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Morten Andersen

Publications and source records attributed to Morten Andersen.

At least 19 recordsLinked to original sources

[How participation in a clinical trial affects doctors' choice of treatment].

In a retrospective cohort study, the effects of participation in a company-sponsored clinical trial on asthma drug prescribing were investigated. Ten trial-conducting practices were compared with 165 control practices. Conducting the trial did not influence guideline adherence measured as the prevalence of inhaled corticosteroid use among users of inhaled beta2-agonists. However, participation in the trial led to an increased preference for sponsor's drugs.

English Abstract↗

Factor analysis improves the selection of prescribing indicators.

OBJECTIVE: To test a method for improving the selection of indicators of general practitioners' prescribing. METHODS: We conducted a prescription database study including all 180 general practices in the County of Funen, Denmark, approximately 472,000 inhabitants. Principal factor analysis was used to model correlation between 19 register-based indicators for the quality of non-steroidal anti-inflammatory drug (NSAID) prescribing. RESULTS: The correlation between indicators ranged widely from 0 to 0.93. Factor analysis revealed three dimensions of quality: (1) "Coxib preference", comprising indicators directly quantifying choice of coxibs, indicators measuring expenditure per Defined Daily Dose, and indicators taking risk aspects into account, (2) "Frequent NSAID prescribing", comprising indicators quantifying prevalence or amount of NSAID prescribing, and (3) "Diverse NSAID choice", comprising indicators focusing on the width of GPs' formularies. The number of indicators for measuring the important aspects of quality in prescribing of NSAIDs could be reduced substantially by selecting the indicator in each dimension with the highest factor loading. A high preference for coxibs indicated both appropriate and inappropriate prescribing, as revealed by the correlation of the indicators in the first factor. CONCLUSION: Correlation and factor analysis is a feasible method that assists the selection of indicators and gives better insight into prescribing patterns.

Anti-Inflammatory Agents, Non-Steroidal↗

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↗

How conducting a clinical trial affects physicians' guideline adherence and drug preferences.

CONTEXT: General practitioners are frequently involved in clinical trials sponsored by pharmaceutical companies but the effects of participation on their prescribing patterns have not been evaluated. OBJECTIVE: To determine how conducting a company-sponsored clinical trial influenced physicians' adherence to international treatment recommendations and their prescribing of the pharmaceutical company's drugs. DESIGN, SETTING, AND PATIENTS: Observational cohort study in Funen County, Denmark, comparing 10 practices that were conducting a trial on asthma medicine with 165 control (non-trial-conducting) practices. The study population included 5439 patients treated with asthma drugs from the trial-conducting practices and 59,574 patients from the control practices. Practices conducted the trial between April 26, 2001, and October 7, 2002. MAIN OUTCOME MEASURES: Adherence to guidelines measured as use of inhaled corticosteroids among asthma patients. Prevalence of use of the company's drugs and the trial sponsor's share of the total volume of asthma drugs prescribed. RESULTS: The baseline proportion of asthma patients using inhaled corticosteroids was 68.5% in trial-conducting and 69.1% in control practices. Conducting the trial did not influence guideline adherence (odds ratio [OR] after 2 years, 1.00; 95% confidence interval [CI], 0.84-1.19). In trial-conducting practices, the sponsoring company's share of the total prescribed volume of asthma drugs increased compared with control practices (6.7%; 95% CI, 3.0%-11.7%). This could be attributed to a significantly higher preference for the company's inhaled corticosteroids (OR, 1.26; 95% CI, 1.04-1.54) and trends toward increased prescribing of the company's other asthma drugs. CONCLUSION: Conducting a trial sponsored by a pharmaceutical company had no significant impact on physicians' adherence to international treatment recommendations but increased their use of the trial sponsor's drugs.

Anti-Asthmatic Agents↗

Narrow and wide prescribers among general practitioners: a cohort study of drug formularies used for new treatments.

