A MiniReview of the Use of Hospital‐based Databases in Observational Inpatient Studies of Drugs

The majority of pharmacoepidemiological data resources are based on data generated in primary health care. Although inpatient data resources have existed since the 1960s, inpatient pharmacoepidemiological studies are relatively scarce. The objectives of this MiniReview were to describe pharmacoepidemiological studies in hospital settings and the underlying databases to provide an overview of research questions addressed by such databases. The studies were retrieved by chain searching. We included pharmacoepidemiological studies in hospital settings containing data on inpatient drug use. Twelve inpatient databases in Asia, the United States and Europe were found. Most databases were automatically collected from claims data or generated from electronic medical records. The contents of the databases varied as well as the potential for linkage with other data sources such as laboratory and outpatient data. Twenty studies were selected and discussed to illustrate the diversity of inpatient pharmacoepidemiological studies. Hospital‐based databases had mainly been used for drug utilization studies and research in adverse drug reactions. Five studies within comparative effectiveness were found. The number of pharmacoepidemiological studies in inpatient settings was low compared with studies from primary healthcare settings. These resources may be under‐utilized.     

Inpatient Drug Utilization in Europe: Nationwide Data Sources and a Review of Publications on a Selected Group of Medicines (PROTECT Project)

Drug utilization (DU) studies in inpatient settings at a national level are rarely conducted. The main objective of this study was to review the general information on hospital medicine management in Europe and to report on the availability and characteristics of nationwide administrative drug consumption databases. A secondary objective was to perform a review of published studies on hospital DU of a group of selected drugs, focusing on methodological characteristics (ATC/DDD). General information on hospital drug management was retrieved from several websites, nationwide administrative drug consumption databases and reports published by governmental organizations. A PubMed search was conducted using keywords related to the selected group of drugs AND ‘hospital drug utilization’. The data sources for hospital DU information varied widely and included 14 databases from 25 reviewed countries. Bulgaria, Croatia, Denmark, Estonia, Finland, France, Hungary, Iceland, Latvia, Norway and Sweden obtain information on inpatient DU at a national level from wholesalers/manufacturers. In Belgium, Italy and Portugal, drugs dispensed to patients in hospitals are registered at a national level. Data are freely available online only for Denmark and Iceland. From the PubMed search, of a total of 868 retrieved studies, only 13 studies used the ATC/DDD methodology. Although the number of DDD/100 bed‐days was used in four studies, other units of measure were also used. The type of information provided for the inpatient sector allowed primarily for conducting DU research at an aggregated data level. The existence of national administrative structures to monitor hospital DU would contribute to promoting the rational use of medicines and improving the safety and quality of prescribing.     

The new Swedish Prescribed Drug Register--opportunities for pharmacoepidemiological research and experience from the first six months

PURPOSE: To describe the content and potentials of the new Swedish national register on prescribed and dispensed medicines. METHODS: The Swedish Prescribed Drug Register contains information about age, sex and unique identifier of the patient as well as the prescriber's profession and practice. Information regarding drug utilization and expenditures for prescribed drugs in the entire Swedish population was extracted from the first six months July-December 2005 and compared with total drug sales in the country including OTC and hospital use. RESULTS: The total quantity of drugs sold in Sweden was 2666 million DDDs, corresponding to 1608 DDD/1000 inhabitants daily. The total expenditures were 1.6 billion Euro. The prescribed drugs, included in the register, accounted for 84% of the total utilization and 77% of the total expenditures. About half of all men and two-thirds of all women in the country purchased drugs. The proportion increased by age. The most common drugs for chronic treatment were diuretics among women (8.8% of the population) and antithrombotic agents among men (7.6%). Psychotropic drugs, corticosteroids and analgesics were more common among women, while men used antithrombotic agents, antidiabetic drugs, lipid lowering agents and ACE inhibitors to a greater extent. CONCLUSIONS: The new register provides valuable data on exposure to drugs and is useful to study patterns of drug utilization. The possibilities for record linkage to other health registers gives from an international perspective good opportunities to explore drug and disease associations and the risks, benefits, effectiveness and health economical effects of drug use.     

Drug utilization study methodologies: national and international perspectives

This paper in the series on pharmacoepidemiology describes the history, development, and present status of drug utilization activities. The various methodologies employed in drug utilization studies are evaluated and presented along with a listing of the principal drug databases available for drug utilization research. An analysis is presented comparing the validity of drug consumption rates based on individual patient usage or drug cost data as adopted in North America and the defined daily dose unit as developed in Europe. Drug utilization derives its importance in pharmacoepidemiology from the fact that it provides the methodological rigor for defining the denominator data needed in pharmacoepidemiological research.     

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.     

Unlicensed pharmaceutical preparations for clinical patient care: Ensuring safety

Most medicinal products dispensed to patients have marketing authorization (MA) to ensure high quality of the product, safety, and efficacy. However, in daily practice, to treat patients adequately, there is a medical need for drugs that do not hold MA. To meet this medical need, medicinal products are used in clinical care without MA (unlicensed), such as products prepared by (local) pharmacies: the pharmaceutical preparations. Three types of pharmaceutical preparations are distinguished: (i) reconstitution in excess of summary of product characteristics; (ii) adaptation of a licensed medicinal product (outside its official labeling); (iii) medicinal products from an active pharmaceutical ingredient. Although unlicensed, patients may expect the same quality for these unlicensed pharmaceutical preparations as for the licensed medicinal products. To assure this quality, a proper risk‐benefit assessment and proper documentation in (centralized) patient registries and linking to a national pharmacovigilance database should be in place. Based on a risk assessment matrix, requirements for quality assurance can be determined, which has impact on the level of documentation of a pharmaceutical preparation. In this paper, the approach for good documentation including quality assurance and benefit‐risk assessment will be discussed and possibilities for patient registries are described to make these crucial preparations available for regular patient care. KEY POINTS

• Ensuring pharmaceutical quality and performing a proper benefit‐risk assessment will guarantee safe use of pharmaceutical preparations.
• Good documentation of (ultra‐)orphan treatments can be collected in centralized patient registries and should be combined with existing information in (inter)national databases and self‐reflection of patients.
• Linking patient registries to a centralized database for adverse drug events is highly recommended as it increases safety control of the (ultra) orphan pharmaceutical preparations.