Computer support for determining drug dose: systematic review and meta-analysis

OBJECTIVE

To review the effectiveness of computer support for determining optimum drug dose.

DESIGN

Systematic review of comparative studies where computers gave advice to clinicians on the most appropriate drug dose. Search methods used were standard for the Cochrane Collaboration on Effective Professional Practice.

SUBJECTS

Comparative studies conducted worldwide and published between 1966 and 1996.

MAIN OUTCOME MEASURES

For qualitative review, relative percentage differences were calculated to compare effects of computer support in different settings. For quantitative data, effect sizes were calculated and combined in meta-analyses.

RESULTS

Eighteen studies met the inclusion criteria. The drugs studied were theophylline, warfarin, heparin, aminoglycosides, nitroprusside, lignocaine, oxytocin, fentanyl, and midazolam. The computer programs used individualised pharmacokinetic models to calculate the most appropriate dose. Meta-analysis of data from 671 patients showed higher blood concentrations of drug with computer support (effect size 0.69, 95% confidence interval 0.36 to 1.02) and reduced time to achieve therapeutic control (0.44, 0.17 to 0.71). The total dose of drug used was unchanged, and there were fewer unwanted effects of treatment. Five of six studies measuring outcomes of care showed benefit from computer assistance.

CONCLUSIONS

This review suggests that using computers to determine the correct dose of certain drugs in acute hospital settings is beneficial. Computers may give doctors the confidence to use higher doses when necessary, adjusting the drug dose more accurately to individual patients. Further research is necessary to evaluate the benefits in general use.

Designing evaluations of interventions to change professional practice

The design and interpretation of experimental studies to examine the effectiveness and efficiency of implementation strategies intended to change professional practice are gaining increasing attention. It has been argued that variations of the simple randomised design are most appropriate in this setting. The principles of block designs and their applicability in this field are reviewed critically, as are the choice of outcomes and approaches to economic analysis. We conclude that more complex designs are not superior per se, and that the design, choice of implementation method and topic, and analysis of such experiments should reflect the circumstances of the study.

A framework for incorporating cost-effectiveness in evidence-based clinical practice guidelines

In England, recent health care reforms emphasise the role of clinical guidelines in promoting effective and efficient health care. Introducing economic data into guidelines raises some methodological issues: specifically, the provision of valid and generalisable cost estimates, the weight placed upon cost 'evidence', and the presentation of cost-effectiveness information in a manner accessible to clinicians. A series of primary care guidelines, explicitly including consideration of health economic information, have recently been published, intended to help clinicians to aggregate the attributes of treatment choices to derive treatment recommendations consistent with both the clinical decision-making process and social objectives. Clinicians involved in developing guidelines responded well to the process and consistently managed to agree treatment recommendations, often after considerable debate about the evidence for treatment. In none of the guideline areas, all of which addressed common diseases, was there adequate information to estimate a cost per quality-adjusted-life-year, and it is unclear how helpful this approach would have been had it been possible. The implications of this method are discussed, guidance offered for economists new to guideline development and future areas of work identified.

Does the UK National Health Service need a fourth hurdle for pharmaceutical reimbursement to encourage the more efficient prescribing of pharmaceuticals?

Reform of the existing mechanisms that influence pricing for pharmaceuticals in the UK NHS is overdue. Currently, the prescribing pricing policy favours the needs of industry over those of the NHS and of individual patients. In a recent consultation document, the UK Government indicated an emerging policy that will provide for the assessment of the effectiveness and cost effectiveness of important pharmaceuticals in the NHS. In developing and implementing this policy, much can be learnt from the situation in Australia, where pricing of drugs is related directly to an assessment of their value for money in specific patient groups. In fact, the differing circumstances between the UK and Australia suggest that the progress achieved by the Australians may be supplemented by further reform to encourage a more rational relationship between the NHS and the pharmaceutical industry. Australia has led the world in demonstrating that a modest form of assessment of 'value for money' may be incorporated practically in the process of licensing and reimbursing new drugs. It is important that this finding is built upon in the UK NHS for the benefit of patients and for society as a whole. It is not clear that the current proposals for reform from the UK Department of Health go far enough to achieve the required changes in drug licensing and regulation.

Choosing an appropriate unit of analysis in trials of interventions that attempt to influence practice

The choice of an appropriate unit of analysis in evaluations in health policy is problematic and errors are frequently made which may undermine study conclusions. This paper describes the structure of randomized trials, issues concerning randomization and replication, and the factors that should be considered when deciding upon the appropriateness of a unit of analysis.