OBJECTIVE: The aims of this study were to analyse (1) if it is possible to classify general practitioners (GPs) or groups of practitioners (practice units) as overall narrow or wide prescribers and (2) to what extent the size of practice drug formularies is associated with general prescribing behaviour, practice activity and demography. METHODS: Data were retrieved from the Odense University Pharmacoepidemiologic Database (OPED) and the prescribing patterns of 177 practice units were analysed in a 4-year period including 2000 and 2003. We characterised the drug repertoire for new treatments using a Formulary Diversity Scale based on two formulary measures, the DU 90% and the Formulary Selectivity Index. Multiple regressions were used to analyse the association between formulary size and practice characteristics. RESULTS: The final Formulary Diversity Scale comprised 15 therapeutic drug groups and 151 different analogues. The average score based on the DU 90% segment was 46 drugs (range: 28-65) corresponding to 30% of drugs available. Using the Formulary Selectivity Index the average diversity score was 0.70. Practices with a high number of patients and a high percentage of elderly patients were more likely to use a wide range of drugs. CONCLUSION: The Formulary Diversity Scale revealed wide variation between practice units, indicating the existence of both overall narrow and wide prescribers among GPs. The number of patients attending the practice and the percentage of elderly patients were directly associated with the use of more analogues.

Cohort Studies↗

Analysing duration of episodes of pharmacological care: an example of antidepressant use in Danish general practice.

Analysing duration of treatment episodes has become a standard task in many pharmacoepidemiological studies. However, such analyses are often carried out in a rather simplistic manner and more subtle issues are often ignored. In this paper, methods of analysing duration treatment episodes beyond simple analyses allowing investigation of the risk for certain events over time are demonstrated. In particular, the use of cumulative incidence functions, cause-specific hazard functions, hazard rate models and expected mortality in analysing duration of episodes is presented. We used these statistical techniques in analysing the early treatment history of patients who started a regular treatment with antidepressant drugs in the primary health care sector in Denmark. We have extracted some important features: The risk of discontinuing and switching treatment was very high around 10 weeks after starting treatment. After discontinuing the first treatment period, many patients soon started a second treatment period depending on the duration of the first treatment period with highest risk around 10 weeks. The mortality rate among the patients in treatment was about three times higher than the expected mortality. The risk of dying immediately after stopping treatment was about twice the expected mortality. The analysis suggests that: (1) there is a critical period for a first discontinuing, switching and restarting treatment around 10 weeks, (2) the GPs prescribing habits have more influence on the patterns than patient or drug characteristics, (3) over time Danish GPs tend to prolong the duration of first treatment period and avoid longer treatment breaks.

Adult↗

Antihypertensive medication and the risk of acute pancreatitis: the European case-control study on drug-induced acute pancreatitis (EDIP).

OBJECTIVE: Angiotensin-converting enzyme (ACE) inhibitors and diuretics have been associated with acute pancreatitis. We quantified the risk of acute pancreatitis associated with the use of antihypertensive medication in the European study on drug-induced acute pancreatitis (EDIP). MATERIAL AND METHODS: The EDIP study is a multicenter population-based European case-control investigation of the association between drug use and acute pancreatitis. Patients between 40 and 85 years of age hospitalized for acute pancreatitis were included in the study between 1 October 1994 and 31 December 1998. For each case, age- and gender-matched community controls were recruited. Detailed information on drug use and potential confounders (e.g. comorbidity, alcohol use) was obtained through a structured interview. RESULTS: In all, 724 patients with acute pancreatitis and 1791 community controls were identified and interviewed. Use of ACE inhibitors in the week prior to the index date was associated with an increased risk of acute pancreatitis (adjusted odds ratio 1.5; 95% CI: 1.1-2.2). The risk of acute pancreatitis associated with ACE inhibitors increased with higher daily doses and was highest in the first 6 months of therapy. Calcium channel blockers increased the risk of acute pancreatitis (adjusted odds ratio 1.5; 95% CI: 1.1-2.1) without an apparent dose- or response relationship. Loop and thiazide diuretic use was not associated with an increased risk of acute pancreatitis. Potassium-sparing diuretics elevated the risk of acute pancreatitis, albeit non-significantly. CONCLUSION: Use of ACE inhibitors is associated with a modest increase in the risk of acute pancreatitis during the first months of treatment.

Acute Disease↗

Patterns of antibiotic use in the community in Denmark.

A cross-sectional descriptive population survey was conducted in 2003 to examine epidemiological characteristics of antibiotic use in the community in Denmark and particularly in the area of self-medication with antibiotics. Self-medication with antibiotics was rare in Denmark. 97% of antibiotics used were obtained after a medical consultation. While the existing legal framework preventing over-the-counter dispensation of antibiotics must be maintained, our results show that, in Denmark, interventions to optimize antibiotic use should primarily focus on the prescribers.

