Indicators for the Automated Analysis of Drug Prescribing Quality

Designing concept maps for a precise and objective description of pharmaceutical innovations

BACKGROUND

When a new drug is launched onto the market, information about the new manufactured product is contained in its monograph and evaluation report published by national drug agencies. Health professionals need to be able to determine rapidly and easily whether the new manufactured product is potentially useful for their practice. There is therefore a need to identify the best way to group together and visualize the main items of information describing the nature and potential impact of the new drug. The objective of this study was to identify these items of information and to bring them together in a model that could serve as the standard for presenting the main features of new manufactured product.

METHODS

We developed a preliminary conceptual model of pharmaceutical innovations, based on the knowledge of the authors. We then refined this model, using a random sample of 40 new manufactured drugs recently approved by the national drug regulatory authorities in France and covering a broad spectrum of innovations and therapeutic areas. Finally, we used another sample of 20 new manufactured drugs to determine whether the model was sufficiently comprehensive.

RESULTS

The results of our modeling led to three sub models described as conceptual maps representingi) the medical context for use of the new drug (indications, type of effect, therapeutical arsenal for the same indications), ii) the nature of the novelty of the new drug (new molecule, new mechanism of action, new combination, new dosage, etc.), and iii) the impact of the drug in terms of efficacy, safety and ease of use, compared with other drugs with the same indications.

CONCLUSIONS

Our model can help to standardize information about new drugs released onto the market. It is potentially useful to the pharmaceutical industry, medical journals, editors of drug databases and medical software, and national or international drug regulation agencies, as a means of describing the main properties of new pharmaceutical products. It could also used as a guide for the writing of comprehensive and objective texts summarizing the nature and interest of new manufactured product.

Occurrence of potential drug-drug interactions in nursing home residents

Objective

It has been suggested that elderly people are at increased risk of drug-related problems such as drug-induced adverse effects, drug-drug interactions and drug-disease interactions. This is particularly the case for nursing home residents because of the often complicated and multiple co-morbidity that occurs in these people. The aim of this study was to develop prescribing indicators to assess systematically the occurrence and nature of potential drug-drug interactions (DDIs) in a cohort of Dutch nursing home residents.

Method

The study was conducted in residents aged 65 years and over in six nursing homes (n=2,355, two-year study period). Computerised medication data for the residents were evaluated with respect to co-prescribing of potentially interacting drugs. All DDIs that were classified as clinically relevant according to the Dutch National Drug Interaction Database were studied. DDIs were classified into three categories according to their pharmacological mechanism: 1 — pharmacokinetic interactions at the level of gastrointestinal (GI) absorption; 2 — pharmacokinetic interactions at the level of metabolism and excretion; and 3 — pharmacodynamic interactions.

Key findings

Thirty-two per cent (n=748) of all residents were exposed to one or more combinations of drugs that could lead to clinically adverse outcomes. The numbers of residents who received drug combinations with a mechanism of interaction from category 1, 2 or 3 were 73 (3 per cent), 164 (7 per cent) and 612 (26 per cent) respectively. The number of medications prescribed was significantly associated with the occurrence of a potential DDI (P<0.05). Drugs most frequently involved were oral anticoagulants, antibiotics and theophylline.

Conclusion

During the two-year study period, about one-third of the residents were exposed to at least one drug interaction considered clinically relevant. Adequate surveillance systems are needed to enable better identification of these interactions with a view to preventing potential clinical problems. Using the prescribing indicators developed in this study, such surveillance could focus on detection and clinical aspects of potential DDIs and possible alternative treatments.

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.

Do the research goal and databases match? A checklist for a systematic approach

To test the appropriateness of a given database for specific research questions, we designed a checklist starting with the definition of an ideal database. This ideal database contains all relevant data on patients, providers and services. It is safe and accessible, input is always accurate, continuity is guaranteed and linkage with other information is easy. Of course no such database exists. Still these features are often taken for granted, but highly influenced by organizational processes in healthcare and prioritization. Starting with the characteristics of an ideal database, one can systematically list the required aspects for research goals and compare these with the available systems. This checklist is used to address important aspects of administrative database research and ethical issues. The increasing possibility to misuse sensitive data needs to be discussed by researchers, administrators, individuals and society. This checklist can also be valuable to others to design or interpret studies based on claims databases.

An epidemiologic approach to drug prescribing quality assessment: a study in primary care practice in France

OBJECTIVE

To assess drug prescribing by primary care physicians in France for various types of conditions, and to identify patterns and risk factors for poor prescribing quality.

METHODS

The orders (n = 23,080) written for patients with five target diseases (acute nasopharyngitis, acute tonsillitis, essential hypertension, osteoarthrosis, and back and periarticular disorders), by primary care physicians (n = 1,049) were extracted from a nationwide prescription database and analyzed according to 17 quantitative indicators of drug prescribing quality constructed on explicit a priori criteria.

RESULTS

Ineffective drugs were prescribed in 32% to 88% of orders according to the target disease. Six percent to 40% of orders resulted in drug interactions, age problems, and overdosage. A consistent pattern of associations between indicators was found, which suggests that drug prescribing quality is multidimensional and is composed of at least five dimensions: placebo, novelty, exoticism, misdosage, and interaction. Several factors associated with indicators were also identified, some of them defining groups of patients at risk (women, elderly, and less educated), physicians at risk (women, aged, and isolated), and contexts at risk (patient's home and disease frequently treated by the physician) of poor drug prescribing quality.

CONCLUSIONS

Drug prescribing by French primary care physicians appears nonoptimal, in terms of both risk of iatrogeny and waste of money. This study further documents the complexity and the multidimensionality of drug prescribing quality. It suggests that more attention must be paid to patients' and physicians' risk factors for poor drug prescribing quality if educational programs and regulatory processes are to succeed in promoting safer and more cost-effective practices.