Evidence into practice. Prescribing selective serotonin reuptake inhibitors

This descriptive analysis examines prescribing trends of antidepressants in English primary care, providing analysis of NHS reimbursement data for groups of antidepressants between 1989 and 1994. Prescribing trends seem unaffected by the release of information on the effectiveness and cost-effectiveness of antidepressant drugs. We found that simple distribution of the results of health technology assessments may not be sufficient to influence practice.

The dilemma of new drugs. Are costs rising faster than effectiveness?

This century has seen a phenomenal growth in the development, understanding and use of pharmaceuticals. Additionally, this period has seen the balance of the treatment needs of patients shift dramatically from infectious to cardiovascular and cancer diseases, and from infancy and middle-age to old age. The value of modern pharmaceuticals to society is undoubted. However, the benefits in terms of health gain, when adequately evaluated, are often more modest than first supposed, and are often achieved at considerable costs and sometimes considerable risks to patients. Data are seldom adequate to attempt a robust evaluation of the cost effectiveness of drugs and compare how cost effectiveness may have changed over time. Rapid increases in development costs coupled with the increasing focus on chronic and old-age diseases make it probable that the cost effectiveness of new drugs is broadly declining, but such a conclusion should be interpreted with caution. The big challenge for the next century with its likely genetic and biotechnological discoveries, bringing as yet unforeseen benefits, risks and costs, is to radically improve the manner in which new drugs are evaluated and diffuse into health systems.

[Impact of mass media on the use of health services. A systematic review of the literature]

BACKGROUND

Mass media may influence the use of health services either through campaigns promoting the use of specific procedures or through the coverage of health related issues outside the context of a planned intervention. To assess their effect on the utilization of health services a systematic overview of primary research was undertaken.

METHODS

Experimental and quasi experimental studies meeting pre defined entry criteria and providing information on the impact of mass media on objective measures on health services utilization were searched through Medline, Embase, Psychlit, Eric, as well as handsearching key journals. Data on the detail and content of interventions were abstracted and raw data describing health services utilization obtained. Effect sizes were calculated for each study and then pooled across studies on the same topic using a random effects model.

RESULTS

Out of 69 papers providing information on the impact of mass media on aspects of health services utilization, 17 interrupted time series met our quality criteria. Fourteen evaluated the impact of formal mass media campaigns, 3 of media coverage of health related issues. The overall methodological quality was rather variable, with 6 studies not performing any statistical analysis, and 7 using inadequate statistical tests (i.e. not taking into account the effect of time trend). All the studies but the concluded positively on the effect of mass media. These positive findings were confirmed by our re-analysis in 7, while in the remaining the effect of mass media was not statistically significant. The direction of effect was consistent across individual studies and the pooled effect sizes revealed an effect upon the utilization of health services that could not be explained by chance alone, ranging from -1.96 (95% CI: -1.19, -2.73) for campaigns promoting immunization programs, to -1.12 (95% CI: -0.49, -2.46) for those concerning cancer screening.

CONCLUSIONS

Despite the overall limited quality of primary research, this review supports the view that these channels of communication may have an important role in influencing the use of health care interventions. Mass media should be considered as one of the tools that may encourage the use of effective services and discourage those of unproved effectiveness.

Evidence into practice, experimentation and quasi experimentation: are the methods up to the task?

OBJECTIVE

Methodological review of evaluations of interventions intended to help health professionals provide more effective and efficient health care, motivated by the current experience of NHS Research and Development in England. Emphasis upon the forms of research appropriate to different stages in the development and evaluation of interventions, the use of experimental and quasi experimental designs, the methods used in systematic reviews and meta analyses.

METHOD

A proposed development process is derived from that used in the development of drugs. The strengths and weaknesses of different experimental and quasi experimental designs are derived from published methodological literature and first principles. Examples are drawn from the literature.

RESULTS

Like pharmaceuticals, implementation interventions need to go through several stages of development before they are evaluated in designed experiments. Where there are practical reasons that make random allocation impossible in quantitative evaluations, quasi experimental methods may provide useful information, although these studies are open to bias. It is rare for a single study to provide a complete answer to important questions, and systematic reviews of all available studies should be undertaken. Meta analytic techniques go some way towards countering the low power of many existing studies, reduce the risk of bias, and avoid the subjective approaches that may be found in narrative reviews.

CONCLUSIONS

The initiative taken by NHS Research and Development in examining methods to promote the uptake of research findings is welcome, but will only prove helpful if careful attention is paid to the different stages of the development process, and different research approaches are used appropriately at different stages.

