taken.

Aged↗

PubMed2000

Drug-induced symptoms of functional dyspepsia and nausea. A symmetry analysis of one million prescriptions.

BACKGROUND: A large variety of drugs have been implicated in causing dyspepsia. Due to the high background incidence of dyspepsia it is impossible to distinguish between spontaneous and truly drug-related symptoms. Most patients with dyspeptic symptoms are treated empirically. Drug-induced dyspepsia might therefore be reflected in the sequencing of prokinetics relative to other medications. AIM: To screen a large prescription database for signs of drug-induced functional dyspepsia, applying a symmetry principle. METHODS: Prescription data on all incident users of cisapride and metoclopramide were used to identify individuals who had started their first therapies with a prokinetic drug and an index drug within a 100-day span. A dyspepsia-provoking effect of the index drug would manifest as an excess of persons with the prokinetic drug prescribed last in this selected population. Relative to conventional analyses based on case-control or cohort design, this principle is robust to confounders that are stable over time. RESULTS: In the cisapride analysis (1825 persons) no single drug had adjusted rate ratios significantly above unity. An inverse signal for antidepressants (rate ratio 0.57; 95% CI: 0.39-0.84) suggests that these drugs may have a therapeutic effect against functional dyspepsia. In the metoclopramide analysis (6126 persons) positive signals were found for 14 drugs, all well-known for causing nausea as a side-effect, with the exception of insulin (rate ratio 2.91, 95% CI: 1.40-8.11). CONCLUSIONS: Drug-induced symptoms of functional dyspepsia are rare and do not contribute to the use of cisapride. The start of insulin treatment may induce nausea.

Adult↗

PubMed1999

[National surveillance of Helicobacter pylori eradication in Denmark. Results based on registration of 34.582 drug prescriptions].

We wanted to characterize the use of H. pylori eradication therapy in Denmark (inhabitants 5,227,862). All H. pylori eradication treatments from a nation wide database covering all drug prescriptions in the period January 1994-June 1996 were identified. We found 28,784 out-patients having a prescription with drugs for H. pylori eradication, accounting for 34,582 prescriptions in total. The incidence of new consumers was 220 per 10(5) inhabitants per year, with a maximum at 70-79 years of age. Eighty-six percent of the patients had only one treatment course. Forty-five percent had an anti-ulcer drug prescribed 1-12 months after the H. pylori eradication therapy. Consumption of antibiotics used for H. pylori eradication accounted for 1.4% of the total consumption of antibiotics. In conclusion, the incidence of H. pylori eradication therapy was fairly stable but with changes in the pattern of drug regimens used. Anti-ulcer drugs were often given after H. pylori eradication therapy, suggesting an inappropriate use of eradication treatment.

Adult↗

PubMed1999

[Polypharmacy estimated by means of a population-based prescription database].

The aim was to investigate estimators of polypharmacy (PP) from a population based prescription database. Data were retrieved from Odense Pharmacoepidemiological Database and contained a 10% random sample (n = 26,977) of drug users in 1994. PP was defined as simultaneous treatment with different drugs, and the duration of treatment was calculated from the date of purchase and the number of defined daily doses prescribed. This estimator was compared with an estimator based on the number of drugs purchased during a three month period. On an average day 8.7% were exposed to minor PP (two to four drugs) and 1.2% to major PP (five or more drugs). Purchase of five or more drugs during a three month period predicted episodes of major PP with a positive predictive value of 80%. Epidemiological measures of multiple drug use can be estimated from a prescription database. Conceptually, an estimator based on the number of simultaneously used drugs is preferable, but the number of drugs purchased during a three month period may be a useful alternative estimator.

Databases, Factual↗

PubMed1999

Helicobacter pylori and risk of ulcer bleeding among users of nonsteroidal anti-inflammatory drugs: a case-control study.

BACKGROUND & AIMS: Peptic ulcer complications related to use of nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most common serious adverse drug reactions. Whether Helicobacter pylori infection potentiates this gastrointestinal toxicity of NSAIDs is still unresolved. In this study, we investigated the role of H. pylori as a cause of bleeding peptic ulcer among NSAID users. METHODS: A case-control study of current users (n = 132) of NSAIDs (including acetylsalicylic acid), admitted because of bleeding peptic ulcer, was performed. Controls were 136 NSAID users without gastrointestinal complications. H. pylori was diagnosed by either increased levels of serum immunoglobulin G or by 13C-urea breath test. RESULTS: Fifty-eight (44%) case subjects had a bleeding gastric ulcer, 54 (41%) had a bleeding duodenal ulcer, 12 (9%) had both gastric and duodenal ulcers, and 8 (6%) had hemorrhagic gastritis. H. pylori was present in 75 (57%) cases compared with 59 (43%) controls. The adjusted odds ratio of bleeding peptic ulcer among NSAID users associated with H. pylori infection was 1.81 (95% confidence interval, 1.02-3.21). H. pylori accounted for approximately 24% of bleeding peptic ulcers among elderly NSAID users. CONCLUSIONS: NSAID users infected with H. pylori have an almost twofold increased risk of bleeding peptic ulcer compared with NSAID users without H. pylori.

Adult↗

PubMed1999

Polypharmacy in general practice: differences between practitioners.

BACKGROUND: Polypharmacy, the simultaneous use of multiple drugs, is associated with adverse drug reactions, medication errors, and increased risk of hospitalization. When the number of concurrently used drugs totals five or more (major polypharmacy), a significant risk may be present. AIM: To analyse the interpractice variation in the prevalence of major polypharmacy among listed patients, and to identify possible predictors of major polypharmacy related to the practice. METHOD: Prescription data were retrieved from the Odense Pharmacoepidemiological Database, and individuals subject to major polypharmacy were identified. The age- and sex-standardized prevalence rate of major polypharmacy was calculated for each practice in the County of Funen in Denmark (n = 173), using the distribution of age and sex of the background population as a reference. The practice characteristics were retrieved from the Regional Health Insurance System. Possible predictors of major polypharmacy related to the general practitioners (GPs) were analysed using backward stepwise linear multiple regression. RESULTS: A six-fold variation between the practices in the prevalence of major polypharmacy was found (16 to 96 per 1000 listed patients; median = 42). Predictors related to the practice structure, workload, clinical work profile, and prescribing profile could explain 56% of the variation. CONCLUSION: A substantial part of the variation in major polypharmacy between practices can be explained by predictors related to practice.

Adult↗