Pharmacoeconomic consequences of measurement and modification of hospital drug use.

Patterns of drug usage affect hospital-based delivery of healthcare in a variety of ways. Adverse reactions to drugs (ADR) precipitate some 5% of admissions and prejudice the care of some 20% of patients who are in hospital, while inadequate drug therapy prejudices outcomes and prolongs hospital stay. Conversely, appropriate application of drugs can promote recovery and increase the quality of care. Well documented examples include prevention of deep vein thrombosis and postoperative wound infections. Accordingly, optimisation of drug use represents a major quality assurance issue in addition to determining cost-efficiency of healthcare delivery. Drug utilisation review (DUR) requires all elements of the quality assurance process. In practice, therapeutically meaningful and cost-efficient exercises can only be mounted if there is knowledge of the linkage between patterns of drug use and clinical outcomes. These processes of measurement are currently rate-limiting in quality assurance. There are various ways that hospital drug usage can be measured. These range from readily available and relatively cheap quantitative methods to methods requiring the availability of expert staff. There is a sequence of methods involving increasing costs and increasing resource demands yielding increasing detail of information obtained. This sequence commences with pharmacy purchases, followed by pharmacy issues to particular clinical areas, prescription or treatment sheet survey, clinical record review, and finally the reports of trained investigators working in the clinical area. The simpler methods can provide useful information and an efficient basis for choosing and planning definitive studies. Once a category of drug use is appropriately targeted for intervention, drug use can be modified by planned intervention with improvement in clinical outcomes and reduced economic costs in many instances. The intervention strategies to modify drug usage may be classed as re-educative, persuasive, facilitative and power strategies. Other models for implementing behavioural change have been considered, including the impact of trained investigators and the use of online computer prescribing with interactive software with appropriate guidelines. The challenge is to achieve sustained change when interventions are implemented. Cost-efficient quality assurance of drug use is possible with modest resources if outcome-orientated activities are prioritised.

Measuring and modifying hospital drug use.

OBJECTIVE: Various methods are available to quantitate medicinal drug use in hospitals. These represent a hierarchy of clinical specificity, complexity and cost of acquisition. Similarly, various strategies and methods are available to modify prescribing patterns. The objectives of this study are to illustrate these processes of measurement of drug use and modification of prescribing patterns using specific examples derived from practice at three major Australian teaching hospitals over 15 years. DESIGN, SETTING, MAIN OUTCOME MEASURES: Methods to measure and modify drug usage in the three hospitals are outlined and 12 examples are presented by specific drug or drug category. Each example includes details of the methods used to detect inappropriate drug use (pharmacy purchases, pharmacy issues, prescription analysis, clinical record review, performance and outcome assessment), the intervention strategies used (re-educative, persuasive, facilitative, power), the methods employed to alter drug prescribing and the relative effectiveness and cost-efficiency of the interventions. RESULTS: Readily available, relatively cheap quantitative methods provide significant information and an efficient basis for planning definitive studies, and substantial modification of prescription patterns is possible through the strategic use of limited manpower and resources.

Thiazine, antibiotic, bilirubin adducts.

1. Electron charge transfer interactions of some phenothiazine derivatives with aminoglycoside antibiotics, beta-lactams and penicillin-related antibiotics and bilirubin were investigated with alternating current titrations. 2. Neither the beta-lactams nor penicillin-related drugs interacted. 3. However, the aminoglycoside antibiotics formed complexes with the phenothiazines. 4. Tobramycin and gentamicin each formed 1:2 adducts with carbenicillin. 5. The phenothiazines interacted with bilirubin forming concentration-dependent micellar adducts which were exciplexes. This may explain the appearance of xanthomata in patients medicated with phenothiazines.

Quality assurance of drug therapy in hospitals: patient serum creatinine values used by ward pharmacists in checking dosage regimens.

A programme for the systematic adjustment of drug dosage in hospital patients with impairment of renal function is described. This programme involves the efficient identification of patients with elevated serum levels of creatinine, the checking of dosage regimens for these patients in terms of known pharmacokinetic data, and advising of medical officers when dosage regimens are in excess of those recommended, or where contraindicated drugs have been prescribed. The procedure, which has been shown to be both workable and effective in a large teaching hospital over a period of more than two years, serves as a model for quality assurance of an aspect of drug treatment with existing staff and with no additional capital costs.