Publication bias in clinical trials and economic analyses

Publication bias is an established notion in the clinical literature; essentially, large studies or positive results are more likely to find their way into the public domain than small studies or negative results. Meta-analysis presents a focus for the problems of publication bias, seeking to summarise the evidence in a particular therapeutic area by retrieving and analysing all available clinical studies. Economic analyses are also vulnerable to publication bias, and at 3 levels: first, in the health-outcomes data available for modelling (resulting from publication bias in the clinical literature); second, in the motivations for conducting an economic analysis; and third, in repeating the process of seeking publication.

EUR-ASSESS Project Subgroup Report on Dissemination and Impact

The objective of health technology assessment (HTA) is to support decision making in health care. HTA does not claim to provide a definite solution to a health care problem, but to assist decision makers with evidence-based information about the clinical, ethical, social, and economic implications of the development, diffusion, and use of health care technology.

Are decisions taken by health care professionals rational? A non systematic review of experimental and quasi experimental literature

Systematic overviews of the effectiveness and cost effectiveness of health care interventions are increasingly available, and yet there has been relatively little attention upon putting their important findings into practice. Furthermore, close attention to the decision making behaviour of health professionals in situations of uncertainty indicates that this may not always be 'rational'. This paper examines developments in the understanding of rationality in decision making from outside the health care setting, particularly the interesting work on 'regret theory', and begins to apply this framework to health care.

Lessons from international experience in controlling pharmaceutical expenditure. III: Regulating industry

This is the third of three papers that review international policies to control spending on drugs and to improve the efficiency of drug use. This paper reviews policies regulating the supply of drugs, particularly licensing and reimbursement controls, price and profit regulation. Price and profit controls contain few incentives for improving cost effective use of drugs, and focus on cost containment and profitability of domestic industry. Carefully monitored economic evaluation could lead to improvements in efficiency and benefits to patients and the health care system.

Lessons from international experience in controlling pharmaceutical expenditure. II: Influencing doctors

This is the second of three papers that review international policies to control spending on drugs and to improve the efficiency of drug use. This paper reviews policies influencing doctors' prescribing of drugs--particularly the use of budgetary restrictions, information and feedback, and guidelines--and evaluates the impact of these policies. Studies evaluating incentive systems are limited, but evidence suggests that providing information on its own will not lead to substantial changes in practice and that more active strategies should be evaluated.

Lessons from international experience in controlling pharmaceutical expenditure. I: Influencing patients

This is the first of three papers to review international policies to control spending on drugs and improve the efficiency of drug use. Policies can target three main groups: patients, prescribing doctors, and the drugs industry. In this paper we examine policies aimed at patients, particularly restrictions on reimbursement (such as prescription charges). Rigorous experimental and quasi-experimental studies suggest that policies to limit the level of reimbursement of drugs reduce the use of essential as well as non-essential drugs and may do more harm than good.

Dealing with uncertainty: will science solve the problems of resource allocation in the U.K. NHS?

In spite of the huge efforts which internationally address the development and assessment of health technologies, the majority of health care interventions have not been formally evaluated for their effectiveness and their likely impact upon health status is largely unknown. This has led to a situation where it is unclear on what basis a health care system might be judged, or for that matter on what basis decisions on the specification of individual services might be made. It has frequently been argued that the only way to build an adequate understanding of the effectiveness of different interventions is through systematically locating and synthesising the available evidence from research, and such systematic overviews are increasingly available in many areas. However, such overviews produce few clear conclusions, and even when the results of systematic overviews show unequivocal benefits for patients, implementing the findings of such reviews remains problematic. Research evidence provides useful information on marginal benefits for patients, though areas where the absolute benefit is high appear to be very rare. The most common finding appears to be uncertainty. Interpreting research evidence is complex, and even very clear findings may prove hard to operationalise. Good quality research will help, but will not solve, the problems of resource allocation in the NHS or in other health systems.

Taylorism in a post-modern age?

F.W. Taylor made an early and important contribution to the organisation of work in an industrial society. His ideas, or versions of his ideas, are once again receiving attention. Some commentators even describe a new or neo Taylorism (Pollitt, 1990). This paper argues that the only theoretical justification for the re-introduction of Taylorist strategies in the workplace is found in the notion of the post-modern world; where rationality is replaced by a ritual of signs and work becomes part of that ritual; where form replaces rationale, and strategies for work are governed by processes of survival in the remnants of modernity.

Assisted conception techniques. On what basis do health technologies become routinely available when they have been assessed as effective?

The possibility of restoring fertility among some infertile couples through assisted reproductive technology has led to questions about the terms under which such treatments should be made available. Although there is now evidence on their effectiveness, there is considerable variation in the availability of these treatments under the U.K. National Health Service.