Adolescent↗

Intensive community pharmacy intervention had little impact on triptan consumption: a randomized controlled trial.

OBJECTIVE: To evaluate the impact of an intensive pharmaceutical care campaign targeting inappropriate use of triptans. DESIGN: Randomized controlled trial. SETTING: 22 community pharmacies in the County of Funen, Denmark. SUBJECTS: A total of 1123 triptan users at intervention pharmacies and 1340 at control pharmacies. INTERVENTION: Intervention pharmacy staff received information on migraine and other types of headache, detection of inappropriate triptan use and other drug-related problems, and techniques for establishing a dialogue with patients. Intervention consisted of a folder and a structured dialogue with the pharmacy staff. The folder included questions aimed at detecting overuse and inappropriate triptan use. MAIN OUTCOME MEASURES: Change in average triptan consumption in doses per month measured by means of a prescription database with information on all purchases of reimbursed drugs at the level of the individual patient. RESULTS: Overall, intervention had no statistically significant short-term impact on patients' consumption of triptans either among incident users (intervention/control ratio 1.02; 95% confidence interval 0.95 to 1.12), or among prevalent users (1.02; 0.97 to 1.08). No effects were observed after 6 and 9 months, apart from a possible borderline effect after 9 months among prevalent users with intermediate triptan consumption (0.93; 0.87 to 1.00). CONCLUSION: The pharmaceutical care campaign did not reduce the use of triptans.

Adult↗

Is it possible to measure prescribing quality using only prescription data?

A large number of prescribing quality indicators based on register data have been proposed and many are used routinely in quality management. Often the content and face validity of indicators have been assessed by consensus methods, but studies analysing other validity aspects are scarce. Prescription data are frequently used for indicators, but they do not provide any direct information about disease and patient factors important for judging the quality of prescribing. If register-based proxies for diagnoses, disease severity or risk factors are employed, validation is essential. The concurrent validity of indicators should be assessed by comparing to a "gold standard" quality assessment at the patient level using all available clinical information. The validity of frequently used quality indicators of asthma treatment has been questioned and should be further investigated. NSAID prescribing indicators are currently under evaluation. In the future, detailed clinical information from practice databases and computerised hospital records will be an important data source for indicators and for validation studies. Furthermore, the statistical and epidemiological properties of prescribing quality indicators need more attention.

Anti-Asthmatic Agents↗

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↗

General practitioners choose within a narrow range of drugs when initiating new treatments: a cohort study of cardiovascular drug formularies.

OBJECTIVE: The aims of this study were (1) to develop and evaluate a new method for investigating personal drug formularies in general practice and (2) to test the hypothesis that there is a difference between personal drug formularies for incident and ongoing drug use. METHODS: In 2002, we studied prescribing patterns of beta-blockers, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin-II antagonists and statins in the County of Funen, Denmark (180 general practices, 472,000 inhabitants). For each practice, we distinguished between an incident drug formulary consisting of prescriptions for new users and an ongoing drug formulary including prescriptions for patients already in treatment. Prescription data were retrieved from the Odense University Pharmacoepidemiologic Database (OPED). Four different formulary measures were evaluated and used for comparing incident and ongoing drug use. RESULTS: General practitioners' (GPs') incident drug formularies comprised significantly fewer drugs than their ongoing drug formularies for all drug groups except angiotensin-II antagonists. The difference in the total number of drugs used was between 1.8 and 3.3. We found differences between 0.5 and 1.6 analogues in the DU 90% (number of analogues accounting for 90% of the prescribed volume measured in defined daily doses) segment and the formulary selectivity index between 0.05 and 0.12. The preference for the most prescribed analogue was 9-18% higher among incident patients. The formulary selectivity index was highly correlated with the other formulary measures and quantified both range and skewed distribution of drug choice. CONCLUSION: Analysing GPs' prescriptions to incident patients is a simple and inexpensive method for studying their own current personal drug formularies. GPs choose within a narrow range of analogues for incident patients.

Adrenergic beta-Antagonists↗

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↗

Hyponatremia in elderly patients treated with desmopressin for nocturia: a review of a case series.

OBJECTIVE: Lately, desmopressin (dDAVP) administered orally has been demonstrated to be an effective alternative in the management of nocturia in adults. Although the safety profile of dDAVP is well known, much of the experience originates from studies in enuretic children and younger adults, and it may not be readily extrapolated to elderly patients. In order to identify factors associated with an increased risk of hyponatremia in elderly patients treated with dDAVP for nocturia, we analysed spontaneous reports accrued from clinical practice in Denmark and Sweden. METHOD: Following a selection procedure, the study base comprised 15 case reports. From the included reports, information was sought on concurrent diseases, concomitant medications and other factors that may predispose elderly patients to hyponatremia when treated with desmopressin. RESULTS: The median age amongst the cases was 81 years (range 61-93 years) and 80% were females. For seven of the patients, the hyponatremia occurred during the first 3 weeks of treatment. The symptoms presented by the patients led to hospitalisation in all but one case. Among patients with information available on concomitant medication, half of them were treated with cyclooxygenase inhibitors. An excessive fluid intake could only be ascertained in one case; all 15 patients eventually recovered. CONCLUSION: In elderly patients treated with dDAVP for nocturia, an increased risk of hyponatremia exists in the first weeks of treatment. Compared with younger subjects, risk factors other than excessive intake of fluid appear to contribute to this adverse drug reaction.

Age Factors↗

General practitioners prefer prescribing indicators based on detailed information on individual patients: a Delphi study.

OBJECTIVE: To assess the face validity of both simple and advanced quality indicators for prescribing in general practice. METHODS: In a three-round Delphi study, 100 randomly selected general practitioners (GPs) in Denmark rated 18 indicators for prescribing of non-steroidal anti-inflammatory drugs. All indicators were based on prescription register data and focused on different prescribing aspects. Advanced indicators contained information at the patient level, viz. age, sex and history of drug use, while simple indicators only used drug statistics at practice level. Indicators were rated on a nine-point Likert scale. Consensus among GPs was defined as interquartile ranges of three or less. A median rating of 7-9 was interpreted as face validity and a median rating of 1-3 as no face validity. RESULTS: Participation in the study was accepted by 44 GPs and 37 completed all three rounds. Three indicators based on patient level data and focusing on adverse effects were assessed to have face value. One indicator focusing on costs and based on practice level data was considered unsuitable for evaluating the quality of prescribing. Consensus was not reached for the remaining indicators. CONCLUSIONS: GPs do not regard simple indicators based on aggregated data at practice level as suitable for evaluating the prescribing quality in general practice, but prefer indicators that rest on clinical data at the patient level.

Anti-Inflammatory Agents, Non-Steroidal↗

The impact of population ageing on future Danish drug expenditure.

Population ageing is likely to place an increasing burden on future health care budgets. Several studies, however, have demonstrated that the impact of ageing on future hospital expenditures will be overestimated when not accounting for proximity to death. This is because the greater health care expenditures among the elderly are not only due to age per se but due to the high "costs of dying". Similar studies for pharmaceutical expenditures are scarce. The aim of this study was first to estimate the impact of the ageing Danish population on future total expenditures (public outlays as well as private co-payment) on out-of-hospital prescription drugs, holding everything but demographic changes constant. Second, it was to describe the association between age and drug expenditure among survivors compared to that of decedents, and to evaluate the extent to which drug expenditure is increasing with proximity to death in the last 2 years of life. Taking expenditure during the last year of life and the changes in mortality rates into account, future expenditure of prescription drugs was projected by multiplying the estimated mean annual drug expenditure according to age, gender and survival status by the predicted future number of Danes in each stratum, and subsequently, summing up across all strata. A generalized method was developed to account for expenditure several years prior to death. The projection was based on current drug utilisation from a representative prescription database covering the county of Funen, Denmark, and the most recent Danish population forecast for the period 2003-2030. The total population was projected to increase by 0.8% during the period 2003-2030, while the increase was 58% for people aged 75 years and over. The total drug expenditure was projected to increase by 16.9% during the same period when accounting for proximity to death, while it was 17.9% when this was not done. The projected growth in drug expenditure was not merely due to the drug consumption of the elderly. Moreover, the drug expenditure of elderly decedents was only increasing slightly with proximity to death. We conclude that the ageing of the population per se is likely to increase future expenditure on prescription drugs. This predicted increase, however, is small compared to recently observed increases in drug expenditures. The results of the study indicate that Danish policies aimed at limiting the increase in public drug expenditure should focus on rational pharmacotherapy and on the promotion of prescription of cost-effective pharmaceuticals-rather than targeting the drug use of the elderly or reducing the reimbursement generally.

Adolescent↗

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↗